Loose Pinion on Park 370 BM

[zen]

The pinion has loosened on the output shaft of the brushless motor in my Blade CP Pro. The small gear sticks and doesn't spin freely right next to the can and at the end of the output shaft, but in the center of the shaft it spins freely.

I am concerned that it has caused some wear on the shaft as well as the hole in the brass pinion itself. One thought is to clean the gear and the shaft and solder the pinion back on. I would use green loctite but am afraid it won't hold because of the play. The pinion is no longer an interference fit.

Does anyone have any ideas or suggestions? Similar stories?

Thanks—

Glen

[haf4046]

I have used solder on the inside of the pinion hole in a pinch to keep me flying before, but I think you need to get a new pinion ASAP. If you're using the eflite brass pinions they are only $2 at the LHS, thats what Im using on my CPP with the BL 370 motor.

[carlo_the_wonder_frog]

Pick up a pinion with a small grub screw, grind a small flat spot at the right point on the motor shaft and tighten the pinion down so that the grub screw is tightened down over that flat spot. Unfortunately the E-Flite pinions are friction fit and pressed on, check some of the online sites for the correct pinion size with a grub screw . I think that the HDX300 heli has those types of pinions and they are the correct pitch to use for the CP gear.

[zen]

carlo— I will look for HDX pinions. Thanks. The E-flite gear seems too small in its construction to last very long. Just isn't enough 'meat' in the walls around the hole to stand up to the stress involved.

The image below shows the relative size of the hole in a new and the used pinion gears.

[haf4046]

FYI here is a link to a pinion with grub screw, it is from the same line as the 10t used by John Adams
on his CP Pro.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000179312&I=LXBGE4&P=K

[zen]

FYI here is a link to a pinion with grub screw, it is from the same line as the 10t used by John Adams
on his CP Pro.

http://www3.towerhobbies.com/cgi-bin/wti0001p?&W=000179312&I=LXBGE4&P=K

Very interesting. It is a pinion for an RC car. I just pressed on another brass E-flite pinion (liberally wet with green loctite) but maybe I'll order one of these for next time.

[haf4046]

Yes it is from a car, but the important thing is that it has the same .5 pitch module as the Eflite gears (and the same as Trex and a lot of other popular heli's)