striping spur gears

[rcdave]

I started hearing a weird noise from the car, and found it was a missing tooth. As I kept using the car, I lost a couple more teeth.
Finally all the teeth are stripped on the spur.

I heard somewhere that there is a fix that you can do involving a couple of extra ball bearings.

I think that mabye the complete stripping was maybe from the motor moving, but not the destroying of one or two teeth here or there.

Help.

To replace the spur gear, I think I just have to remove the rear gearbox, and not the front. Is this correct.

Thanks in advance.

**** By the way I cracked one of the rims in 2 places, can you use 2 part epoxy like you use to hold the propellor shaft together or do I have to boil the tire in water to remove it from the rim, and buy a new set of rims. *******

[bigboss]

Hi Rcdave
Stripping the spur almost always begins with the motor moving out of position (toward the front & downward) the angle of the pinion gear wears the spur gear in a hurry & broken teeth are the result. Once a tooth is gone the next one to go is very fast indeed. The only way to avoid this is to replace the Burton head motor clamp screw with a cap head (2.5 mm Allen driver) screw that is longer, this lets you use more force to tighten the clamp.
Also you will need to check the motor position in the clamp after every run (just to make sure).
The spur gear is removed by undoing the slipper nut, so it will come off the shaft toward the front gearbox but the motor mount assembly gets in the way, so actually you have to open the front gearbox top as well as the rear. It's easier to work if the whole shaft is out of the chasis, if you have not looked at the state of the crown & pinion (inside the diff) since you have built the car, than this is a good time as any to do it.
Now for the rims, did you crack the rim itself or just Chip the edge of it?
I have chipped all of my rims front & rear on the edges but only cracked one of the fronts, but it was a bad one & I decided not to try and fix it, so I can't help you with what type of glue works or not, sorry.
hope this helps

[chris burgess]

you also need to check that the spur is actually the correct one. weird i know, but if you look at the new 73tooth spur, against the old 73 tooth spur you will see what I mean....one of them has to many teeth for the diameter of the spur.

if that sounds wrong, please help me out here northy, as i have partaken in a little alcoholic drink. i know what i want to say, but typing is slow, and thoughts are mumbled!

[pro4nut]

You don't need to take off the front gear box top.

Take off the rear top and lift the shaft up and pull backwards job done, should save about 10 to 20 minutes

[rcdave]

thanks for all the help

I split the rim in 2 places almost right beside the other one. Guess I better replace it.
Hopefully boiling it in hot water will remove the glue enough to save the tire and the foam.

[restimax]

ideal would be to be able to mount to the back the motor mount disck!
I use the long screw and key and tightening strongly I do not resolve