Trouble shooting a motor

[flynow1]

Without hooking up an ESC and batteries is there a way to check the resistance between the wiring legs and get a good idea whether the motor is good. I'm assuming that the resistance should be low and all legs should be the same but we know what happens when we assume. I have a Fluke VOM so the reading will be accurate. The motor I’m looking at is a 3650 - 1800
Thx

[sailr]

You can get a general idea that way. The three legs should be the same resistance. But without knowing the I.R. of the motor when new, it's hard to say if your readings will have any relevance. One of the other big reasons for motors to get weak is the magnets losing their magnetism because the motor has been run too hot. Not sure how you would check those magnets to see if they are still as strong as when new. Maybe somebody else can shed some light on that.

[flynow1]

Good point.
thx

[siberianhusky]

Gaussmeter, measure the magnetic flux, once again you would need an initial value or range, not sure if you would need to take the magnets out of the motor though, the only ones I've seen are for guitar pickups. Both magnetic poles are exposed in most of those.

[m4a1usr]

Without hooking up an ESC and batteries is there a way to check the resistance between the wiring legs and get a good idea whether the motor is good. I'm assuming that the resistance should be low and all legs should be the same but we know what happens when we assume. I have a Fluke VOM so the reading will be accurate. The motor I’m looking at is a 3650 - 1800
Thx

Depends on the meter you own. Since resistance is extremely low in motor windings I doubt most own a meter capable of measuring the actual winding resistance. You would need something along the lines of a Fluke 8808A which is a 4 wire measurement device. At extreme low measurements you need something very precise. A typical 2 wire VMM/DMM is not going to do it. If you have access to a Megger Meter it can be made to work but again. Its not going to be a $100 device. Your going to need a meter that costs around $500 plus to do the job.

John

[sailr]

the meter I had to buy to get the IR of my new aircraft outrunners a few years ago cost me $380! I still have it for some reason. Haha. No need for it after the project was completed.

[flynow1]

Thanks for the reply. Seems like the answers I'm getting is maybe, sort of, could be etc. It appears that even with additional measuring tools that a definitive result is up for grabs. I think I'll just replace the motor with new. That seems to be more economical anyway.
Thanks again

[sailr]

Yep...new motor is definitely the cheapest way to go!