As far as I’ve been able to discover the duty cycle control seems to only work if connected via PPM instead of UART. When in PPM you lose the temp, current, and wattage data on the remote. You can still get the battery voltage if you hook up the vx3 receiver to the battery +. There might be a way to make duty cycle work w/ UART but I’ve tried and not had any success.
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Hey, friend. Are you setting your VX3. Maybe you can check out their VX3 and 75200 setting blog: https://bit.ly/3mL0TRg
link not valid, please check
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I think in two weeks i could try, but by now i,m out of the proyect.
Thanks
So blew my VESC 75200 with some salt water and just replaced it and made sure I waterproofed the mastplate box better. Anywho, before this happened and I was testing the board it seemed to only pull 30amps on the water, the vx3 said only 4-5 mph and that was full throttle.
Fast-forward I replaced the VESC and reprogrammed it per @ludwig_bre video. I dropped the mast into the pool and am now getting 70ish amps against the pool wall. I opened up the VESC tool app and compared that the app says I am pulling 150a.
Not sure which to believe but am inclined to believe the VESC more than the remote, which sucks because I would like the right data visualized in my hand. Anyone have experience with this?
TIA
Remote shows the battery current, VESC tool probably motor current, those two are not the same.
E.g. at 50% duty cycle of the VESC, battery current will also be 50% of motor current.
That’s a function of propeller pitch, KV of motor, etc. In general best would be to have almost 95% duty at the desired max speed you want to achieve (most efficient)
So when users are saying 60amps to get out of water and 30 while crusing that is battery current and not motor?
Depends on who says that 
And depends on the battery voltage. I for myself can foil at 12A to 15A 
(battery current)
Dang, that’s impressive. I weigh 108kg so wonder how much that plays into it.
I got up standing today for the first true trial and boy is it fun but hard! I have a 67L board and 1900cc front foil so that is going to have a steaper learning curve from what I’ve read. Have a 72500 with a 12s13p 21700 battery pack. Just getting it to plane is rough and I keep hitting the current limiter and faceplanting it.
I may just be too big and I can deal with that. I guess I just need to double check what the battery, ESC, and motor can handle and add that into the VESC tool.
Does reverse work with the vx3? I turned everything on in the app but still doesn’t seem to work.
Also is there a way to do gps overlay with the 72500, bluetooth and vx3? I don’t want to buy another module to do it if at all possible.
I think you can. 75200 has two slots
The current limit shouldn’t cause a face plant or sudden stop.
My advice.
Set the battery limit to what the bms/ battery can handle. Around 130A
Set the motor current to 200A
Set the abs max current to 250A
Then in profile set the power limit to approx 5000W. Make sure it is set to save after power cycle.
Using the power limit feature will adjust the current as the voltage changes so you get a more consistent feel, until the battery drops enough that the increased current doesn’t provide enough power.
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I don’t think it works like that, current equals torque and torque needs to match the load for a given speed or acceleration.
in a constant power output the battery would have to supply more current at a lower battery voltage, only way of getting this is to increase motor current - and torque, so there will be either a higher speed or acceleration.
Actually if the current limit causes the ESC to stop suddenly it might cause a face plant.
That would negate setting high current values. At 12S it would only allow about 100A.
There are times I pull 7.5kw on startup…
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I’d suggest (I know it works for someone over 100kg):
- Set motor current to 200A
- Set absolute max current to 250A
- Set Slow ABS current Limit to True
- Set battery current to 150A
Stay forward and lying down on the board till its on the plane, then stand up keeping your weight forward. Then just give a little rear foot pressure and the board should pop onto the foil easily.
I’ll try this l, thank you. Yeah I can get up it is just a slow progression of slowing moving forward enough and fast enough to not have the nose dive. It probably takes 150yards to get there and I have to make sure I keep the draw low enough so the ESC doesn’t cut out. I’ve gotten up and carved at this point but hitting the current limit is frustrating hah.
If you get a cutout it’s not the current limit that’s the issue, it’s either a bms overcurrent protection or an esc overcurrent protection (“abs max current” parameter for a vesc)
If it’s the esc that is cutting power then chances are the motor matching/parameters aren’t correct for the motor.
I can get cutouts at max current with my vesc, but i’ve only run the parameter identification and didn’t tune the motor control more than this.
What I mean is reaching to the current limit shouldn’t cause to esc to cut out. The settings are wrong and abs_current is probably too low.
Using power setting in profiles is the correct way to set up the vesc. Otherwise every time you pull the trigger to 100% you will get a different result as the voltage decays. But up to you.
What motor are you using that allows 7.5kW?
65161 - It doesn’t sit at that power long, probably max 5 seconds. Once the board is planing it comes down to about 4kw
Careful, I’ve fried one pulling that sort of current!