I changed the bearings, washer and lock ring (purchased the recommended parts from McMaster and Boca Bearings) and that FLIPPIN crunching noise is still there! I ran a bench test on the BL's for 10 min at 1/4 throttle and don't see a significant difference in temps...motor in question is on boom 8. I gave it a thorough visual and blew it out with pressurized air before re-assembling it (it was clean when I took it apart). I checked everywhere on the boom and landing gear for a potential culprit (loose screw) and found nothing. Is that engine junk or is that just the noise it makes and I'll have to live with it. My worst fear is a failure and possibly hurting someone. Any thoughts...same experiences? I'm stumped. Thanks! Original post and video: http://forum.freeflysystems.com/index.php?threads/crunchy-motor-noise.838/#post-10629
If the motor was involved in a bad landing with a prop strike there is a chance that the motor shaft is bent. Something you might try is to take the motor off of the arm, but keep the CS mounting plate on it. Mount it in a vice or type of hold down device and run it up. If the noise goes away it is in the frame. Still there, would suspect bent shaft.
I did flip it a few weeks ago, not hard, it just bounced and flipped over (in the grass) during a rough landing. That very well could be the problem. I'll check it out. Thanks.
Travis: Check this out: http://forum.freeflysystems.com/index.php?threads/replacing-the-bearings-on-a-qc-3328-motor.563/ Let me know if it doesn't answer your question. Andy.