Anyone checked out field weakening on a vesc? Should allow increased rpm past the theoretically FOC maximum. I’d like to try it out but don’t want to risk my working setup yet… Need a backup vesc 
or wait until the fall.
Unfortunately it looks like it causes a massive drop in efficiency with typical esk8 motors. That probably applies to our motors as well.
Yes it would lose efficiently compared to a higher kv motor, but only in the range where the lower kv motor couldn’t reach before.
I was thinking you would only need it in for a boost at times, such as when your are normally maxed out on motor rpm. If you never top out your motor rpm you wouldn’t get any loss of efficiently
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I’m extremely interested in this too. It’s something I’ve always wanted to try on an Efoil. I think it is a much safer platform to test this on compared to dealing with concrete riding a skateboard 
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I will test it with 12s and a Flipsky FSESC 200A.
Field weakening is a gamble on propeller drives due to power increasing exponentially with rpm so it’s best to increase it slowly in steps when you try it. Good luck!
I’m running 10Amp of field weakening on mine currently. With my 14s battery I’m not sure I am hitting the field weakening range in the water - but can definitely tell out of the water. Going to try my 12s next, I was constant running into the top end of that battery, so this may help.
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Any news on FW? Settings would be nice. For balance boards, people set FW current rather high, 30A seems standard, some push it even higher. They also set the threshold low, 70% or even lower.
I had to change my vesc recently and installed firmware 6.2 on the new one, so I might try it out. 63100 outrunner on 12S. FW current 20A, start @80% seems hood values to start with.
I had been running it at like 80 or 90% with something like 10A if if I remember right. Mostly was just handy in current control so I wouldn’t get the awkward zero throttle response when I hit the top end of duty cycle when I was foiling (and give you some extra speed). Didn’t try and mess with it too much because I didn’t have bluetooth and my VESC was buried…
I got to replace my vesc as well, so hadn’t been riding with it this spring yet. Next one will have bluetooth for some easy setting changes. Also too many good windy days to wingfoil…
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One of the things i was wondering since i started digging in DIY efoils couple days ago. FW increases max RPM substantially yet torque in this range seems to be less. Efficiency wise, on the VESC Onewheel corner we do not see much loss using 40 to 50A starting at 50% DC. Basically always using some FW.
Now on land, in the higher speed range we dont need all the torque (using 50-80Nm outrunners) as we’re rolling already. The motor amps are much lower compared to accellerate state. Im not sure how it would translate to a prop in the water hence im very interested to see some logfiles of motor amps used.
Propeller power is proportional to rpm^3 so the motor amps will increase exponentially with the rpm
In this case using FW can be an issue. Or is it tried and tested by now in this sport?
How “hard” are flipsky’s motor specs btw? They spec a motor rated 60A max 200A?
Field weakening can be used of course, it just needs to be adapted with reason. I never needed it since it hurts enough falling over 40kph 
No chinese motor spec can be considered firm.
I would be careful about activating FW with Shitsky Vesc, since you mentioned your onewheel, on my e-bikes I fried two 75/100 “Vesc” controllers, One died after less than a kilometer, the second died instantly, just as I left the driveway.
Believe it or not I figured it might have been the BMS that killed the controllers, so… I ordered another one! Now without a BMS, Field Weakening has been a game changer, a stock e-scooter that does 40km/h now does 60, 6 months no issues at all.
Sorry for the rant, I wouldn’t recommend using it on an e-Foil, I believe a Propeller is already loaded harshly as it is, I would leave FW for e-scooters/bike etc, just to reduce my chances of getting stranded in the ocean.
No rant really. BMS connected to a vesc has a chance to kill your controller for sure, especially if connected via (non isolated) CANbus.
FW…im not afraid of the controller as im planning to use Tronic x12. Bms will be charge-only.
But as opposed to land-pev’s the demand for torque thus motor amps increeases with RPM on efoils, the chances are likely to load the motor too much.
I really have so much to learn about efoil building lol.
Bms connected to vescs an issue, what do you mean? Via CAN is not done if it isn’t the vesc (trampa) bms or some other unusual higher end bms.
Yup, propeller drag/load is quite a bit different than tyre friction, I’m no engineer but I feel like FW on a foil would be similar to overvolting land EV motor uphill.
Now if that’s your first build I would go WAY cheaper than the Tronic, gotta waterproof the heck out of the 600$ controller haha, ballsy move!
Again, i do not know which bms es are used by the community. On vesc OW i exclusively use high-end material and canbus connectivity. And bad canbus can ruin your system pretty badly. Course asphalt is pretty unforgiving.
Will give FW a try once i build a board:)
Tronic bareboard around 450, but excellent thermals and massive headroom spec wise. Think couple hundred € will pay off in the long run.