Alright, @DEEIF has been kind enough to let me mess around with his board to try and get the most out of it.
- SRB v5 #1
- 21/78 gearing
- pair of Lil focer hw3.0 connected via can
- SKP 6485 151kv
- 20s ( 4s 10Ah power hobby Lipos in series. )
- 150mm gears
- so 51.4mph/82.8kph gearing (no load)
- OSRR albert “racing remote”
- freesk8 robogotchi for telemetry.
- firmware 5.3
- 0.05/0.11 ramping times. 15% deadband
In the end i’m trying to see if it can compare at all to the power and feel of my board which is SRB v5 #3 on 8s castle XLX2 setup now with a pair of Hobbywing 70125. on which i’ve done 15kw pulls. AFAICT castle is BLDC commutation, no motor amp limiting,
I took it out last wed to Intro2Speed slowly ramping up battery and motor amp settings, till i got to 100/150 per side.
My main test was coming out of a corner (5-10mph?) and trying to full pin onto the straight (peaking at 30mph ) I noticed that it didn’t have quite as much pull (lack of punch) at first till it got to higher RPMs. @redbeard torgo also rode it and made a similar observation. ( said all vescs are like this )
Initially I thought this might be maxing out the motor amps. and it looked from logs like i was very close to 150/side.
So I upped motor amps to 200/side.
I then threw a ABS OVERCURRENT FAULT, managed not to die. discovered slow ABS max was not enabled, and that ABS max was set to 225/side. I enabled slow ABS and set it to 350 a side. ( is that ok? ?? )
I also lowered fault stop time from 100ms to 75ms.
Then I then got some other cutout, for which i didn’t get a fault for. but I realized later i didn’t properly check both vescs.
and my confidence was shaken. getting a cutout full pull is sketch. makes me wish I had a dyno of some kind to really put this through it’s paces without risking my body.
but I did pull more than 150motor amps.
from the numbers in robo logs I think i pulled 10kw at one point, so not bad. but not enough.
I rode it again at Night Session Intro2Speed on sunday, with settings back down to 100/150 i don’t think we pulled it as hard. @MarioChacon and I both rode it, i haven’t looked at the logs to see what kinda power we did yet. but we didn’t have any faults… thank god.
Another observation is that under no load i get a strange fluttering around 85% duty cycle. I had assumed this was a no load problem. but i’m concerned it might be a settings problem.
need to post video of this.
- How high should be the limit for motor amps?
- How high should ABS max be set?
- what other vesc settings should i be double checking to push things at this level?
- what is with the 85% dutycycle no load flutter.
- will PID tuning be needed to solve the “lack of punch” at low end issue.
- how many people are going to push the expo setting idea?
Thanks to folks who made such experimentation possible.