Riseabove has a wonderful tutorial on how to convert your Dremel into a micro mini disc sander for jewelry. I had been looking for a way to setup my own sanding system and after alot of research and experimenting, I came across hers and couldn't wait to try it.
There was only one problem: the cutoff wheel itself. After reading the comments lots of folks posted (some helpful, some not), it was made clear that using the cutoff wheel was not a good idea, since it can't take pressure on the top and could break and send pieces flying! Way too dangerous! One guy said he used acrylic, but couldn't cut it into a perfect circle. I knew I wasn't going to go out and buy acrylic just to cut a sloppy circle so I set about looking around the house for something else.
Step 1: Find an Appropriate Size Bottle Cap!
Yep. I said it. A bottle cap. You need a plastic one. Rummage around in your recycle bin. Look for empty bottles in the cabinet and bathroom. These are just a few that I found that work perfect for my project.
Step 2: Drill a Hole!
One of the best things about some plastic bottle caps is that the dead center is already marked! No right angles, no corners of paper, no eyeballing. Use a black marker to make it easier to see! Make sure to cap is screwed on to the original bottle, hold on to the bottle and DRILL SLOWLY! Plastic mangles easily and if you go too fast you'll be left with a messed up hole and a bunch of plastic threads.
Step 3: Screw Onto Your Mandrel
That's it. I decided to use hook and loop tape for my system, since I will be using many different grits. The sandpaper doesn't come off, but there are other issues. I don't know how I'm going to label my grits, since I don't have anywhere to write the number on. I also used the industrial strength type and that stuff is SUPER STICKY! I had a rough time getting my screw through the pad and I almost ruined my die cutter. Goo Gone cleaned everything up though. Clean it soon, because the adhesive sets HARD! I used a 1-1/2 inch punch to cut the circles for the sandpaper. I think I'll have to leave my mandrel on this sander though, and just purchase another one to have for generally Dremel stuff. They don't cost too much.
Hope this was helpful!