Originally Posted by
qbnut
I have made two axes bots with chains and one with spurs, and I'll say that there's no right or wrong solution - each has advantages and drawbacks. You do have to be more precise with spur gearing and as mentioned above, mounting them into HDPE doesn't really work, you would need more rigid bulkheads to use them.
On the other matter, go bushings all the way. Whilst bearings work they make maintenance hard, as you have to take the whole thing apart to change or fix. With bushings and a dead shaft it becomes an easier job to just slide things out if you need to fix.