Gruber
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M.L. Toys
KidsWheels
Gruber
HobbyMasters
M.L. Toys
KidsWheels
HobbyMasters M.L. Toys
Gruber
KidsWheels
Need new motors? Grind a gearbox? Adding teeth to a pinion?
By Glorydays
#147093
Sup Guys!

I recently posted a video of my Son's "Birthday Dune Racer" we upgraded to 24 volts with Banebots 775 18 volt motors. Today he put it through the paces.

Long steep grassy hills, dirt trails and a lot of skid-brake drifting. Failure was on the long steep grassy hill, actually coming down at a stop, not going up. And we had failure in the gear box .....and it was the last place I thought a failure would occur . The final Drive Gear! Not the part that mesh's with the hub but one of the heavy strong teeth.

1st gear looked perfect, as did 2nd and 3rd, but on closer inspection this is what I found.

gear.jpg

There was an air pocket during molding that seems to have perpetuated the breakage of this pretty tough looking gear.
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By lexx0116
#147111
Did your son shift gear a lot? like forward then reverse right away and such? Seem like you need final output gear replace (might as well go with the orange color since it is stronger I think). I'm the process of converting my sons' dune racers to 18v and along side, I am getitng some spare parts as well (buying cheap pw off CL for safe keeping). If you can search through CL and FB market place for cheap pw, you better off getting those than buy just the parts new online through ebay or other means. For 24v conversion, did you have any ESC or speed throttling on yours?
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By Hammer-fm
#147114
Thanks for posting that Glorydays -- looks like they still have some occasional QA problems at the factory.

I too have been stockpiling spare gears and gearboxes anytime I can find a decent deal... I like to push the limits a bit much at times, though I also find they often break without any obvious stress. Having extra gears around means I don't feel quite so bad when something goes 8-)
By Glorydays
#147150
lexx0116 wrote:Did your son shift gear a lot? like forward then reverse right away and such? Seem like you need final output gear replace (might as well go with the orange color since it is stronger I think). I'm the process of converting my sons' dune racers to 18v and along side, I am getitng some spare parts as well (buying cheap pw off CL for safe keeping). If you can search through CL and FB market place for cheap pw, you better off getting those than buy just the parts new online through ebay or other means. For 24v conversion, did you have any ESC or speed throttling on yours?


No he's pretty experienced and careful not to shift between forward and reverse without a full stop. If he does he looks at me like a puppy that just peed on the carpet :lol: so he knows.

And no didn't have any ESC, I'm good mechanically and creatively but I am no where near as electrically inclined as many of the guys on this forum. The things I've done to his vehicles were fun but a little of a test for me with no wiring experience, but really not that hard. I think the gear failure was due to the air pocket posted in the picture, however if we keep breaking parts I may try a ESC with a separate break pedal.

We have run his Lightning McQueen (it was his sister's first) with the same gear box for 6 years now. It "FLY'S" at 18volts,
with HPI GT 550 motors, and still runs great.

I think it can be hit or miss with the tolerances of these gearbox's, they are toys and as you replace inferior parts, hopefully you may get better quality controlled parts that will last a good amount of time.
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