I also have an 8520 and my drill chucks are fitted with 1/2" straight arors
and I use those with the 1/2" collet. No problems at all with either or
with a couple of flycutters with integral 1/2" shanks. I bought a Procunier
1E with a 1/2" straight shank and it doesn't look as though the shank or
arbor could be replaced - your Tapmatic may be the same way. Criterion
makes an MT2 arbor, threaded 3/8-16 for their 2" boring head and that works
well, though a couple of washers have to be used at the top of the drawbar
as the arbor doesn't seem to be threaded deep enough to take all of the
drawbar.

Some of the more esoteric tooling require a different solution. A Tree
boring head and a 3" Rotary Tech indexable carbide flycutter both have 3/4"
straight shank and for those I use a 3/4" end mill holder from Busy Bee in
Canada. I also have a Wohlhaupter UPA2 boring head with tanged MT2 arbor.
The arbor seems to fit in the spindle OK and the tang doesn't seem to
interfere with anything but I haven't actually used it yet. It's in mint
condition and I don't want to have it pop out of the spindle under power.
Although that's not likely, it cost too much to take a chance. Eventually I
'll get someone to grind off the tang and thread it for a drawbar.

Mike


"Eddie" wrote in message
ink.net...
I have a nice little Clausing mill with a Morse Taper #2 spindle. The
drawbar and collets that I got with the mill are threaded 3/8 16tpi. The
Clausing head is in great shape with only about .0002 runout with a
collet.
My question is in regard to the type of tooling I should be using in this
spindle. Here is an example. I have a Tapmatic tapping head with a R8
shank
on it now. The tapping head is in good shape and I'm assuming that I could
change the R8 shank on it fairly easily so I could use it with the
Clausing
8520. I also have a real nice 1/2 inch Albrecht keyless drill chuck that
currently has a MT#2 shank with a tang. I don't know if I should be use
the
MT#2 tang chuck in he Clausing either but it's a real nice drill chuck.
When looking through tooling catalogs, ebay, etc. I have found several
sources for MT#2 shanks that could be swapped out for the several real
nice
R8 and MT#2 tang shanked tools that I own now. The thing is though, I
would
guess that the best shank to be using in the Clausing 8520 would be a MT#2
taper shank threaded for a 3/8 16tpi drawbar like my collets but I haven't
yet found a source for these type of shanks (3/8 16tpi MT#2) that could be
installed on my drill chucks, tapping head, small shell mills, boring
head,
etc.
The one nice drill chuck that I got with the mill has a 1/2" straight
shank
that I currently hold in my 1/2 MT#2 collet when I use it with the
Clausing.
This set up seems fine for the drilling I've done so far.
My question is basically this. I've got some nice tooling that will
require
new shanks for use on the Clausing. If I can't locate and buy shanks for
my
tooling with MT#2 threaded 3/8 16 on the end to draw into the Clausing
spindle with my drawbar should I try and buy more 1/2" straight shanks for
my tapping head, boring head, small shell mills, etc, and mount my tooling
using a 1/2 inch collet?
I believe that the manual states that I shouldn't use MT#2 tooling with a
tang in my spindle. As I mentioned, the milling head and spindle on this
machine is in great shape and I would hate to spin a tool in the MT#2
spindle. Should I change out the MT#2 tanged shank on my Albrect drill
chuck? Another question, do I want to apply a light coating of oil in the
spindle and on the collet before I draw them in or do I want to pull the
collet in dry? Probably a newby question but I don't have much experience
using collets yet as I never has a set with my Delta or Atlas lathes and
this is my first mill. One more question. How hard do I torque the drawbar
on this baby? I could relate to terms like crank the @#@! out of it, but I
would be a little more comfortable of I could get an answer in terms of
in-lbs or similar since that's what I'm used to in auto repair
specifications. Much thanks for passing along the knowledge.
Eddie