I am trying to use the VESC 4.12 with the Castle 1406 sensored 4600kv motor and an 18v power tool battery but I can't seem to get it configured for proper BLDC operation. No matter how I adjust the settings the BLDC autodetection doesn't seem to work. The best I can get is that it runs nice and smooth during the first two detection sequences but the motor goes crazy on the third one and the detection fails. I noticed that that the sort of motors people use for electric skateboards have VERY different properties. Is it possible to get the VESC to work with this particular type of motor? Once it's configured properly I plan on controlling the rpm via a potentiometer.
Background: This is for an atypical purpose. The motor is to be connected to a modified airplane motor with the intake and exhaust ports sealed and a tubulation installed in place of the glow plug. Connected to the tubulation are varying lengths of 0.062" and/or 0.040" plastic tubing connected to pressure transducers. The purpose of this is to apply a sinusoidal pressure to the tubes so the frequency response of the tubing can be plotted from 0 to about 650 hz which should equate to about 40k rpm.
Thanks for any help.
I am not an expert in this, but the ERPM limit for the Vesc 4.12 is 60.000 Your motor has 1 pole pair, so at 18V the ERPM are 18V*1 pole pair*4600kV =82.800 , definitly beyond the specs of the VESC 4.12 . However this is probably not an issue during testing since the detection duty cycle is only 0.2 on default. have you tried varying the detection parameters, i.e. current or rpm on the bottom left of the VESC tool? I for example had to increase the current a bit for proper detection since my motor was hooked up to a mountainbike wheel with lots of inertia.
JL2579
Hmmm the specs for the motor say that it is a 4 pole motor which would be 18V * 4 pole * 4600V = 331,000 ERPM which would vastly exceed what the VESC can do. I noticed that the autodetect feature spins the motor multiple times. It will run smoothly at a constant RPM the first couple times but the third time it accelerates and then the motor makes a sort of click and then it stops and the autodetect fails. Maybe that is the motor hitting an ERPM limit or something. It seems like I'll have to use a lower voltage battery or a different motor with a lower KV rating and less poles, or both.
I did vary the current and ERPM parameters a lot and the best I could get it to do was run smoothly for the first two cycles and fail on the third during autodetection. Varying the duty cycle didn't seem to do much.
It's pole pairs, not poles. So 18 V * 2 pole pairs * 4600 rpm/V = 165600 erpm.
I think the problem is you risk destroying the DRV chip over 60000 erpm, so I wouldn't try to run a motor faster than that on VESC4.12.
Also keep in mind the KV number is a theoretical number. Under load, even slight load, it will be lower, won't it?
Yeah, but if it is 20% lower, your motor will be dissipating 20% of the power that goes through, or max 80% efficiency. You really want to stay within 5% of what the KV number predicts.....