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Max ERPM of Myxa

Hello,
for a powerful propulsion solution we tested a VESC ESC, which kind of works but we had problems to achieve the needed electrical RPMs (ERPMS). The limit of VESC 4.12 is about 60000 ERPMs, which is a little bit too low for our application.

How many ERPMs can be achieved with Myxa?

Uwe

Generally, 100000 ERPM is achievable; higher speeds bear the risk of instability under load. We are working on a new state observer that allows even higher speeds.

Thanks for your reply! I will give it a try.
Uwe

Hi,
Is there any update on the new state observer? I’m looking to use the Myxa ESC for a project where I need about 160k ERPM (peak, average is about 110k). Do you think this is achievable or is the 100k a hard limit?

Our initial experiments with a modification of MRAS proved unsuccessful so far. This is currently a low priority because none of our major customers require operation above 100k RPM. Could you share a few words about the configuration of your propulsion system here?

It’s for a 16kg VTOL with 8 lifters. I’m planning to use a T-motor MN501-S 300KV (28P) with a T-motor 14x4.8 carbon prop running on 45V (12s LiPo).
I need about 2kg thrust per motor with 4kg peak.
At the altitude & temperature (1000m, 30°C) I’m targeting this is about 106k ERPM hover/150k ERPM peak.

If energy efficiency is not a major concern in your application, you may want to use simpler controllers like BLHeli. If it is a concern, then you may need to review your motor configuration because high electric frequencies induce higher transformer losses in the motor. Consider choosing a motor with a lower number of rotor poles to reduce the current frequency, or increase the load by adjusting the propeller configuration, if possible. FYI @dmitry.ramensky

Energy consumption is not the main design driver for this. There is unfortunately no space for a bigger propeller. I do have another motor option (MN5208 KV340) with 22poles which brings the ERPM down to 84k/118k but this one isn’t sealed as nicely.

I am mainly interested in the Myxa for the configurability & telemetry over UAVCAN, as well as the possibility of customizations.
How well/bad do you think the Myxa would perform at the ERPMs of the two motor options I have? You mentioned the risk of instability under load. What would happen in such a case?

I expect it would work in the lab under ideal conditions but load variance and other random external influences common to powered flight would throw a wrench into the control loop. It is usually accompanied by nasty transient processes that may damage the electronics and/or the motor itself.

Is a 14-pole motor an option? We could help you choose the right configuration.

Yes, switching to a different motor would be an option. I’ll contact you via email.