MMM Killed my 8XL

[bruce750i]

I just thought something was in the drive train making a clicking noise, so I tried reverse (sometimes that clears the it out) nope still clicking. So I drove it back to me to investigate the clicking. MMM 6s power had popped the end bell, and split the magnet. The motor was at 195f and the rotor was just slapping around in the windings when I was driving it. But the MMM just keep on feeding the amps. It ran for about 30 min run time total mostly street then I hit the dirt for some rooster tails and over rpm it a little by 20000

[Pdelcast]

Originally Posted by bruce750i

I just thought something was in the drive train making a clicking noise, so I tried reverse (sometimes that clears the it out) nope still clicking. So I drove it back to me to investigate the clicking. MMM 6s power had popped the end bell, and split the magnet. The motor was at 195f and the rotor was just slapping around in the windings when I was driving it. But the MMM just keep on feeding the amps. It ran for about 30 min run time total mostly street then I hit the dirt for some rooster tails and over rpm it a little by 20000

Lucky you didn't kill the MMM too. IF the motor was that hot, you were a little over geared to run for that long...

[lincpimp]

Plus 6s is a bit much for the 8xl. The high rpms may have killed the magnet. At least it was a cheap motor.

you didnt have a clamp? and 195 wasnt to bad considering, my bet is the over rpm

[bruce750i]

Yes hot but I thought some of that was due to the motor failure and me still driving it like 30 seconds more. emaxx 3905 geared 22/72. 30 minutes total over two days not all at once.

[bruce750i]

No clamp on it. It had popeed the front off twice before due to wreaks.

heres a link to my dead 8XL
http://i300.photobucket.com/albums/n...d/DSC03207.jpg

[bl-is-future]

Originally Posted by lincpimp

Plus 6s is a bit much for the 8xl. The high rpms may have killed the magnet. At least it was a cheap motor.

Yep 8xl is only rated for 40000 rpm and at 6s it is going about 45000

[sleebus.jones]

One thing I've learned from testing motors is that the second anything seems amiss, I get off the throttle and walk over to the r/c. I've spun off one endbell and separated two rotors. Stopping and checking has saved me ESCs I know. You certainly don't want the magnet in there flopping around and shorting the windings. Zzzzzzt!

[bruce750i]

It was time to put the ol work horse to out to pasture, just glad it didn't blow my MMM.

[DRIFT_BUGGY]

These motors arent meant to be run over 40 000rpm or even around that mark, running a 8xl on 6s would make it around 43 000rpm so battery probable killed the motor

[bruce750i]

Okay maybe not 20000 rpm over but I agree. I didn't give max Rpms much consideration. the MMM is awsome just came with a little bad r/c mojo for me.

[luvsrc]

Originally Posted by bruce750i

Okay maybe not 20000 rpm over but I agree. I didn't give max Rpms much consideration. the MMM is awsome just came with a little bad r/c mojo for me.

My suggetion is for you to get a 10XL and gear it according to speed you want to be on the safe side or get a better quality motors like the NEUs if you have more money to burn like Neu 1515 2.5 d as my personal choice on 6s lipo

yea those things dont last to long unless you epoxy the front endbell, good thing your mmm is still good

[sleebus.jones]

Yep, I have a 10XL and it works great in my emaxx.