I’ve managed to upgrade my Shapeoko with belts on the outside. This gives me more working width and also moves the belts further away from debris. I ran a test and it works really well. I need to add a clamp down system, the pressure clamp approach mostly works but I have had one problem with it when a cutout piece moved while I had stepped away and popped the Lexan piece up in the air. Otherwise, the milling performance has been excellent so far into hard plastics (no problem with HDPE).
For the belt mountings, I used steel used for home construction (“Strong Tie”) and cut it into four pieces, then drilled it using measured templates. I did have to use longer 5 mm bolts because of the extra thickness of the plates.
It will make my limit switch mounting trickier, as my limit switch mounting holes were used to mount the steppers on the outside.
I am using thick Lexan for my stepper mounts and it works really well. The four holes in the corners are tapped for 5 mm bolts.
I reused the old Dremel mounting spacers for the stepper spacing mounts and also used extra parts that came with my second Y stepper kit from Inventables to complete the mounting.
All metal from the original Shapeoko kit is unaltered – nothing has been drillled, everything is either stock or has been bolted on (except for a couple of bolts I cut to shorten them).
stepper-mount zip file containing nc and cb files.