The Betaflight Settings I Paste Into All My FPV Drones

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I’ve been replacing the Helio Spring flight controllers in my 5” freestyle quads, and I’ve been building and repairing a couple of HD micros over the last few months. I had to configure Betaflight on all these quadcopters when I set up the new hardware, then I had to configure them all again after Betaflight 4.0 was released.

I don’t manually reconfigure each quad by hand. I always save a diff before upgrading a quad. If I’m upgrading from Betaflight 3.5.1 to 3.5.3, or from one nightly build to another, I’ll just paste that entire diff in after flashing. It’ll be back up and running in seconds.

My 4-inch Kestrel Build

You can’t just paste you diff back in when upgrading from 3.5.3 to 4.0. The new version just doesn’t fly the same. Settings that may have flown well before may fly poorly in 4.0, or they may even smoke your motors!

What about setting up a fresh quad? Can you just paste a diff of one of your other quads in and call it a day? Sometimes you can, but I have a special diff file set aside. I’ve pruned out all the PID, filtering, and serial settings. All that’s left are the settings that should work on all my quads: rates, switches, Crossfire settings, and OSD settings.

I’m going to walk through which settings I keep, why they’re important, and why they work well on every quad in my bag from my TinyHawk to my 5” Flowrides!

Features

I used to paste in settings related to PID loop timing, ESC protocol, and minimum throttle. Those settings vary too much between my various builds. My blheli_s builds may use DSHOT600 or Multishot, while my blheli32 builds always use DSHOT1200. I usually have to fix it anyway, so why bother pasting it in?

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feature -AIRMODE
feature TELEMETRY

I disable air mode, because I have air mode on a switch. It is nice to be able to drop back to rate mode when I want to skid under a car!

The only quad I own that doesn’t support telemetry is my TinyHawk, so I enable it here as well.

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beacon RX_SET

I don’t use buzzers on any of my builds, so I enable the DSHOT beacon.

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set small_angle = 180

Before Betaflight 4.0, I usually left the accelerometer disabled, but I do enable it on some quads, like my TinyHawk. In the event that I do enable it, I want to make sure my quad allows me to arm while it is upside down.

Betaflight 4.0 can show G-force on the OSD, and it can show you maximum G-force reading on the summary screen. This has encouraged me to enable the accelerometer, so I’m glad I’ve been pasting the small_angle into all my builds!

Radio settings

Most of my builds use TBS Crossfire, so I don’t mind pasting that in.

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set serialrx_provider = CRSF

My TinyHawk is my only quad using SBUS.

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rxrange 0 988 2011
rxrange 1 988 2011
rxrange 2 988 2011
rxrange 3 988 2011

The goal is to have the ends of your stick travel reading 1000 and 2000 in Betaflight. I tweaked the settings in my Taranis, but it was impossible to get them spot on. They would either read a bit high, or a little low. For a long time, I flew with them overshooting the 1000 and 2000 marks by 11 or 12 nanoseconds.

The rxrange command lets you set those limits correctly. My receiver tab now reads exactly 1000 to 2000 nanoseconds for my sticks.

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rxfail 4 s 1000

I fly with my RSSI or Link Quality on channel 5. This lets me display my control link’s quality on my OSD. When you failsafe, your RSSI or Link Quality will just get stuck, so it might not be obvious to you that your signal is gone.

This command sets channel 5 to the minimum value. That way, when you do failsafe, your OSD will start blinking at you!

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set vtx_band = 5
set vtx_power = 3
set vtx_low_power_disarm = ON
set vtx_freq = 5658
set vcd_video_system = NTSC

I fly with the same people most of the time, and we each have a designated channel. These settings put me on Raceband 1 with power level 3.

The vtx_low_power_disarm settings puts my VTX at 25 mW when I’m not armed. This helps keep me from knocking my friends out of the air when I plug in or land near us.

OSD settings

OSD settings and positions are safe to paste from one version of Betaflight to another. Sometimes the names change, but that won’t hurt anything. You’ll just end up with something missing from your HUD!

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set osd_units = IMPERIAL
set osd_warn_batt_not_full = OFF
set osd_warn_batt_warning = OFF
set osd_warn_batt_critical = OFF
set osd_warn_visual_beeper = OFF
set osd_warn_core_temp = OFF
set osd_cap_alarm = 950
set osd_vbat_pos = 44
set osd_rssi_pos = 2448
set osd_tim_1_pos = 407
set osd_tim_2_pos = 2422
set osd_remaining_time_estimate_pos = 343
set osd_flymode_pos = 333
set osd_throttle_pos = 2409
set osd_vtx_channel_pos = 2415
set osd_ah_pos = 200
set osd_current_pos = 2433
set osd_mah_drawn_pos = 2441
set osd_craft_name_pos = 2453
set osd_gps_speed_pos = 2369
set osd_gps_lon_pos = 82
set osd_gps_lat_pos = 65
set osd_gps_sats_pos = 2390
set osd_home_dir_pos = 2395
set osd_home_dist_pos = 35
set osd_compass_bar_pos = 266
set osd_altitude_pos = 341
set osd_pid_roll_pos = 423
set osd_pid_pitch_pos = 455
set osd_pid_yaw_pos = 487
set osd_debug_pos = 1
set osd_power_pos = 321
set osd_pidrate_profile_pos = 345
set osd_avg_cell_voltage_pos = 2402
set osd_pit_ang_pos = 257
set osd_rol_ang_pos = 289
set osd_battery_usage_pos = 392
set osd_disarmed_pos = 138
set osd_nheading_pos = 311
set osd_nvario_pos = 279
set osd_esc_tmp_pos = 82
set osd_esc_rpm_pos = 2
set osd_stat_tim_2 = OFF
set osd_stat_max_dist = ON
set osd_stat_used_mah = OFF
set osd_stat_bbox = OFF
set osd_stat_bb_no = OFF

I’ve always tried to keep my OSD somewhat minimal. I feel that cell voltage, RSSI, and flight time are quite necessary.

I like to have my quad’s name listed. That makes reviewing DVR footage easier, and it helps my friends know who they’re tuned into. At this point, fitting all my data on one line would be a tight fit.

Most of the time, I don’t need to see my VTX channel and power info, but sometimes it comes in handy. If I’m getting poor signal, it is nice to see if I’m running at 200 mW or 800 mW. On the rare occasions when I change channel, it is nice to have something to refer to when a friend asks what channel I’m on, too.

There’s still room left on the second line, so I squeezed in amp draw and mAh consumed.

Then I added GPS to all my 5” quads, and I had to expand to a third line! I’m disappointed that my OSD is getting so crowded, but I tried to keep that new line spread out towards the edges!

OSD settings for Betaflight 4.0

Betaflight 4.0 now has support for up to three OSD profiles. You can have different elements active in each profile.

I haven’t decided how I’m going to make use of this. Currently, I paste in OSD settings to enable the GPS data that I like to see. My micro quads don’t have GPS, so I wind up manually disabling those options during setup.

I might move the GPS data to a separate profile. That way, I can just change profiles on my quads without GPS!

Rates

In my opinion, rates are the most important thing to customize on your miniquad. Everyone prefers a different feel, and you need to find yours.

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rateprofile 0

set roll_rc_rate = 192
set pitch_rc_rate = 192
set yaw_rc_rate = 165
set roll_expo = 15
set pitch_expo = 15
set roll_srate = 60
set pitch_srate = 60
set yaw_srate = 40

These are my rates. I keep my yaw linear and quite a bit more gentle than the other axes.

These rates feel right to me on my 5” miniquads, but they’re a little aggressive on my micros. In any case, it is a good starting point for any quad I might fly!

Modes

These are my modes. Don’t use my modes. In fact, you should probably be getting all these settings from your a diff from one of your own quads!

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aux 0 0 3 1550 2100 0 0
aux 1 46 1 1925 2100 0 0
aux 2 13 2 1550 1700 0 0
aux 3 26 1 1550 1700 0 0
aux 4 28 3 1750 2100 0 0
aux 5 30 3 900 2100 0 0
aux 6 35 2 1925 2100 0 0

I use a single three position switch, switch SG, on my Taranis X9D+ for arming and choosing rate or air mode. The first position is disarm. The middle position is rate mode. The final position is air mode. Most of the time, I just flip the switch all the way to one end or the other.

Switch SD activates either my beeper in the center position and turtle mode in the final position.

Switch SA enabled blackbox logging in the center position and GPS return to home in the final position.

That’s it!

I’m surprised there’s not more. This looks like everything I paste into a brand new build.

I don’t paste out of this file all that often. Only when I build a completely new quad or a new major release of Betaflight show up.

My Hyperlite Flowride quads

I have three identical 5” Hyperlite Flowride quads. I don’t paste this file into each of those. I set one up, and get it flying the way I like. Then I paste that good config into the other two!

Conclusion

When you have a bunch of quadcopters to configure, don’t rely on your memory. Get in the habit of saving diffs before making major changes to your quads. It is easier to paste in your old config than it is to make sure you don’t miss an important checkbox in the Betaflight configurator.

Even just cherry picking lines from your Betaflight 3.5 diff when upgrading to 4.0 is easier than hunting around the configurator trying to make sure you didn’t miss an important setting!

Did I miss anything? Do you have a similar diff that you paste into all your new quadcopters? Do you have any questions? Let me know in the comments, or stop by our Discord server to chat about it!

One Month with an HD Micro FPV Freestyle Quad

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I’m not sure how accurate the title of this blog post is. I’ve been working on my Kestrel HD micro FPV frames for several months. I’ve probably been flying it with a Caddx Turtle V2 for something closer to a month and a half, but that would make for a convoluted title, hayna?

I’ve been carrying a 2.5” or 3” micro FPV drone in my bag for two years, but the Kestrel is my first micro capable of capturing HD footage. I’ve avoided these kinds of builds for a long time, but the components for micros are getting better, and the FPV cameras that double as HD recording cameras have improved quite a bit, too.

Going into this, I had some ideas of how my 3” micro and lightweight 4” builds would compare to my heavy 5” freestyle. I think I’ve been messing around with the micros long enough to have some useful data and opinions about my experiences at this point.

HD micros should be more durable

For the most part, I still think this is true. My 680-gram 5” freestyle quad has so much more inertia than my 225-gram 3” Kestrel or my 270-gram 4” Kestrel.

Sure, the smaller motors are built with smaller bearings and thinner material, but you won’t be subjecting them to as much stress in an impact. It ought to be harder to smash motors.

My 4-inch Kestrel Build

The micro frames are thinner and lighter. I thought for certain that my Kestrel’s arms would break by now. I made them just about as narrow as I thought I could get away with. I assumed they’d need to be one or two millimeters wider, but they’re holding up quite well!

It is unfortunate that the Caddx Turtle has been rather fragile. I killed my first Turtle when I got stuck in a tree. Very, very high up in a tree! I had to do a lot of gymnastics in both turtle mode and air mode to wiggle the quad free, and I had to wiggle free several times, because I kept getting stuck on more branches on the way down!

The Caddx Turtle must have taken a voltage spike or something while I was jamming on the throttle trying to break free. It stopped recording while I was still in the tree, and it hasn’t worked since.

Today, I smashed a lens and an ND filter. My Caddx ND filters arrived today, and I just had to try them out. The winds were up over 15 MPH today, so I didn’t expect to get great footage, but I wanted to try them out.

Broken Caddx Turtle Lens

After flying a battery on my 4” Kestrel, I swapped the filter over my 3” Kestrel. As soon as I gave it a bit of throttle, it tried to shoot up to the moon, so I had to disarm. It landed upside-down on concrete. The ND filter was smashed, and the plastic lens was snapped in two.

In my first month or two, I’ve burned through a $65 camera, a $7 ND filter, and a $10 lens. These aren’t expensive components, but I’ve been flying with a GoPro HERO5 Session on my big, heavy quad for more than a year, and I’ve only destroyed one GoPro. I’m not excited about this trend so far.

At least today, it was only the lens that broke. If the threaded shaft of the Caddx lens were made of metal, I probably would have smashed the camera’s housing or sensor!

HD micro quads are safer

This mostly comes back to weight again. I’ve had my 680-gram 5” freestyle quad up over 120 MPH. I don’t get up to speeds like that very often, but can you imagine what would happen if I hit something? It would be like shooting a frozen turkey at a high-speed train.

Even if I just have to disarm my big quad while it is 200 feet in the air, whatever is underneath is going to have a bad time—hopefully it is just grass or pavement! This is why we’re so careful about when and where we fly.

My 3” Kestrel is a rather light build. It comes in at about 225 grams with a 650 mAh 4S battery. With that battery, it has enough juice for about five minutes of fairly aggressive freestyle flying. It weighs about 1/3 as much as my big, scary quad, and it can’t hit 120 MPH.

It is a bit like the difference between a basketball and a dodgeball. If I throw a basketball at your face as hard as I can, I might break your nose. If I do the same with a dodgeball, you’re going to be unhappy, but you’ll be fine.

I’m not saying you can just start flying your micro quad near people. Those props will still cut someone quite badly, and it is still heavy enough to hurt someone!

HD micros cost less than a full-size miniquad

My 3” Kestrel build costs around $250. My 5” freestyle quads cost more than twice as much, and I have to strap a $200 to $300 GoPro on top of those quads. I think it is awesome that it is possible to capture decent HD footage for the price of a GoPro.

Is it really cheaper, though? I can strap a $100 refurbished GoPro HERO4 Session to a $130 bind-n-fly 5” quad, and I know that I’ll get better footage. That aging GoPro is so much better than a Caddx Turtle. The Caddx Turtle or Runcam Split need the equivalent of GoPro’s SuperView!

At the rate that I’ve been breaking Turtles, I’m worried that this is going to get expensive. Time will tell.

Don’t forget about batteries. The 650 mAh 4S packs I use on my micros cost half as much as the 1,000 mAh 6S packs I use on my 5” quads, and my micros tend to fly a little longer on each pack.

5” freestyle quads fly better than 3” micros

Due to a combination of Earth’s gravity, air density, and the scale of human construction, 5” miniquads are the sweet spot for FPV freestyle. They’re heavy enough that 10 or 15 MPH winds don’t shake them around. They’re light enough that they can accelerate quickly, and their props are the right size and weight to make them agile.

You just can’t huck a 250-gram micro quad over an obstacle. I can punch the throttle on my 5” freestyle quad for a second or two, cut the throttle, and flip upside down. My momentum will easily carry me over a tree.

The 250-gram 3” quad doesn’t have the momentum or inertia for that. The air is thick enough to slow it down. If I attempt the same thing with my 3” or 4” Kestrel, I will most likely not make it over the tree!

This isn’t just a problem for micros. 5” racing setups without GoPros don’t have the same problem. They’re built lighter than freestyle drones to begin with, and they’re also not carrying a 110-gram GoPro. The 5” racer will carry farther than the 3”, but not as much as my heavy 5” freestyle build.

No matter how hard I try, I just can’t tune in my rates to make my 3” feel like my 5”. I’m sure some of that is in my head, and if I flew the 3” exclusively for a long time, I would adjust.

3” and 4” micros are lighter

Weight can be a blessing and a curse. We already talked about the light weight of a 3” micro making it safer than my beefy 5” quads. Micros are also easier to carry.

They take up less space, their batteries weigh less, and in my case, each battery lasts a little longer!

My huge ThinkTank backpack weighs about 27 pounds when fully loaded. That’s with three 5” quads, a 3” quad, plenty of batteries for each of those quads, all sorts of tools, a LiPo charger, a big field-charging battery, and a comfy 2-pound chair. I usually only take this bag when I’m driving.

My AmazonBasics DSLR Bag

When I’m riding my electric bike, I take my AmazonBasics DSLR backpack. With one 5” quad, six batteries, and a chair, it weighs about 12 pounds. That setup will keep me flying for almost 24 minutes.

If I pack both my 3” and 4” Kestrel, I can carry 45 minutes’ worth of battery. Not only that, but I can squeeze those two quads and all that battery in under 10 pounds. It isn’t a huge savings in weight, but any weight savings is nice when you’re walking, and the extra 20 minutes of flight time is awesome!

A $100 GoPro beats a $65 Caddx Turtle V2

These two cameras are barely comparable. I’m disappointed in almost every minute of footage I’ve captured so far with my Caddx Turtle.

The field of view on the Turtle seems narrow, and I miss SuperView. You can’t set the Turtle to 30 frames per second, because you’ll be stuck with that slow frame rate in your FPV feed. You absolutely have to use an ND filter to push the shutter speed high enough to get acceptable footage out of the Turtle.

I would get much better footage with my old $120 BFight 210 with a refurbished, outdated, $100 GoPro Session.

Even with the ND filter, the Turtle seems to dislike my style of flying. Slow, cinematic footage looks alright. Quick moves look sloppy compared to the footage from a GoPro.

That said, though, I feel like I’m actually getting some usable footage out of the Caddx Turtle now that I’m flying with an ND16 filter!

I don’t understand why you’re flying a freestyle micro quad!

As I’ve been going through the pros and cons here, I’ve noticed that I’m listing a lot more cons than pros, right? Some of those cons are huge, too. The cheapest, oldest GoPro Session is drastically better than a Caddx Turtle. That seems like a good enough reason to skip HD micros all together.

Even considering all these cons against the pros, I’m still excited about having an HD micro quad in my bag, and I’m having a lot of fun designing a frame! Being able to carry nearly an hour of fun in a bag that weighs less than 10 pounds is awesome. I don’t always need to be capturing the best possible HD footage, do I? It is OK to just go out to have fun!

That’s what I was already doing with my Leader 3 micro. Adding an HD camera to that kind of setup isn’t expensive, and it is nice to have access to that footage, even if it isn’t the best.

If all I needed was a hold-my-beer quad, my old BFight 210 with a cheap GoPro would work great. My Kestrels can handle that job, but they’re also useful in situations where a 5” quad like the BFight 210 would be too loud or feel too dangerous.

Conclusion

I like HD micro quads. They’re inexpensive. They fly almost as well as a 5” freestyle quad, assuming you don’t need the extra momentum. The HD cameras are almost good enough.

The situation will only get better. Cameras are getting better. Frames are getting better. Flight controllers, 4-in-1 ESC boards, and motors are getting better. Props are getting better. Literally everything related to micro quads is improving!

3” micros are a great way to get into FPV. They are cheaper and safer than their 5” cousins, and it doesn’t cost much to add reasonable HD video recording to your build. If you want to get into FPV freestyle, and you want to record decent HD video, spending $250 or so on a build like my Kestrel with a Caddx Turtle would seem like a pretty good plan!

What do you think? Is your experience with HD micros similar to mine? Do you think I’m going to have the same thoughts, opinions, and experiences over the next six months? Let me know in the comments, or stop by our Discord server to chat about it!

So Long Helio Spring, Hello iFlight SucceX F7 TwinG!

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When I graduated from my bind-n-fly Holybro Shuriken X1 to my first custom 6S-capable 5” freestyle quad, I used Holybro’s stack: a Kakute F4 flight controller, and an AtlAtl VTX. I was using individual ESCs at the time, but I soon upgraded to a Tekko32 4-in-1 ESC, and I’m still using those today.

At the time, I was happy with how my quads flew, but they were far from perfect. I didn’t realize how far from smooth they were at the time, though. I was having trouble with one of my builds, and this fancy new Helio Spring flight controller was just showing up on the market. I figured, why not give it a try?

My Old Helio Spring Flight Controller

The Helio Spring has a separate F3 chip dedicated to gyro filtering. It has an F4 chip that runs Betaflight, Butterflight, or RaceFlight, but all or most filtering in that firmware is disabled. Until recently, the filtering running on the F3 chip was proprietary.

It was amazing. This was probably around the time when Betaflight 3.4 was released. I’d never flown a quad that felt so locked in and responsive. I remember the big smile I had the first time I came in too tight on a power loop and expected a bunch of propwash oscillation, but there was none. I went home and ordered Helio Spring boards for all my quads.

Helio and Butterflight have both had issues. Helio seemed to have dropped off the face of the Earth for a while, but then out of nowhere, they released a new IMU-F update. That update was a huge leap forward again, and it breathed new life into my Helio Spring quads.

Helio is dead. Development has stopped. As far as I can tell, my Helio Spring quads will be stuck on Betaflight 3.5 forever. I’ve been running Betaflight 4.0 nightly builds on my 3” and 4” micros, and I like it a lot. How long can I wait before upgrading my 5” freestyle quads?

Helio’s IMU-F won’t be leapfrogging Betaflight again.

Waiting for the next big thing

I knew there would be a feature I just couldn’t live without. I didn’t know what it would be, but I figured it would be a few months away, right?

There have been some minor advances since the Helio Spring’s release. Some flight controllers have a relay that cuts power to your VTX for an improved pit mode. I’d like to have that, but I don’t really need it.

Dual gyro sensor fusion looks interesting, and there are a couple of flight controllers that support it. These flight controllers have a pair of identical gyro chips, and one of those chips is rotated 90 degrees. The flight controller takes the average of the output from both gyro sensors. This gives you a reduction in noise with almost zero cost. It doesn’t add any latency at all, and it doesn’t even require a noticeable amount of CPU time!

Not only that, but if one of the gyros fails, you can configure Betaflight to ignore it. That could be handy!

We upgraded one of Brian’s Helio Spring quads last week

My friend, Brian, had a dead Helio Spring that needed replacing. I recommended he try the iFlight SucceX F7 TwinG flight controller. It doesn’t have a pit mode relay switch, but it has a pin for camera control, dual gyro sensor fusion, and an F7 microcontroller. I haven’t even looked into how to make use of the camera control pin!

My New iFlight F7 Flight Controllers

It is a nice board, and the installation was quick and painless. The pinout of the iFlight F7’s ESC connector doesn’t match the Tekko32 4-in-1, but the connectors are compatible. Disassembling and reassembling an 8-pin cable to connect the two boards was probably the most time-consuming part of the transplant, but only because we triple-checked, then rechecked our work. Putting the battery input on the wrong pin would have been bad news!

The iFlight F7 TwinG is a nice-looking board. It has a clean layout. It has plenty of UARTs. What’s not to like?

I couldn’t wait to upgrade mine

I’ve been exclusively flying 3” and 4” Kestrel builds for more than a month. Last weekend, I took out my 5” Flowride quads for the first time in a while. It was fun. Those heavy freestyle builds suit my flying style much better than the 250-gram builds, but I was unhappy with how the 5” quads were flying. I was getting more propwash than I would like, and they felt a little off on quick, sharp movements followed immediately by a quick throttle input.

I didn’t want to put time into looking at the tune on these builds that are stuck on outdated versions of Betaflight, so when I got home, I ordered a pair of iFlight F7 flight controllers!

My upgrade didn’t go smoothly!

I made a mistake. I soldered in the first iFlight F7 flight controller, plugged in a 3S battery along with a smoke stopper, and all I got was the ESC startup tone. I didn’t get the tones you would expect to hear after the ESCs communicate with Betaflight.

I fried the flight controller. I checked, rechecked, and then checked a third time when I was correcting the order of the wires in my ESC to FC cable. The only spare 8-pin cables I had on hand that were long enough had all black wires, so I was trying to be careful.

As it turns out, I had the order completely reversed! That’s not the end of the world, though. I still have another iFlight F7 on hand, so I fixed the wire and soldered it in.

It worked great this time, but when I was buttoning up the quad, I noticed on of my rear arms was loose. Several months ago, I slightly bent a bottom plate in a crash. I guess it has been breaking more and more ever since. Of course, that’s the quad I transplanted the new brain into, right?

First flights with a loose arm

I put the FC in Friday evening, and I didn’t notice the arm was loose until after I had the top plate back on. I have a spare bottom plate, but I didn’t have a chance to disassemble it that night. Saturday morning, Brian informs me that we’re going to fly at the golf course, and I don’t have time to charge batteries and swap bottom plates before I have to leave!

It was OK, though. The quad flew amazingly well even with a problematic arm. This shouldn’t surprise me, though. I’ve never noticed a difference in the air between my two Helio Spring quads, although I’m certain I made this one worse by wiggling the arm a bunch when I was testing to see how bad it was!

I only got two batteries in. I had changes and repairs to my 3” and 4” Kestrel quads that needed testing, too. I don’t think I could have asked for a better upgrade!

Betaflight 4.0 has made some huge leaps compared to Betaflight 3.5, and that’s what I was stuck with on my Helio Spring quads. Propwash handling is improved. I’m pleased with the overall feel of the quad. Whatever they’re doing with stick input filtering, gyro filtering, and feed forward these days is just awesome.

I’ll have a pair of solid, sturdy Hyperlite Flowride quads with iFlight F7 flight controllers in a few days. If the weather cooperates, I won’t even bring my micros out with me next week. I’ll concentrate on testing and tuning the new flight controllers.

Conclusion

At this point, we’re kind of being forced to migrate away from our Helio Spring boards. You can keep flying them until they die—that was supposed to be my plan! I like to keep my fleet as identical as possible, so once I upgraded one quad, the rest were going to quickly follow.

If you’re upgrading from a Helio Spring, I think the iFlight F7 with its fancy new dual-gyro setup is a good choice. It has plenty of UARTs, the layout of the board is great, and subjectively speaking, it flies great!

Do you think this sort of dual gyro setup is the future? Do you think I should have saved about $5 by using a single-gyro board? Do you prefer a different flight controller? Let me know what you think in the comments, or stop by our Discord server to chat about it!

You Should Use a VPN to Protect Your Privacy

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I avoided subscribing to an anonymous VPN service for a long time, but I changed my mind about five years ago. I did some research, and narrowed my search down to a few candidates. I wasn’t even going to bother pulling the trigger—I just didn’t feel like I had much need to keep any of my Internet activities anonymous.

Then I learned that Private Internet Access would allow me to pay for their service anonymously using a Walmart or Starbucks gift card. It costs a few dollars more, but sneaking around James Bond-style sounded like it would be fun to write about! I bought a gift card, took some pictures and screenshots, and got myself set up with an account with Private Internet Access. Then I completely forgot to write about my adventure!

I don’t believe paying with a gift card is an option any longer, but you can pay with various cryptocurrencies.

The service works great. It usually has no trouble keeping up with my FiOS Internet connection at home, and Private Internet Access allows you to stay connected on up to ten devices at the same time—up from five devices when I signed up! I set it up on my desktop, laptop, and all my Android devices. I particularly like the Android client. It is just a wrapper around OpenVPN, but it has a nice “Internet Kill Switch” checkbox.

I also have a virtual machine on my KVM server that is always connected to the PIA VPN. If I feel the need to hide any traffic from my ISP, I just set that host as my default gateway, and it will route the traffic through the VPN for me.

Why am I writing about this now?

A while back, I was contacted by a shady-sounding VPN provider. They wanted me to advertise their service on my blog and use their affiliate program. I’m always cautious when companies contact me like this, and I don’t like to endorse products or services that I don’t actually use.

All providers of this sort of VPN service are going to be slimy or shady in one way or another. You don’t want them to log your traffic or connections. You don’t even want them to know who you are, or tell anyone that you’re a customer.

You’re quite possibly a little shady, too. Maybe you just want to make sure the folks on the coffee shop’s WiFi aren’t snooping on your traffic, but you also might be using the service to watch something on Netflix that isn’t available in your country.

I’ve been a happy customer of Private Internet Access for a long time. Their prices are reasonable. Their policies seem reasonable. They also happen to have an affiliate program, so I signed up.

If you click any of my links to PIA in this post, I will get a small slice of your payment.

What are you trying to protect yourself from?

When you’re away from home and connected to someone else’s network, you’re much more vulnerable to attack. Other users just like you might be trying to attack you, and the owner of the network could easily be snooping on your traffic.

My long time solution to this problem has been to push all my traffic over an ssh tunnel to one of my own Virtual Private Servers. This is a simple solution for someone like me. It keeps me safe from people on the local network, and it lets me bypass plenty of corporate firewall restrictions. I trust the operators of my data center just as much or more than I trust my ISP.

There are some downsides to using the ssh tunnel. It keeps folks on the local network from snooping on my traffic, but the servers I’m connecting to will see the IP address of my Virtual Private Server. There are also the problems that can occur when tunneling TCP over TCP on a congested link.

That IP address is most definitely tied directly to me. My data center knows exactly who I am. They know where I live. They have all my billing data.

If you’re trying to keep anonymous, then this will be a problem for you. An ssh tunnel to a VPS is also not something my mother could use.

Using a VPN like Private Internet Access will protect you in the same way as my ssh tunnels, but it will also provide an additional layer of anonymity. If you use a payment method that isn’t tied to your identity, it will be extremely difficult to match the IP address that shows up in server logs to your actual identity.

Among other options, Private Internet Access uses OpenVPN, but they also provide a friendly client application to get you connected, so it is definitely something my mother could manage to use. This is easily worth $3.49 per month.

Why not use a free VPN service?

They say that if you’re not the customer then you must be the product. This is what makes me shy away from free VPN providers.

If you’re worried about a hotel or coffee shop snooping on your traffic, then why wouldn’t you be worried about your VPN provider doing the same thing? Selling information about your activities would certainly be one way for a free VPN service to make money.

I’m happy to pay $3.49 a month in an attempt to mitigate some of that risk.

Is a VPN enough?

If you’re asking this question, there’s a good chance you’re more paranoid than I am. If you’re trying to hide from the government, or you’re doing something illegal, then you need to hide behind more than an anonymous VPN service.

I am far from an expert at hiding from the government, but if you’re just trying to protect yourself when using the free Wi-Fi at the airport, then an anonymous VPN like Private Internet Access is exactly what you need.

Why did I choose Private Internet Access in the first place?

It has been quite enough years since I made the decision to use Private Internet Access, so my memory is a little hazy.

  • Up to 10 concurrent VPN connections
  • OpenVPN works on Linux and Android
  • The Internet Kill Switch checkbox in the Android app
  • Decent scores in That One Privacy Guy’s VPN Comparison Chart
  • $3.49 per month is more than reasonable (on 2 year prepay)

The ability to use the Private Internet Access service on ten devices simultaneously was a good fit for me. That had me covered on my desktop, laptop, phone, and Android tablet. In addition to those four devices, I’m also connecting to PIA with one of my virtual servers here at home.

The “Internet Kill Switch” feature in their Android client is particularly useful. This may not be the case any longer, but when I signed up for PIA, none of the Android OpenVPN client GUIs were equipped with a similar feature—Private Internet Access uses OpenVPN.

When the “Internet Kill Switch” is active, your phone or tablet won’t accidentally attempt to leak data over your unsafe connection if the VPN disconnects. This is exactly the sort of safety net you need when connected to a sketchy Wi-Fi access point!

I know enough about OpenVPN to accomplish the same thing by hand—I’m already doing this on one of my machines. You shouldn’t have to know how to do this, though. It should be easy to configure, and PIA makes it super simple to enable.

The Android app also allows you to bypass the VPN on a per-app basis. I use T-Mobile, and they don’t bill me for data when streaming video or music from most popular services. With the PIA app, I can bypass the VPN for YouTube, Google Music, and Netflix, and just leave the VPN active all the time and not worry about accidentally wasting my valuable data when I’m out and about watching YouTube videos.

Conclusion

I’ve been using Private Internet Access as my VPN provider for years. They’ve done a fantastic job. They recently raised their prices, but I’m not entirely sure by how much. I’m not intimately aware of their pricing structure, but it looks like their 2-year prepaid plan has gone up by $0.15 per month. At the same time, they increased the number of concurrent VPN connections from 5 to 10. That’s a great deal.

PIA seems like a reasonable company. They contribute to open-source projects. They score well on That One Guy’s VPN privacy chart. Their prices are pretty good, and you’re definitely not the product. The Android app is quite good.

What do you think? Am I an idiot for recommending and using PIA? Do you have a better suggestion? Tell me what you think in the comments!

The EMAX TinyHawk is Fun, Inexpensive, and Awesome!

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I’ve had my EMAX TinyHawk for quite a few months now, and I just realized that I haven’t actually sat down to write about it yet!

I’m excited about brushless Whoops, and there are a lot to choose from now like the Mobula 7, the Eachine Trashcan, or the EMAX TinyHawk. What is a Tiny Whoop? Why would you want a brushless Whoop? Why did I choose the TinyHawk?

The real Tiny Whoop is a ducted, brushed micro FPV drone, and it excels at indoor flying. There are other brushed Whoop clones, like the NewBeeDrone AcroBee, or cheaper, less capable clones like my Eachine QX65.

EMAX TinyHawk

There are two things I dislike about these brushed Whoops. Brushed motors have a limited lifespan. They may only last about four hours or so. These quads are also rather fragile. They don’t get into too much trouble, because they weigh less than 25 grams, but I’ve broken a few Whoop frames.

Brushless motors won’t wear out. You might step on one and break it, but you’re not going to smash one of these in a crash like we can with our heavy 5” quads. This makes the brushless Whoops more durable, and reduces the time you have to spend maintaining them.

So why did I choose the TinyHawk? The Mobula 7 and Trashcan can run on 2S batteries, so they can generate a lot more thrust than the 1S power of the TinyHawk. Doesn’t that make the TinyHawk a terrible choice?

I’m not a professional Whoop-class racing pilot. I’m not even an amateur. I just want a fun toy to fly indoors, and I want it to always be ready to fly.

The TinyHawk is overbuilt, and probably a bit overweight. Its shell is sturdy. The props are thick and tough. As long as nobody steps on it, and no dogs decide to grab it out of the air, I expect my TinyHawk frame to last. I wouldn’t be surprised if I have put more than 100 batteries through my TinyHawk, and it looks just like it did when I opened the box.

At the time that I bought my TinyHawk, people were regularly breaking their Mobula 7 frames. I hear that HappyModel has improved the Mobula 7’s frame since then, but I still feel that the TinyHawk has a leg up here.

FPV looks like fun! Should I start with a TinyHawk?

I believe the EMAX TinyHawk bundle is the best way to get started FPV, especially if you’re on a budget. The TinyHawk bundle plus a six-pack of additional batteries will cost you less than $200. You’ll have an indoor FPV drone, a controller, an FPV headset, and enough batteries to fly for nearly 30 minutes.

I think the bundle is a steal, and it is possible to set it up to use the bundled controller to practice in a simulator. Everyone flying a 5” FPV freestyle or racing quad needs to learn to fly in the simulator.

If you do move on to bigger and better FPV quads, you won’t be able to use the bundled controller. You will be able to use the headset for a while.

Project Mockingbird

If you have a TinyHawk or any other brushless Whoop, you need to check out Project Mockingbird. They have documentation for tweaking Betaflight to make your brushless Whoop fly better—much better!

I tried their Betaflight brushed Whoop settings on my Eachine QX65 last year, and the difference was like night and day. It made the QX65 more responsive, and it had a lot less trouble with propwash when descending from the second floor of the house.

When my TinyHawk finally arrived, I didn’t even give it a test flight before applying Project Mockingbird’s brushless Whoop settings. If you have any complaints about how your TinyHawk handles, go check out Project Mockingbird.

Can I fly the TinyHawk outside?

You can, but only in the same way that you can drive a go-cart on a Nascar track. The TinyHawk is extremely fast in the enclosed space of your house, but a small park will feel huge, and it will take forever to fly from one side of the park to the other.

Wind will also be a problem. A light breeze will just make it difficult to aim your TinyHawk through gaps. On a properly windy day, your TinyHawk may not be able to fly faster than the wind, and it might get carried away!

If this is your first experience with FPV, you’ll have some fun outside with your TinyHawk. Just be careful not to lose it!

Charging lots of 1S batteries

The 6-port USB charger than comes with the TinyHawk works, but it is extremely slow. I’m using the charger than came with my Eachine QX65. Similar 1S chargers are available on Amazon. At 600 ma per port, it is probably twice as fast as the TinyHawk’s USB charger, but it requires a DC input—I use my big 6S field charging LiPo.

TinyHawk and Batteries

My friend Brian uses the CX610 charger. It has 6 ports, and each port charges at 1 amp. That’s nearly a 2C charge rate for our 450 mAh TinyHawk batteries, and it charges nearly twice as fast as my charger, but it also requires a DC power supply or a big LiPo battery as an input. These were hard to find when Brian ordered his—I think he ordered the last one available at Amazon that day! They seem to be more common now.

With the CX610 and six or eight batteries, you can probably manage to fly continuously for more than an hour. Don’t buy my charger. Get the CX610. It is about the same price, and a much nicer piece of hardware!

A drone for every occasion

I have two or three 5” freestyle quads. They’re big, heavy for their size, and they capture awesome video footage. You’d never fly one of these indoors, and they’re not appropriate in every situation outdoors. Sometimes the space is too confined. Sometimes it’d be too risky to fly something so heavy and capable of causing so much damage to people and property.

I also carry a 3” freestyle quad. It is built with a tiny HD video camera on a vibration-absorbing Kestrel frame, and it weighs just over 220 grams. The entire build costs less than [the GoPro][gp] I send up on my 5” quads. It would be difficult to break a window with this little guy, but it would still cut someone up pretty badly if it hits them. It would also be much less upsetting if I lost this quad in a lake or river.

Then I have my TinyHawk. I’m not going to capture any amazing video footage with this thing, but it is extremely safe. I’ve flown it right into my face, and it didn’t do any damage. We fly them in the house around our pets and children all the time.

Conclusion

If you think flying FPV looks like fun, you should pick up a TinyHawk bundle. If you’re already flying a larger quad, and you have an FrSky radio and a set of goggles, but you don’t have a brushless Whoop yet, I think you should buy a Tinyhawk.

The TinyHawk strikes a good balance between performance, enjoyment, durability, and cost. Many of the reasons for choosing your 1S or 2S brushless Whoop will be subjective. I’m glad I chose the TinyHawk, and I’d make the same choice today.

Unless you have some specific goals in mind, I don’t think you can make a bad choice in a brushless Whoop. They’re all inexpensive. They’re all durable. They’re all fun.

What do you think? Do you prefer the Mobula 7 or the Eachine Trashcan? Do you prefer old-school brushed Tiny Whoops? Tell me what you think in the comments, or stop by our Discord server to chat about it!

My 4-Inch Kestrel - Can I Keep It Under 250 Grams?

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My open-source Kestrel frame is easily configurable. For my first build, I filled the frame with components that I already had on hand—the guts from a Leader 3 bind-n-fly quad. I knew that I wanted to try to fit a 4” HD quad in under the 250-gram limit, but I wanted to work out as many design bugs as I could first.

The design work on the Kestrel is pretty much complete. I found a few bugs when assembling my 4” build that didn’t show up on the 3”, but they were all easy to correct, and the changes didn’t introduce any incompatibilities with my official 1.0 release. I’m so glad I don’t have to increment to version 2.0 already!

I don’t have any sort of legal requirement to stay under 250 grams, so I’m just using that figure as a guideline. I can get away with using components that aren’t quite suited to the lightest build possible. The FC, ESC, and VTX modules are overweight, but they really aren’t all that heavy. Using lighter, less-capable electronics might have saved me 10 to 15 grams.

That’s not a lot of weight, but my build comes in at 270 grams with a 650 mAh 4S battery. My build does manage to come in at 244 grams with a 450 mAh 4S battery, but that battery is on the small side.

I’m right on the edge here. If I could save 10 grams on my components, and then save another 10 grams by using a 550 or 600 mAh battery, that would be awesome!

My goals for this build

I’m writing this section of the blog before having a chance to actually fly my 4” Kestrel build. It is fully assembled and configured, and it survived a test hover in the front yard last night. It has been raining all day, so I won’t be testing it for a few days.

I want to be honest. I want to tell you what I’m hoping to get out of this build before I can actually verify my hopes and hypotheses!

I used to fly 6” and 5.5” props on my freestyle miniquads. I didn’t fly 6” for long, but I flew 5.5” props for the better part of a year. On the same quad with the same motors, 5” props are more responsive and have a higher top speed compared to 6” props. 6” props have more bottom end that you’ll really notice when pulling out of a dive, and they are significantly more efficient.

5.5” props land somewhere in the middle, but I used to get about 20% more flight time compared to 5” props. Will this relationship between 3” and 4” be similar to the relationship between 5” and 6”? That’s my hope!

I’m a little concerned, though. I once tried 6” props on my BFight 210 with it’s 2204 motors. I didn’t lose any flight time, but I didn’t gain any, either. The 6” props were just too heavy for those motors. Will the 1606 motors be beefy enough for 4” props?

I’m expecting significantly longer flights out of the 4” props, assuming the motors I chose don’t wind up being ridiculously underpowered. I owned a 4” FPV miniquad a long time ago. It was big, heavy, and used 2204 motors and 1,300 mAh 4S batteries.

I expect the 4” setup to be smoother than a 3”, and I’m hoping it doesn’t feel too sluggish when doing snappy freestyle. I feel like my 220-gram 3” Kestrel might be a bit too snappy, so I’m thinking I might enjoy the 4” build!

What if it is terrible at freestyle?! I decided to use a big, heavy 1,000 mW VTX in my build. Assuming that I’m correct about this being more efficient, I would enjoy the idea of having a sub-250 gram medium-to-long-range HD quad!

I don’t trust static thrust tests—especially from manufacturers! A quick look at the numbers tells me that the 4” props on the 1606 motors should be able to cruise along at 30 to 40 MPH while consuming about 40% less power. They’re also capable of producing nearly double the amount of thrust with 4” props, but at the cost of about 30% higher amps. How is that going to work out in the real world?

If things work out in my favor, I will be able to cruise longer and meet or exceed my 3” Kestrel’s flight times when doing aggressive freestyle.

The parts list

My old 4” Holybro Shuriken 180 Pro was a scaled-down 5” racing quad. My new build is attacking this problem from the opposite direction. I’m scaling up a 3” micro, so instead of using 2204 2750 kv motors, I’m using EMAX 1606 3300 kv motors. This is why I’m referring to my build as a light 4” quad.

  • 4” Kestrel frame
  • EMAX 1606 3300 kv motors (4)
  • Aikon 20x20 AK32PIN 35a blheli32 4-in-1 ESC
  • Aikon 20x20 F4 flight controller
  • RaceDayQuads Mach 3 1000 mW VTX (mmcx)
  • Luminier AXII antenna (mmcx)
  • Caddx Turtle V2
  • TBS Crossfire Nano

The Aikon stack is total overkill for this build. That little 20x20 stack can easily power a 5” 6S racing quad. It would have absolutely no trouble driving my 680-gram 5” freestyle quads.

I’m certain that there is a cheaper, smaller, lighter FC and ESC combo that could drive these motors and props. This is going to be my test platform, though. I have a plethora of interesting motors and props lying around. I have some efficient 2205 motors that I’d like to try with 5” props. I have all sorts of 2306 and 2207 motors, too. Maybe I’ll try a ridiculous 6” Kestrel. It is easy to cut arms and stick them on this fuselage!

My 4-inch Kestrel

The VTX and antenna are on the heavy side, too. The VTX is only 6.5 grams, and the AXII only adds another 2 or 3 grams. The little 200 mW VTX and tiny whip antenna from my Leader 3 weighs less than 4 grams.

These heavy components are buying me versatility for testing and some extra VTX juice for long range. I guess my light 4” build is a bit on the tubby side!

Minor problems with my Kestrel design!

I was worried that the Aikon AK32PIN would be too long to comfortably fit on my Kestrel’s bottom plate. I didn’t want to alter the spacing between the mounting points of the side plates, but I could see that there was some wiggle room to push the front and rear stacks closer to the edges.

I was only able to move each stack forward or backward by 3 mm, and that made the build a lot more comfortable. Unfortunately, this also pushed my Caddx Turtle’s 20x20 board too close to the camera!

I raised the top plate a bit to make more room for the stack. The combination of the bottom plate, side plates, and the bushings that hold everything together is rigid enough, but it will flex quite a bit in a crash. This will make it harder to damage your flight controller in a crash, and give you a bit more room to build.

The center stack uses M3 holes as of version 1.0. I have grommets to bring those holes down to size for M2 stacks while providing a bit of vibration isolation for your flight controller. The grommets work great, and the M2 screws are no problem.

I didn’t remember to leave clearance for the head of an M3 screw! There’s a cutout in each arm that leaves enough room, but the arm bracing plate won’t let an M3 screw head pass. This was an easy problem to correct, and I was able to work around the issue when assembling my 4” Kestrel with an M3 center stack.

How does the 4” Kestrel fly?

Other than a few mistakes that I’ve made, the 4” Kestrel is flying great! A lot of what I suspected is true. Even though it is only 20 or 30 grams heavier than most 3” builds, it feels bigger. It reminds me more of flying a 5.5” or 6” quad. It still gets up to top speed quickly, and it catches itself from a fall with barely any throttle.

What kind of mistakes did I make? My side plates are rather floppy, and I’m only certain about what caused one of the problems that has these things flopping around!

When I moved the front and rear stacks outward, that created an opportunity to carve some material out of the bottom plate. This was a mistake, because my bottom plate is now quite flexible!

Also, a pair of my bushings are fitting loosely, but only on the left side! These aren’t fresh bushings, but they don’t have a lot of mileage on them, either. I’ve adjusted the bushing holes and the tabs with every prototype. I think I’ve just pushed things too far. I’ve added 0.5 mm back into the tabs in the model. We’ll see if that fits better.

My side plates are floppy enough that the camera shakes around. It looks terrible!

I also made a mistake regarding the propellers. I had a few pairs of HQ 4x4.3x3 v1s props in my drawer. I shopped around a bit, and that was the gentlest prop I found, so I ordered a few more.

GetFPV is one of the few stores that stocks HQ 4x3x3 v1s props. I haven’t flown them yet, but I’m excited to try them. They should be arriving before the end of the week.

I don’t think 4” props are ridiculous for a 1606 motor, but I’ve been worried that the HQ 4x4.3x3 would be too aggressive for such a small motor. It flies well, but it isn’t as efficient as my 3” 1306 Kestrel with HQ 3x3x3 props.

The 4.3 pitch props cruise at around 35 MPH with 22% throttle. That’s at least 10% less throttle than my 3” Kestrel. I spent an entire 650 mAh pack flying around like that, and couldn’t fly any longer than 6 minutes. My 3” Kestrel usually hits 5 minutes doing pretty aggressive, heavy-throttle freestyle. I’ve never tried for endurance on the 3”, but I know I’ve accidentally flown longer than 6 minutes on it before!

Conclusion

So far, I like the 4” Kestrel, and it is showing some promise. If all the HQ 4x3x3 props wind up doing is bringing the efficiency in line with my 3” build, I’ll be extremely pleased. I think I’m going to enjoy the 4” build more than my 3”, even if it doesn’t offer me longer flights. It just suits my flying style a bit more!

I believe there’s a good chance I’ll see significantly longer flight times out of the gentler pitch 4” props. It would be nice to be able to put that heavy 1000 mW VTX to good use. I’ll know in just a few days, but I’m not patient enough to wait until then to publish this blog!

Do you think I’ll get an extra minute or two out of the HQ 4x3x3 props? Do you think a similar build could be squeezed in under 250 grams with a big battery if I used a lighter FC, ESC, and VTX? Or do you think I should stick to 3”? Do you have any questions? Let me know in the comments, or stop by our Discord server to have a chat!

Expensive FPV Gear Doesn’t Always Boost Your Confidence

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Confidence is important when flying FPV freestyle. If you’re nervous and shaky when you’re aiming for a gap or trying to clear a tree, you’re much more likely to miss the gap or get stuck in the tree.

When I was flying FrSky receivers in my quads, I was often nervous when flying over trees. At the time, I didn’t think I was hitting failsafes all that often, but I bet I was losing my control link once every week or so. I didn’t think it was all that problematic at the time, but every time I lost control, it was like resetting my confidence’s timer.

I’d be nervous for a few days—especially when I was upside down over a tall tree! I’d start getting my confidence back, and then I’d hit another failsafe.

Having reliable gear is important, and my gear wasn’t reliable enough. I invested a few hundred dollars into TBS Crossfire hardware, and this problem was almost completely eliminated. You can’t completely eliminate failsafes, but they are no longer a regular occurrence for me.

You can often spend some of your hard-earned money to buy yourself some extra confidence.

Flying an expensive FPV quad can be scary!

The first time I decided to fly my quad over a little creek, I was nervous. My thumbs were shaky. I wasn’t really prepared to climb down the ten-foot ledge or go swimming to retrieve my stuff. Visibility under all the trees wasn’t great, so I was worried a ghost branch would pop up at the last second.

I swapped my $200 GoPro HERO5 Session for my older $100 GoPro Session. I was still sending $650 or so down into that creek. I could lose a $40 Crossfire Nano, a $60 ESC board, a $45 Runcam Eagle, and all sorts of other bits and bobs. A slew of $50 components adds up quickly!

These days, I have an even less risky option. My 3” Kestrel build with Caddx Turtle V2 HD camera costs less than $250. I have a lot more confidence when I’m sending $250 into a precarious situation!

Start with inexpensive quads

If you’re new to the hobby, you’re going to goof up. You’re going to obliterate a quad. You’re likely to lose a quad.

We hosted three different quadcopter build classes at TheLab.ms makerspace. We cautioned everyone. After a large 450 mm quad flew away on someone from the first class, we started really hammering those words of caution into everyone. Even so, someone lost a quad within a few days of each class! They were so far gone that we never saw them again.

I’d rather see you get this out of your system with a junker of a quad. I’d be bummed out if I helped you build something like the $600 quads I fly, and you wound up losing it the first time you went out flying by yourself. I’d much rather see you lose a $130 BFight 210. Does anyone know what the modern equivalent of the BFight 210 happens to be?!

The BFight 210 was great. At least four of my friends flew them, and they flew them a lot! They’re light, inexpensive, and surprisingly durable 5” FPV quads. They are a little under-powered, but they’re efficient. Beginners are regularly getting 10-minute flights out of their BFight 210 quads, but they’d feel much too heavy with a GoPro strapped to the top.

That’s OK, though. Losing a GoPro is a bummer. You should definitely buy accidental damage insurance, but that insurance only works if you manage to recover the camera! The first time I strapped an HD camera to the top of my quad, it flew off in a crash. The TPU mounts we use today work much better, but losing your camera or your entire quad is still a risk.

You’ll be braver with less than $150 in the air than you would be when risking $350 or $500 on a flight!

A light, budget-friendly build of my 3” Kestrel can be squeezed in at around $250. 3” quads don’t feel as solid and locked in as a 5”, but it is a great way to get started if you really must have HD recording capabilities right away.

Upgrade the gear in your hands first

You use a lot of expensive gear when you fly, but the only piece of equipment that’s really at risk is the quadcopter and its payload. The rest of your gear is sitting safely in your hands or on your head!

When I started out, I used a cheap 200 mW VTX on my quad, and a cheap set of box goggles. Even with a directional antenna, we felt like flying 1,200 feet away at a low altitude in an open field was pushing the limits of our video quality. I used to tolerate some pretty awful video in those days. What do you expect from a $12 VTX and a $50 set of goggles?

Upgrade your goggles and video receiver

Today, I use a better VTX, and I’ve upgraded to a set of Fat Shark Dominator goggles with an [ImmersionRC RapidFire module][rf]. My new setup costs ten times more than my first set of box goggles, but I couldn’t imagine going back!

I rarely use a directional antenna on my RapidFire module. I almost always fly with a pair of omni antennas. We often fly at an abandoned golf course here in town, and I regularly fly 1,500 feet away without a directional antenna. I didn’t even realize I’ve been flying that far until I checked a map! I’ve even dropped down into a creek to fly under a bridge that was 1,200 feet away.

Fat Shark Dominators with RapidFire module

Needless to say, upgrading to a RapidFire module has been a huge confidence boost. Most of the time, though, the RX5808 module that I had when I bought my Fat Shark goggles was just fine, and a huge upgrade over the cheap box goggles.

Upgrade your radio

If you went the cheap route on your radio, with something like a FlySky FS-i6 or Turnigy Evolution, you should think about upgrading your radio before upgrading your quad. Crossfire modules have dropped in price to compete with FrSky’s R9 gear, and I would almost recommend skipping FrSky’s 2.4 GHz hardware.

Taranis X9D+ and Spektrum DX6

I’m still a fan of the Taranis X9D+. It costs a bit more than the Taranis QX 7, but it comes with a rechargeable battery, a charger, and it is compatible with Crossfire without any soldering. Buying a rechargeable battery for the QX 7 eats into your savings, and having to remove the battery to charge it is a pain. The NiMH battery in the X9D+ isn’t great, but it sure is convenient!

The Underground FPV Nirvana radio looks interesting, too. I fly with my thumbs, so it would be a comfortable radio for me. The FlySky antenna can be folded out of the way, and it is compatible with Crossfire right out of the box.

Upgrade your charging setup

This won’t help you fly, but it might save you some time and effort, and that time savings will pay off over the long run.

I started out using one of the cheap “4-button” chargers. It maxed out at around 5 amps. That wasn’t a problem, until I learned how to parallel charge.

I’ve since upgraded to an ISDT Q6-Pro, and I have the charger attached to a Bat-Safe. The Q6 Pro maxes out at around 14 amps. I can charge six 1300 mAh 5S packs in just over 22 minutes.

My Field Charging Setup

The ISDT charger has a nicer interface, and it can balance charge roughly three times faster than my old charger. I believe this is why the ISDT charges so much faster than my old charger, even when both are pushing the same amperage.

Waiting an hour for six batteries to parallel charge on my original charger wasn’t a huge problem, but it was an annoyance if I needed to charge more than six batteries—six identical batteries, even!

It is nice to be able to charge a set of 5S, a set of 6S, and a set of micro-sized 4S packs in about an hour, even if it doesn’t actually help me fly any better!

Upgrade your bag

I remember being very excited when a whole bunch of research pointed me towards the $15 tactical backpacks. There were quite a few people excited about them, including Stew from UAV Futures. It was a good deal, and I really did like that bag.

My Old Tactical Backpack

I didn’t realize how much time I was wasting every time I went flying. I usually had to unstrap a couple of quads from the outside of the bag, and I had to unpack my box goggles, Taranis, and my battery bag before I could get started. I also needed room to set all that stuff down somewhere near the bag.

When I was done flying, I had to carefully fit all that stuff back into my bag. It took a few minutes to unpack, and then roughly twice as long to repack the bag.

I’ve since upgraded to an expensive FPV backpack—a ThinkTank FPV Airport Helipak. I’m not saying you should go out and buy a $200 backpack, but I’m so happy that I did!

With a big bag like this, I just set it down, open the lid, and start flying. Everything has its own spot, and nothing important has to be loaded underneath other items. I can remove or replace batteries, my Taranis, my goggles, or a quad quickly and easily. I don’t set anything down next to my bag anymore.

My ThinkTank FPV Airport Helipak

When I put down my radio or goggles, they go right back in their assigned home. When it is time to leave, I don’t have much more to do than zip up my bag and pack up my chair.

This may seem like a minor victory, but I’m saving myself ten to fifteen minutes every time I fly. Sometimes that means I can get one or two more batteries in before it gets dark. Is that worth $200? How much is it worth to you to get one more pack in, and how many times does this have to happen before the bag has paid for itself?

You don’t have to spend $200 on a backpack. I also have an AmazonBasics DSLR backpack. It is much smaller, so I can’t pack everything in there—the soldering iron and field charging battery have to stay at home!

It is great for when I hop on my electric bike to ride to the park. My fully-loaded ThinkTank bag weighs 26 pounds. The smaller backpack never weighs more than 12 pounds.

With that smaller bag, I can either bring my 3” Kestrel and 90 minutes’ worth of battery, or I can bring my 5” Flowride and 20 minutes’ worth of batteries. I can’t fit as much in there, but I operate it just like the ThinkTank bag—everything has a place, and gear goes back in that place when I’m not using it.

Either bag is more efficient in the field than the old $15 tactical backpack. People often say that the best bag for your FPV gear is the bag you already have. No matter what sort of bag you use, you should do your best to make efficient use of it.

Conclusion

Sometimes you can spend money to buy confidence. If you keep burning out ESCs, have a flaky gyro on your flight controller, or your quad sometimes just does a flip of death for no reason, then you are just going to have to spend some cash to fix it. If you just can’t see where you’re going, you might have to buy a better camera or VTX.

I don’t know about you, but my nerves can’t always handle flying 680 grams and $750 in new or scary situations. My thumbs get shaky if I might smash a heavy quad into somebody’s car, or I might drop my quad and GoPro into a lake or river.

My 4-inch Kestrel HD Quad

I like having a $250 HD quad to get myself warmed up in new places or situations. I hope to be a better pilot one day, and those situations won’t feel new or scary anymore. Until that day, I’m going to make sure I carry an inexpensive quad!

What do you think? Do you sometimes get shaky thumbs when flying in a new or sketchy spot? Do you carry an old quad or a cheap quad for those situations? Tell me about in a comment, or stop by and chat about it on out Discord server!

Building a NAS: Buy Lots of Drive or Just What You Need?

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So, you’ve decided that you want to build your own NAS. I bet you’re investigating hard drive prices and your options for RAID levels. At least, I hope you are!

Should you buy the biggest disks on the market? Do you have to buy all your disks up front? Should you use ZFS or a more traditional RAID setup? How much redundancy do you need?

Some of Brian's NAS builds

There are so many questions, and there is no single answer that fits everyone situation. I’m going to attempt to answer some these questions from my current point of view. My hope is that you and I are in similar situations!

My home NAS stores my important, personal data. I created all of this important data myself, and I’m spending money out of my own pocket on this hardware. I paid for the cameras that take the photos and record the video. I paid for the drones that capture the video that accounts for the bulk of my storage these days. I paid for the server and all the hard drives.

I prefer to keep as much money in my wallet as possible. In the past, it has been my job to spend other people’s money on things like this. They paid me to choose the hardware. They paid me to configure the hardware. They paid me to maintain and support the hardware. Well, not just me. In most cases, I was part of a team of people.

When spending other people’s money, I’m happy to pay for extra stuff. If there’s a 0.1% chance that using something like ECC RAM could keep me from getting out of bed at 3:00 AM, that would have been worth quite a few hundreds or thousands of extra dollars; after all, it isn’t my money!

If my home NAS fails at 3:00 AM, I won’t notice until the afternoon of the next day. I have backups. I know my data will be easily available on another machine in the house. If the house burns down, all my data is sitting on a different continent. I’ll be able to get it back.

Do I need to buy all my drives up front?

It depends.

When my friend Brian built his first DIY NAS back in 2012, I told him that he needed to give ZFS a try. ZFS has been around a long time, but it was only a part of FreeNAS or FreeBSD for a couple years at that point. ZFS has a lot of useful, advanced features: block-level checksums, extremely flexible snapshot and volume management, and RAID rebuilds don’t touch unused parts of the file system.

Even today, though, ZFS has one major disadvantage over something like Linux’s software RAID system. ZFS doesn’t allow you to add additional drives to an existing zpool. If you want to be efficient with ZFS, you need to build your array with as many disks as you can right away.

Let’s say your little home server has room for eight drives. For the sake of simple math, let’s say you decided to use 1 TB drives that cost $100 each, and you want to have one disk worth of redundancy in your array.

If you buy eight disks and configure set them up as a ZFS RAID-Z array or a traditional RAID 6 array, it will cost $800 for 7 TB of usable space.

You don’t need 7 TB today. You only need 3 TB, and you know these 1 TB drives will be half the price in a couple years. So you buy four disks. Now your smaller RAID-Z has 3 TB of usable space, but it only cost you $400.

What do you do in two or three years when you run out of space? If you’re running ZFS, you can’t just plunk in another drive.

You can replace your 1 TB drives one at a time with 2 TB drives. When you replace the final drive, you will have doubled your space. This can be an expensive operation, and you’ll may be stuck with four old, unused drives.

You can add four more drives. You’ll have to create another zpool, which means you will lose one more disk’s worth of storage to your RAID-Z redundancy. Maybe you’ve lucked out, though, and 2 TB drives now cost $100. You’ll have two redundant disks and a total of 9 TB of usable space. That’s nearly 30% more storage for the same price, and you’ve managed to gain a little more redundancy.

Will disks be twice the size for the same cost when you decide to upgrade? I can’t tell you that. So far, we’re just making up prices to help form a picture in your mind.

You can add disks to Linux’s software RAID arrays after they’re built

Let’s go back to the point where you decided to start with four drives, but instead of running ZFS, let’s use Linux’s MD layer to built a RAID 5 array.

What happens in two years when you run out of space? You don’t have to spend $400 on another set of disks. You can buy just one more 1 TB disk, or you can future-proof yourself a bit and add a 2 TB disk instead. Either way, you can pop that disk in, run a few simple commands, and in a few hours you’ll have an extra 1 TB of space available on your RAID 5 array.

Each time you begin to run low on space, you can simply buy another disk—at least until you fill up your case!

Don’t use RAID 5 or RAID-Z

RAID levels that use parity for redundancy, like RAID 5 or RAID-Z, are great when you’re on a budget and write speeds aren’t important for your workload. Any reasonable RAID 5 array will have no trouble saturating that Gigabit Ethernet network you have at home in either direction, and let’s face it, if write performance were truly important, you’d be using solid-state disks!

At some point, though, the single disk’s worth of redundancy started to get worrisome. You have an increased likelihood of a disk failure during a RAID rebuild, because you’re probably going to be touching every sector on every disk. On top of that, as drives have gotten bigger the odds of hitting a spontaneous read error during the rebuild started approaching 100% when disks were just 300 or 400 GB.

Disks are ten times larger now, so you really want to have two disks worth of redundancy in each array—this really goofs up the math on my RAID 5 examples above, doesn’t it? This means you should be using at least RAID 6, RAID-Z2, or RAID 10.

My previous example isn’t so bad with Linux’s software RAID 6!

Let’s go back. You bought four hard drives, but you’re going to use RAID 6 or RAID-Z2. This means you’re giving up two drives’ worth of storage to redundancy in each array.

In the case of both RAID 6 and RAID-Z2, you’ll spend $400 on hard drives, and you’ll have 2 TB of usable storage capacity. In both cases, half of your storage is allocated as redundancy.

In two years, you decide to add another four drives, but this time they’re 2 TB at $100 each. If you’re running RAID-Z2, you can create a second RAID-Z2 pool. You will have 6 TB of usable storage, and half of your storage space will be allocated as redundancy.

If you’re running a Linux MD RAID 6 array, you can restripe across these additional disks, and you don’t have to buy them all at once. Just to keep it fair, though, lets say you did buy those same four additional 2 TB drives at $100 each.

Unless you rely on some fancy partitioning footwork, you’ll end up in roughly the same position. Linux’s RAID 6 implementation will ignore the second half of those 2 TB disks. You’ll have 6 TB of usable storage on your RAID 6 array, but you’ll have 4 TB sitting around. When you eventually replace the original four drives with larger ones, that space will become available.

What do you think? Should I write a blog post about that supposedly fancy partitioning footwork?

There’s too many made up prices

I’ve been adding drives to my arrays at home for decades, but before I had a blog, I had absolutely no record keeping. In the real world, things tend to be messier than this. When you start with four drives, at least one of them will probably fail before you need to upgrade to expand your array.

What do you do when a drive fails? I usually order a fresh drive from Amazon, then I wait for the manufacturer to process my RMA. That way, I don’t have to worry for too long about a degraded array. That also means I’ll have a spare disk in a few weeks, so I get to expand my array early!

That’s great, Pat, but what do these dollar figures look like in real life?

I am no longer the kind of guy that builds great, big NAS machines. There was a time when I stored a lot of data at home. My old desktop at home in 2001 had an 8-port 3Ware IDE RAID card and a stack of 30 GB IDE drives! Even after that, it was common for me to have a machine with at least six large SATA disks at home—my arcade cabinet has room for nine hard drives!

If you’re looking for a larger build, you need to talk to my friend Brian Moses. These days, my storage needs are rather small. When I built my Linux KVM virtual machine server for my office, I used a pair of 4 TB hard drives in a RAID 10 array for the bulk of the storage. You did read that correctly. It is a RAID 10 array with only two disks.

Flying FPV freestyle quads has resulted in a sharp increase in my data hoarding rate. If I had just left well enough alone, it would have taken at least six years for my DSLR photos to fill the storage on my NAS VM. I’m now accruing more FPV video every single month than I accrued in six years of shooting RAW photos with my DSLR!

This forced me into an early upgrade last year. This means I do have some real-world data!

In 2015, I bought a pair of 4 TB 7200 RPM drives for $140 each. That gave me 4 TB of usable storage for $280.

In 2018, I bought a third 4 TB 7200 RPM disk for $110. That brought my usable storage up to 6 TB for a total cost of $390. I know. That’s only a $30 savings! I wasn’t expecting to expand so soon, though.

Today, almost exactly one year later, I can buy an HGST 4 TB 7200 RPM disk for $72 with free one-day shipping. If I could have held out a little longer, I would have saved $70!

Who cares about $70? This is too much work for such a small savings!

I haven’t just saved money. If I had bought three disks in 2015, all my drives would be five years old today. That’s not the case, though. Two of my drives are five years old, and one is only two years old.

I’m on track to add a fourth disk in about 12 months. Assuming I don’t have a drive failure before then, I’ll have two six year old drive, one three year old drive, and a brand new disk. I start to get nervous when all the drives in my array are four or five years old!

Next year, the average age of the disks in my array with me 3.75 years, and by that time I will have saved at least $140.

What made you decide to use RAID 10? How can you have three disks in a RAID 10?

I didn’t need much storage, and I prefer to have two disks’ worth of redundancy. You can’t have fewer than four drives in a RAID 6 array. You can build a RAID 6 with a prefailed drive, and it will act like a RAID 5, but you still need three drives. At the time, I only needed about 1 TB of storage for my NAS and some extra scratch space for my other virtual machines.

I only needed two drives to build a RAID 10, and my virtual machines could benefit from the faster write speeds compared to RAID 5 or RAID 6.

I like to say that Linux’s RAID 10 implementation follows the spirit of the law rather than the letter. Linux’s RAID 10 implementation makes sure that each block exists on two disks—more if you want to be paranoid.

If you have two disks, Linux’s RAID 10 operates just like a RAID 1 mirror. You can lose either disk, and you won’t lose any data.

If you have an odd number of disks, like the three disks in my current array, Linux’s RAID 10 implementation will stagger your data. The first block will be on disks one and two, the second block will be stored on disks three and one, and the third block will be stored on disks two and three. With three disks, I can lose any single disk without losing my array.

In all cases, there are two copies of my data spread across array.

Things will be safer once I reach four disks. At that point, I will be able to lose up to two disks without data loss. Unlike RAID 6, which two disks I lose is extremely important! Your odds of surviving the loss of two disks in a RAID 10 increase with drive count. With RAID 6, you can lose any two disks without losing data.

Isn’t your cost per terabyte higher with RAID 10?

Yes, and the comparison will continue to get worse as my array grows. I appreciate the extra performance of my RAID 10 array, but I could definitely live without it. The biggest advantage for me was the up-front cost.

On day one, it cost me $280 to have 4 TB of usable space. Assuming I used 4 TB drives, and I would have, it would have cost $540 to have at least that much space available with RAID 6—only $420 if I cheated. I would have had double the usable space, but I didn’t feel this was necessary at the time.

Next year, I expect to have 8 TB of usable RAID 10 storage, and it will have cost me $460 or less.

As far as storage is concerned, at four drives, RAID 10 and RAID 6 would a tie. Starting with the fifth drive, RAID 6 would have netted me 50% more storage per additional drive. Because of the pair of SSDs in my home server, I can’t use more than four hard drives without adding a PCIe SATA controller. I’m going to do my best to avoid that anyway!

Calculating data growth, age of disks, and whatnot

When I was growing my RAID 10 last year, I was already thinking about writing this blog post. I even wrote up a quick and dirty script to help predict some useful information: how often you’ll need to add a new drive, how much each new drive may cost, how much money you’ve saved so far, and the average age of the disks in your array.

Drive Addition Predictor Output

My little Perl script is extremely dirty, and it isn’t nearly intelligent enough—that’s what happens when you spend less than 10 minutes on something like this!

I built in a concept something like depreciation. Each month, it assumes that a new drive will be slightly cheaper than the month before. I massaged that number to roughly align with my real-world experience, but that prediction will eventually fail.

4 TB drives will continue to drop in price right up until they stop manufacturing drives that small. Then the prices will start to slowly rise for a while. How do you build brains into the script to estimate when you should buy larger drives?!

I’m thinking about making the script a little smarter and converting it to Javascript. We’ll see if I ever get around to it!

Conclusion

I feel like this post rambled on longer than it should have, so I guess it is time for my tl;dr!

I prefer being able to purchase my storage as needed, at least here at home. It saves me some money. More importantly, it keeps my hard drives fresher. The drives in your NAS are spinning around 24 hours a day. They’re going to wear out. The odds of a drive failure increase dramatically in the fourth and fifth years of service. It is best to keep your hard drives as young as possible!

Most importantly, please remember that RAID is not a replacement for backups! RAID helps prevent downtime. RAID does not keep your data safe.

Do you run ZFS? Do you fill your NAS with disks when you build it, or do you add storage as needed? Do you just hope to win one of Brian Moses’s NAS builds that is already stuffed full of hard drives? Tell me about it in the comments, or stop by [our Discord server][bw] to chat!

Can You Run A NAS In A Virtual Machine?

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Of course you can. There is absolutely nothing stopping you. My home NAS is running in a virtual machine.

Should you host your NAS as a virtual machine? I don’t know anything about your needs, but I bet you can get away with running a NAS in a VM. It is definitely the correct option for my use case!

Some folks will tell you that running your NAS in virtual machine a terrible idea. I’m going to tell you why they’re wrong, and I’m going to help keep you from making mistakes that would make those people correct!

What a is a NAS?

The acronym stands for Network-Attached Storage. In the old days, We used to call them file servers, but I guess that just wasn’t fancy enough. Anything that shares files on an IP network qualifies as a NAS. In the old days, we even used IPX, but we didn’t use the term “NAS” back then.

Some of Brian's NAS builds

Your cheap Wi-Fi router with a USB flash drive plugged into the back. Your old Windows XP laptop that’s sharing all your movies. My own virtual server running Samba on Linux. My friend Brian’s beefy DIY NAS servers and his EconoNAS boxes. They’re all network-attached storage devices!

What isn’t a NAS?

A NAS doesn’t transcode video. A NAS doesn’t have to be using ZFS. A NAS doesn’t require ECC RAM. A NAS doesn’t host virtual machines. A NAS isn’t an iSCSI target—that’s a SAN!

Running extra services like a video transcoder, iSCSI targets, or virtual machines will make your server more versatile. They aren’t part of the NAS.

But what if I want to run Plex on my NAS?!

That’s fine! A NAS server is just a file server, and a file server is just a computer. You can do whatever you like with your computers.

You want to host VMs on your server? Go for it! Just make sure you have enough RAM and CPU to handle the load of those virtual machines.

A NAS doesn’t need much processor power or a ton of RAM—your Gigabit Ethernet or Infiniband connection will be your bottleneck most of the time. Transcoding video doesn’t require much RAM or disk, but it sure does need a lot of CPU.

This is exactly the sort of use case where virtualization excels. Your NAS isn’t making much use of your processing power, and your Plex transcoder isn’t fully utilizing its disk or RAM. If you put them both on the same box, you’ll make better use of your hardware.

Some of my virtual machines

Why virtualize each service? Why not put the NAS and Plex server on the same machine?

Plex communicates with services on the Internet. That’s enough reason for me to want to keep my file server separate from Plex. I want Plex to be able to see my videos. I don’t want my bank statements or drafts of my upcoming blog posts leaking out to the Internet!

Am I building a NAS that transcodes video, or a transcoding server that serves files?

This is almost a silly question. You might use a truck to haul plywood home from Lowes. You might use a minivan to drive your family to the arcade.

You can pack your family into the pickup truck, but you might only have those goofy little fold-down seats in the back. You can haul plywood in your minivan, but you’re going to have to fold down or remove the seats.

Each can do the job of the other. Your preference will be based on which task you do more often. If you’re hauling six kids around every day, you want the minivan. If you’re running to Home Depot three times a week, you’ll want a truck.

These are two options that can handle two very different jobs. Maybe you don’t have six kids, and you never bring plywood home from Lowes. You don’t need a large vehicle. Maybe you’re like me, and you only need a Miata.

Sharing files to a handful of computers at home doesn’t require much CPU or RAM. It doesn’t require a truck or a minivan. You can build a little Atom or Celeron machine that sips power and doesn’t cost much.

If you need to transcode video on demand, you’ll be looking at entirely different motherboards and processors. You’re going to be looking at trucks or minivans. Are you building a NAS that also transcodes video, or a beefy transcoding machine that happens to serve files?

I don’t know which server is the truck or the minivan. I’m sure you get the idea.

QUESTION: The streaming devices on every TV in my house can play back 4K content using all the common codecs just fine, and buying three or four of those is cheaper than the CPU it would take to transcode. What on Earth is everyone transcoding?!

Everyone says I should run ZFS on my NAS!

I agree with them. Running ZFS on a NAS is a fantastic idea. ZFS computes and stores checksums of all your data. When ZFS reads your data back from the disk, it compares the data to the checksum. If it doesn’t match, it knows your data is corrupt.

If ZFS is able to read that same data from a different disk, it can correct that error. Standard RAID levels won’t even detect that kind of error, so they can’t correct for it.

Ryzen 1600

ZFS isn’t the only file system option with checksums, but it is one of the best and most advanced. The Linux kernel’s device mapper layer now has a module called dm-integrity, and I’m interested in trying it out. It adds a ZFS-like checksum layer to any block device.

I have a feeling that I’ll have to tear down the RAID 10 on my KVM server to set it up, and I’m not excited about putting in that work!

Redundancy is important

Earlier in this post, I said that all you need for a NAS is a USB flash drive. That may qualify as a NAS, but it would be a pretty terrible file server!

Hard drives fail, and they fail often. Backblaze’s data says that 5% to 10% of their hard drives fail every year.

RAID is not a replacement for backups

RAID prevents downtime. If you don’t have hot swap bays in your server, you will have to take your server down to replace a dead hard drive, but at least you don’t have to go through the time and pain of a restore from backup.

RAID won’t save you from a lightning strike. RAID won’t save you when a bad SATA controller mangles all your disks. RAID won’t save you when your file system gets corrupt. RAID won’t save you when you accidentally delete something. RAID won’t save you from malware.

ZFS has some nice features that can mitigate some of these risks. Regular snapshots will probably protect your from malware and accidental file deletions, but not much else.

It is fairly common to have a second drive in an array fail as you are replacing a disk. Rebuilding a RAID requires reading every bit of data from each drive, and it can take quite a few hours for the process to complete. This can be stressful for a drive that is already near the end of its life.

Storage is cheap. Backups are expensive. Have you ever wondered why your IT department wants to limit your storage space and the size of your inbox? Adding a few more disks is cheap. Backing up all your data and sending it off-site every single day is expensive!

Wait a minute! If ZFS is so great, why aren’t you using it on your NAS?!

I set up my NAS virtual machine almost five years ago. My NAS is running Linux, and at that time, ZFS support on Linux wasn’t so great. Ubuntu had only just started shipping native, in-kernel ZFS support at that time. I’d already used the ZFS FUSE file system on another machine, but it didn’t perform all that well.

I am not a fan of FreeBSD, and I have no need for the FreeNAS’s convoluted web interface—I work much faster at the command line. Plenty of people use FreeNAS, and I’m sure I could have run it in a VM.

ZFS combines many of the features of Linux’s separate MD and LVM layers. This makes ZFS powerful and convenient, but ZFS is currently missing an important feature.

You can’t add disks to an existing ZFS zpool. If you want to expand your storage, you have two choices. You can replace every single disk in your zpool, but this can be expensive. You can create an additional zpool, but if you’re using RAID-Z2, you’ll be wasting two more disks’ worth of space on redundancy.

Linux’s MD and LVM layers allow me to easily add additional disks to my RAID 10 or RAID 6 arrays. When I run out of space, I just buy another drive.

ZFS was created by a company that sells expensive, high-end servers. Every time it has been my job to spec out servers in a data center, I almost always filled the chassis with disks. That’s exactly what Sun expected their customers to do.

If you’re spending your own money, there are plenty of good reasons wait until you actually need more storage before buying more drives. Prices decrease over time, and the older a drive gets, the more likely it is to suffer a mechanical failure.

Which device should host my NAS?

I like to consolidate my services as much as possible. Also, I’ve always encouraged people to run their in-home services on hardware that already needs to be powered on all day long.

For a long time, I hosted my NAS and other virtual machines on my arcade cabinet. My NAS needs to be accessible 24 hours a day, and having my arcade cabinet ready to go at a moment’s notice was awesome. Why waste 30 to 60 watts on two different machines that are usually idle?

You probably don’t have an arcade cabinet.

I needed to get my NAS VM closer to my desktop, because CX4 cables for Infiniband aren’t very long!

Does my NAS virtual machine need its own RAID?

I had about four different headings here with about 1,500 words explaining the advantages and disadvantages of various RAID configurations. It was dry, boring, and probably not all that helpful. Instead, I’m just going to tell you what I do, and why I do it.

On my own setup, my virtual machine host has a RAID 10 array with LVM configured on top of it. Some of my machines use LVM block devices on that RAID 10 array as disks, but most of them use disk image files that are stored on an ext4 volume on my RAID 10. I take a performance hit by using image files, but they tend to be more convenient than block devices.

Parts for my KVM server

My virtual machines don’t need any RAID configuration. All the disk redundancy work is handled by the host. The less specific the virtual machines are to the host, the better. It makes it easier to shuffle machines around.

If a drive fails, or I expand my storage, the virtual machines will be completely unaware.

The RAID 10 array on my KVM server is encrypted. If someone pulls the plug and carries the box out of my house, they won’t be able to access any of my virtual machines. With this setup, I don’t have to enter a passphrase into each VM when they boot up. I only have to unlock one encrypted volume when the KVM server boots up.

Is there any reason to set up your RAID in the NAS VM?

Yes. If you’re running ZFS or dm-integrity on the host, and there is a checksum or read error, your NAS virtual machine will never know about it. ZFS may tell you that it corrected an error, or it may tell you that there is a file with a bad checksum, and it can’t fix it.

Which file has the bad checksum? If you are running a set-up like mine, you’ll have to do a lot of work to find out. ZFS would tell me that there was a checksum error in the disk image file of my NAS VM. ZFS on the host doesn’t understand what’s inside that image file, and the NAS VM may have no idea that there was an error.

If the error can be corrected, ZFS or dm-integrity will correct it. This will be the situation most of the time. If you’re starting to lose data to irrecoverable errors, you’re already in big trouble anyway, and it may be time to test your backups.

How do I set up a RAID or redundant zpool in a virtual machine?

Very carefully. Remember when I said there are reasons people will tell you it is a bad idea to run a NAS in a VM? If you set up your RAID inside the VM, and you make a mistake, you will greatly increase your chance of data loss!

You have to make sure each virtual disk is pointed at a different physical disk in your server. You have to make sure that your virtualization software makes your virtual machine’s connection to the disk as direct as possible. It isn’t difficult, but you have to be meticulous. If you goof up, you can make things extremely fragile!

ZFS needs to be as close to the disks as possible. You don’t want the host doing any caching. You don’t want the host absorbing any read or write errors. iXsystems has a post about how to run FreeNAS with ZFS in a virtual machine, and it explains the various pitfalls.

I’m still going to say that you should follow my lead and set up your old-school RAID or ZFS on the host. Unless you have a really good reason to have the VM do this job, I doubt it will be worth the hassle for you.

What does Pat store on his NAS?

I store data that doesn’t comfortably fit on the SSD in [my desktop computer][]. For the most part, that is the RAW files produced by my DSLR and FPV flight footage.

A lot of people use their home NAS to back up the data on their computers. I prefer my backups to be off-site. I use Seafile to meet both my file syncing and backup needs. Seafile is an open-source Dropbox equivalent. It keeps all the data on my desktop and laptop in sync, and 90 days of file history are stored on the server. All the data on the server is encrypted on my end.

If I need to restore a file, it will be on the Seafile server. If the SSD in my desktop fails, I have a recent copy of that data on my laptop, so I don’t have to wait for everything to download. I’m quite pleased with the functionality, redundancy, and cost of this setup.

The only important data on my NAS that isn’t backed up is the GoPro footage of my FPV freestyle flying. The volume is huge, and the older it gets, the less value it has. The footage I collect each month is nearly as large as the collection of photos I’ve taken with my DSLR over a four-year period—200 to 250 GB.

Storage on my NAS is rather inexpensive, so I don’t yet feel the need to delete any of the old footage. That said, I’m extremely unlikely to rummage through flight footage from two years ago. Most of the footage is mundane. Finding 20 seconds of interesting footage among 45 minutes of a day of flying is tedious.

I could be served nearly as well if I just threw a large hard drive into my desktop computer.

Conclusion

Everyone’s needs are different. Sharing files is the least important job handled by my little homelab server. Adding disks to my KVM box to supply storage space for my NAS VM was inexpensive, and it adds less than 10 watts to my overall power consumption.

I don’t see a need to invest the money, electricity, or time into setting up and running a separate piece of hardware to store my large files.

How are you handling your file-storage needs? Do you have a dedicated, beefy NAS machine like the ones my friend Brian Moses builds? Did you win one of the NAS servers he’s been giving away over the years? How are you handling your backups? I’d like to hear about it in the comments, or you can stop by our Discord server to chat with me about it!

The Kestrel HD Micro Quad Frame Version 1.0

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I’m excited. I started working on my open-source HD micro frame roughly two months ago. Since then, I’ve assembled a Shapeoko XXL CNC machine, learned how to use the machine to cut carbon fiber, and I’ve flown several iterations of my frame design. I’m certain that there will be more changes to come, but I am quite pleased with the design so far, so I’ve decided to slap a Version 1.0 sticker on it!

My current build is using EMAX 1306 4000 kv motors, and it weighs 223 grams with a 650 mAh 4S pack. I usually get around 5 minutes of fairly aggressive freestyle out of it.

My friend Brian transplanted his Diatone GT-M3 to a Kestrel frame. With his HGLRC 1407 motors, he’s coming in at 253 grams with the same battery. He’s a bit over the 250 gram limit, but not by much!

The Kestrel is licensed under the GNU GPL 2

I planned for the Kestrel to be open source from the beginning, but which license should I use? The choice of license was actually quite simple. I borrowed an awesome fillet function for OpenSCAD from Github, and that fillet function was licensed under the GNU GPL.

Since I wanted to include that function in my source code, I had to license it under the GNU GPL 2 as well.

My 3-inch Kestrel

There aren’t a lot of open-source FPV quadcopter frames to choose from. The most popular would be the TBS Source One frame. How does releasing an open-source frame help you?

If I stop manufacturing frames, you could still acquire spare parts from someone else—I haven’t even figured out how to manufacture or sell these frames! If you have access to a CNC machine, you can cut your own. I wish CNC machines were as readily available as 3D printers!

If the source code is available, won’t that make it easier to clone the Kestrel?

Yes, it will, but only slightly. Copying a frame is extremely easy. All you need is the piece of the frame and a scanner. Almost anyone could pull it off.

I am much more excited about giving you the ability to cut your own frame than I am worried about someone selling copies of my design!

What can I do with the source code?

The Kestrel is designed using OpenSCAD. OpenSCAD is an open-source CAD package. Instead of creating your objects by dragging and dropping various shapes and operations around the screen with your mouse, everything is defined using OpenSCAD’s programming language. Everything is built from unions and differences of basic shapes like cubes, spheres, and cylinders.

If you’re a programmer, this may be easier for you to handle than a traditional CAD package. OpenSCAD excels when you need to build objects that match precise measurements. You’ll start to get into the weeds when you try to model more organic shapes.

Early model of the Kestrel's motor mount

Modeling in OpenSCAD requires more work up front, but it can pay off in the long run. The most time-consuming task when creating the Kestrel was getting the guitar-shaped motor mounts right. The mounts are built up using a configuration of hulls and fillets of a variety of discs.

The diameter and spacing of those discs is based on the distance between the motor’s mounting holes. The entire mount had to work well with the 9 mm hole spacing of an 1106 motor up to the 16 mm hole spacing of a 2207 motor. Getting the ratios and angles correct to make either extreme look right was challenging!

I think it was worth the extra work. There are quite a few important parameters of the frame that can now be adjusted by simply adjusting the measurements in variables at the top of the OpenSCAD source code.

  • Motor mount hole spacing
  • Arm length
  • Arm angle
  • Arm width
  • FPV camera’s protection diameter
  • FPV camera’s relative positioning
  • Side plate thickness
  • Height available to the stack
  • Grommet hole length and height
  • Grommet tab depth and width

Do you want to build the tightest 2.5” HD micro quad? You can punch new measurements into two or three variables, and you can get the props as close to each other and the fuselage as you’d like.

Some of the Kestrel's variables

My 3” configuration pushes the motors out just about as far as they can go. If they were much longer, I would have had to extend my motor wires. Longer arms help deliver clean air to each propeller, and the extra leverage makes the quad more stable.

Do you want to fly a spindly, lightweight 6” HD quad? You could easily cut some crazy arms for the Kestrel, and I am more than a little tempted to try this!

The bushings probably need tweaking

Are they bushings or grommets? McMaster-Carr calls them grommets, but I seem to keep changing my mind.

This is the part of the frame that I need to get right. The Acrobrat comes with three different sets of bushings with various hardness ratings. McMaster stocks an appropriate bushing, and a 100 pack was less than $10. I didn’t get to choose the stiffness, though. They’re rated at a shore hardness of 55. That’s pretty close to the medium-stiffness bushing that ships with the Acrobrat.

The Kestrel's suspension

I can’t modify the stiffness, but I can adjust how tightly the grommet fits over the tabs on the bottom plate. My first prototype was too tight. I don’t even think the rubber was loose enough to absorb any vibration at all!

I’ve loosened it up quite a bit. I made the tabs narrower, and I made the oval-shaped grommet hole in the side plate a bit taller. There’s a good bit of play in there now—hopefully not too much!

I’m going to try a 4” build!

The 3” version of the Kestrel is flying quite well. I’ve had some trouble with my 1306 build, but I think I’ve gotten it mostly under control—I hope! Brian’s 1407 build is flying great, even though he didn’t quite manage to fit under the 250-gram limit—not that he has any need to!

The new arm interlocking system

I’d like to order some parts to build a lightweight 4” quad. I’m having a hard time choosing hardware. I like the EMAX 1606 3300 KV motors, but choosing a 20x20 stack is difficult!

The motors aren’t much heavier than my 1306 motors, and longer, thicker arms will only add about five extra grams. I’m hopeful that my build will fit in under 250 grams, but I won’t be too upset if I exceed that weight.

It has been two years since I flew a 4” quad. That old 4” quad had 2204 2750 KV motors. I’m hoping that the difference between a heavy 3” build and a light 4” build feels a lot like the difference between a 5” and 5” quad. It should have more bottom end, so it will be easier to catch the quad when falling out of a dive. It should also be more efficient, so I’m expecting to get longer flights. It will probably be less responsive, but the 3” almost feels twitchy to me, so that might be a bonus!

If the 4” build flies well and fits in under 250 grams, I think it will be an interesting build for the parts of the world with serious weight restrictions!

Motors are easy. Finding a 20x20 stack that I like is hard!

There are a few problems with moving to 4”

Tiny boards for 2.5” and 3” micros are plentiful. 4-in-1 ESC boards that can properly handle larger motors and props are somewhat larger, even when they use the 20x20 mm mounting pattern. They also tend to require M3 screws instead of M2 screws.

I can just drill larger holes in my central stack and call it a day, but I have a better plan. I’ve ordered some tiny grommets from McMaster-Carr. If I measured correctly, these grommets should work well for soft mounting a stack that requires M2 screws. The hole these grommets fit into should be just about the right size for an M3 screw, so these will allow for either configuration using the same mounting holes.

I’m looking at two stacks. The Lumenier MICRO LUX V3 stack and the Aikon AK32PIN stack.

These are both 20x20 stacks that require M3 screws. They’re both F4 flight controllers with blheli_32 ESCs. The Aikon ESC is quite a bit larger, but it is capable enough to be used in a 6S 5” miniquad. The Aikon ESC alone costs as much as the Lumenier stack.

The Aikon ESC will be a tough fit, but it looks like I can squeeze it in. If I do go this route, and fitting such a large ESC is too difficult, I will probably adjust the length of the fuselage to compensate. Am I going to be moving past version 1.0 this quickly?

The source code is hosted on Gitlab

The OpenSCAD source code, a simple build script, and SVG and DXF output files for several arm configurations are being hosted on Gitlab.

There are configurations for two sets of 3” arms, one set of 4” arms, and a ridiculous set of 6” arms. Only one set of 3” arms has been flight tested. All the 3” and 4” arms are built by the build script, and the SVG and DXF files to cut those frames are in the output directory. I left the 6” arms out of the build script, because they’re just crazy.

What makes the Kestrel unique?

I wanted to build a 3” Acrobrat, but I don’t think the Acrobrat is the frame for me. I wanted to use 1106 motors, and I wanted to keep the weight down. The Acrobrat is a big, heavy frame. I believe it comes in at 54 grams with all the hardware. I hoped I could build something more appropriate for my own needs, and I think I’ve done a reasonable job!

Brian's 1407 Kestrel

The Kestrel uses individual, replaceable arms. Those arms are easily configurable, so it should be possible to run anything from extremely short and tight 2.5” props on 1106 motors, 5” props on 2207 motors, or anything in between. Each arm is held in place with a single screw, so they are easy to replace in the field.

The arms are positioned to keep the props completely out of view of the HD camera.

I wanted to fit three 20x20 stacks, just like the Acrobrat. Having all that space makes it so much easier to build and repair your micro quad. In addition to room for three stacks, the M3 screws for the motors also line up with a standard 30.5x30.5 stack.

The Kestrel uses a suspension system like the Acrobrat’s. The weight of the battery and HD camera are separated from the vibrations of the motors by rubber bushings.

My 3-inch Kestrel

A Kestrel frame with long 3” arms currently weighs 39 grams. That’s about 15 grams lighter than the Acrobrat. I’m quite certain the Acrobrat is sturdier, but I’m hopeful that the Kestrel is just sturdy enough! Time and crashes will let us know for sure.

How do we keep Pat working on open-source frames?!

I’d love to tell you to buy a frame, but selling frames isn’t easy—especially if you’ve never done it before!

I’m just barely beginning to investigate having 3” Kestrel frames manufactured. There’s no shortage of companies in China that will do this sort of thing for you, and it seems inexpensive—even for fairly small batches! I’m more than a little worried about attempting this, but if there’s enough interest, I’ll do what I can to have frames manufactured.

Carbon fiber 3mm

I plan to at least offer a limited quantity of 3” Kestrel in my store on Tindie. If you’d like to buy a Kestrel, you can always get in touch with me, and I’m sure we can work something out. I don’t even know how much I should charge!

If you think I’m doing interesting work, and you’d like to see me continue, you can always become a Patron. A few dollars a month goes a long way towards carbon fiber, replacing dull end mills, and helping me recoup the cost of the CNC machine.

I’ve probably already gone through $50 to $100 worth of carbon fiber sheets on test parts. Every tweak to the frame eats $5 to $10 worth of material, and after two or three frames, I need to throw away a dull end mill. The costs add up fast!

You can also help me out on Youtube. Subscriptions are awesome. Comments are even better. More eyeballs on the Kestrel will make it easier for me to work out manufacturing!

Conclusion

I’m excited to be contributing an Open-Source FPV quadcopter frame to the community. I wish CNC machines were as prolific and available as 3D printers, but I’m still hoping someone will be interested enough to cut a frame for themselves!

I’m starting to send frames out for testing. If you’re interested in testing the Kestrel, feel free to get in touch with me. I’m planning on sending some out for not much more than the cost of the carbon and shipping. Does it count as selling if I’m losing money?

Are you flying an Acrobrat? Are you flying a different HD micro frame? Have you been hoping for a lighter Acrobrat-like frame with replaceable arms? I’d love to hear about what you’re flying! You can leave a comment below, or you can stop by our Discord server and chat about it!