Rockwell 1 x 42 Grinder/Sander Wheels and Tires

thingiverse

I picked up a Rockwell 31-351 1x42 belt sander/grinder for cheap. After purchasing it, I found out that several of the wheels were either broken, missing their tires, or missing compeltely. These parts are only currently available via ebay so I decided to make my own replacements. The Rockwell 31-351 appears to use the same wheel sizes as the more common 31-350 and the less common 31-352 so these will likely work on those machines as well. The drive wheel has a hole for a set screw to hold it onto the drive shaft. This hole should be tapped with a 5/16 x 18 tap and then filled with a 5/16x8 set screw. The idlers both fits over 6203-2RS bearings. Print two copies or each, place the bearing between them, and glue the two sides together. Both idlers are crowned; The large idler has a .4mm crown. The small idler has a .265mm crown. I printed all of the wheels in PLA and it seems to be working well so far. All tires should be printed with TPU. A less flexible TPU would probably be appropriate; I used some 3dsolutech TPU that is pretty stiff. These all have a relatively tight fit but I found they still tended to slip off. I ended up glueing these to the wheels using JBWeld Plastic Welder epoxy. I found the best way to apply this is to: 1. Slip the tire onto the wheel. 2. Stick a small screwdriver into the gap between the tire and the wheel 3. Mix up the epoxy and load it into a syringe. 4. Stick the end of the syringe into the gap behind the screwdriver. 5. Dispense the epoxy as you slide the screwdrive/syringe around the perimeter of the wheel. 6. Remove the syringe and screwdriver and make sure the edge of the tire and wheel are aligned. Allow to cure. The tires should be usable with the original wheels as well if they are still in a usable state.