[misterfoo]

Originally Posted by Mark Pettit

We accomplished it by purchasing the ROBOT-SPROCKETS-2005 kit that is $79.95 at http://www.ifirobotics.com/kitbot.shtml
There are a couple of other threads that already discuss this.

We used 4x drive last year and it was great, this year we are modifying the setup to have the same. I have not checked with the mech team this week, but I know the conversion is underway from 2 wheel to 4 wheel drive.

If you want to be very simple, you could order a double chain sprocket from Mcmaster. We also converted our wheels to use 5/8 shaft with a similar sprocket and a keyway.

Here is what I found.

http://www.mcmaster.com/

Search for Double-Strand (page 932)

Steel Double-Strand Plain-Bore Sprockets for ANSI #35-2 to #60-2 Roller Chain