esk8 passion has already hit me a couple of years ago. After an oftenly modified single motor belt driven street board I got bored and wanted to DIY the next level.
First step was designing my own hub motor for a stealth street board. Some drafts and night shifts at the computer later, the design was done:
Step 5: Heart beating test (where I’m currently stuck ) and the little beast shivers like it is cold
First I thought it was this ordinary “cogging” because I tried it unsensored but the second identical motor which I haven’t modified yet runs perfectly.
Conclusion: Something went wrong during my modification Thus I need some help troubleshooting:
What could cause this shaking forward / backward moving of a brushless motor?
Milling was mainly for feather key grooves. Little task but not too easy if you have to do it on the circumference in a more or less precise angle at home with improvised machinery
I fear it might be some inaccuracy between the axis of the rotating part containing the magnets and the axis of the part with the coils…
The next days I will check this
Does the bad motor pass detection?
If it does, does it have smiliar values to the working one?
Did you run both motors to make sure they were alright before modifying them (APS are great when…well when they’re great )
obvious stuff:
Check the windings are they dented somwhere?(short circuit in the stator)
Are the magnets intact in the can?
Are the bullet connectors on properly(check for bad soldering)
Have you verified its not an ESC issue?
misalignment issue, any signs?
Maybe if it has tighter bearings it needs more current to turn over than its getting? Assuming it worked before and now doesn’t all I can guess is that or u shorted it.
With regard to detection: yes, it beeps once and after that it trys to turn on throttle input.
Unfortunately I didn’t test it before modifying it. But it is my third APS motor and the other two identical models (one with similar 100kV, one with 130kV) work perfectly fine on the same ESC.
I had to squeeze the wires through a small groove, maybe I squeezed to much:
Some ambiguity here. What motor controller are you using? Sounds like something other than a VESC/Vesc-derivative?
You can try testing your sensors with a multimeter, as well as the phase wires themselves.
Many other BLDC motor controllers will only run sensored if the sensors are correctly phased. Try swapping pairs of hall or phase wires (there are twelve possible combos between the two, and only two will likely work).
My go to way for testing motors is to measure the resistance between the 3 phases. The resistance should be equal for all 3 windings. You could also compare them to the other motor were you are sure it runs fine.
If your multimeter can do that you can also check and compare the inductivity.
I am using this APS, but the unsensored version. It is working perfectly for years now @8S and max. 60A for the motor. Braking works fine and even starting in very low speed works smoothly.
As the other identical motor works without issues, I would exclude the ESC as error source. Swapping phase wires didn’t solve it
Hopefully tomorrow I’ll have time to measure the resistance of the phase wires and check for obvious damages of the wires insight.
Getting an accurate phase resistance without an expensive multimeter isn’t possible but precise inductance numbers are possible and just as good for telling if the motor is shorted but you have to test with the rotor off. and the magnets will alter the reading greatly.
Rewinding motors here you come. Which will be cool and u can compare to the stock performance
Rewinding is taking the windings off the iron cores and putting on new windings. A ton of work tbh, and has to be done precisely. If there is room for more copper, you can actually improve the motor’s power, either by having more rotations of the same wire, or a thicker gauge wire.
Does it work, if you start it by hand and than you give throttle? Since you are saying you have the unsensored version of the ESC, it seems very likely to me that it will only work this way.
Unsensored controllers, specially ones derived from RC airplane designs like that one, have issues with inertia.
Since you significantly increased the spinning mass by adding a tire, you’ve also significantly increased the moment of inertia, which can make controllers like that simply fail to start.
I second the idea of trying to give it a spin by hand to get it moving before applying throttle.
If that doesn’t work, I highly recommend upgrading to a VESC or derivative thereof.
If you want a good VESC for cheap have a look at the cheap focer 2. There’s a group buy organised by @ doomy and you can get a cheap forcer 2 for 30€ if you are good at soldering. I recommend paying extra and have the DRV and the SMD stuff soldered. The rest is not hard to do at all. Even if you can’t solder at all, doomy can do it all for you for a little bit of extra money.
:
) and the little beast shivers like it is cold 
Thus I need some help troubleshooting:
)
