wrote in message
...
I would not reject a mill on the sole grounds for having a M3 spindle
taper.

On a small mill the space between table top and spindle nose is at a
premium, consequently you will want to keep the cutting tools as close
to the spindle nose as possible. This would require collets, and from
personal experience M3 collets hold the tool much tighter than R8
collets.

M3 collets are advertised in the Home Shop Machinist, and I have used
a set for about 20 years. I used R8 collets professionally and I
thought they did a very poor job of holding cutters. With R8 collets
the cutter may pull out, that is why end mill holders with a set
screws are sold. With an M3 collet I have never had this happen.

I arranged for a "jacking" type draw bar in my mill. This draw bar
pushes the collet out of the spindle nose so you don't have to beat
the daylight out of the draw bar end to get the collet to release; M3
collets hold very tightly and require a healthy thump to release
otherwise.

Also, Morse taper shanks with a soft and unmachined ends cost less
than $10 each and are suitable for making special cutter holders for
boring heads and fly cutters.

Thanks.

Much food for thought. As someone else suggested I am looking at another
mill sold locally for $200 more. Just comparing the specs including
accessories the latter mill has a 3/4 HP motor compared with less than 1/2
HP for this one. It also comes with a drill chuck and a "quick change collet
chuck" including 8 collets. None of this is mentioned with the Busy Bee one.
The Z travel is full 21/4 inches more.

http://www.houseoftools.com/product.htm?pid=18460

I had a look at the costs of end-mill holders for MT3 and they are double
that of R8. I surmise I would need at least two - 3/8 and 1/2? The collets
as well as the drill chuck, however, would give additional versatility?

I wonder if one added all the extras whether the local purchase might work
out about the same.

The additional problem is that one cannot always trust the specs as
printed - House of Tools has been wrong in the past!

Things are never simple...

--
Michael Koblic,
Campbell River, BC