helical gears and my new Scorpion motor!

[ryem3]

So, I'm flying my pro with a brand new -8 V2 Scorpion installed, maybe 6 flights now. First, it has some weird issue reaching peak RPM. Then I take off, give it a pitch pump and it makes some very weird noise. Try again, same thing. I bring it down and look at the motor. The shaft has moved up about 5 mm, moving the pinion almost up to the grub screw .

So, I figure the motor is blown. I've never rebuilt a Scorpion, so I don't know the insides very well. I see there is a circlip on the top, but can't tell about the bottom. Then I notice there is a grub screw for the shaft. I see two holes, but only one screw. I check the screw and it is totally loose! Looking at it, there is no loctite on it whatsoever. I realize I happened to find another grub screw about the time I added the motor, but couldn't find what it was for. I guess I found what it was for! Pushed the shaft down into the bottom piece and secured with both LOCTITED grub screws! Looks like I'm good to go again.

As others have said, no doubt the helical gears add another dimension of force on a motor, especially when you pull high amps. Also, worthwhile double checking those screws on new Scorpion motors. This is only my second, but I had no idea I would need to check anything to fly with it.