@shaman running into issues again on steep hills…DRV faults everywhere when maxing out the throttle. Tried increasing commutation frequency to 30KHz and battery max to absurd levels (130A) to no avail.
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After a whole day of troubleshooting trying to find a way to mitigate the DRV fault issue under high current/low rpm conditions, these are my findings:
- No settings seem to particularly improve the behavior besides limiting motor amps as much as possible. This includes DRV OC settings, current filter settings, switching frequency, current controller decoupling…everything I felt I understood and wouldn’t destroy the controller.
- Also run detection multiple times at different currents, RPMs and time constants with consistent results, so no luck on that front.
When that didn’t work, I dissasembled the heatsink and redid part of the soldering, in particular the DRV (for which I used the hole in the bottom and went to town on the ground pad with tons of solder and flux), C35, C36, C37, C15 and C31 (which I had to solder myself) and the inductor. Finally, I bridged the hell out of the resistors next to the phase wires, which I missed during assembly.
Repeating the testing seemed to improve things a lot, and I went up to 60 motor amps (which in the end triggered the fault), but could not get it to fail at 55A. The fault was the same but as before, but reported absurd current values, such as -328A instead of 50/70.
Bear in mind that my testing was inside the house, clamping the board to the floor which was covered in a thick rug, which stressed the drivetrain enough to trigger the fault consistently.
I hope it helps someone and maybe @shaman can add as to why it got better, but my money is on the DRV ground pad, which was improperly soldered by JLCPCB. I’ll try to test the board in real conditions ASAP and maybe add some more data.
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Hello all,
After a few weeks I got the time to test my CheapFoccer 2. I would like to thank everyone involved and this welcoming community.
After flashing my CheapFoccer2 with the files from Shamane’s github account, I tried to setup the wizard, but there seems to be a problem. A weird one, I don’t know if it’s a hardware or a software one, but I’m thinking that it’s probably a software problem.
Here is a video of the problem :
What do you think ?
Thank you very much in advance.
Have you checked to see if any faults were thrown? Before turning off the CFOC2, reconnect it to the VESC_Tool, go to the terminal (lower left side), and type Fault and Faults
Try using a vesc tool version that matches your firmware. I think that will fix your issues.
https://drive.google.com/file/d/1GDVLFcPFf0MpjXtSnRGoMyiQljMRAtGX/view
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Hello,
Thank you for your replies.
I tried both, since it seems that I have the 5.1 FW version I used the 2.06 Vesc tool version. sadly without success.
And for when I type on the terminal fault or faults I get :
“No faults registered since startup”
But When I type other things I get normal replies.
What might the small noise be ? It’s sound like a relay.
Could it be a safety flag that triggers and shuts down the device ?
Thank you,
Yeah this could very well be what was wrong. Making sure the DRV is soldered correctly is one of the first things to check.
The performance you are getting now seems more normal but still sounds like something could be tuned or improved.
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Shaman,
I’m helping a buddy build one of these…
We’re probably going to use a 6384 sensored outrunner. I understand the CFOC2 can take 12S - but not sure how many watts it can handle. We’ll probably setup water cooling for it.
If the CFOC2 can’t handle the watts, I have to decide whether to go with two motors and 2 CFOC2’s or go with the Serious FOCer. Your advice would be greatly appreciated. Thanks!
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Interesting approach to a hydro foil!
watt wattage is needed?
The Little FOCer can do 5kW peak if that something of interest.
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Yeah. He and I kite-foil during the windy season, and this is the way to get a bit of water therapy during the off-season.
Good question. The motor we’re looking at claims it’s good for 4600 watts. You think a CFOC2 could safely do that much? Just thinking outloud… 12S would put us at about 48V, so that would mean about 96A continuous from the batteries. Seems high to me.
The other options I’m thinking are to use the Serious FOCer, or gang two of these motors on a single shaft and drive them with two CFOC2’s connected by CAN bus. That’s effectively what I’m doing with my mountain board.
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Sorry to be a bother again @shaman but real world testing revealed the fault consistently above 45A…gonna do the v1 resistor mod, but this time I’m positive everything is soldered as good as it can be. Running out of ideas…
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Today i flashed the new beta firmware (5.03) to the mountainboard and the onewheel. ASS seems not to be working well and when switching to sensorless its doing the same thing (HALL mode on the onewheel works fine):
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ASS seems to have a dependency on motors with temp sensors and other factors that may or may not have been disclosed by Trampa. I’ll be experimenting with ASS on my own very soon
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Well regardless of what the motor can do, what wattage is actually required? So a metr log would give good data on what kind of power is actually needed.
The little FOCer can 5kW peak and 3kW continuous with good cooling. This might do the trick. Otherwise you’ll have to wait for the Big(formerly serious) FOCer.
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Yeah it’s gonna be hard for to help without my own hands on the situation. The CFOC2 is capable of 75A operation at least in my own experiences. Are you using the recommended Mosfets from the BOM?
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Unfortunately we won’t know until we build it. It’s easy enough to do the calcs for the load while foiling, but it takes quite a bit more power to get up onto foil; but we’re not sure how much more. Once we get it working, I’ll be happy to log current and post results.
Are you using the recommended Mosfets from the BOM?
We haven’t built this yet. I have a couple of spare CFOC2 1.0’s I can loan him until he gets his. Mine are using the standard MOSFETs from the BOM. When we build his we would use the same unless you suggest something else.
Thanks again.
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Mine are CFOC2’s. Is that what you mean, or are you talking about the Little FOCer from the other thread?
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Is that 75A battery or motor?
Thanks.
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I got NCEP60T18s instead of T20s…Seems like a worse version with higher Rds and higher gate threshold voltage, but I don’t know if it would make a difference (please, please, please say yes)
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