Delta 31-250 Drum Sander Gears & Bracket

These models are intended to be replacement miter gears and an improved bearing bracket for the Delta 31-250 18-36 drum sander.

Please note that this design is a slight departure from the original nylon miter gears that used a roll pin to secure the gear to the handle shaft. In this model, I cut a keyway in the shaft (using a dremel) to accept a 1/8" key. You can buy these keys at any hardware store. The model for the gear that is to be mounted on the shaft has a hole that can be tapped to 10-24 pitch to accept a grub screw that will tighten onto the keyway. With that, these are NOT an OEM replacement, as I designed new gears that do not exactly match OEM. This means that you will need to print these as a set to be used together, you cant just print one to mate with an OEM gear.

HIGHLY recommend printing at 100% infill and with a nylon or carbon fiber reinforced nylon. I used Polymaker Fiberon PA612-CF15 and it's been printing very well on my MK4S with a hardened nozzle and 270/35 nozzle/bed temp.

The upgraded bracket uses a sealed bearing instead of the OEM sheet metal solution. I used these ones that have a 3/8" ID to match the shaft OD. You may have to make a small "burr" on the shaft where the bearing will sit to get it to press securely as the diameters are a pretty close match. I ended up just using the collar with the grub screw that sits near the plastic ball on the handle side, tightened it down where the bearing will sit, which created enough of a burr for the bearing surface to bite onto.