Limitless Why is my pinion gear loose on my engine shaft?

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DavefromCA

Active Member
Messages
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Location
Santa Barbara, CA
Arrma RC's
  1. Granite
  2. Typhon 3s
  3. Vendetta
As I was about to mount my engine into my Limitless, I noticed the pinion is not snug on the shaft. I just checked my amazon order, and the pinion is 5mm, and the engine is a 2050kv spektrum that takes 5mm shafts.

One thing that may have happened, this engine was in a 6s Vendetta, one of the screws came loose on my Hot Racing Spur Gear and the whole set up took a beating. The engine seemed okay, but maybe the shaft got hammered on?

If the shaft is ruined, is there any chance of saving the engine? The pinion gear is new.

EDIT Just tried another pinion, also loose

IMG_2139.jpg
 
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In my experience they don’t fit “snugly” like you mention. Did you tighten down your grub screw though? With blue Loctite? The grub screw should keep the pinion in the proper orientation on the shaft and help it seat correctly.
 
I have not tightened it on. I have changed many 3s pinions, and while I wouldn't describe them as having tight tolerances, this one is just plain loose. Like I am surprised how much I can move it.
 
They will be loose until you tighten the grub screw down. Highly suggested to use blue loctite as well to keep it from coming off.
 
My recommendation is to install the pinion and set your gear mesh. Once everything is in place spin the spur gear and look for loose and tight spots. Nothing is perfect so as long as the gear mesh is relatively consistent your good. If there is a big difference then your pinion has issues.
 
My eyes are not that good but that d shaft on the motor looks distorted and twisted. I am not on edible right now either.
 
I think you guys are right about the shaft. If that shift is distorted, is there any way to save the motor or just spend the $40 for a new one?
 
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I think you guys are right about the shaft. If that shift is distorted, is there any way to save the motor or just spend the $40 but for a new one?
Being the cheap sob I am, I would take a dremel and try cutting that off even. Not sure that would work as it might throw off balance and cause inner bearings to wear out prematurely. Someone with intelligence will chime in shortly.
 
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