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Problem with stripped spur gears in my 1/8 scales

Problem with stripped spur gears in my 1/8 scales

Old 06-07-2015, 06:40 PM
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Default Problem with stripped spur gears in my 1/8 scales

I have an OFNA GTP2E and a Kyosho Inferno GT2 VE. Both have RC Monster single speed conversions installed running Traxxas Revo spur gears.

I keep stripping the spurs from hard breaking. I have my brakes set at about 37% on both cars and drag breaks also around 37%. I even have even negatively curved the break graph.

It happens with or without ABS breaking. I have tried fast, mid, and slow ABS. I have tried metal spur gears which last longer but eventually wear down and strip also.

I have gone thru at least 12 Revo Spur gears in the last 5 months! It never happened with the stock OFNA and Kyosho spur gears but the cars were not as fast at the time so it was easier to stop.

Can anyone help me?!

Last edited by tc4basher; 06-08-2015 at 05:58 PM.
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Old 06-08-2015, 01:52 PM
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No one has any suggestions or insight? These stripped spurs are getting annoying and causing unessesary accidents!
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Old 06-08-2015, 02:14 PM
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Post photos of spur gears, maybe I'll give suggestions!!!
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Old 06-08-2015, 02:54 PM
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Originally Posted by tc4basher View Post
I have an OFNA GTP2E and a Kyosho Inferno GT2 VE. Both have RC Monster single speed conversions installed running Traxxas Revo spur gears.

I keep stripping the spurs from hard breaking. I have my brakes set at about 37% on both cars and drag breaks also around 37%. I even have even negatively curved the break graph.

It happens with or without ABS breaking. I have tried fast, mid, and slow ABS. I have tried metal spur gears which last longer but eventually wear down and strip also.

I have gone thru at least 12 Revo Spur gears in the last 5 months! It never appened with the stock OFNA and Kyosho spur gears. The cars were not as fast at the time so it was easier to stop from slower speeds.

Can anyone help me?!
What is the point of having drag break at 37% and max break 37%. This means the moment you release the throttle you are generally hard breaking. Without any modulation, like on/off switch....
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Old 06-08-2015, 05:23 PM
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Originally Posted by sbd View Post
What is the point of having drag break at 37% and max break 37%. This means the moment you release the throttle you are generally hard breaking. Without any modulation, like on/off switch....
The point of having drag break and max break at 37% is so I wont have to manually break much. The wear and stripping happens when I manually brake. Manually breaking if initiated hard enough causes a nasty crunching sound and its usually when it strips. The drag break engages smoothly and softly and does not cause the wear and stripping.

Here are some pics of some of the worn and broken spurs.
Attached Thumbnails Problem with stripped spur gears in my 1/8 scales-worn-integy.jpg   Problem with stripped spur gears in my 1/8 scales-worn-38.jpg   Problem with stripped spur gears in my 1/8 scales-worn-36.jpg   Problem with stripped spur gears in my 1/8 scales-broken-steel.jpg  

Last edited by tc4basher; 06-08-2015 at 06:00 PM.
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Old 06-08-2015, 06:44 PM
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how do you set the mesh of gears?
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Old 06-08-2015, 08:34 PM
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Originally Posted by Geezatec View Post
how do you set the mesh of gears?
Usually just by eye or sometimes I use a piece of paper. I always make sure theres some play between the gears. Usually about 1 mm between.
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Old 06-08-2015, 10:24 PM
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1mm backlash too much. START WITH CELOPHANE plastic wrap, if to tight double the thickness but my opinion 1mm too much. Chewing gum wrapper tin foil or double up Scotch tape is small enough.

Last edited by Geezatec; 06-08-2015 at 10:42 PM.
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Old 06-09-2015, 12:14 AM
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Originally Posted by Geezatec View Post
1mm backlash too much. START WITH CELOPHANE plastic wrap, if to tight double the thickness but my opinion 1mm too much. Chewing gum wrapper tin foil or double up Scotch tape is small enough.
Well everytime I try to mesh it up tighter than about 1mm it makes the car sound rough like the mesh is too tight. Sound tells a lot about proper mesh right?
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Old 06-09-2015, 01:11 AM
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You can get it quiet. Double a strip of scotch tape or a grocery reciept. 20lb copier paper my opinion is too much. If you want it quieter use 64 spur gear with 64 pinion, but not recommded with off road.
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Old 06-09-2015, 09:06 AM
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Originally Posted by tc4basher View Post
Well everytime I try to mesh it up tighter than about 1mm it makes the car sound rough like the mesh is too tight. Sound tells a lot about proper mesh right?
Check to make sure your motor mounts are straight. Check to make sure the teeth on the pinion aren't worn out, as worn pinions chew up spurs like nobody's business...

Considering the mesh issue, I'd rather it be noisy than strip gears constantly. I can't speak for the quality for "RC Monster" equipment, but most aftermarket upgrades are of lesser quality than their OEM counterparts. That's most likely a contributing factor as well.
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Old 06-09-2015, 09:36 AM
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Sounds like your mesh is way off, 1mm is huge. I am usually in the .1mm range. I would find the tight spot, so rotate until the gears get tight, then just enough gap to rock the gears.

If your really noisy at a good mesh, I would think that you might have gears that are not quite the same pitch. Are the pinion and spur from the same company?
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Old 06-09-2015, 10:32 AM
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I'm guessing a bent or bad layshaft. Bad or broken bearings that give under stress and allow friction.

BTW, 1mm backlash is way too much. All the strength of a gear is at the root, not the tip. Good luck.
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Old 06-09-2015, 11:34 AM
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Thanks for the suggestions guys. I will try tighter mesh and possibly some new pinion gears. I'm using Tekno mod1 pinions and a couple of traxxas mod1 pinions but I think they could possibly be worn down from using them with the steel spur that got worn down.

I dont think bent shafts is the problem because the wear and stripping happens on both cars and the kyosho is still pretty new. I've only been using it regularly for less than a week. Is there a good way to test if it is bent?
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Old 06-09-2015, 11:42 AM
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Set minimum brake in speed control equal to drag brake.
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