What I’ve Learned About 4-Inch Miniquads

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When I started designing my Kestrel, I knew that I would have to experiment with 4” propellers. 4” props don’t get a lot of love, and that has been a problem. Lots of people fly 3” or 5” props, so there’s a huge selection of props. Since nobody flies 4”, there are only three or four props worth trying, and none are a great fit for what I’m hoping to accomplish.

What was I hoping to see?

I remember the first time I tried 6” props on my 5” quad. It had some fairly powerful 2600 kv T-Motor F40 Pro V2 motors. I figured it wasn’t going to work out well. Larger props need to spin slower, and those high-kv motors had me a little worried.

I quickly learned that it wasn’t a real problem. If my memory serves, I was getting roughly 30% longer flight times compared to 5” props. This was true whether I was doing slow, cruising, long-range-style flights, or punchy freestyle flying.

My 3-inch Kestrel

When flying 6”, you will see a lower top speed compared to 5”, but you’ll gain a ton of grab in the air. If you’re falling out of a long dive, the 6” props can just catch you like nobody’s business.

Math and pi tell us that a 4” prop has a disc area that is 77% larger than a 3” prop, while a 6” prop only has 44% more surface area than a 5”. It is a bigger difference, but I was hoping to see the same sort of changes: longer flight times, more bite on the bottom end of the throttle, and lower top speeds.

Can we build a sub-250-gram 4” freestyle quad with an HD camera? Will flight times be long enough for some long-range flights? Will it feel more like a 5” freestyle quad?

My testing with 6” had me concerned

A bunch of us own an old Bind-N-Fly miniquad from Aurora RC called the BFight 210. We all loved it. I got my first one free as a review unit. I immediately bought another for my nephew. Several friends also bought them. It was always going on sale for $120 or less, and we all bought them during sales. It was a tremendous value.

It wasn’t a speed demon, and it felt terrible if you tried carrying a GoPro. I believe it had 2205 2300 kv motors. New pilots were regularly seeing 9-minute flight times. My record on a long-range style cruise was over 11 minutes. How amazing would the BFight 210 be with 6” props?!

BFight 210

It was terrible. The 2204 motors just didn’t have the power to handle such a big prop. It felt terrible, and flight times didn’t improve. In hindsight, this isn’t surprising. At the time, it was a bummer.

4” props on a 270-gram Kestrel

I missed the 250-gram mark with my 4” Kestrel build, but I know I could bring it down and save a few dollars doing it. I used the beefy Aikon AK32PIN 20x20 blheli32 4-in-1 ESC, and I used a big 1,000 mW VTX. If I switched to a Diatone Mamba F4 20x20 stack, a 200 mW VTX, and maybe pulled back from a 650 mAh to 550 mAh 4S battery, I’d save $40 and easily shave 20 grams off the build.

My 4-inch Kestrel Build

There are tons of 4” props available, but most of them are for airplanes, and many of the rest are ancient, inefficient bullnose propellers. The best props I’ve found to pair with my little EMAX 1606 2800 kv motors so far are the HQ 4x3x3. I’m aware of the new EMAX Avan Scimitar 4x2.4x3 props. I plan to throw a few into my cart the next time I’m ordering miniquad supplies!

UPDATE: I did order some EMAX 4x2.4x3 props!

I have to say that overall, I am mostly pleased with the way my 4” Kestrel build flies. It feels more like a 5” freestyle quad than any 3” I’ve flown. I feel more confident coming out of sketchy split-S maneuvers or power loops that just weren’t lined up well.

That was the good news

Propwash handling is terrible with this combination. Mark Spatz has an excellent video explaining why gentle props on powerful motors make it much easier for your Betaflight to fight propwash, but I can’t seem to figure out exactly which video that is! I have relatively big, heavy props on relatively tiny motors.

Sure, I can fly around this propwash, but I always forget that I need to. I try to fly it like it is my 5”, and that doesn’t work out.

I’m also not seeing any real gain in efficiency. My 220-gram 3” Kestrel with 1306 motors usually manages 4 or 5 minutes of the sort of freestyle flying that I tend to do. The 4” rarely makes it past 4 minutes.

When I’ve purposely taken slow, boring flights with the 3” Kestrel, I’ve pushed past 8 minutes of flight time. I’ve never managed more than 6 minutes with the 4” Kestrel.

That said, I’m willing to give up that extra minute of flight time. My 4” Kestrel feels much more like a 5” freestyle quad than my 3” build!

The Caddx Turtle is just awful

The first obvious problem with the Turtle or Split is that the HD video and FPV video settings are tied together. There’s only one sensor on that camera. That means ISO and shutter speed are shared, and the settings that make the HD feed look reasonable make for a poor flying experience.

The field of view on the Turtle is tiny compared to a GoPro with SuperView. That’s always a disappointment.

NOTE: I’m sorry. I rarely upload Caddx Turtle video, because I just dislike it so much. The video I embedded here looks kind of hokey, I think. Maybe I need to start uploading my vlogs in 60 fps when flying with the Turtle?

The Turtle produces serviceable HD footage when you’re flying slow and just cruising. Once I start doing quick, snappy moves, I’m disappointed with the video. I just can’t get enough motion blur into the image, even with an ND filter. It just looks like a slideshow. I don’t like it.

These cameras are getting better every few months. The Caddx Tarsier and the Runcam Split Hybrid both look like a huge steps in the right direction.

What can we do if 4” props are too heavy?

I’d really like to try a biblade version of the HQ 4x3x3. I even emailed HQ to ask if they had anything like that. The response was confusing, so I’m going to assume this won’t be an option.

I decided to take matters into my own hands. I dropped my heavy vise onto the bed of my Shapeoko CNC machine, and I clamped in one of my old 2306 motors. I positioned the router about 1.75” away from the center of the motor, and I manually cut down some of my HQ 4x4.3x3 and HQ 4x3x3 props.

This worked surprisingly well!

I don’t have a lot of data on 3.5” props

I’ve flown two batteries so far. They weren’t even fresh batteries. They’ve been sitting in my bag at full charge for the better part of a month. They fly just fine, but I don’t feel comfortable comparing efficiency to what I used to see on freshly charged batteries.

These cut-down props are now bullnose props. Bullnose props should be significantly less efficient than a properly designed 3.5” prop. We don’t have any of those to compare with, though. A 3.5” prop has 36% more disc area than a 3” prop, so this is much closer to the upgrade from 5” to 6” props.

I can tell you that the huge propwash problem is almost completely gone. Like with any quad, if I try my hardest, I can definitely coax some propwash oscillation out of the 3.5” bullnose props. I know for sure that I hit some accidental propwash at least once, but it wasn’t as bad, and it would have been easy to avoid.

I’m going to have to do some back-to-back testing. I need freshly charged batteries. I need to fly some 3”, 3.5”, and 4” props. I need to fly more than one battery on each prop, too.

In any case, I’m pretty excited.

Shaky video on my 4” Kestrel

I’ve been cutting Kestrel frames for my friends, and I don’t really enjoy spending a ton of time in the garage cutting carbon fiber; it is too hot out there!

That means my two Kestrels are built using my oldest parts. Most of the magic on the Kestrel happens where the bottom plate meets the rubber suspension. I have to size that tab just right. Too small, and it just wobbles around. Too large, and the suspension doesn’t absorb vibration. This has been tweaked a bit on almost every bottom plate I’ve cut.

On top of that, I’ve also redesigned the bottom plate to make it more rigid. Of course, my two Kestrels use old bottom plates. My tabs aren’t quite the right size, and my bottom plate is much less rigid.

I noticed that my 4” Kestrel’s fuselage can be twisted quite easily. I figured my less-rigid bottom plate was weakening in all my crashes, and it probably is, but I also learned that the McMaster-Carr grommets get soft and deformed over time. I swapped some new grommets in, and that helped a lot.

The Business End of the Kestrel Frame

It is still looser than I would like.

Here’s the bummer. I swapped out the grommets and swapped from 4” to 3.5” props at the same time. Did the stiffer grommets correct the problem? Are my 3.5” props just a little unbalanced? They have to be a little out of balance, right?

I’m due to cut myself some up to date bottom plates. I’m just not looking forward to disassembling the entire Kestrel to replace one plate!

9 months flying HD micro freestyle quads

In many parts of the world, there’s a 250-gram weight limit on model aircraft. I’m not too worried about this today, but it sure seems like the same sort of rule will be coming here, too. I think it is prudent to be testing the waters.

I also love the idea of having a hold-my-beer quad. When I’m flying my 3” Kestrel, I can record HD footage, and everything in the air costs around $250. That’s including the battery. That’s somewhere between the cost of a GoPro HERO5 Session and a HERO7 Black.

Sure, the quality isn’t nearly as good as a GoPro, but I also won’t feel as bad when my Kestrel gets stuck on a roof or sinks to the bottom of the ocean.

That seems to be the only time I would really want to fly one of my 3” or 4” micros. My 5” Falcon freestyle quad flies better, records better footage, and I’m rarely worried about the possibility of losing the whole thing.

On the other end of the spectrum, if the spot that I’m flying isn’t a good fit for my 5” freestyle miniquad, I’m probably not going to fly a 3” either. There’s a much better chance that I’ll be monkeying around with my minuscule EMAX TinyHawk Freestyle if there’s likely to be people or delicate property nearby.

I keep saying that things are constantly improving. By the time the United States has a 250-gram weight limit, maybe the successor to the Caddx Tarsier will be as good as my GoPro Session. I’m sure Betaflight will continue to improve. Motor and prop selection for micros will only get better.

Until that time, my 3” and 4” Kestrels will be relegated to occasional flying.

Is the rubber suspension required? Is it even helpful?

This is the real question. I decided to use the Acrobrat-style suspension on the Kestrel, because it sounds like an excellent idea. Does it really help?

My honest answer has to be that I have absolutely no idea! Maybe there should be a 3” and 4” version of my open-source Falcon frame? That would be a good way to test the effectiveness of the suspension.

The Kestrel's Suspension

I hope that the suspension is helpful. Maybe a fresh build with brand new props doesn’t need the rubber bushings at all, but what happens when you bump a tree? Will the bushings save your footage?

If the bushings would save my footage after some slight prop damage, they’d be worth the additional hassle!

Hardware problems in my 3” and 4” Kestrels

I broke my 3” Kestrel a long time ago. I got stuck in a tree, and had to use turtle mode quite a lot to wiggle it loose. It was stuck quite well, then it fell down a few branches, and got stuck again, and then a third time. When it finally hit the ground, the Caddx Turtle was dead. It wasn’t dead when I started my attempt to recover the poor thing.

It hasn’t flown quite right ever since. It’ll fly OK if I add a ton of filtering, so I haven’t made the effort to fix it. The new revision of the Diatone stack is only $38, but I didn’t really want to take everything apart and resolder every connection!

Last week, an ESC on my 4” Kestrel failed. This is both a surprise and a bummer. I chose a relatively expensive and heavy ESC board for that build. I figured that an ESC that folks are using in 5” racing builds with 2207 motors ought to be bulletproof on my tiny 1606 motors. It wasn’t.

The smart, frugal thing to do would be to replace the ESC board with the little Diatone ESC. I’m not going to do that.

I ordered a pair of Diatone Mamba stacks, and I’m going solder them into both my Kestrels next week. Sure, the Diatone F4 flight controller is a downgrade from the F7 board that is currently in the 4” Kestrel, but I like the idea of them running the same inexpensive hardware.

I’d like to be able to point to either of them and say that you could build either for around $250 or less!

I’ll use this repair opportunity as an excuse to cut new bottom plates for my Kestrels. I have the oldest prototype plates in mine, and they have extra material cut out to make them lighter. That also makes them quite a bit softer. It is time to bring my own builds up to match everyone else’s!


I’ve used quite a lot of words just to explain that I’m excited about trying 3.5” props. That’s really all I’m here to say today. I’m excited about 3.5” props, but I don’t have much solid data to give you at this point. I’ll fly some more over the next week or two, and we’ll see what I find out!

What do you think? Have you tried 3.5” props? Are you flying 3” or 4” props? Do you think splitting the difference is interesting? Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it!

Slow USB Flash Drives Are All Right As Long As They Are Cheap

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I’ve been doing my best to post quality deals over at Butter, What?!, and several of those deals have been extremely cheap USB flash drives and microSD cards made by Silicon Power. After posting those deals, I noticed that a few of the folks over at /r/buildapcsales are really upset about Silicon Power’s USB flash drives.

As stated on their listing on Amazon, these flash drives have a USB 3 interface. However, the product listing also states that the drives only manage read speeds of 70 megabytes per second and write speeds of a measly 5 megabytes per second.

Presumably, this is because Silicon Power is using old, cheap flash chips. I ordered a pair of the 64 GB drives for $9.99. My tests showed 40 megabytes per second on reads and 19 megabytes per second on writes. That is a good bit faster than USB 2, so these drives are benefiting from the USB 3 interface. They just aren’t benefiting all that much.

Slow drives are just fine, especially when they’re cheap!

When I was young, we used to trade 5.25” floppy disks with our friends. They might bring a save game over to our house, or I might send them home with a copy of the game I just bought. The polite thing to do is bring your own floppies, right?

That didn’t always work out. I was often scrounging around the house for an old, dilapidated floppy disk that could be sacrificed. You didn’t want to waste one of your good disks on an inconsiderate friend!

Skip ahead 10 or 15 years, and we’d be talking about CD-R discs instead of floppies. Skip another 10 years to today, and we’re talking about USB flash drives.

If I discover that I need to send you home with two seasons of a TV show that you just can’t stream from anywhere, I’m going to throw it on a USB flash drive.

You don’t have a USB flash drive with you?! That’s just fine. I’m going to throw it on one of my slow $5 drives. If you forget to return the drive, it is no big deal.

What else do we use flash drives for?

I use mine for small, occasional backups. Sure, most of my backups are stored in the cloud, but there are a few things that I like to keep on hand locally. Specifically, I store a backup of my Bitwarden password vault, my ssh keys, and my GnuPG keys on a flash drive. Slow is fine for this, because the data is so tiny.

Every once in a while, I need to create a bootable USB flash drive. Most of those times, I’m only copying about 700 megabytes onto the flash drive. Even on a slow drive, that will only take a minute or two.

What would I use a fast, expensive USB flash drive for?

I’m struggling to come up with a use case. I don’t even own any fast flash drives. The arrival of Dropbox and similar services probably put the last nails in the USB flash drives’ coffin for me. Why run around with data in your pocket? All my data magically shows up on every computer I own automatically.

Maybe you haven’t caught up to the rest of us. Maybe you’re still manually copying files around and running them from one place to another. I’d rather see you get on board with the convenience and simplicity of file sync than see you buying lots of fast USB flash drives!

The Silicon Power 128 GB USB flash drive made me sad

They aren’t the only manufacturer that I should be picking on. I’ve posted a deal on a slow Kingston drive in the past, too. However, there’s a Silicon Power flash drive that I really want to pick on, though.

Their 128 GB USB 3 flash drive was on sale for $9.99 with free Prime shipping. That’s about as good of a deal as the 2-pack of 64 GB drives from the week before. I almost posted it on Butter, What?!

I couldn’t find anything in the product description about actual transfer rates. There’s a bunch of talk about the huge speeds of the USB 3.0 bus. They might even be implying that their drive is going to make good use of those speeds. There’s no mentions of tested, real-world transfer rates.

There are plenty of customer reviews talking about how slow these drives are.

This is disappointing. I’m happy to buy something that is slow, as long as you tell me about it up front, and the price is right.

In this case, the price is right, but the advertising is deceptive. I don’t like that.


I’m going to keep posting these sorts of USB flash drive sales to Butter, What?!, but only if the product descriptions are honest. I can’t keep buying them, though. I believe I’ve bought every flash and microSD deal I’ve posted so far. I’ll probably buy one more pair of cheap USB flash drives, then I’ll have to stop for a while. My collection is getting too big!

What do you think? Do you agree with me that cheap, slow flash drives are a good value? Do you prefer faster drives? What are you doing with them? Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it!

I Competed In My First Drone Race!

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We have an active and awesome MultiGP chapter here in Dallas, and their field is just a 25-minute drive from my house. I’ve been invited out to their races before, but I never managed to make it out. I know from the days when I used to occasionally take my car out to the local drag strips that organized racing isn’t really my cup of tea.

A few weeks ago, Brian and I drove across town to go flying with Alex Vanover. He convinced us that we should go out to Carrollton for some drone racing. I went out that Friday to spectate, and I decided I should give it a try, so I signed up to race the next week.

Even just spectating was fun

I got to see some fast racing quads, and I had the opportunity to meet some cool people. We told some folks about our favorite, secluded flying spot here in our neighborhood, and we had three or four new friends show up for some freestyle flying with us the next day. That was awesome!

The fine folks at Dallas Drone Racing had a couple of televisions set up along with a projector. The screens were all showing a grid of FPV feeds, so even if you don’t have your own equipment, you can still see what the pilots are seeing.

I brought my Fat Shark goggles. They gave me a better view of the action, but they definitely weren’t required.

I’ve always avoided racing, because I dislike all the organization that is required. You’re always waiting for your turn. Everyone flies in a certain order. When your next turn comes up, you had better be ready; you can’t just let someone go ahead of you and just take the next spot.

Half of the participants were just there to have some fun flying and hang out with their friends. They’re doing exactly what my friends and I do when we fly at a park, except they get called up to run a few laps every once in a while. It’s not that much different than what I’m already doing!

Racing isn’t quite like I expected!

In the past, my friends and I have set up children’s soccer goals with the nets cut out and used them as drone racing gates. They’re not much higher than your waist, and not all that much wider than they are tall. The MultiGP gates are huge. I bet you could drive a Miata through them.

My brain didn’t want to understand the scale of the track. Compared to the places where we usually fly freestyle, the entire track was tiny. Something about the length of the track combined with these big, honking gates just doesn’t compute for me.

I broke my first quad before finishing a lap!

There’s more than a little hyperbole in that statement, and it was totally my fault due to lack of testing. A few days before the race, I broke the Immortal T antenna on my favorite quad’s Crossfire Nano module; that poor thing has taken such a beating over the last 15 months!

When I got home that day, I replaced the antenna. I put the quad in one corner of the house, and I wandered around the house with my radio. I had perfect signal all throughout the house, so I figured I’d be in good shape. I figured wrong.

I bumped one of the inflatable gates during my first lap, and I fell out of the sky. I tried to use turtle mode to flip back over, but I just couldn’t arm the quad. I noticed that my link quality was reading 7. The antenna wasn’t the only problem with that Crossfire Nano!

No big deal. I had two more quads in my bag. It was just a bummer that I missed out on my first three practice laps.

I need way more practice

I knew my fingers were shaky the entire time. I didn’t think they were shaking as much as the first time I flew down in our little creek near the house, but listening to my GoPro footage makes me think otherwise. I wonder how many times I’d have to go out racing before that will stop?!

Speaking of GoPros, I’m pretty sure I was the only goofus flying a heavy freestyle quad with smooth, gentle freestyle props, and carrying a GoPro. I was also the only pilot with GPS. The best I managed was 57 MPH on the long straight through the finish line. I’m curious how fast the really fast pilots were going!

The gates are big, and once I got used to the scale of the track, they weren’t too hard to hit. The problem I had was with puzzling out which gate to aim for next. There were two parts of the track that I miscalculated almost every time.

At one of the two-story gates, you were supposed to go through the top part, S-turn and reverse through the bottom, then do about a 180-degree turn to the right to line up for the next gate. My eye liked to catch one of the inflatable flags, and I would accidentally aim for that flag instead of the gate.

I had a similar problem at one of the other double-decker gates. By the time I realized my mistake, I’d be way out of line for hitting the next gate. That isn’t so bad, because I could still manage to make it through the right gate. The problem is that the weird line I was on would leave me going in mostly the wrong angle when coming out of that next gate.

I did better and worse than I expected

That first night when I went out to spectate, I formulated some opinions. It looked like those big gates would be easy to fly through, and I anticipated that I would be able to compete with 1/3 to ½ of the pilots that I saw flying that night.

The gates were easy to hit, though I did bump into more than my fair share. The race I competed in was the final race of the Mission Food series, and I get the feeling that things were a little more competitive than the race I spectated. I think the course was a little meaner, too.

I had several laps around 45 or 46 seconds, and my best lap was just over 42 seconds. I had some laps at just over 60 seconds even when I crashed and had to flip back over. The lap timer failed to call out my times pretty often, too.

I even did better than I thought!

I was going to tell you that I failed to string together three of those 45-second laps into a single race, but I’ve learned that that isn’t even true!

On my final race, the robot that announces lap times read out 1:36 for my first lap. I remember thinking that this sounded awfully high, but I just pushed ahead. I crashed on my last lap, and I bent a prop badly enough that I couldn’t take off.

As it so happens, that lap reading was incorrect. According to my GoPro footage, I did complete three laps at 0:48, 0:45, and 0:42. I crashed on my fourth lap. That’s the lap I wasn’t supposed to be taking!

I’m much more proud of this run than I thought I was!

Just because I was finished doesn’t mean everyone else was done!

I got knocked out rather quickly. I believe I got to squeeze in three practice runs that should have been about three laps each. When I moved on to the heat I was actually competing in, I didn’t really fly any differently. As far as I was concerned, I was still practicing!

There was plenty of racing to watch after I got knocked out of the competition, and it seemed like every race was over faster than the one before.

Would I do it again?

Sure! I don’t think I’d want to race every week, but it’d definitely be fun to do on occasion. Drone racing is something I should get better at. I’m certain that if I were a better racer, then I would also be a better freestyle pilot.

I’d definitely be willing to go out to spectate more often. There are a lot interesting and friendly people at the local drone races. It is fun to see what sort of quads they’re flying, what sort of hardware they choose, and just generally see what they’re all up to!


If you’re flying FPV, you should find your local MultiGP chapter and stop by to see what they’re up to! I had a lot of fun, they’re a great community, and there’s a lot to learn from them, especially if you’re new to the hobby!

Are you already participating in drone races? How do you think I did on my first time out? Are you an FPV pilot somewhere in the vicinity of Dallas, TX? Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it. Rarely a week goes by that we don’t organize a small flying meet-up in Discord. Maybe you’d want to join us?!

Spending an Afternoon Flying with Alex Vanover

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We had an awesome and extremely interesting experience this week. Brian and I got to spend an afternoon flying miniquads with one of the fastest FPV drone racing pilots in the world.

How this came about was rather curious. It was my birthday a few months ago, and I can only imagine that I’m quite difficult to shop for. I’m one of those terrible people that immediately buys just about everything I really want.

My Falcon Frame

We already knew that Alex Vanover lived somewhere nearby. Brian’s wife, Julia, noticed that he had an hourly rate listed somewhere on the Internet. I guess that you could pay Alex to work on your broken miniquads. For all we know, he posted this information a few years ago and completely forgot about it.

Julia told him that we didn’t need anyone to work on our quads. She just wanted to know if she could hire him to fly with us. I have absolutely no idea how that conversation went, but a couple of months later, Brian and I found ourselves in the car driving out to a small airstrip on the other side of the metroplex to meet up with Alex Vanover.

Meeting Alex Vanover

The Dallas/Fort Worth metro area is rather large. Brian and I left Plano at around 2:00 p.m., and we headed west. About 30 minutes into our journey, we were nearly driving through our old neighborhood in Irving, where we lived nearly 20 years ago. About ten minutes later, and it felt like we were leaving civilization.

After another 15 minutes passed, we were making our way slowly through the roadways surrounding a small airstrip. Google Maps had us off course by one street. We could see Alex just off in the distance. He was carrying a big racing flag out to the end of the field; we could see he was in the middle of setting up his practice track.

Vanover is an interesting guy. He’s 19. He’s an amazing freestyle pilot. He lives in a hangar at an airport. We were standing next to the field where he put in most of his huge number of hours of practice that made him into one of the fastest drone racing pilots in the world. How cool is that?!

We introduced ourselves, and Alex asked what sort of flying we wanted to do. We quickly decided to drive to a nearby park for some freestyle flying.

I have to wonder what Alex was expecting

I’ve seen videos of drone racing. I’ve seen what the DRL tracks look like. I’ve never actually attended an actual drone race.

I assumed Alex would be expecting us to be hardcore drone racing fans. At worst, I figured he’d expect us to act like my mother would when she ran into the local TV weatherman. You wouldn’t have wanted to be that weatherman!

Later, I gathered that he expected us to have quads that flew poorly. It sounds like that’s fairly common, and I bet it is more likely to be the case when someone is actively looking for help.

I’m not good at PID or filter tuning. If I have a machine that is flying all sorts of wrong, the best I can do is take guesses to try to get it flying better. I do understand the settings well enough that I can take a quad that is flying OK and make it fly a little better, though.

What did we actually do?!

The three of us sat at a picnic table, we took turns flying, and we talked a lot. This is pretty much what I do every time I go flying with friends. Why should it be any different when hanging out with a professional?

The first thing Alex took up with his 5” racing build. He flew it using one of my brand new 1,000 mAh 6S packs. He told me that he’d feel bad if he smoked my brand new battery, but I told him to do his worst. I got these oddly shaped batteries on sale for $18 each last week. Killing one wouldn’t be a big loss, right?!

Watching ridiculously fast racing footage on YouTube is one thing. Seeing a professional racing pilot blast around under the trees at full throttle less than 10 feet away from you is a very different experience! If I were smart, I would have at least gotten DVR footage of that run. Unfortunately, I’m not that smart.

He discharged my battery in less than 2 minutes, and it was a ton of fun to watch. The difference between my casual flying and the flying of a pilot that runs through 100 batteries a day while practicing is nothing short of astonishing.

I think I flew three batteries. I’m pretty sure Brian only flew one, but it was the most impressive contiguous five minutes of flying I’ve ever seen him do. Alex put a few batteries through a DRL Racer 4, and he put one battery through my Falcon build.

That last part had to be my favorite. Watching a skilled freestyle pilot do things that I simply can’t do using my own machine was awesome. Not only was he flying the quad that I fly every day, but Alex was flying a frame that I designed.

Alex had nice things to say about my quad, my frame, and my tune. I even have some of the kind words on video! I wouldn’t feel right publishing any of that video. It is just the tail end of flight footage on the GoPro. I don’t know that either of us realized any of the words would have wound up on a recording.

I don’t want the world to get the mistaken impression that my open-source frame is awesome just because Vanover said nice things to me about it, especially when neither of us realized he was still on camera.

That said, it was nice to hear praise from a professional.

I need to fly with better pilots more often

This is the most important lesson I learned while flying with Alex Vanover. He didn’t explicitly give me this advice. He’s only seen me fly one afternoon. For all he knows, that’s exactly the way I fly every day.

It isn’t. I know I pushed myself a little harder. Sure, I did the same boring thing I do every time I fly at a new park. I spent most of my time doing split-S maneuvers over all the trees. It is an easy, safe move.

Who am I kidding? I do the same thing at the abandoned golf course where I fly every single week!

There was a particular cluster of trees Alex showed us while he was flying the DRL Racer 4. There’s a rather large and mostly vertical gap in the center of the cluster. I explored the gap, then I did a tall power loop over those trees. I wasn’t lined up, so I aborted.

Vanover said, “Ah! It looked like you were going to go for the gap!”

I don’t think I have the skill to have lined up the gap from that angle, but I did go right back in and try again. I would have taken another pass at it even if Alex hadn’t egged me on. I lined up the power loop again, dropped down through the gap, and I smashed directly into the base of the largest tree trunk on my way out!

It was no big deal. My battery got ejected, I broke the hub of an Ethix S4 prop, and broke the tip of another prop. I replaced the props, loaded a fresh battery, and I tried again. That attempt went much more smoothly.

I was definitely more aggressive than I would normally be at a brand new park, but I was also being cautious. I like the title of this blog post. Can you imagine if I had to use the title Spending an Afternoon Getting My Quad Out of A Tree With Alex Vanover?

I would say Brian was similarly encouraged. You should check out his flight video, too.

You should book a flying session with Alex Vanover!

We asked if he’d like to do this sort of thing more often. We probably asked twice. If this was just a weird, one-time thing, I might not have even written about it.

Alex said that he would like to do this sort of thing again. I also know his schedule can be hectic. I don’t know exactly what he charges. This was a birthday present, so I’m not supposed to ask that sort of thing. I have a rough idea, though, and I don’t believe he charged us enough.

The most comparable event I can think of is Kwad Camp. I know how much Kwad Camp costs. Sure, Kwad Camp is a much longer event, and there are more pilots to talk to, but you’re also competing with more than a dozen other people for their time.

More importantly, those pilots aren’t Alex Vanover. Sure, the guys at Kwad Camp are great pilots, and they all seem like good people. They’re not racing on television. They’re not one of the fastest pilots in the world.

I have nothing but flight footage

I brought my Osmo Pocket, but I didn’t use it at all. I wanted to have a good time. I didn’t want to use the afternoon as a vlogging experience. Alex didn’t really sign up to be some sort of guest on my YouTube channel, and I wouldn’t even have wanted to ask him to.

I have no pictures, no videos, and no selfies.

I just wanted to have fun. Just like I do every time I go out flying with friends. We spent more time chatting than flying. Just like when I go flying with my friends.

After the flying session

After we were packed up and heading to the car, we invited Alex to grab some dinner with us. Brian and I had to eat on the way home anyway, and it would have been rude not to extend an invitation. I figured there was a 50/50 chance that he would decline the invitation.

On one hand, we probably already used up more time than he had been paid for. On the other hand, everyone has to eat.

There really wasn’t a lot of food close to the park. We wound up stopping at Wendy’s. I heard a rumor that you can get a Frosty there!

What do you do at dinner? You exchange stories. Brian and I mostly had stories that you probably wouldn’t care about, especially if you’re here to read about drone stuff. The only thing relevant to this blog that the two of us talked about were the quadcopter build classes we hosted at Plano’s Makerspace.

Alex had fun and relevant experiences to share with us. We learned more about Rotor Riot’s trip to Croatia. We got some behind-the-scenes information about how Alex lost his quad and GoPro while flying at the Game of Thrones castle. We got to hear some interesting stories about DRL. Now that I’ve met a DRL pilot, I’m going to have to tune in to see what it is all about!

Alex invited us out to come check out the Mission Foods drone race in Carrollton tomorrow night. I plan to attend, but I’m worried that it is going to get rained out!

Wrapping up the day

We took the ten-minute drive back to Alex’s hangar. On the way back, we chatted about the weather; it seemed like quite a mild day for Texas sitting in our spot in the shade. We talked about growing up in Texas, what it is like living out of the way at an airport, train derailments, and our almost complete lack of abandoned buildings to fly at around Dallas.

While driving past the runway, I pointed while wondering why the end of the roof straight off somebody’s porch was sitting next to the runway. Alex was kind enough to explain to me that the tetrahedron was a wind indicator.

We drove past Vanover’s practice track and pulled into his driveway. We had three identical ThinkTank backpacks in the car, so we had to make sure Alex didn’t take the wrong one; I’m not sure which one of us would be more disappointed if that happened!

I fished out one of my prop tools to leave behind with him, we exchanged pleasantries, and before I knew it, Brian and I were driving away.


Alex is an interesting guy. I would say that he’s almost exactly what I expected. He’s friendly, knowledgeable, and polite. He’s very excited about what he’s doing, and that’s always fun to see. He’s had some awesome experiences, and he’s only at the very beginning of his journey.

If you’re thinking about hiring Alex to fly with you, to help you with your miniquad hardware, or to have him help you become a better pilot, I would highly encourage you to do so!

My Thoughts on Open-Source Hardware

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I happened to watch Thomas Sanladerer’s video about designing a replacement part for his MPCNC build. I can’t stop thinking about it.

This situation is fascinating to me. A lot of the discussion floating around the Internet about this seems to involve the motives of one or both parties. That’s interesting, too, but I want to steer clear of that side of things.

I have my own open-source hardware designs. I’ve thought about having some of them manufactured. I’ve put a bit of thought into the licensing, and what that licensing protects me from and allows end users to do. I’ve also put some thought into the viability of marketing my potential products.

Your copyright and license protect your design, but not your hardware

If you’re Apple or Ferrari, this isn’t quite the truth. They have huge budgets and top-notch legal teams.

You, me, Thomas Sanladerer, and Ryan at V1 Engineering don’t have this luxury. I doubt any of us could afford to fight in court over these minor details. For us, the copyright protects our designs but not the hardware.

If I feel that the shape of the fuselage of my Kestrel is an important part of my marketing, I had better have filed for a trademark. If you decide to cut something similar, I won’t have the power to stop you.

Even if you are cutting the carbon fiber using my open-source CAD files, I don’t believe I would be able to stop you from selling what you have manufactured. I don’t believe that the copyright of my CAD files could be applied to the product that’s been cut by your CNC machine.

You don’t need our CAD files to copy our designs

With my quadcopter frames, all you need to do is buy one frame and drop the physical parts onto a flatbed scanner. You don’t need my design files at all.

My 3-inch Kestrel

Even if you did need to redesign the parts manually, that isn’t a gargantuan task. If Thomas Sanladerer can create a parametric part that is compatible with the MPCNC in a few hours, then maybe the design isn’t really all that valuable.

We aren’t entitled to profits

I would love to have my breadboard vise manufactured. It is a 5-hour 3D-printing job, so to sell them, I have to charge quite a lot for 25 cents worth of plastic. You shouldn’t buy one from me. You should print your own!

I’m excited about my 5” freestyle miniquad frame, but I don’t think I’ll try to have it manufactured. Sure, it is precisely the frame that I want to fly, but it just uses my favorite ideas from a bunch of existing frames. You should just buy one of those.

I think my 3” Kestrel frame is unique enough, but I don’t think the market is big enough to justify the effort and investment of acquiring inventory. I’ve seen how big the third largest FPV quadcopter store in America is, and it isn’t big at all. Micro quads are currently a niche within a niche, and I’ve heard a bit about the volume of electronics being sold for custom 3” builds, and it seems to be quite low.

Even if I had locked up all this intellectual property of mine as tightly as I could, I don’t think I’d be making any serious money with any of this stuff.

You aren’t entitled to our designs

I think everyone is already aware of this, but I still think it is important to bring it up.

When I started my journey into the world of CNC, I quickly learned how much different the CNC community is compared to the 3D printing community. Open-source is everywhere in the 3D printing world; most of the best slicers, models, and 3D printer designs are open-source.

Open source CAM software for CNC machines is light-years behind open source slicers. When you search for beginner CNC projects, half the search results are people asking how to make money with their machine. The landscape is just so very different!

Low-cost alternative suppliers may help you make money

Twenty years ago, everyone was stealing copies of Microsoft Office and Windows. Microsoft had no interest in stopping you. Every home user of Office was another advocate for the use of Office at the workplace, and businesses did pay. It was only in recent history that Microsoft really started clamping down on this sort of piracy.

The Arduino is another example. You can buy a genuine Arduino Uno for $22 plus shipping. You can buy a more advanced Arduino Leonardo clone with free 2-day shipping from Amazon for $9.99. You can order similar boards straight from China for half that price.

There are plenty of people willing to pay the extra $12 to $15 to support the original. The people that buy the clones for $5 to $10 are still helping to grow the size of the Arduino ecosystem. Everyone wins.

Would Arduino be making more money if they didn’t open-source their design and software, and if they kept the cloning at bay? The number of projects using an Arduino would be smaller, for sure. Maybe they’d be doing OK, but I doubt it.

Would you rather take 100% of the profits from a small project, or 20% of the profits from a huge project?

Open-source hardware can reassure your customers

I’m just a guy cutting carbon fiber in his garage. If I do decide to have my Kestrel frames manufactured for me, and you decide to fly my frame, how do you know replacement parts will be available a year from now? My product may be a flop, and I can never have a second batch produced. Maybe I’ll go bankrupt. Maybe I’ll get hit by a bus. Anything can happen.

I want my customers to know that they can produce their own replacement parts if need be. If I go bankrupt, maybe another company will step in to fill the void. Maybe my customers could have a friend cut some carbon fiber for them. Maybe they’ll order parts from CNC Madness using my CAD files.

The Arduino enjoys a similar advantage.

What about the MPCNC?

I like the MPCNC project, but it isn’t for me. If V1 Engineering had an account at Patreon, I would subscribe without hesitation, but I have no interest in buying their product or building this machine.

The kit looks tempting at only $275. The recommended spindles are much smaller than what I run on my Shapeoko. The two recommendations are priced at either $53 or $109 at Amazon. You’ll need to source $12 worth of conduit, and you’ll need to run about $30 worth of filament through your 3D printer.

V1 Engineering sells the 3D-printed parts for $135, and I think that’s a great value. The time and effort to print your own parts isn’t inconsequential, not to mention the potential reprinting of failed parts. I would definitely spend the extra $100 or so to have that work done for me.

That’s under $550 for a machine that is roughly comparable in size to a $1,680 Shapeoko XL. I’d even be willing to bet that the MPCNC could handle almost every cutting job I’ve attempted on my Shapeoko XXL.

That said, the MPCNC won’t begin to approach the rigidity or power of my Shapeoko XXL. They’re different machines for different jobs at different price points.

MPCNC STL file licensing

The STL files for the MPCNC are licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. As with many open-source licenses, this means that any changes you make to these STL files must also be released under the same license. You’re also not allowed to profit from the sale of those STL files.

Whether you’re allowed to sell the parts you print using the STL files could probably be argued either way. I don’t really want to touch on that part of the discussion.

What I do find interesting is that this license cuts both ways. If anyone published an improvement to the MPCNC STL files, and V1 Engineering wants to integrate those changes, then V1 Engineering has to follow the license as well. V1 Engineering doesn’t own the copyright to those new changes, so they can’t sell those changes, either. They’d have to obtain permission from the copyright holder of those new changes.

I don’t know how this is being handled today, but I could see this creating a schism at some point in the future.


I hope I wasn’t too hard or too easy on either Ryan at V1 Engineering or Thomas Sanladerer. I wanted to explain the research I’ve done and the thoughts I’ve had regarding open-source hardware over the four years since I published my breadboard vise to Thingiverse.

What do you think? Do you prefer to use open source hardware? Have you published any of your open hardware projects to the world? Do you have a project I should know about? Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it!

What Happens When Brian and I Start Another Blog?

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About four months ago, Brian Moses and I started another blog. We decided that this was a good idea almost two years ago, but life and procrastination got in the way. Near the end of April, I said to hell with waiting and planning. I decided I was just going to stand up a nearly empty, completely undecorated Jekyll site.

That right there is the most important piece of blogging advice I could give anyone. Stop waiting. Write something now. Post it on the Internet. It doesn’t matter what it looks like. It doesn’t matter if your theme is perfect. It doesn’t matter what blog engine or theme you choose. The sooner you post your words, the sooner Google will find them, and the sooner people will start reading them!

What were our plans for Butter, What?!

I think I covered out plan pretty well on the first blog I posted on Butter, What?!, but I can cover the basics in a short paragraph or two.

We wanted a place to post content that just wouldn’t fit on patshead.com or briancmoses.com. Just about everything I’ve ever written on patshead.com has involved some amount of research or testing, and some sort of value that I’ve personally added to the topic.

I wanted a place where I can just write a paragraph or two simply explaining why I think something is interesting or cool, and then give you links to the content.

We also wanted a place where we can collaborate, and not just with each other. Brian and I also want to collaborate with other bloggers and content creators, and we want to use whatever social media and Google search clout that we might have to help promote other people that are doing interesting things.

A rising tide raises all ships

Maybe there’s a limit to just how much love Google search will give patshead.com and briancmoses.com. Ever since Google started shifting their search results more heavily towards YouTube videos and gigantic websites, our traffic has taken quite a hit. I’ve been hovering at right around half the traffic I used to see roughly two years ago. I don’t want you to think I’m unhappy about this, but I’m certainly not excited about it!

If Brian and I split off some of our time to write content for Butter, What?!, would we see less traffic on our own blogs? Would Butter, What?! drive some traffic back in our direction, or will it just be a one-way street leading out of our sites and into Butter, What?!

A rising tide raises all ships. At least, that’s what we are hoping. Butter, What?! is just getting out of its infancy stage, but it seems to be working. The traffic at patshead.com isn’t dropping, and I’m seeing a trickle of traffic coming to patshead.com from Butter, What?!

Here’s a real piece of data. According to Matomo, I saw 53 confirmed visits referred from Butter, What?! in August. Any of my blog posts that rank between my top 30 and 40 would see roughly as much traffic. This is definitely a good start!

Our real goal is to help more than just our two old ships and the S.S. Butter, What?! Now that Google is starting to notice us, it might be time to start reaching out to other bloggers!

I remember when I started blogging at patshead.com

I bought patshead.com right around the turn of the century. For a decade, just about the only thing on the site was the animated gif of my spinning head. In 2009, I started blogging and set up Google Analytics. In 2012, I switched from Google Analytics to Piwik, then sometime later the open-source Piwik project changed its name to Matomo.

In the early days of my blog, I was excited when I saw 10 visits in a day. When I would write a new post, I would double or triple my page views for the day just by Googling my own site to find URLs to include in my new blog post. About a year later, I was seeing 50 visits each day, and I was no longer capable of significantly skewing my own reporting.

I don’t have easy access to all my historical data, but I remember that for a long time my search traffic was doubling every six months. It wasn’t a steady rise, though. It would be pretty level most of the time, then it would suddenly take a jump towards bigger and better numbers. Brian’s results were similar, and it took quite a while for this to plateau.

We’re at the point today where the traffic graphs for Butter, What?! are looking like a hockey stick. We don’t have a ton of content written yet, so I expect we’re nearing our first plateau, but we don’t know for sure!

How much traffic is Butter, What?! seeing?

The new blog went up on May 2, 2019. Traffic from Google was pretty much a dial tone until the middle of July. Until then, nearly 100% of the traffic to Butter, What?! was a result of our tweets, Facebook posts, and links from our existing blogs.

Traffic from Google was still extremely tiny in July, but it was finally a steady trickle. Before the month was over, we were seeing 10 clicks per day from Google search.

Butter What Matomo Data

I started to get excited at the beginning of August. Butter, What?! had almost twice as many search clicks in the last week of July as it had the entirety of the previous three months. I was excited, even though we only saw 60 clicks that week. I was excited, because the numbers were still growing every week.

Today, we’re seeing 30 to 40 search clicks per day, and it looks like that number is still increasing.

August was the first month that Butter, What?! broke 1,000 visits. We had more visits referred from Google search in August than we had total visits in July: 686 vs. 581. August was exciting!

The quality of traffic is better than I expected!

Brian and I are always looking at metrics like average visit duration and average time on page. Visit duration tends to be higher when you have a lot of relevant and related content. Google might point you at patshead.com, because you’re interested in my virtual machine host. Then you might see my blog about my 20 gigabit-per-second Infiniband setup, so you’ll stick around to read that.

Butter, What?! is young. It doesn’t have a ton of content. A lot of the content that it does have is designed to point you towards other content, like those YouTube videos I post every Monday. I expected we’d see a lot of short visits, but that hasn’t been the case.

Butter What Matomo Data

I haven’t checked Brian’s Matomo data, but most days, Butter, What?! has an average visit duration nearly double what I’m seeing on patshead.com!

I imagine that has more to do with patshead.com having over 300 articles, and most of those posts are getting quite old. If you manage to click on a blog post about an old Android phone that I owned 5 years ago, you probably got here by mistake, right? You’re going to leave quickly!

Our old blogs also do a much better job of making our other content available to our readers: recent posts are listed in the sidebar and related posts are listed at the end of a post. Butter, What?! doesn’t have any of that yet, and this is another reason that I’m surprised that our time on site has been so high and our bounce rate has been so low.

Traffic is light, but not insignificant!

If this were 2016, the 1,001 visits Butter, What?! had in August would have felt completely inconsequential to me. It isn’t 2016 anymore. Brian and I have had our search traffic drop by nearly 50% since then.

Those 1,001 visits are right around 4% of the combined traffic of patshead.com and briancmoses.com. Even if things don’t improve, the search traffic alone from Butter, What?! will account for 5% of our total traffic in September.

If Butter, What?! accounts for 10% of our traffic by the end of the year, I will be quite pleased with our efforts!

What will next month look like?

If search traffic levels off, then September will compare to August in much the same way that August compared to July. We’ll see more search clicks in September than we saw total visits in August.

Butter What Matomo Data

Google’s search console says we’re leveling off. We have roughly the same number of search impressions this week as we had last week, but our click-through rate is up from 3.5% to 4.5%.

Brian and I haven’t been doing as good of a job at posting and reposting our new Butter, What?! content on social media lately. I feel better about relying on search traffic anyway, but I’m going to try to do a better job at this in the near future.

UPDATE: What did the next month (September) look like?!

I don’t think one month’s additional progress warrants a whole new blog post, but I do think it is worth posting an update to let you know how true my predictions turned out.

Butter, What?! saw 2,111 visits in September with 1,786 of those visits coming from Google. That’s twice as many visits as we say in August, and search traffic is 2.5 times higher.

Search Traffic for September 2019

In August, Butter, What?!’s traffic accounted for about 4% of the combined traffic of our three blogs. In September, that number rose to nearly 9%.

I’m quite pleased with these numbers.

I don’t expect the increase in traffic to be as big in October. According to Google’s search console, Butter, What?!’s traffic is only up 10% this week compared to last week. I’m still excited about that; compounding a 10% improvement each week will add up fast! Just not as fast as 2.5 times.

UPDATE: October’s numbers!

Butter, What?! saw 3,723 visits in October with 3,229 of those visits coming from Google. We didn’t quite double the numbers from September, but I’m definitely pleased with these numbers. Total visits are up more than 75%, and clicks from Google are up 90%.

If traffic levels stagnate, November will still see 17% more search traffic than we saw in October.

In October, Butter, What?!’s traffic accounted for more than 11% of the combined traffic of our three blogs. I’m impressed by this, because patshead.com traffic is up 12.5% and briancmoses.com traffic is up 25% over last month.

I don’t have any conclusions to draw. I just wanted to post an update with fresh numbers!

UPDATE: November’s numbers!

November isn’t a terribly organic month. Four a couple days, Google decided to send 1,000 clicks per day for a couple of days to one of my blog posts that rarely sees more than 15 clicks in a day. That inflated my numbers a bit. Not only that, but Brian just posted his 2019 EconoNAS build and giveaway. Not only does that give him a big traffic bump for the duration of the giveaway, but it usually gives me a small bump in traffic, and Butter, What?! is seeing extra NAS-related clicks as well.

Butter, What?! saw 6,012 visits in November with 5,344 of those visits coming from Google search. This looks a lot like last month. The numbers aren’t quite doubled, but they’re not far behind that figure!

Butter, What?! began to consistently see more than 100 clicks per day from Google search early in October. We aren’t quite seeing 200 clicks per day just yet, but we’re close. We had a 4-day period with more than 200 clicks each day last week, and we have days as high as 250 clicks in the last week. The low days are still dipping below 200 clicks, though.

In November, Butter, What?!’s traffic accounted for 14.5% of the combined traffic of our three sites. I was surprised it gained so much ground. About half way through the month, patshead.com started seeing roughly 20% more search traffic each day. Even with that gain and Brian’s giveaway running for a few days in November, Butter, What?! still closed the gap by quite a good margin!

In November, patshead.com is up 35% compared to October. I didn’t do the math on Brian’s numbers. Sorry!

UPDATE: Numbers for December?!

This will probably be my last monthly update. In a couple of months, it will time to erase all these little updates and compile all this data into a single fresh blog post.

Butter, What?! saw 7,763 visits in December with 6,795 of those visits coming from Google search. Growth has slowed down, but I’m still pleased. This is an increase of 29% compared to November.

For most of the month of December, Butter, What?! saw more than 200 search visits per day. Most days in the last week of the month saw more than 250 search visits, so I won’t be surprised if we see another 25% or 30% increase in January.

Traffic at patshead.com is down 6% this month. I blame this on the weird day or two in November that had an extra 1,000 to 2,000 search visits. I’m still up 25% compared to October, and my day to day traffic looks pretty nice the past few weeks!

Even with the extra traffic from the DIY NAS giveaway, Butter, What?! is still managing to account for a higher percentage of our total traffic compared to last month. This month, Butter, What?! accounted for 16.5% of our combined visits!

UPDATE: I said I wouldn’t post an update in January!

I’m posting an update anyway. Butter, What?! saw more daily clicks from search in late December and early January than it had ever seen before. Then it dropped down to number similar to late November. We were up in the 250 to 275 click range. We are back down in the 200 to 250 range now.

The dip in traffic started a few days before Google made their weird update to how they’re displaying search results. Is it a coincidence? Maybe. Probably. Neither patshead.com or briancmoses.com saw similar blips.

Traffic at patshead.com is up 13% this month, and that’s 5% higher than November. I’m excited about this. My traffic from search has been stagnating at about 1/3 of my old peak traffic for almost an entire year. Today, I’m not far behind my peak!

Butter, What?! saw 8,121 visits in January with 7,085 of those visits coming from Google search, and Butter, What?! accounted for 18% of our total traffic.

Why do I keep posting these updates?

It isn’t really for you guys. Gathering this data and writing these little summaries is forcing me to think about our traffic data!


I have no idea who the target audience for this blog post might be, but I’m excited about how things are going, and I figured it might be interesting to someone! We started a new blog, and it is starting to accrue some content and gain some search traction.

How do you think we’ll be doing next month? Or by the end of the year? Do you want to get involved with what we’re doing? Let me know in the comments, or stop by the Butter, What?! Discord server to chat about it!

Designing My Carbon Fiber Prop Tool

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I’ve been looking for an idea for something I can send out as a perk to my patrons on Patreon.com. I’ve also been on the lookout for a part that I can squeeze into the wasted areas of my carbon fiber sheets.

Carbon fiber sheets aren’t ridiculously expensive, but they also aren’t what you’d call cheap. Some of the parts for my Kestrel and Falcon frames have rather odd shapes, and they need to be oriented in such a way that the length of parts follow the strands of carbon. I wind up with a lot of 1” by 2” areas all over the place that are just too small to fit quadcopter parts.

I’ve already written at length about why I’m designing this prop tool over at Butter, What?! In this blog post, I’m going to tell you about what I learned while designing this prop tool. If you want to read about why I’m designing this prop tool, you can read about it at Butter, What?! I had to overcome some new problems related to CNC machining that don’t apply to my usual 3D-printing designs.

A CNC router can’t cut sharp interior corners

A CNC router, like my Shapeoko XXL, cuts material with a round bit. If I just subtract a 8mm hexagon from my carbon fiber, each of the six corners will have a radius that matches my endmill instead of a sharp corner. Without that sharp corner, my 8mm nut driver won’t fit over the 8mm prop nut!

In theory, this isn’t a big deal. You just have to tell the CNC machine to cut a little deeper into each of those corners. They call these cuts “dog bones.” What’s the best way to add dog bones with a parametric OpenSCAD design?

CAD and CAM have close ties in the CNC world

I toyed with two different ways of accomplishing the same goal. I’m disappointed because both options require my OpenSCAD model to be aware of the diameter of my endmill, or at least be set up to accommodate the largest endmill I might use for this operation.

I’m using a 2mm endmill, because that’s what I use to cut Falcon and Kestrel parts. I’d like to be able to cut prop tools as part of the frame cutting jobs.

On every CNC part I’ve designed so far, all the cutting operations for my perimeters involve an inside or outside contour tool path. That means that the 2D CAD file that I’m exporting matches the dimensions of the physical part. Instead, you can tell your CAM to follow your CAD file’s path with zero offset.

I toyed with the idea of experimenting with that third option. I could scale down my hexagon by the radius of my endmill. Then I could just add a perpendicular 1mm line at each of the six corners. Just the fact that I haven’t attempted this before seemed like a good enough reason to give it a shot, but I quickly realized that it was going to be a lot more work to plot out the shape I needed with OpenSCAD.

I abandoned this idea so quickly that I don’t even have a screenshot of what it looked like!

Prop Tool Dog Bones

I was also disappointed that this option would only work with a single endmill. I would have to export a new SVG file if I wanted to use my 1.6mm endmill, and that would be a bummer.

for (i=[0, 60, 120, 180, 240, 300]) {
  rotate([0, 0, i])
    translate([hex-c, 0, 0]) cylinder(d=2.1, h=t, $fn=12);

Instead, I placed a 2.1mm cylinder near the six corners of my 8mm hexagon, and I’m pleased with the result. It leaves room for the corners of the prop nut, it was easy to model with a simple for loop, and it will work with any endmill up to 2mm in diameter.

The scale of 3D printing makes this sort of thing simpler!

Working with a 0.4mm nozzle and relatively soft plastic is quite a bit different than working with a 2mm endmill and rigid carbon fiber, aluminum, or steel!

In either case, there needs to be a bit of clearance between the walls of my prop tool and the nut. With ABS plastic, it doesn’t matter that the 0.4mm extrusion of plastic doesn’t make perfect corners. That tolerance between the tool and the nut is probably already large enough to make up that tiny amount of extra material in the corners, and even if it isn’t, ABS would be soft enough to just get out of the way the first time you use the tool.

If we were cutting this tool out of steel, and we didn’t cut the dog bones into the six corners, we would have a real problem.

Engraving my website on the side

This was fun. It was my first attempt at a v-carve operation. When you engrave lettering to shiny, reflective aluminum, it shows up pretty well all by itself. When you engrave into carbon fiber, it still just has a matte black finish, and you can’t see it.

I borrowed some white nail polish from my wife. I slathered it generously over all the letters, then let it dry. I wasn’t sure how to remove the excess nail polish without ruining the finish of the carbon fiber sheet, so I just scraped it off with another flat piece of carbon fiber. It was strong enough to remove the excess nail polish, but not so hard that it would scratch up the smooth surface.

It worked better than I expected. There are a few problems with the first prototype. A few of the letters seem slightly misshapen. The details might just be a little too fine for the carbon fiber sheet’s epoxy to hold together well.

I’ve scaled the letters up from 4mm to 4.5mm tall, and I’m planning on cutting the next one at about half the speed. With any luck, that will clean up most of the problem areas!

I’m quite pleased with how my first attempt at both v-carving and nail polishing came out!


The prop tool is open-source, and it is licensed under the GNU GPL version 2. I added the OpenSCAD source code, dxf, and svg files to the falcon-frames repository on Gitlab. The OpenSCAD source is a little rough. I didn’t put much work into making sure it was cleanly parametric. It has quite a few magic numbers sprinkled about, because I was more concerned with getting the hex openings sized correctly.

What do you think? Would you use a carbon fiber prop tool like this? I know I prefer my $15 Speedix prop tool, but I’ll be adding a carbon fiber prop tool to all my bags. Are you as good at misplacing prop tools as I am? Let me know what you think in the comments, or stop by the Butter, What?! Discord server to chat with me about it!

Backing Up My Bitwarden Database

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I’ve been using Bitwarden for a little over a month so far. I’m enjoying the experience, and I haven’t had any problems, so I expect that I will continue to use Bitwarden as my password manager for the foreseeable future.

That means I need a way to back up my Bitwarden database. Keeping my passwords backed up happened for free when I was using Keepass. Your Keepass database is just a securely encrypted file, and my cloud storage solution kept a copy of that file on each of my computers, my phone, and my tablets. There was also 90-days’ worth of history stored on my Seafile server.

Bitwarden is different. There is no password database file. From my perspective, everything is magically stored on the server. How am I going to keep a backup? Can I automate it? Where should I store the backup?

While I’m at it, I figured this would be a good time to update the backup process for my ssh and GnuPG keys as well!

When will I need to use a Bitwarden backup?

I did some testing for my own peace of mind. I disconnected my laptop from the network, completely shut down my web browser, and fired it back up again. I wanted to make sure that I had access to all my passwords even when the Bitwarden servers aren’t available.

As you would expect, this worked just fine. I can access my passwords, and I was able to export a CSV dump of my database without access to the Internet. What does this mean?

My Bitwarden backup script in action

It means that I will still be able to dump my passwords even if the Bitwarden company disappears off the face of the Earth over-night.

I don’t need daily backups, but that would be nice. In practice, I probably only need a backup any time one of my core passwords changes. If I lose my Slashdot password, they’ll let me reset it via email. If I lose my Gmail password, it would be a huge pain in the butt!

The Bitwarden CLI

The Bitwarden command-line tool seems pretty good, but its export functionality falls short of what I was hoping for. The command-line tool, the native application, and the browser plugin all have similar limitations, but I was able to set up something that will get the job done.

Exporting requires that you decrypt your vault. It would be nice if you could just pull your vault out of the app in its existing, unreadable state, but I wasn’t really expecting to be able to do that.

The Bitwarden CLI can export a CSV or JSON file, but it has to write to a file. You cannot export to STDOUT. I was hoping to be able to do something like this:

bw export --output - | gpg --output myvault.csv.gpg -e -r thehead@patshead.com

You can’t do this. Bitwarden’s CLI doesn’t respect the tradition of using - as the filename to designate STDOUT.

Ugh. I don’t want my plaintext passwords to touch the disk.

I finally found a use for my USB drive with Brian’s face on it!

If I can’t encrypt the exported data before it touches the disk, then I guess I’m going to have to store Bitwarden’s CSV file on an encrypted disk. The export is going to be a manual process anyway, since it will require me to enter my passphrase, so why not use an encrypted USB flash drive?

I encrypted the flash drive using LUKS. If you’re on Windows, you could probably use something like Veracrypt. You could most certainly use a GUI to configure your LUKS encrypted disk, but I have absolutely no idea how to do that. These are the commands that I used:

cryptsetup luksFormat /dev/sdb
cryptsetup open /dev/sdb TemporaryName
mkfs.ext4 /dev/mapper/TemporaryName
cryptsetup luksClose TemporaryName

I may as well back up my ssh and GnuPG keys

I don’t often make backups of my ssh or GnuPG keys. I could write 2,000 words about my key-management practices, but I will try to be brief.

My ssh keys allow me to log into machines that are extremely important to me: my blog’s web server, my virtual machine host, or my NAS. I have at least one unique ssh key on my laptop, desktop, and tablet. If any one of those three computers is lost or compromised, I can easily remove its corresponding public key from all my servers.

Since I have different keys on three different computers that can log in to all my servers, I don’t need backups of my ssh private keys. If my laptop dies, I can simply generate a new key and update all my servers using one of the other two good keys.

GnuPG is different. While my ssh keys identify who I am and which machine I’m using, my PGP key only identifies me. There is no replacing my root PGP key. If I lose that private key, I’m probably in trouble. All sorts of backups and important files would become completely lost.

My PGP key doesn’t change very often. In fact, I’m long overdue for a fresh key! I even have a hard copy of my PGP key printed out.

Even though my PGP and ssh keys are encrypted and have strong passphrases, I don’t feel comfortable storing them anywhere in the cloud. As long as I’m going to be backing up my Bitwarden passwords to a USB flash drive, I may as well include my desktop’s ssh and GnuPG keys, right? It only requires an extra tar command or two!

I’m not sure that was brief.

My backup script

You don’t need to script any of this, but I did. I’m lazy. I can’t automate the entire process, but at least I can automate some of it!

#! /bin/bash

dir=/root/usbbackup  # bw cli snap won't write to /tmp
datestamp=$(date +%F)


cryptsetup open /dev/disk/by-uuid/$uuid usbbackup || exit 1

mkdir $dir || exit 1

mount /dev/mapper/usbbackup $dir || exit 1

## backup ssh and GnuPG keys and configuration
tar cf $dir/ssh-$datestamp.tar /home/wonko/.ssh
tar cf $dir/gnupg-$datestamp.tar /home/wonko/.gnupg
tar cf $dir/ssh-$datestamp.tar /home/wonko/.ssh

/snap/bin/bw unlock  # I don't know why I need this, but I do?!
export BW_SESSION=$(/snap/bin/bw login thehead@patshead.com --raw)

/snap/bin/bw export --output $dir/bw-$datestamp.csv

/snap/bin/bw logout

gpg --output $gpgdir/bw-$datestamp.csv.gpg -e -r $gpgrecipient $dir/bw-$datestamp.csv

echo New files on USB drive at $dir:
ls -l $dir/*$datestamp*

echo New Seafile GPG files:
ls -l $gpgdir/*$datestamp*

umount $dir || exit 1
rmdir $dir || exit 1
sync # for paranoia
cryptsetup luksClose usbbackup || exit 1
sync # for more paranoia!

echo Backup complete, USB drive synced and unmounted.

My backup script isn’t exciting or sexy, but I figured somebody might ask about it, so here it is!


I feel a little safer. My passwords can survive if my house burns down or Bitwarden’s hosting goes out of business. Even if both catastrophes occur on the same day, there will still be a GnuPG encrypted copy of my passwords stored on my Seafile server.

What do you think? Are you using Bitwarden? What are you doing to keep your passwords safe? Do you have a semi-automated backup process like mine, or do you manually export your database every once in a while? Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it!

One Month with Bitwarden

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It almost feels too soon to be handing in a report on how well Bitwarden is working out after only a month of use. I’ve learned something important since migrating from Keepass. Something that I managed to completely gloss over when making my decision to migrate. It may have made me change my mind, so I think it is important to tell you about it!

Hosting your own Bitwarden server has a weird caveat

Bitwarden is open source, and you can host your own Bitwarden server. I’m excited about having the ability to host my own server, but I didn’t want to go down this road. My initial investigation didn’t go terribly deep. Once I saw that the documentation looked good, and the process was pretty simple, I put in check in the “ability to host your own server” box on my list.

I’ve since noticed that you can’t just host your own Bitwarden server. Your server needs a key that is provided by bitwarden.com. At a glance, this feels sketchy to me. This is what the Bitwarden documentation has to say about server keys:

Each Bitwarden installation requires a unique installation id and installation key. The installation id and key is used to:

  1. . Register your installation and contact email so that we can contact you in case of important security updates.

  2. . Validate licensing of paid features.

  3. . Authenticate to push relay servers for push notifications to Bitwarden client applications.

You should not share your installation id or installation key across multiple Bitwarden installations. They should be treated as secrets.

They want to protect their revenue stream, and they’re allowing you to use their push notification infrastructure so that your server can communicate with the Android and IOS clients.

There is an alternative to the official Bitwarden server

There is an unofficial Bitwarden-compatible server written in Rust. If you feel that having to obtain a key to host your own server is weird or creepy, Dani Garcia’s Rust server looks like a fantastic option.


This isn’t the only reason to look at Dani’s Bitwarden server implementation. The official Bitwarden server is rather heavy. It requires 2 GB of RAM and quite a bit of storage. You probably won’t be able to just throw an official Bitwarden server up on a random VPS that you already have. You’ll probably need a RAM upgrade.

The unofficial Bitwarden Rust server only requires 10 or 20 megabytes of RAM. You can squeeze that in just about anywhere, and it even runs on a Raspberry Pi!

Everything else has been fantastic

I’m impressed with Bitwarden so far. I haven’t had any problems. Once I learned the control-shift-L hotkey to automatically fill in passwords, it has been smooth sailing.

The Firefox extension works great. All my passwords were imported from Keepass without any issues. After an initial hiccup, the Android app has been doing a fantastic job of populating username and password fields.

My cheap Blu phone’s battery-saving nonsense was goobering things up at first. It was killing the Bitwarden app, and when it did, the app would lose its accessibility status. It wasn’t obvious right away why this was happening, but once I dug into my Android system settings to disable battery-saving features for the Bitwarden app, everything has been working perfectly.


Within a few days of posting about my migration to Bitwarden, three comments showed up recommending three more open-source password managers that I never heard of. This space seems to be crowded, and I plan to do more research in the near future. It might be time for a password-management version of my old cloud storage comparison blog!

Bitwarden has all the features I was looking for, but what pushed me into the migration was when I learned about the third-party audit of Bitwarden that was conducted late last year. It didn’t get a perfect score, but they quickly addressed the serious issues, and they put plans in place to address everything else.

What do you think? Did I make a good move when I migrated to Bitwarden? Do you prefer Lastpass or 1Password? Do you use an open-source password manager? Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it!

EMAX TinyHawk Freestyle: An Awesome Upgrade Path For Beginners?

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I am excited about the new EMAX TinyHawk Freestyle micro drone. It is fast, fun, and relatively safe. It is also inexpensive, and it is a fantastic upgrade for beginners on their path towards flying full-size FPV miniquads.

We finally have an awesome upgrade path for beginners!

I started flying with a Spektrum DX6 radio. I believe they cost about $230 at the time. That was only the radio. Then I bought a toy quadcopter with no FPV camera, a Blade Nano QX, for $60.

The TinyHawk and TinyHawk Freestyle

Today, you can buy the TinyHawk Ready-To-Fly kit for $165. That bundle includes the original indoor TinyHawk drone, a set of FPV goggles, a radio, one battery, and a charger. My old DX6 is an infinitely better radio than the one in the TinyHawk bundle, but that doesn’t really matter. Throw in a 6-pack of extra batteries for $25, and you’ll still be under $200.

Not only will you still be under $200, but you’ll already be flying FPV. When I bought my radio, that $230 just gave me the ability to fly something. I still needed to buy quadcopters, goggles, and chargers. I spent so much money!

Until the TinyHawk Freestyle showed up, the upgrade path from the TinyHawk kit was bumpy. You could stick to micros, like the Diatone GTR349, or something like my 3” Kestrel. Maybe you’d want to skip that, and move up to a real 5” miniquad. Your goggles will work well enough, but the radio in the EMAX kit isn’t ideal for something so big, aggressive, and dangerous.

This is where the new TinyHawk Freestyle comes in. Unlike the original TinyHawk, you can fly the TinyHawk Freestyle outside, even when it is windy. In fact, that’s the only place you should fly it. It is much too powerful to fly indoors. If you’re a beginner, though, you may have trouble flying the Freestyle on a windy day. It took my friends and I lot of practice before the wind stopped being an issue for us, even with our heavy quads!

If you’re a beginner, here’s what I suggest you buy:

UPDATE: You might want to skip the original TinyHawk RTF bundle. Emax has released the TinyHawk II Ready-To-Fly Bundle. You can check out Jeremy Cook’s post about the TinyHawk II at Butter, What?!

That’s $295. You certainly don’t have to buy it all at once, but all that stuff costs less than what I spent on just [my Spektrum radio][dx6] and a toy quadcopter with no camera. This blows my mind. You can get into the air flying actual FPV, and you can have the tools to practice in the simulator for less than I paid for my first radio.

NOTE: I’ve read and watched in several places that you can bind the RTF kit’s controller up to the TinyHawk Freestyle, but a friend of mine has been having some trouble. It seems possible, but it may not be as easy as I hoped. Stay tuned, and I’ll let you know how it goes!

I wish this was available when I started flying three years ago. Having to spend $500 or more just to get started flying FPV required some deliberation. Spending $165 would have been an impulse purchase. I would have bought a TinyHawk RTF kit immediately after seeing my friend Alex fly his old Blade Vortex 250!

Are the TinyHawk and TinyHawk Freestyle the best in their classes?

It probably depends on your definition of best, but I would have to say that they are not. The whoop-like TinyHawk isn’t the fastest or best handling brushless whoop. It does hold its own, though, and it is probably the most durable brushless whoop you can buy.

The TinyHawk Freestyle falls into the toothpick class of drones. Toothpicks are supposed to be small, light, fast, and safe. The more weight you add to a quad, the more damage it will do to a person when you accidentally fly into their face. KababFPV has a video where he flies his 35 gram toothpick build into his face at full speed. This is the sort of toothpick I want.

The TinyHawk Freestyle pushes the definition of a toothpick a little past KababFPV’s specifications, but it isn’t too bad. I should point out that EMAX doesn’t claim the TinyHawk is a toothpick-class drone.

There are bigger, heavier, insanely faster quads than the TinyHawk Freestyle that claim to be toothpicks. By some definitions, those quads are much better than the TinyHawk. If you want something quick, snappy, and relatively safe, the TinyHawk Freestyle is probably the quad for you—especially if you’re already flying a TinyHawk or TinyHawk S!

Did you buy a TinyHawk Freestyle? What do you think of it?

I did buy a Freestyle, and I like it a lot. When I saw the specs, I was excited. The first thing I thought of was my old KingKong 90GT—my first micro FPV quad.

The motors are the same size and of a similar KV. My modified 90GT ran 2.5” props, just like the Freestyle. They’re similar enough in weight and size. Micros have made a lot of progress in 2 years. I figured the motors on the TinyHawk are more powerful, and I was confident that the ESCs are a huge upgrade, too.

I was right. It is a huge upgrade over the KingKong 90GT.

Pat created a problem for himself

I plugged in my TinyHawk, unlocked the VTX, bound it to my Taranis X9D, and pasted the configuration for my OSD and switches into Betaflight. I was ready to fly, so I put my batteries, goggles, Taranis, and TinyHawk Freestyle into my little backpack, hopped on my electric bike, and rode to the park.

I’ve had a concern since placing the order for my TinyHawk. After I started using TBS Crossfire, I wound up taking my Taranis apart to tuck my FrSky antenna inside the radio. This hasn’t been a problem with the original TinyHawk, but I was concerned that I wouldn’t have enough range outside.

My worries were quickly confirmed at the park. I lost my control link as soon as I went behind a big tree. I couldn’t powerloop or S-turn any trees, but I still gave it a bunch of stick, and I ran it through its paces in the open space.

How does it fly?

I hear the Freestyle flies better on gentle 65mm biblade props. I don’t have any of those yet. I’m pleased with how it flies on the heavy triblade props that it ships with. They seem to have good grip down low, and they handle propwash way better than I expected, but they quickly run out of steam at full throttle.

If you’re a beginner, this won’t matter. You won’t be breaking any speed records, but it sure isn’t slow. I think EMAX chose the right props. The TinyHawk Freestyle is targeted toward beginners. You don’t want to lose a 95 MPH drone on your first flight!

I think it feels great. It is quick, crisp, and responsive. I saw that AndyRC has a tune to eliminate some of the high-throttle oscillations, but I didn’t even get a chance to hear them. The little guy is so quiet, and I’m an old man. I’ll have to do a full throttle punch right next to myself and listen for it!

Did Pat choose the right toothpick?

The original TinyHawk isn’t the best brushless whoop, but it is the best brushless whoop for me.

The TinyHawk Freestyle isn’t the best toothpick. It is a bit on the tubby side for a toothpick, but it isn’t the biggest. Being heavy makes it a little slower and a bit less safe than the lightest toothpicks. That said, I think the TinyHawk Freestyle is a good compromise and a great value, especially if you’re already a TinyHawk or TinyHawk S pilot!

Ever since KababFPV showed off his first toothpick, I’ve been wanting one. Specifically, I wanted a toothpick that could make use of the batteries and charger that I already have for my TinyHawk. Batteries and chargers are one of my biggest investments. Sure, whoop batteries are cheap, but I don’t want a fourth set of batteries to maintain and carry!

At any rate, I needed to try the TinyHawk Freestyle, because I want to be able to recommend it to you. I don’t like recommending things I haven’t used myself.

I suppose the answer is yes. I definitely chose the correct toothpick for my purposes!

I have to complain about a few things!

The TinyHawk’s camera is awful. The Freestyle seems to have the same camera as the original TinyHawk. It is fine for whooping around the house, but it was a real disappointment outside. My FPV camera standards are pretty high, though. I doubt I’d be happy with any of the whoop-size cameras.

I’m also disappointed that the VTX is only 25mw. One of the reasons that I upgraded from the Leader 120 to the Leader 3 was the higher power VTX. I would feel more comfortable with a 200mw video transmitter. It isn’t the end of the world, though. When you fly a tiny drone so far away that you need 200mw, it usually becomes extremely difficult to locate your quad after a crash. They’re so tiny!

EMAX TinyHawk

I know a lot of people will be excited about the nice carrying case. It is the same case that the original TinyHawk ships in. The trouble is that the TinyHawk Freestyle doesn’t fit in the foam insert with the props on. I took the foam out, and it just barely fits in there.

I’m not excited about the carrying case. I’d rather have cheap packaging and an extra battery or something. I assume I’m in the minority!


I’m way too excited. EMAX has just made life so much easier for new pilots. You don’t have to think about it. You can just buy a kit with everything you need to get in the air and also practice in a simulator. When you outgrow the indoor TinyHawk, you can easily upgrade to your first outdoor FPV quad.

This is so much better than when I got started!

What do you think? Do you like the original TinyHawk, or do you prefer a different brushless whoop? Are you looking to upgrade to a toothpick? Is there a toothpick that you like better than the TinyHawk Freestyle? Do you think this is as fantastic for beginners as I do?

Let me know in the comments, or stop by the Butter, What?! Discord server to chat with me about it!