Just ordered a replacement motor for my new (to me) FMS P-51 Snoot's Sniper. I'm not sure how long the previous owner had it, or how many flights he put on it, but on my second battery yesterday (the first two batteries I put through it since purchase) I noticed an odd, high-pitched grinding sound at higher power settings. I brought it in, landed, looked at it, and put her back up in the air for the remaining 90 seconds of battery. Landed. Came home.
That evening, I turn the prop and I hear a grinding sound. Take off the spinner and prop down to bare shaft. Turn the shaft and the grinding is coming from the motor itself. Something is making contact. Keep in mind, this is the stock motor (FMS 4250-KV540). So I logged on and ordered a replacement motor.
Decided to sit down and tear into the motor to better understand how they're built and what might be the problem. Turns out, several (6 to 8) of the magnets weren't glued down. They would simply slide up and down...none turned sideways or anything crazy. Some local folks said to try re-gluing the loose magnets and see if that was the problem. I still couldn't really tell what was actually grinding. So after watching some You Tube videos, I gave it a shot, made matters worse, smeared glue everywhere, and just tossed the motor in the trash.
Any thoughts on this? Is this a typical issue? Everything is stock on the airplane and I'm using a 4S 3000mAh 35C battery.
(Photos attached)
Thanks in advance!
That evening, I turn the prop and I hear a grinding sound. Take off the spinner and prop down to bare shaft. Turn the shaft and the grinding is coming from the motor itself. Something is making contact. Keep in mind, this is the stock motor (FMS 4250-KV540). So I logged on and ordered a replacement motor.
Decided to sit down and tear into the motor to better understand how they're built and what might be the problem. Turns out, several (6 to 8) of the magnets weren't glued down. They would simply slide up and down...none turned sideways or anything crazy. Some local folks said to try re-gluing the loose magnets and see if that was the problem. I still couldn't really tell what was actually grinding. So after watching some You Tube videos, I gave it a shot, made matters worse, smeared glue everywhere, and just tossed the motor in the trash.
Any thoughts on this? Is this a typical issue? Everything is stock on the airplane and I'm using a 4S 3000mAh 35C battery.
(Photos attached)
Thanks in advance!
Comment