I’ve cut my teeth on Arducopter with a Pixhawk 2.4.8 in a hexcopter, and would now like to try it out in my T-Rex 500 heli. The usual place for the gyro or flight controller is on the bevel gear casing behind the main shaft, but the Pixhawk 2.4.8 is too bulky to comfortably fit there.
I understand that there are other boards that can run Aruducopter (e.g. Matek), so can anyone please recommend a suitable board that is significantly smaller than the Pixhawk 2.4.8?
Good day,
you can look for mro pixracer r15 or if you want an fc with h7 mcu you can look for the mRo control zero standard or control zero OEM with a custom board… also pixracer pro is suitable
@Dave84 provides some good choices. I would stay away from the matek boards. You could checkout CUAV as well but they are a Chinese company so it may take longer to get to you depending on where you live.
As for the location you are considering, I would stay away from mounting it on a transmission case as there could be vibrations that would cause problems. I know that is a smaller heli but try to keep the controller as close to the CG as possible and on a rigid part of the frame. you can mount is sideways on a vertical frame plate. The firmware can calibrate the IMUs for that orientation with no problem.
Checkout the Tradheli wiki here. it provides some useful set up tips and procedures.
Lastly, you will get more responses from tradheli users if you post on the traditional helicopter thread here
Thanks for those suggestions David and Bill. The Pixracer r15 looks good. But why the warning about Matek boards?
I hadn’t thought about mounting it on the side frame – that makes larger FCs possible. The flat top of the transmission case just seemed to be the logical place, as close as possible to the CG, but that habit started when it was just a tail gyro, which didn’t have any option for sideways mounting!
I’ll check out that Tradeheli wiki and the traditional heli thread. I’m still finding my way around this forum.
In my personal opinion matek aside the MCU, they are using components that are out of date, aside it if you want flash the ardupilot firmware you need to put the board in a DFU mode coz its not an ardupilot board, while with some of the supported board you can connect with an usb cable and flash immediately the firmware you need use.
I see, thank you David. Using a supported board makes good sense for me.
I suggest mRo pixracer pro… its equipped with H7 MCU and same sensors of the Control Zero
Hmmm, I can’t find mRo pixracer pro available in UK, and on the US sites it’s about 3 times the price of the pixracer r15 and seems to be about the same physical size. The technical jargon is beyond me – I can see it seems to be a difference processor, but I don’t know the pros and cons of either processor.
Well H7… mcu perform more fast and its also power saving, its equipped also with a dual can ports if you want add can periphs to your project, aside all of that you need check your project for choose the fc
Thanks David. My ‘project’ is very simple – just a T-Rex 500 fbl heli with no fpv or any other add-ons, so I guess the r15 is the one for me.
Yes r15 it’s for your case.
Don’t forget that pixracer servo rails are not powered so you need to supply your esc and servos with an alternative power source. I ve done more than 500 flights with mro pixracer r15 and i don’t have found any issue
I have 3 Pixracers, they have performed well for years now.Bur F4’s are long in the tooth. New builds have been with Matek H743’s. Current tech and better performers. I don’t understand this idea that they are not “Ardupilot Boards”. Of course they are, Ardupilot firmware has existed for these boards not long after they were released. They come flashed with Betaflight, trivial to flash Ardupilot. I really don’t understand this viewpoint. Matek boards are all over this forum in every vehicle type.
Go with a PixRacer if that’s what you want but I don’f get the above comments.
Dave and David, thank you. Always good to hear alternative views. I’ve already got a Matek 7xx in a racing quad with Betaflight, so I’d be happy in principle with Matek. Which version do you use Dave, the wing or the mini? Looks to me that the wing version comes in some kind of housing which would be easy to mount on the heli with double-sided tape. Silly question maybe, but does the Ardupilot version for the Matek boards have exactly the same functionality as the version for Pixhawk?
Decisions, decisions …
Hi Alan,
I have a mini in a 5” quad and a Slim looking for a build. I helped out on a larger quad build that used the Wing version. That craft is impressive. I haven’t had a Traditional Heli in a few years so I would defer to Mr. Geyer for that related info.
Yes, same firmware functionality as a pixhawk.
I personally don’t have any experience with the Matek boards except for those that I have helped set up for heli’s. Generally, they are designed a little different from most. So the set up is different for the servos/esc outputs. The boards I have seen had dedicated outputs for ESCs. They are an inexpensive flight controller and from what I remember only have 1 IMU, so there isn’t redundancy in that respect. IMHO, you get what you pay for. Take that for what its worth, just one person’s opinion.
I will add that you may need more than just double sided tape to mount the flight controller. Vibration management is important with these flight controllers not only from the control signal side of it but also for the attitude/velocity estimation (EKF). you’ll want to verify that your controller is isolated good enough especially for the EKF. For the control signals, we can use the software filtering to remove most of that noise. @dkemxr might have some suggestions for his installations of matek boards on how he isolated the flight controller.
The H743’s have 2 IMU’s, an ICM20602 and an MPU6000. Baro is up to date (DPS310), CAN BUS, loads of outputs and UARTS, BEC’s and direct battery power input. Nice boards, packed with features for a good price. Integrated OSD also but I understand you don’t have interest in that.
You definitely need more than double sided tape to mount these boards w/o internal isolation. I have had good success with various strategies. This is how I mounted the Matek H743-Mini with 2 sets of grommets. On another craft 1 set was good. That depends on the rigidity of the frame.
In my experience PixRacers (original/R15) also need good isolation. Double sided tape hasn’t worked for me with those FC’s accept in a Plane.
Thanks for all that input. One good thing I’ve learned about Arducopter is you can see your vibration levels in the logs and, thus, know when your mitigation measures are working.
Hello @abenn1
As Bill wrote, it will be easier for you to write in the traditional heli forum, as more heli users people are checking it.
I do have 3 Pixhawk 2.4.8 flying on my 450 helis, you have to check that you have the newer version without the memory problem that confine your memory. works flawlessly.
I use CUAV for my Trex 550 heli that also works also flawlessly.
I have also the Matek systems, mine is 405, ment for fixed wing, tried installing the arducopter firmware, as the memory is small, a lot of the system ability was truncated, so eventualy i changed to INAV, which needs less memory, but gives you less ability (will not work on helis)
If possible get the CUAV (I use Pixhack V3) and fly safely 
Thanks ZvikaF, I’ve learned a lot here, mainly that many people have Arducopter working in their helis, and there’s a few different boards to choose from. I note that the CUAV V5 nano doesn’t have internal damping. I haven’t seen that mentioned in the specs for the other controllers mentioned in this post. Sounds like it should be a desirable feature.
As you and others have posted, I’ll try and post in the traditional heli forum when I have further questions.
@abenn1. Hope you don’t mind but I moved this thread to the heli discussion topic of Arducopter.