Large Reduction Single Speed Gearbox

[techhelpbb]

Originally Posted by InspectorGadget1073

Our team is only using 6 inch wheels. Please help us all.

What sort of help do you need?

Are you trying to target a certain number of feet per second?
or
Are you trying to target a certain ratio?

Resources on ChiefDelphi that can help you:
JVN:
http://www.chiefdelphi.com/media/papers/2059
Thad house:
http://www.chiefdelphi.com/media/papers/2681
Chris L:
http://www.chiefdelphi.com/media/papers/2165

As pointed out before if you can't get a ratio high enough from an existing gear box use that gear box to drive a belt or chain sprocket and then select those pulleys/sprockets to multiply the ratio.

For example: If a AndyMark ToughBox has a default ratio of 12.75:1 and drives a double 1/2" bore #35 sprocket with 12 teeth. Then drive the wheels with a 24 tooth sprocket (which happens to even fit a 4" AndyMark wheel) you have an additional 2:1 so that's total a 25.5:1 gear ratio at the wheel hubs. If you used the 15 tooth double #35 sprocket that chain will be a ratio of 1.6:1 so total that's 20.4 at the wheel hubs. If you play around with alternate gears within the ToughBox you can take that further. It's easy to get an additional 3:1 in just sprockets and chain using a 12 tooth #35 to a 36 tooth #35 sprocket especially if your tires are larger than 4" to add clearance for the chains (so with 12.75:1 and 3:1 that would be a total ratio at the wheel hubs of 38.25:1 and that's not even the maximum).

Make sure to consider the losses in the system that's why I linked the various common calculators.

I see AndyMark clearanced out all the StackerBoxes. I bought a bunch. They can feed into each other to multiply over and over the gear ratio just by assembly. Too bad they had 3/8" shafts. Each StackerBox had a 14 tooth and 50 tooth gear stock. So you could easily stack 3 and get a ratio over 45:1.