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. 
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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.
Yeah, I was a bit perplexed why I was getting this overheating issue, perhaps it was the heat shrink supplied with the VESC that was the issue (was a board that a guy from Enertion had sitting on his desk to replace my stubborn board that kept blowing DRVs). The Vesc was sitting pretty cramped inside my battery enclosure, which may have something to do with it as well.
I never got a shutdown either, but after a few seconds of hillclimb or braking, I would notice a decrease of performance to the point that the board could no longer climb. No issues with this setup though, now that I have the enclosure. In fact, I bet it could handle crazy amounts of current now that it has a really good heatsink.
Just tried out my new 10s board with this motor. It’s a beast! Using 120A/45A motor/battery current, a 15:40 ratio, and 83mm wheels, it’s just crazy powerful. No problems so far. Will post a build thread soon.
15:40 is very low gearing and with 83mm wheels and 120a motor current, your acceleration must be insane! Keep an eye on your motor to make sure its not overheating. If you feel it’s getting too hot then you can back off your motor current to bring the temp down.
At the very most, the motor is warm to the touch, but not so hot that you can’t touch it for an extended period of time. I’ll try a hill climb test to see how it performs.
wow, that enclosure is awesome! it looks like it protects and cools the vesc perfectly
@Hummie I recently switched from single motor to dual and the vescs don’t get hot anymore as my single one did but on my single (6374) old build the vesc overheated significantly. I’m quite heavvy (~105kg) and I wasn’t able to climb hills at speed when the vesc overheated and I had to break softly to make breaks not to cut out. I guess with dual, with smaller motors and/or if you’re 70kg or less that is less of an issue.
Really proud of the enclosure. It looks like I may have a deal with the professor I am working with to make some eSk8 parts, this might be one of them!