Wow, the fun I've had and the things I've learned along the way with this little project. But at long last, I'm happy to say that I've actually finished the build! This whole thing started as a way to relax and pass the time during the holidays. I was thinking at the time, that I'd actually be able to finish things a month ago and end my holiday break with something that was at least ready for some test flights and tuning.
5 fried speed controllers later, lesson 1: If you want somewhat reliable electronics, buying the cheapest-you-can-find parts isn't always the cheapest way to get where you're headed. The 25(30)amp speed controllers I had chosen seem not to have been able to handle the idle current of a motor and and BEC. Sizzle, pop went two of my first 4 speed controllers. Being down to two, and needing three, I ordered another two. I was sure to get three of 6 that worked... right? Thankfully, there was a slew of alpha and beta releases for ACM 2.1 and 2.2 to play with on the sim to pass the time. That was a whole lot of fun all the same. Not that I'm anywhere close to being a coder or developer, but tracking the code changes and offering some feedback on things as they progressed is a lot more interesting way to wait for a new code release that may or may not come with release notes like a lot of closed systems.
Then two weeks later the little box from China arrived, Hooray! So I spent a while basking in the warmth of my soldering gun... and within minutes of finishing, I was back down to two working ESCs. ARGH!
Quick, Simple and Cheap had turned into annoying, frustrating and flammable. I gave up on the cheap parts, and ordered 3 "official" jDrones Arducopter speed controllers from Dany at CanadaDrones. First class service, really. I ordered after 10PM, and I had a tracking number before going to bed. They came in a day later, and that put a quick end to my headaches. I was finally able to calibrate the throttle, and see all three motors spin without the unpleasant stench of burning silicon and shrink tube. Hooray!
All up weight is about 890g. Each motor/prop is about 600g of thrust max, for a total of 1800g. I was wondering about having three props all running in the same direction, but decided it was better to have one reverse prop, instead of relying entirely on the servo for yaw stability. I'm no aeronautical engineer, but my gut feeling is that if I can eliminate 2/3 of the unwanted torque, things should be a little more docile. And I get a lot more thrust pointing down on my rear prop. Seems like a win-win. I'd love to hear a few other opinions on the pros and cons of that particular choice.
I've only just now installed all three props, and taken her off the workbench to look at her away from the clutter. Seeing as it's really nothing more than a few bits of wood and two tape cases, with a whole lot of wires tied to it, I'm a little surprised at just how cool it actually looks. She hasn't left the ground yet, but she looks cool. That's gotta count for something, right? Honestly, I've never built something like this that didn't come RTF or in a kit. All done by the seat of my own pants, with a few suggestions from the folks here.
Tomorrow is going to be a big one, where I get started on powered tests if I can make the time. It'll be tied down to some weights to see if there are any major yaw or balance issues, and to trim the servo arm length to get as close to neutral yaw as I can at hover speeds. After that, will probably be a props on load test tied down to make sure she doesn't shake herself apart or burst into flames with the motors running at flight speed for the duration of a battery.
God willing, it won't get loose and slam into the ceiling, or bury a prop in my forehead...
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Sooo, after my package getting delayed an extra day in the mail, I finally got things reassembled last night. I've now got jDrones 850kv motors and 20a ESCs mounted. God I hope that's the end of my burning component problems.
I got as far as radio setup, ESC calibration and checking motor direction, but it was too late to really do any kind of testing. I also got fed up of tinkering with the config to stuff it into my old 1280 every time, so she's sporting a nice new APM2560 as well. While I had things apart I also decided to reinforce the rear motor platform as there seemed to be some flex in it. It was originally just a square of 3/8" balsa, which was probably a bad choice. It's been beefed up with a 1/16" square of basswood glued cross grain to the balsa. That whole thing is further reinforced with the motor mount and yaw hinge bolted through, so it seems very solid now.
I'm encouraged by a few reports of tricopters at least being able to hover in stabilize mode without any messing around of PIDs. Still no mag for it until my APM2 arrives, so I won't be going outside, but I hope to at least make it as far as PID setup and hover testing this weekend.
Glad you enjoyed it Tomas! There is a lot of technical information on DIYDrones, so I didn't want to be too technical and dry, I thought it would be nice to have a not too serious and fun to read.
My original order was 4 motors and 4 ESCs. Then another order of another motor and 2 more ESCs. Then O ordered 3 jDrones ESCs. From all that, I now have 2 cheap motors, and 2 jDrones ESCs. I've given up on the cheap parts entirely and last night ordered 3 jDrones motors and a replacement jDrones ESC. I'm regretting not making that choice from the start.
Cool project and I like your way of writing about it, makes me smile.
Nowadays when I buy stuff for multicopters I always buy an extra ESC and motor, and some props and prop adapters. Because it´s so frustrating waiting for replacement if (when) something failed. Magnetoes can come loose from over-speeding the motor, but that can hardly have been the case here.
I flew a lot in my backyarod, and now in my house. That's why I built the the mini quad:
and soon to be micro quad:
I'm awaiting eye surgery, for one eye, so no driving around for me right now. Hopefully, this summer I'll get out to the field.
Good to know! So where do you go to fly your quad?
Yes, I'm in Ville St. Laurent, but I just moved back. I've spent the last decade in Ottawa, but before that another 20 years in Montreal with a few shorts stints out west in Calgary and Victoria.
@Ellison, I didn't realize you were in Canada also. And a fellow Montéalais even!
@Don: Yeah that would look sick! too bad I will run out of purple eventually! hehe only 4 left I think!
I know that the 3DR ones (diydrone own store) are still purple but I cant speak about them as they are not from the same factory! (and I am not implying that they are not good, I just don't carry them, except on complete 3DR Quad kits, and I've never played withe them... not enough hours in a day to play anymore!) So even when I run out you should be able to find your source of purple ones if you need!
My wife keeps asking me if I can start to carry pink parts! I think they will look sick... but really how many girls are around here? yeah that is what I taught.... ;)
Don, I see where you're coming from. But don't mind the wait so I always order with air mail delivery, not that express is any faster, and I don't mind doing a little soldering. And when I started my quad, Dany's shop was no there yet, so ordering from the US or HK was the only option. ;-)
@Dany, I sort of like the purple ones! Maybe one black in the rear and two purple in front? Or the other way? lol
@Ellison, I just don't have confidence in HKs low end components anymore. The jDrones ones come ready to go, with the required connectors, shrink tubing, prop adapters, and mounts. Getting a 10$ HK motor, and still having to get the other stuff, plus the shipping, really it doesn't work out to be much savings at all.
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