If I need to I guess I can. But this is the same as the current mount with the thinnest section being 2.75mm. So far there have not been issues. But, I suppose this could be a weak spot.

The top is a separate body as well, and will be mounted with screws. Maybe I should shave 0.5mm off the back side though just to make sure it doesn't bind. 15 hour print just for it to not align would be annoying...

I sometimes print smaller subsections of things like this to avoid disappointments ;)

Got too many printers now - I bought a chonky one to print fasterly and biggerly.

Hobbywing Tunalyser came in today.
Here is a photo with a Slot Machine 13.5 pulling almost 20 amps.

I will say the Tunalyser is a pretty nice piece of equipment.


https://cimg6.ibsrv.net/gimg/www.rct...490f1ab2d.jpeg

And here is a pic on an ESC running my telemetry unit.

The harness coming off the driven motor is for testing with timing. Doesn't need to be on the actual unit.

https://cimg8.ibsrv.net/gimg/www.rct...f8ad91e3e.jpeg

Update on Timing. I have proof of concept for measuring timing on one phase. I am attaching pic of a function generator setup to output 2 square waves at 303hz and phase shifted 45*. Then with the arduino I am measuring the phase shift on external interrupt pins. I am printing the output to the serial monitor for now, printed variables are frequency, RPM, and Timing.

https://cimg7.ibsrv.net/gimg/www.rct...f11ad7b166.jpg
https://cimg7.ibsrv.net/gimg/www.rct...cb488d6343.png

For a clean look, install your esc on top of the mount.
Hobbywing Just Stock pictured with Sanwa rx.


https://cimg4.ibsrv.net/gimg/www.rct...bd7ae8b1c.jpeg

Looks good! Did you make that coupler that connects the motors together yourself?

I did not. Machining metal is out of my scope. I really need someone who can do that...

Anyway, that is from Amazon, 3.17 - 3.17mm coupler.

https://www.amazon.com/dp/B08QFNDP3H...t_details&th=1

More testing with timing tonight. It is getting better, lol. Below are some pics that show a Slot Machine 13.5 @ 40* on the can and the readout from my code. Then @ 45* on the can with readout. Finally I put an R1 v21s 21.5 @40 on the can and the readout. Now R1 always read lower on the can by 4-5*. And my Motolyser confirms that. Now there are caveats... The pwm gets in the way of the bemf reading so I have only been able to read at full throttle. Anything less and all the readings are way off. I'm still working on it, lol. But this is progress!

https://cimg8.ibsrv.net/gimg/www.rct...68cf6a1d6a.jpg
https://cimg0.ibsrv.net/gimg/www.rct...5c71f236bf.png
https://cimg1.ibsrv.net/gimg/www.rct...ce0d399bc7.jpg
https://cimg2.ibsrv.net/gimg/www.rct...7aa60c3f45.png
https://cimg3.ibsrv.net/gimg/www.rct...f0ccf85750.jpg
https://cimg5.ibsrv.net/gimg/www.rct...c06be4c481.png

The SkyRC style analyers can only measure timing at full throttle as well. I'd say that's an acceptable limitation.

I took a turn trying something else this evening. I hooked my telemetry unit up to the MiniPro flywheel unit and ran a run using my telemetry unit. I had to tweak the code a bit to use 2 hall effect sensors instead of just one for RPM. I need to add the third, I'll work on that later. But for a first attempt I am pleased with the outcome. This is a Slot Machine 21.5. It compares pretty well to the MiniPro output with one big caveat. My numbers don't go above 65% efficiency. So there is that...

For anyone curious, I redirected serial output to a terminal monitor called RealTerm. I then took my readings and added them into excel and created formulas for Torque and Power. My initial sample rate is 10hz. I was having issues going above that due to my voltage and current averages interfering with the rpm. In order to proceed I am going to have to completely rewrite the code for faster sample rates. My original telemetry unit doesn't need to update faster than once per second, or 1 hz.

EDIT: Looks like I didn’t start the data quite right on the graph. I just need to grab the first values, so the power at 0 rpm is 0. Torque will also be zero, nature of the flywheel…

https://cimg0.ibsrv.net/gimg/www.rct...b6a46dbae7.png

65% peak efficiency sounds like it's in the right ballpark. Most dyno results of RC motors I've seen are in the 50-70 range.

I had a request to add "KV" to the readings. I took this chance to revise the software a bit. I also changed from reading the high low pulse for rpm to using hardware interrupts. Also I cleaned it up a bit to be able to run both my telemetry module and a motor analyzer in tandem with each other. Here are some pics of running the SkyRC unit with my telemetry module. I also am comparing to my 5.5 digit bench dmm to show that my telemetry unit is more accurate for voltage, and KV is dependent on voltage.

https://cimg7.ibsrv.net/gimg/www.rct...a848e445f2.jpg
https://cimg9.ibsrv.net/gimg/www.rct...edb8524fd7.jpg
https://cimg2.ibsrv.net/gimg/www.rct...d6f7de7537.jpg
https://cimg3.ibsrv.net/gimg/www.rct...8dfafe9255.jpg
https://cimg4.ibsrv.net/gimg/www.rct...1063d7eaa7.jpg
https://cimg5.ibsrv.net/gimg/www.rct...a4b37908c8.jpg
https://cimg8.ibsrv.net/gimg/www.rct...38a5855e5f.jpg
https://cimg9.ibsrv.net/gimg/www.rct...f09c1a90b1.jpg
https://cimg0.ibsrv.net/gimg/www.rct...8e7867277a.jpg
https://cimg1.ibsrv.net/gimg/www.rct...3fa5957f90.jpg

I had a motolyser shootout last night and tonight. I took an R1 21.5 and a Trinity 13.5 and ran each motor at 30, 35, 40, 45, 50 degrees timing. I ran each of these on the SkyRC, Tunalyzer, Motolyser, and my telemetry unit. I also ran each test unloaded and then loaded with my Load Master using the 2 ohm resistor bank. This was interesting, and took absolutely forever... my conclusions are that the readings are all over the place, lol.

So caveats:
The Hobbywing Tunalyzer and the Trinity Motolyser both use 7.4v for the test voltage. To try to get close to the same on each test, I used my variable voltage power supply as a power source dialed to 7.75v. So there is a slight difference with the SkyRC and my unit for voltage.

Also, with the 13.5 on my telemetry unit with an esc, at 30* timing and unloaded, the current is actually higher than at 35*. I spent a good amount of time re testing and verifying this. I also ran my telemetry unit in tandem to make sure it was reading correctly. When using a analyser to drive the motor, it looks good. But when using an esc this behavior pops up. I got nothing... I tried both a Hobbywing Juststock, and an XR10 pro gen 1. Unfortunately I can't exactly test a motorlyser and an esc in tandem...

Anyway, instead of putting a ton of pics on here, this time I am just linking to my github repository. https://github.com/trilerian/Dyno-Results

EDIT:
Added graphs with Current vs KV.

Case redesigns to allow for a little cooling of the motors.


https://cimg4.ibsrv.net/gimg/www.rct...558f28585.jpeg