All -
With nothing much to chat about on the forum lately, I have been out in the shop tinkering. I decided that if I'm going to switch to a router for my (main) high-speed spindle, then it probably should have the ability to hold small tooling like the Proxxon does.
I bought the Dremel collet and nut kit and proceeded to make an adapter that has a 1/2" shaft so I can easily put it in either the router or a TTS collet. I specifically chose Dremel because:
1. The tooling I have does not fit the Proxxon collets very well at all, probably because they are metric;
2. I can't just go get a Proxxon collet; and,
3. I can buy new Dremel collets and nuts nearly anywhere, anytime. I probably have a few of them stuck to the bottom of my flip-flops.
You'll ask how I did it, so I'll save your fingertips. Here's how you can make one:
1. Chuck a 2.5" piece of 1/2" drill rod in a TTS collet.
2. Clamp a lathe tool in your vise (I have an aluminum block that holds 3/8" triangle insert holders).
3. You could write a program, but I just typed the G-Code line by line into the Mach DRO. Anyway, turn the bottom 0.8" or so of the rod down to 0.275" diameter.
4. Take the TTS collet (with the rod still in it) out of the spindle and grab the collet shank in your vise with the rod pointing up. The TTS ring will get it pretty darned plumb.
5. Find the center of the rod using your favorite method.
6. Drill the center of the rod about 0.9" deep using a drill just a little larger than the Dremel collet shank (from memory, I think I used 0.180").
7. Whip out that threadmill that you made about a month ago and thread the outside of the rod to 0.275-40. You *did* make a threadmill, didn't you? Get the threads good and sloppy so they will allow the collet to do the centering.
8. Put the TTS collet and rod back in the main spindle, and clamp your Dremel or Proxxon or whatever into your vise so that its spindle is inclined 60 degrees. Chuck a small, straight grinder into it (I used the "diamond" cylinder-shaped grinder from my chinese "diamond" 1/8" set). Sure they are diamonds. They seem more like blobs of chrome plating. Anyway, they stayed on long enough for this job...
9. Center the mill spindle by eye over the tip of the grinder and slowly lower the spindle (uhhh, with both spindles running) until you have cut a nice 60 degree taper inside the rod. The dremel collet should now fit the inside your adapter, the collet should mate with the taper, and the nut should thread on outside.
Right after I made it I put a fairly long 3/32" burr (not the one in the photos) in it and measured 0.0003" TIR about .375" from the end of the small collet. I moved the holder to the router and measured 0.0005" TIR. No adjustment, no careful setup, just put it in and tightened it. That's probably on the outside of good enough for very small cutters, but it probably won't break them. I can regrind it in the router once I get the mount made for that if I need better alignment.
Enjoy!
- Just Gary