Summary This is so I can add a Dremel 3000 to my printer to do some milling and engraving. The three bolts up top are to adjust run-out at the bit end. Take off the nose nut and thread a Dremel into the print after you have added the bolts, there are threads built in. Also has a vent/finger hole for locking it to change bits. Adjust the bolts to true up the bit. This is a work in progress. I am busy as a whore at a Viagra convention so I haven't gotten much further than this. The latest file has recesses for jam nuts not seen here on the prototype. Pardon the crappy print, I shifted a layer but recovered and I was so close to the finish just I tripled the print speed and just let er buck. Fits a fan too. Also fits my fan adapter I published earlier. Mounting bolts will fit my machine, not sure about you. Designed to mount on a flat plate and has a lip at back to help line it up. Print Settings Printer: Monkey Shit Fight Rafts: No Supports: No Resolution: .2 Infill: 20% Post-Printing Add bolts and nuts. 1 and 3/4 inch by 3/8 coarse or fine thread for the centering ones. 1 inch by 3/8 th for mounting bolts. Yeah I know it's heavy stuff but I hate tiny hardware. These are cheap and easy to find.