Death of a motor

[jkflow]

How to kill a motor:
a) Have tons of fun jumping
b) don't bother checking stuff between sessions
c) ..let'er rip!
and that leads to:
d) Order new one..Jenny to the rescue.

From what I can tell, the rear can came loose. I noticed one screw was missing while the other ripped through the can itself. Downhioll from there, the kevlar ate itself up rubbing on the motor and eventually the magnets exploded. ...Amen..

 

[SrC]

Running the motor very hot (200+ deg.F) and/or worn out unlubed/unmaintained/unreplaced bearings causes this.
Been there once. But I learned from that experience.
Checking for bearing slop due to wear and watching your gearing and temps usually promotes better durability of the Armature.
The motor as a whole is just a disposable throw-away at some point.
Your actual mileage will vary.

 

[Crewchief227]

Yep, that's a grenaded motor if I ever seen one. So long as you check the bearings (I just spin the caps with bearings in them on the removed motor shaft), clean out dust debris with an air compressor, and put them back together shimmed right, they should last quite awhile. Brushless motors are hard to kill, most die from heat that causes the rotor magnets to lose the epoxy & kevlar binding them to the shaft, and centrifugal force does the rest. Other factors include overgearing which leads to excessive amp draw (that can kill your esc, trust me), which can melt you solder on your bullets while you bash, and you're left with cold solder joints, and again more amps, more heat, then boom!

 

[jkflow]

Can is still ok but 2 screw holes ripped out where the back shell mounts. Front bearing was an upgraded one from Jim's and its toast, my guess, when it desintegrated at full blast, it got damaged. Back bearing seems fine as the shaft ripped out. I'll just keep all of this as shelve queen to tell a story. I already have a 'spare' can and simply not worth my time but it does make for a good show and tell.

 

[JvG]

Not to mention that smell from a burnt motor

Does heat also reduce the magnetism?
I just replaced my motor after 3 years and it feels stronger somehow.

 

[jkflow]

It does, but not at the temperatures that a motor will see. Higher temps will reduce it but it really depends on the material. We are talking glowing not just hot to the touch and again it will reduce magnetism.

 

[Vr6woes]

My original motor went the same way. User error, been running in very dusty conditions with total lack of maintenance, you live and learn.
Mine looked the same as that only also full of fine dusty paste. Amazed it lived as long as it did. Landed a large jump and the car just threw on full anchors.
Actually have a feeling the new one is on the way out as it is now very easy to spin. Wheres when new it you could feel like magnetic notches as it turned, if that makes sense.

 

[jkflow]

Easy spin is not a good sign, loss of magnetism somehow? Definitely not normal.

I now seal the extra mounting holes either with tape or silicon, a dab will do. Dust still gets through the bearings and I intend to clean this one now every 20 packs or so, pending conditions.