23.5 EMT Conduit Sanding Drill Bit

thingiverse

This printed part along with a hex bolt / nut, and one or two smaller screws will act as a specialized clamp drill bit that lets you sand EMT conduit to a nicer finish than the dull mess it comes from the store. - Simply bolt the 5/16" hex bolt into the bit holder with a 1/2" hex wrench (13mm) snug but don't overdo it. - Add one or two 6-32 x 3/4 (shown) or M3-10mm screws to the side holes which act as clamp downs on the EMT conduit. - Stand the pipe vertically on the floor and tap the bit onto the top of the conduit with a rubber mallet until it's fully seated. It should be a tight fit but go in all the way. - Attach the assembly to your drill as a drill bit - Find a way to clamp your drill to your table and have something stable hold the other end of the conduit up, preferably level. Note: Don't over tighten the side screws. Snug is just right. I use a bench vice to hold my drill upside down and zip tie it for stability. On the other end I have a tie down strap that i have hanging from my shop ceiling which holds the conduit nicely. I plan to release a drill mount and conduit holder as a separate set of thing files to make this easier.