Motor stuttering when I try to accelerate - where's my problem?

Torqueboards has a nice sensored one of the same kv and size. @JLabs (buildkitboards) has a 208kv version as well which I like since it’s sealed. @Kaly has a 230kv version of Jlabs motor I’m using.

Lastly I have an extra 5065 200kv if you need one locally.

Haha I literally just did that, and it does provide resistance for all combinations.

Hm, weird, you could try taking it all apart and visually inspecting the wiring, stator, and magnets to see if anything’s weird.

I might just have to do that at some point soon. And I may hit you up for that extra motor you have. Maybe I could come by SF someday this week and see if your motor works with my FOCbox/board setup? I’d like to try another motor on the board first before I get a new one just so I know that the motor I have doesn’t work.

Sure, I thought you lived by the Marina though

I’m a student at UC Berkeley :slight_smile: I’m living in south berkeley right now.

Cool, just PM me whenever you want to drop by.

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Thank you so much for your help!!

Did you resolder new cable on the FocBox… if so make sure you didn’t knock or short circuit any or the resistor near by.

How do I make sure that didn’t happen when I re-soldered the bullet connectors?

He meant if you soldered new phase wires to the vesc circuit board not new connectors to the wires.

If you soldered new connectors to the phase wires, then you might have got a cold solder joint. Especially if you used a low temp soldering pencil.

Example: I use either a 300 watt soldering gun or a butane torch. And put flux inside the connector and pre-tint the wire.

Hey @Nicolai - apologies if this has already been suggested as I’ve only had time to skim read the thread but I’ve watched your videos and the symptoms are identical to a problem I had with the R-SPEC motor too which I’ve now managed to correct - see my thread for detailed info

The cause was a shorted phase wire where the shrink tubing had become exposed over time and 2 phase wires touched creating this jerky confused effect. The solution was to remove the stator, solder the frayed wires (not sure if this was totally necessary as it was only a couple of loose threads) and shrink wrap up both exposed phase wires so they couldn’t touch and hey presto - no more jerky only smooth goodness!

I would love it if this helps, but you may already have checked this?

!!! Dude this is huge, thanks so much!! I was gonna take apart my R-spec today to see what the matter was, your thread is hugely helpful. I’ll let you guys know how it goes! Thank you @DanSkates!

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:grin: Hey my pleasure - I’m pretty sure that you’ll find that to be the problem - I reckon the sleeving must just ride up over time eventually exposing the phase wires and if 2 touch that’s when the motor gets confused.

Give me a shout if you have any questions and I’ll try to help. Getting the stator off is fairly easy once you get the centre axle out but it does take a little bit of force :muscle: One word of advice too once you lift the phase wires out - remember exactly how they lay before, it sounds stupid but I didn’t do this and whilst they went back in fine and were perfectly secure 1 must have done an extra half lap as it was shorter than the rest! Actually they were all slightly different lengths so I had to trim them all and refit the bullet connectors :smile:

Hi, I am having a similar issue of cogging, however it only cogs under mid to heavy throttle. It is still ride-able if I really baby it, yet it will cog if I try to accelerate at all. Braking is fine. do you think it could be the phase wires? I’d just like opinions on it before I take apart the motor.

I think I may have FINALLY found my problem!!! There’s clearly a thin strip of phase wire that’s been broken through the motor use. @DanSkates there’s one final step that I need some guidance with, and that’s how to remove the last blue metal housing part of the motor so that I can re-solder and patch the broken wire. Can you walk me through how to do it? Thanks everyone so much for the help!

It is glued so with enough force you should be able to take it off. Maybe try some gentle taps on the inside where the bearings are (not on the bearings themselves!) might get the motor apart. I have not done this before but I have seen people do it when rewinding motors. Be sure to protect the wires that are not broken right now so that you dont do more damage. And do not use heat that would melt the enamel on the wire and short the motor completely.

Time for a new motor…

Well that might be an option :smiley: If you are going to buy a new one I would try to fix this one if I were you, you can not make it worse

He could make it short out and break his Vesc though. shorted phase wires are known to burn up DRV chips. In my opinion, once the windings get broken it’s time to get a new one.