@Gamer43 how did u get such good speed out of your hoverboard motors? Do u know what their original kv might have been?
I think @Skirra uses 9inch ones but his speed seems to be lower, at least for now
U could rewind for a better motor but the idea that higher kv can take more current is true but it takes more current out of a higher kv motor to produce torque and in the end thereās no greater efficiency
@Hummie I fully agree, efficiency isnāt quite what I am looking for- rather reasonable speed while staying under 20A current consumption. Interesting thing I noticed after I switched from star to delta is that now Iām getting some cogging at start up. I guess that loss of torque is affecting the startup. Any ideas how to fix that?
@Okami Iām running 8 inch version currently to keep board in balance with forward wheels.
Havenāt done full speed test in new configuration because of the -10C that is going on outside 
All the good ideas are more than welcome though.
Higher motor current. Maybe the phases arenāt all wound with equal turns and imbalanced voltages possible with delta. If u had a cheap induction meter u can see if the rotor is off. Higher motor current is an easy try
@Okami I have a pair of 8-inch hoverboard motors.
Their original top speed at 10S was only 14 mph, which comes out to a KV of about 15. The motorsā windings were originally in WYE configuration. I opened up the motors and reconnected the windings to be in DELTA configuration.
The start-up is a little anemic now, as the torque per ampere is reduced by a factor of square-root(3) (and the changes I made to the VESC settings didnāt compensate accordingly), but the throttle is much smoother.
I didnāt have suitable high-speed front trucks on my board, so speed wobble would start at 16 mph and was really bad at 20+ mph. Sudden changes in acceleration would trigger speed wobble.
@Gamer43 Mind to share your vesc conf? Been playing few hours with the settings for now, havenāt got to a point where Im happy with results. Are you running them in BLDC?
@Skirra I am running FOC. You will want to run FOC since the torque ripple in BLDC is going to make some noise and cause inefficiencies. Youāre going to want your hall sensorsā¦ I noticed that when I reconfigured my motors into DELTA configuration, the Sliding Mode Observer on the VESC couldnāt lock on until about 3500 ERPM; when the VESC attempted sensorless transitions below that speed, the motor would cog. When the motors were in WYE configuration, the motor would cog during start-up if I ran it in purely sensorless mode. The observer has issues at low speeds; no amount of D-axis current injection would stop the cogging.
You will want to tinker with the advanced settings. Try a switching frequency of 25khz or higher (this made the most significant improvement), I found the sweet spot for my motors around 29-31khz. Set Dead-Time Compensation to 0.600uS. Set minimum current to 1 or 2 A (this was just so I wouldnāt get obnoxious whining at really low throttle), Motor Current is Ā±30A Battery Current is Ā±10A. Again, start-up (on a hill) was a little anemic with these settings, 40A motor current should be sufficient for flat and hill starts. (I apologize for not posting screenshots, the settings for some reason didnāt save in VESC tool and my VESCs are locked away in an aluminum enclosure, Iāll post screenshots if I have time).
If you are unable to get satisfactory results running the motor with a VESC, I recommend trying them with one of those āsinusoidal/FOCā ebike controllers, though not sure if you can find one that will work at 10S. They are actually cheaper than VESCs, but many are not programmable and are a bit bulky.
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@Gamer43 ank you for this informative post! I reconfigured my motor tab, went a lot lower with my current values and inserted same values as you told.
After that I did FOC detection and tried if cogging is still there. This time it was gone and with enough throttle I could start from dead stop. I guess some sacrifises has to be done to get better low speed performance.
With DTc at 0.6 there was some weird behaivour. Motor was cogging higher speeds quite violently which made me lower it to 0,1.
With switching frequency I noticed some improvements as well. It seemed most stable between 29k - 31k as you said.
Thank you once again! Here is my conf for future readers.
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Why are you using the bldc tool instead of the new vesc tool? 
@Skirra
@Mich21050 When I bought focboxes I downloaded software from their website and have been sticking with this for now. Am I missing some vital features compared to vesc tool?
As far as I know you donāt but maybe someone who has a focbox can helpā¦ Iām only using ānormalā vescs
Itās just the newer versionā¦
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Are you still interested in rewinding? Currently in delta configuration you are looking at a kV of ~ 24 mech. rpm/V. If you give me all the info on the stator dimensions:
*stator inner and outer diameter (without the metal 3 prong piece) *slot depth *sslot width *slot opening width
And rotor dimensions: *Magnet thickness *Can thickness *inner diameter to magnets
Iāve been using some simulation tools that can devise a winding pattern for you that will give you your desired kV. Iām interested to test how accurate it is in a real world application if you want to give it a go.
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@Deodand Sure no problem. I would more than thankful for some simulation.
Do you need simply dimensions or .step file would do as well? It would be interesting to see the magnetic wave behaviour
I think iāll try rewinding soon once again, my hands are already healed from last time 
@Deodand Here you can see the requested dimensions. I quickly modelled this motor, minor hand measurment errors might be there. https://drive.google.com/open?id=1mktiQDosbIz0QMT4VzFiifR7NJLBpWP3 .step file https://drive.google.com/open?id=10YITC8aa49_Q1IHteUZtwr1f63NU5sRi
Yeah, so used a similar AaABbBCcC winding pattern. See the above image for slot fill. With your 1.2 mm wire and 6.5 turns per tooth you should have seen a kV around 82 rpm/V in the WYE connection pattern fill density of 20% and a winding resistance of 70 mOhm. At 10 turns the kV should be around 52 rpm/V with a slot fill factor of 30% and resistance of 105 mOhm. 15 turns per tooth should get you a kV of around 35 rpm/V in the WYE connection with a fill factor of 46% and a resistance of 158 mOhm.
Iād recommend 10 turns per tooth with a Y connection I think. It might make your life easier to use 3 parallel strands of 0.7mm wire or 2 of 0.8mm wire which will behave similar in every way but may be easier to bend into the slots etc.
Not sure why your windings before didnāt work though, definitely a concern. Hereās a few little plot of 10 turns per tooth Magnetic flux for fun:
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@Deodand Thanks for screenshots! What does those red spots at the ends mean? Also can you simulate situation where wire is 1-2 mm away(offset) from stator teeth? I think this might be cause of my issue since wire might be too far away. Would be interesting to see, how it looks like in that case. Is it possible that one pole could cancel the opposite one if they are too close? (current flow is opposite)
If we look at the calculation. Is it electrical or mechanical rpm?
Mechanical RPM, multiply by 15 for ERPM. I donāt think the problems with gap between wire and stator teeth are causing the issue you are seeing. You would see this as some inefficiencies whereas what you describe is basically it not working nearly at all. Probably an error in your winding pattern somewhere/somehow.
The red spots are just zones of high magnetic field concentration, probably more iron losses there since the material will get re-magnetized. Could also just be artifacts from FEA who knows.
This is MotorAnalysisPM right? been playing with it, amazing tool
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lots of fun
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@Deodand Any chance you still have the Motoranalysis sim files and DXFās within reach. I must be doing something wrong, but I simply cannot get the hoverboard motor modeled.
I want to use a hub motor as a direct drive for my CNC Mill, but so am trying to work out what the turns ratio and if it is even feasible.
Out of interest, what is the minimum amount of turns you could safely use? 3 turns? 2 turns? I am hoping to get about 4000 to 5000 rpm out with a 28V supply, but I could also use a 48v supply.
Would be very greatfull if you could upload the sim files please. This is the first time I am trying this kind of thing and have so far failed miserably.
Thanks