What the actual F**K just happened?

This just happened:

So I finished my board about two weeks ago and decided to not take it on the busy streets before I was feeling really comfortable with it and had tested it all the way through. So today it did a little more testing. A nice evening ride on my new awesome board and I finally felt comfortable enough to try and go fullspeed. I was afraid before because I did not have any longboard experience before that. I went fullspeed (43km/h btw.) and even raced the board uphill to test its limits. And guess what? It was awesome. Everything went totatlly fine. So after about 25min I decided to ride back home ( still 73% battery left). I was not going fast (on a flat street) ( I think about 20 km/h), when it suddendly the motor kind of blocked. I do not know if it completely blocked. It caught me off guard (enjoying the evening breeze) and it threw me of the board like a rocket. I managed to pull off a proper landing and all I got was a little scratch on my back, but imagine that happening on a normal street with somebody behind me. Anything that would have been driving behind me would have just gotten straight over me (aka --> dead). So I am really glad that I am still in testing phase and after that will be for a long while. However after it threw me off I immediatly looked at the board and found that the turning the motor by hand was really difficult. Then I tried pushing the board like a normal longobard, but it was really hard. The motor just kind of blocked ( not totally but rotating was a lot harder). So the rest of the way I rode the board home ( It was working totally fine exept the motor was turning harder and don’t worry I didnt go faster than 5 or 6km/h) Btw. I was about 5min away from home. When I took another look at the motor at home I found that I was back to normal again (btw. directly after the accident I turned the board and the remote off waited a little and then turned it on again, but nothing changed). And by normal I mean you could easily push the board or rotate the motor by hand with almost no resistance, like it should be. Has anyone any Ideas what happend? Maybe you @Namasaki ( we have a smilar build) or you @Jinra ( you have loads of experience I think) Maybe I pushed it to hard the minutes before? But I would say it had about 30sec rest before I drove again after coming back downhill. I think the total ride was about 20min. Could the vesc have overheated (because it is covered up), but that would not explain the motor behavior would it?

My build: Alien 6374 200KV Bestech BMS 10S lipo battery Maytech VESC

Stuff like this most often is because of your VESC settings. Please post the screenshots.

Along with your VESC settings, tell us what remote you were using as well, and post the VESC settings for that too.

alright just a sec

Could be your remote/receiver, sending a full brake signal when loosing connection to the hand held radio. What remote do you use? Any remote used on a board should never ever send a brake signal when loosing connection. Unfortunately some do, especially some models designed for esk8. I once had a motor that had a bad contact somewhere in the windings. Caused the same issue. Full brake at speed, randomly after being O.K. for days.

First check what happens when you switch of your remote. Does the board brake?


but that does not explain why the motor was so hard to rotate when the board was turned off

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If it happens when the board is completely off, it’s probably your phase wires shorting. You have to make sure no two phase wires on your motor are touching or it’ll be hard to turn even when off.

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here you go @Jinra @wmj259

I use the APS remote and their receiver.

@Jinra nope. I dont think thats the case.

It must be internally shorting in the motor itself. Try wiggling the motor cables around in different positions with it off and see if the motor is hard to turn at any point.

If the enamel coating on the phase wires (inside the motor) are worn or insufficient it can be shorting.

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the motor once received a little bump. ( more like scratiching the street a little). But that was two weeks ago.

whatever I do with the motor does not change anything. Also it kind of felt like that the resistance was getting less over time.

If you want to see what I’m talking about. disconnect your phase wires and touch any two of them together and try turning your motor. Does that feel similar to how it was when your board cut out?

Yeah it was kind of like that. Question is why did it last for a couple of minutes and then suddenly was gone. And has not come back yet. I guess what you are saying is I should prepare to buy a new motor

Also, If those wires thouch or anything like that inside of the motor. You could still ride it? Because I could.

It could have shorted in a certain position, then it moved out of that position and was no longer shorting. That’s why I asked you to wiggle the phase wires around as much as possible to see if you can recreate it.

Alternatively, it could be shorting with the VESC. It is a Maytech VESC so I wouldn’t entirely trust it in terms of reliability.

This is absolutely possible, it happened to me when I was riding the board around without the wires plugged in to test the motor angle. The two leads bumped together and the board stopped instantly lol didn’t expect it at all

So the vesc could be shorting as if I let those motor wires touch itself? Is there a way to narrow down, whether it is the motors fault or the vescs fault?

You just gotta test, no one on this forum will be able to say for sure.

but how do you suggest? I cannot recreate the scenario of driving on the street in my garrage.

Your integrator limit and bemf coupling parameters seem kind of low, could you post detection results as well.