[vivek16]

Please don't bump your own threads an hour after creation with nothing more than "bump" written. Many here would be glad to help you out and just haven't gotten around to looking at your thread yet.

If I were you I would go with the 5.95:1 ratio. It will provide you with the least torque while using the tough boxes. While this is still too much, you can fix it enough in the programming if you are using the 5.95:1 option.

I'm not sure of your machining capabilities but have you considered making your own gearboxes? It's not too hard to make a simple one with a decent mill. You could do a ratio of 12:50 with the CIM gear going right to the output gear ( a 4.167:1 ratio)

You might also want to use a larger sprocket on the shaft of the gearbox to get a lower ratio (with the 5.95:1 option of course).

-Vivek