I need a gear calculator

[BrianG]

Originally Posted by Modding_out

Hmm. so your telling that no mater what the size the idler gear is, it doesn't affect the gear ratio? How does that work?

Think about it, there's no reduction at all. Like MM said, it's just to add a little extra distance between the shafts and/or reverse the direction. When an idler gear is present in this way, you could just divide the output by the input and disregard the idler. But, to keep things consistent, you could figure in all the gears. Consider a tranny with an input of 20T, idler of 10T, and an output of 40T:

Disregard the idler: 40T/20T = 2
Figuring in the idler: 40T/10T X 10T/20T = 4 X .5 = 2

See? Same thing!

However, if you add an extra gear to the idler area, things change. Basically, you'd have the input gear meshing to an idler gear. But if you have a smaller (or larger gear) that is on that same idler shaft meshing with the output gear, the ratio then is Ouput/Idler1 X Idler2/Input.

My page has many transmissions listed and shows the various tooth counts whether the tranny has 2, 3, or 4 gears: http://scriptasylum.com/rc_speed/_data.html