I had a Weller rotary tool already.  I first ordered a flexible shaft 
for it from Micro-Mark (#14260 ~$25).  Later, saw a similar item for 
a similar price at Home Depot (but no s/h), so shop around.

I rigged up 2' pipe clamp as a bench stand to hold the tool.  I put 
on a stone grinding tip and tried it out.  Two problems.  I felt a 
rotary burr (file-like) cutter would be better.  So I ordered set 
#80470 from Micro-Mark ($28).  Next I felt the need for variable 
speed and foot control.  High speed would wear out the shaft bearings 
fast (at 20,000 RPMs, the sucker gets hot!) and being able to cut at 
slower speed give me more options.

I decided to get a good Dremel brand foot control.  I found the best 
price on-line at Walmart's site.  I figured if "old Weller" gave out, 
I could upgrade it to match the foot control.  But I also saw some 
very economical complete sets on eBay.  They were tempting, and I 
would have tried them if I was starting from scratch.  They are 
complete with a rotary tool, flex shaft, and foot control.  However, 
I would not expect them to hold up to heavy usage.

I uploaded some pictures of my rig in a new "Chamber Work" photo 
album on the MPWork site.  Its not real pretty, but it works great.  

I used the rig to create a round nose (bullet-like) chamber in a HR 
diamond Beechler tenor MP I had.  The high baffle in the Beechler 
extends all the way for the full length of the window to the bottom 
of the "U".  It just about fell off the cork of my 10M when tuned, so 
it was asking to be enlarged.  Cutting it out was a lot of fun.  I 
may do more to it if the palm keys do not go sharp on me.