[qnetjoe]

Looks good. Here a couple of suggestions:

1) I would take a look at self aligning bearings. By the looks of it you are just using a standard flange bearing. How are you retain the bearings

2.)You might also consider putting the sprockets on the outside of chassis as it would be easier to work on once you put a mechanism on top.

3.) Consider modifying it so you can easily remove an entire side of the chassis.

4.) You have a large rectangular piece of tubing for the inside mounting rails. That seems a little excessive. You might just consider mounting you entire wheel assembly into a large piece of tubing instead.

Hope this helps