Help with some apparent motor damage

[mrwis@yahoo.com]

Guys,

Returned from FFest 2016 with two planes that went down after I lost radio contact. I'm in the process of repairing them but know little to nothing about looking at the internals of the motor.

As you can see from the image one motor with the most damage has the casing pushed outwards, the other motor on the plane in the image might have shifted a bit. I did run that one up and did spin pretty good. Maybe a bit worse then new.

So.... I'm looking for suggestions. I know you can get replacement bearings for these Suppos. I'm assuming you take the lock ring off the back of the motor and your in (?) From what I can tell the shafts to not appear to be bent. Will I be able to reposition the casing and go with it? Do I need to replace the bearings and how would I know that? Is it not a concern at all? Or do they need to just be scraped?

Thanks in advance.

UPDATED: OK stupid me.... In my rush to get this plane completed for FFest I made the firewall and forgot to drill out the center hole for the shaft so it was pressed up against the firewall therefore pushing the casing out. Once I unscrewed the motor from the firewall it went back into position. Funny thing was that the plane flew fine for 3 flights before we lost radio connection. I'll drill the hole out and put it back together. I did run it up and it seems to run fine. Not exactly what a bad bearing would look or sound like but I think this one is fine.

I'd delete this post but in this forum it looks like I don't have that option.

 

[cranialrectosis]

Naw don't delete it. It's a cautionary tale about getting in a hurry and forgetting to drill out the center hole for the firewall!

Thanks for the lesson.

 

[Craftydan]

um . . . Are you SURRRRRE everything is OK?

Most motors I've played with have pretty tight tolerance between the bell and stator, and a retaining clip (usually a C or E clip) between the motor shaft and rear bearing holds the motor in place.

The reason I mention this is the magnets will hold the bell in place, but a tractor prop is pulling it apart. I've seen on several occasions where the clip failed and in a strong throttle punch, the bell separated from the stator mid-flight.

So for that much play, I'm wondering if either you've popped off the clip (begging for the motor to fly apart) or the rear bearing has been damaged by over-pre-loading it. It's also possible the bell has slipped on the motor shaft so there is play between the clip and bearing, but the lack of a hole in the firewall wouldn't have caused that. Might want to take a closer look before trusting that motor.