Yes it is set at 420A but scary bit seems this is what Flilsky recommended to overcome some issues… honestly to push speed I will just use the 300A opto seal, this thing is a beast and I won’t cry for a week if I burn it hahaha. Still convinced the 75200 can work well, it is just a setting to find. Even free spining it seems to be cogging a bit sometimes, I will upload a video. The weird thing is when I set ppm range with the wizzard this cogging noise disappear, then it is back there as soon as I leave the wizard. Wondering if all the issues could be input related
Worth the shot to try in duty control no reverse rather than current control then ( my 2 cents …)
It doesn’t seems to work well at all in duty mode no reverse
Did you also get the 420amp recommendation from Flipsky support?
No it was like that after running the foc wizard…
I read an old post on the A200s where it is advised to disable V0 V7 and set switching frequency up to 60Khz. Gona give it a go and keep an high on FETs temp. If it doesn’t help I will revert to 30Khz and try to play with stator compensation.
Problem solved, I recalculated flux linkage, the formula I used the first time was wrong.
I found a post where Benjamin Vedder gives
Flux linkage =60 / (sqrt(3) * poles * pi * kv)=60/(sqrt(3)16pi*130)=5.3mWb
Gain=1000 / (lambda^2) where lambda is flux linkage = 1000/5.3^2=35.6%
These calculated values are really close to your values Alexandre.
Straight away no more cogging and ABS. Increasing stator compensation to 15% also made a difference at high current.
7 Likes
pretty happy with this. Using a low aspect 1200 and the 6 inch lift prop. Next step 7 inch prop and smaller high aspect wing
And this is same front wing and just using a smaller rear wing
3 Likes
Love the GPS glitch on the top speed in the last pic. Imagine doing 114kph on an efoil, you’d fall apart if you fell!
1 Like
You already feel crash above 40kmh a bit haha
1 Like
It’s interesting that this value is just based on some datasheet info. I thought there is actually some measurements needed to include wire sizes and whatever. But apparently I have no idea at all.
Are there more of those motor detection values which can be calculated externally? I don’t trust my VESC to do this right 
would it be possible to calculate the resistance out of a metr log (motor current and voltage)
I don’t trust it too. A mate is going to measure the inductance and resistance with an LCR meter
Possible also that way :
Best to measure Ri … of the motor in warm water to simulate the heat of the load
Yes let us now if this works. According to this thread it might be not easy since there is no high load during LRC measurement
Interesting, I will check just out of curiosity. Everything runs really well now. The only issue I have is with 95kg and a small board (125x56cm) I can’t get up using a 850cm2 wing. I can see in the log the motor can’t get rpm to increase and motor current hit the 200A limite. I’m a bit reluctant to increase max motor current further. In the log above you can see the first 3min where I try to get up with the 850 then I swap for the 1200.
This make me wonder what Lift ESC current rating is as people foil on the 4’2 with the 120ha (775cm2)
My guess would be around 150-160 Ish max current, but certainly not 200A imho.
A temperature sensor in the motor would be great.
You could bump up the current untill a certain temp is reached and therefore really get the absolut limit out of the motor before it would burn out.
I really doubt a big guy can get up on a 4’2 (127cm) and 775cm at 160A but maybe I’m wrong.
Well @Manufoil props to you. I did try today with the calc Flux value, in my case it is 120kv motor which has 6 Poles = 15.35 mWb (before I had 16.x-ish). The observer gain would be 4.26%. And indeed the motor runs straight away noticeable smooth. Still I have some syn issue around 90-95% duty, but compared to before it is really damped. So this value has lots of potential for tweaking, I may rise or decrease at a bit to test what will happen. Interestingly, my start is not so powerful anymore, I even needed to raise the motor current to 170amps (160amps before) to take off a bit faster. So now with lower flux I am missing a bit of punch for start and have higher current. Whoever can enlighten me about this, it is very much appreciated. Let me close with a log:
Cheers
2 Likes
Interesting, same finding here, less punch but it solved the ABS issue and cogging. Run overall smoother. I also have higher motor current to get on the plane. What switching frequency are you using? Depending your setting you can increase frequency a bit or play with stator saturation compensation to try to solve the sync issue at high duty.
When I use the opto seal 300A the motor seems to have way more torque, I’m just worried of how high the motor current is going to get on the plane as you can’t monitore it, in theory it could go up to 300A I guess which I don’t really want.
A variable flux setting, that would be a neat feature. Higher flux setting for low rpm and lower flux for high rpm. Anyway, I think switching frequency is 30kHz and I know about that stator compensation, I think it is more for low rpm and high current, so at start where I have the 170amp