So you didn’t change battery? Just esc to vesc?
6S to 10S with same motor SK3 245 6S was ESC - 10S VESC I did not get any failures - just performance was not as good as with 10S. Power was the issue, lack of acceleration, changed to 192 kv motor and bingo. Good acceleration and good top speed.
6S 245 was a good all rounder 10S 245 lacked torque
Maybe it was your motor max amp setting (on the low side). This plays a huge role in performance in the low speed torque. Since a Car ESC (or whatever you were using) likely doesn’t limit motor current, this might be why you had worse performance from the VESC.
yes, that’s correct - I like cake a beer, so even with increasing max amps it wasn’t enough.
I like the way an ESC can take abuse without complaining and am tempted to go back to the dark side for a 12S set up but am holding off until VESC 6 has been trialled.
@Alanhunt123 here’s the best thread we have on the subject, compliments of @chaka. TLDR: Your VESC and motor will be fine as long as the 60K RPM threshold is not exceeded. You would likely experience an increase in available torque with a lower KV motor, at the cost of a lower top speed of course. If it were me, I’d keep the motor you’ve got. If you upgrade in the future you might consider 192kv.
I feel that the VESC the ERPM should be programmed into VESC firmware. Maybe there are some scenarios where you’d want to exceed it, but it seems to just cause problems for folks. I had a DRV fault once during bench testing. Seems like an avoidable problem!
I have only put about 10 miles on my build, but its 10s dual vesc sk3 6364 245kv, erpm limit 60k, and I have had good torque and no vesc issues so far.
It has been said that lower KV and Larger motors like the 6374 produce more torque and is usually the best choice for a single drive. 6355 190kv motors work well on 10s in a dual drive. I have found( thanks to @Hummie who led me in this direction) that increasing your motor max amps in the bldc tool will also increase power/torque especially at lower speeds. I got noticeable improvement on my dual drive with Vescs and 6355 190kv motors by just uping the max motor amps from 60 to 80, with no ill side affects caused to the Vescs or motors.
Thanks for sharing that. Good to know that the Erpm limit in the bldc tool really works.
I’ve tried using really low ERPM limits, and it seems to work well. For example, I limit my reverse ERPM to 5000 to avoid backing up too fast. It never gets jittery around the limit, so I may end up limiting my forward ERPM to something like 50k-55k, since I don’t want to go faster than that anyways. In fact, when I first tested my VESC on 8S, I limited to 40K, and never experienced any issues, the soft cutoff worked like magic!
I have my motor max set to 70, the recommended max amp stated on Hobbyking, but my motor stays pretty cool. I’ll try bumping up to 80, should give a nice boost! We’ll see if my belt can hold out… just upgraded to a steel pulley.
The information your sharing about the erpm limit is very good. Maybe I’ve missed something along the way but this thread is the first I’ve seen where someone actually ran tests with erpm limiting and was able to offer conclusive results. This kind of knowledge is a real game changer. As for the motor max amps, my motors are rated for 80 amps. I have run the motor max as high as 100a With just a little warming while driving hard uphill. At 80a motor max, they barely even get warm. The person who got me to experiment with this setting is running his at 200a in FOC mode! 100a felt like more power than I needed so I backed it down to 80a
Great to hear! I’m always trying to get more involved in the E-Sk8 community.
That’s insane! Must be a beast with tons of startup torque! This type of setup must really benefit from having a sensored motor. I have yet to venture into the sensored territory, but will likely pick one up if/when my current motor dies.
I don’t think he’s running sensor motors. Just FOC mode in the Vesc. And you hit the nail right on the head. He said it gave him lots of startup torque
Interesting. I am hesitant to try FOC on my VESC, since it is an Enertion board, which is already known to be finicky. Plus, I kind of enjoy the sound BLDC gives me. Is startup torque better in FOC, even with sensorless?
@devin, who is now just over his banning period…haha, got me on the 200 motor amp limit. they are 200 amps for a fraction of the commutation time, the “duty cycle” and the inductance of the motor coils smoothes out the pulses out to an average amperage much lower.
a stated motor amp limit is suspect besides. 200 motor amps feels much smoother, much better early acceleration, and has less cogging and I can start from a dead stop with the slightest rocking.
Should I try this with BLDC? Maybe something like 150A? I have more than adequate cooling on my mosfets, as I custom CNC milled an aluminum VESC enclosure that doubles as a massive heatsink. Will post pictures if anyone is interested
Oh ya, I’ll bet CNC heat sink Vesc enclosures would sell like hotcakes here! Post some pics please!
This enclosure has a raised surface inside it that the MOSFETs sit on. I used some thermal paste to transfer heat between the MOSFETs and the enclosure. The top MOSFETs have a “Bridge” that makes contact with them and transfers heat to the case through the mounting screws (which are also coated with thermal paste).
Since I switched from heat shrink to this enclosure, I went from having power loss after 20 seconds of going uphill to no power loss on any hills at all. The enclosure really does an overkill job of keeping those MOSFETs cool, as well as looking beautiful under the board.
Here is the one caveat preventing me from manufacturing more to sell. Since the enclosure was designed using WPI licensed software (Solidworks) and machined using WPI owned machinery (Haas VM2), I would run into legal issues very quickly with WPI.
This summer, however, I am working for a professor that owns a custom CNC shop oriented towards small production sizes, mainly for hobbyists or educational teams, such as a robotics team. So, we may be able to strike a deal making some of these. For now, the VESC enclosure remains off the market.
I’ve never hit an overheat shut down running even one large hub motor and 200 motor amp limit. before i was running two motors at 70 battery and 70 motor each and never had a shut down either. no heat sink or special cooling.