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6 gears

Posted: Wed Oct 23, 2019 5:18 am
by eugine
Hello all.

I am building an RC10 Runner for vintage local racing on a dirt track.

We usually use 13.5T brushless motors but my RC10 is a six gears (so no slipper).

My question is do you know if the 6 gears will handle the 13.5T with timing and a 120A ESC?

If no, is there a way to install a slipper or must I upgrade to stealth? They're rare and almost expensive as a complete dirt car on Ebay...

Re: 6 gears

Posted: Wed Oct 23, 2019 9:00 am
by jwscab
13.t motor is probably about as hot as an old 12t brushed motor. Lots of guys would run the 6 gear back then with low turn winds. It should survive OK, the diff at some point will slip and the diff balls could flat spot. That would probably be about the extend of the failure. People have also stripped the idler gears, so having a spare set or two couldn't hurt. there is the outdrive bearing modification that can better support the outdrives, which should improve idler life as well.

you can improve the lifetime by turning down the punch of the motor/esc, and use good throttle control on jumps/landings. Also, tire traction plays a huge role, so if you adjust your traction so that you get a little bit of slip, that will help the diff live.

Re: 6 gears

Posted: Thu Oct 24, 2019 4:49 am
by eugine
Hello
Thanks for the detailed explanations
I will try to find the idle gears
But landing smoothly is not always my best performance with my B6 :D

Here are some pics of my ride but brushed with a 27T.
I have a 14T brushed corally. Do you think it will follow the 13.5T ?

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I love it :love: :love: :love: :love:

Re: 6 gears

Posted: Thu Oct 24, 2019 8:47 am
by jwscab
i would think a 14t would hang pretty well. just watch your run time, gearing and motor temps.

Re: 6 gears

Posted: Tue Nov 05, 2019 11:25 am
by brn2fly
Following, I have a couple of 6 gear cars and was wondering the same thing. I planning to do the outdrive bearing mod. Is it possible to install a slipper on the six gear trans?

Re: 6 gears

Posted: Tue Nov 05, 2019 12:35 pm
by jwscab
not in an easy and reliable fashion. the diff is actually intended to slip some, as you are supposed to not glue the diff rings.

Re: 6 gears

Posted: Tue Nov 05, 2019 12:50 pm
by radioactivity
Hello brn2fly

The 6 gear is a quite poor candidate for a slipper.

If a slipper was added at the Spur gear location…
There would be no independent adjustment of the slipper vs the only other portion of the trans that could perform the task of a differential.
That task would now fall on the tiny 6627 diff thrust bearing. If compared to a modern diff, there is no room inside a 6gear to fit an adequate ball or gear diff.
The original 6gear ball diff functions mainly as a differential but as a “slipper” as well.
It can also have a tendency to act as a “posi” when centrifugal force at high rpm throws the ball outward.
The main trouble is metal on metal, wearing the balls and drive rings. Even the newer ball diffs, if slippage occurs (barking), the rings and balls could use a rebuild to keep it smooth.

Pic is stealth spur vs RC10 thrust

Chuck

Re: 6 gears

Posted: Tue Dec 10, 2019 2:07 pm
by eugine
Hi there
Do you where I can purchase a set of those idler gears ?
Nothing is available online at Amain...
The rare on Ebay have 22$ postage

Re: 6 gears

Posted: Tue Dec 10, 2019 10:57 pm
by radioactivity
eugine

I have no idea what shipping would be but an online retailer has some on their site.
Might try The R/C Pro-Shop. I wanted some so I ordered from them.

Chuck

Re: 6 gears

Posted: Tue Dec 10, 2019 11:04 pm
by GoMachV
If you shop online watch out for places like Active Watersports that are drop shippers. They list items well after they are discontinued and then its a challenge to recover your money.

I have a small stack of new in bag white idlers, great for restoration but not good for a runner. They were the weakest ones made.

Re: 6 gears

Posted: Tue Dec 10, 2019 11:10 pm
by radioactivity
eugine
I have recently seen some $8 printed idlers that I would stay away from too.

Chuck