rkremser

Hello, I was just wondering if anyone had ever setup an automatic transmition for their rc car. and if so how was it done.

NitroNostrils

I don't think it would be cost effective, plus the forums would crash with everyone asking "whats wrong with my tranny?"....

Billyman

My Feedback: (1)

Hmm, both mine came with a two speed auto's.

Works for me!

nodolarsnosense

yeh billiman i agree, virtually all 2 n 3 speeds are autos just in a diff form to real cars, ie they do not use planitary gears, valves etc etc etc
ie 2 completely different systems but both autos

i dont actaully know how an rc auto properly works (i dont own one) and id like to know so if anyone knows any links?

Unstable

alot of nitro cars have 2 speed gearboxes.

basicaly its a centrificle clutch that engages another "gear set" as it disengages the first.


looking at the savage SS instructions [link=http://www.hpiracing.com/index2.htm]http://www.hpiracing.com/index2.htm[/link] (page 18-20) it looks like you have 3 gears on a shaft. one drives the shaft. the next is on a one way bearing (first gear) and the other a slipper clutch.

when the slipper clutch engages second gear the previous gear freewheels on the one way. i have a savage but never had to take apart the gearbox yet.

rkremser

Thanks, it helps a lot. I"m trying to put the concept into a school project. I" not sure if i'll go this route or another but any information helps. BTW we are making dragsters for a mechanical engineering course focusing more on the cad work and the cnc machines we will use but it couldnt' hurt to win the race.

Billyman

My Feedback: (1)

You're kidding me right?

Nitroaddict

nope - he is right on, billyman. all multi speed tranny's in RC Cars are automatics. they operate just like a centrifugal clutch does in your lawnmower. 2 shoes are attached to a one way bearing and housing on the second gear. once sufficiant rpm's are achieved, the force drives the shoes outwards to connect with the clutch bell. this engages the next gear. when rpm's drop back down again, the shoes come back in and the 2nd gear disengages.

Billyman

My Feedback: (1)

Hehehahah!

Nitroaddict, I was jerking nodolarnonsense’s chain. He made a reference to an automotive transmission. I’m a performance auto technician by trade.

As for R/C tranny’s and how they work…..hehe…..been messing with this stuff for 15 years.

I’ve designed and built 2 speed clutch systems for go-carts like 8 years ago. Hmm, wonder what I based them on?

Nitroaddict

NP - billy, i am also an ex-tech. ASE cert on VW, SAAB. Sorry, alot of times humor doesnt transmit over the internet very well.