motor pinion.why so long.

[TSK]

i am new to the zoom and just got a shaft drive version.
i thought the motor pinion was long (9mm)to reach both sides of tail drive gear.
but when i have gone to set mesh it will not touch both sides completly.
dia of tail gear is over 10mm,pinion 9mm.
so why not use a shorter pinion.or am i missing something really easy here.

[BlakeMcBrayer]

The pinion should ONLY mesh with the bottom for the tail drive gear. You will get an instant striped tail drive gear if you have it far enough up to touch the top and bottom of the gear. You'll have enough trouble try to keep the gears together without striping the first one yourself.

[clear4takeoff]

I thought it meshes on the low side with the main gear, then on the TOP of the tail drive gear. There is only a little bit of tolerance to how far the pinion must be pushed on. You try to slide it down far enough to get it 100% in contact with the main drive gear, but still in 100% contact with the top of the tail drive ring gear, without "crashing" on the low side of the ring gear. I'm now only flying a V2 (belt) but I put many flights on three Shogun/Zoom V1s that I built. The nice thing about the shafty is it's so EASY to set backlash!

[dodgey]

Originally Posted by TSK

i am new to the zoom and just got a shaft drive version.
i thought the motor pinion was long (9mm)to reach both sides of tail drive gear.
but when i have gone to set mesh it will not touch both sides completly.
dia of tail gear is over 10mm,pinion 9mm.
so why not use a shorter pinion.or am i missing something really easy here.

hehe - have a little think about what would happen with the pinion contacting the top and bottom of the tail drive gear....

[capebob]

The lower part of the pinion engages the main gear and the upper part of the pinion engages the tail rotor drive gear. The pinion has to be high enough on the motor shaft to avoid engaging the tail rotor drive gear at the bottom. You can use a short pinion and engage the main and tail rotor gear at the same place but the tail rotor will turn backward. To remedy this you take the gear that's on the tail rotor shaft and reverse it. The stock position is that the drive gear is on the left side of the tail rotor gear case and has to be reversed so that the drive gear is on the right side of the tail case.

Whatever you do, the tail rotor drive gear that engages the pinion won't last very long. Keep a good supply on hand.

Bob

[wren1702]

I have a Revo CP which I think is a knockoff of the Zoom/Shogun and had truly awful luck with the Crown gear until...............I saw that when I pressed the pinion on the shaft, it went on a little crooked. Removed it and pressed a new one on very carefully and went from a gear every 2 or 3 flights to flying the same gear for 30 flights or more with no problems! I was was knocking teeth off of the tail drive bevel gear whille working through some tail wag problems, got those solved and the tail gear problems went away as well. All that being said......I still have a belt drive kit on backorder!