Well, I discovered another reason not to use ABS. Assembly was tight but with the help of a knife I was able to make everything come together. But the bearings were tighter against the rails than they otherwise would have been, which was causing the drivers to overheat and the motors to make high pitched noises. Using my dremel I sanded down the rails tonight and now everything is moving much more smoothly. I think once I put it to use the bearings will set and it will roll even better.
I’m going to redo my wiring this weekend because one of the motors seems to be a little out of sync, and then I should finally be ready to make the first cut.