Re: Milling Machine Taper question

Hi Matthew,
Enco had a good deal on a set of generic NMTB 40 holders a few months
ago. You might want to check them out to see if they still do. I
bought the set and I'm happy with it. My Machine is NMTB 40 also. I
had to do some minor grinding on the 'ears' of my quickchange holder,
and play with the set screws on the collar to accomodate slight
variances in the flange widths between the Erriccson and Enco holders.
So it works well for both.

Also scan Ebay periodically for NMTB* or 40 taper, and you will find
occasional hits.
-Lee ( the weekend lurker)

--- In CAD_CAM_EDM_DRO@y..., machines@n... wrote:
> --- In CAD_CAM_EDM_DRO@y..., "Matthew King" <mattking@k...> wrote:
> > I've got a slightly off topic question for you folks, if ya don't
> mind.
> >
> > I've recently purchased a nice, old Milwaukee manual mill - it's
> got an NMTB
> > 40 taper with .625-11 (5/8-11) drawbar thread. What other tapers
> can be
> > used in this machine? Can a CAT 40 be used? It seems to have the
> appropriate
> > taper and drawbar(actually pullstud) thread, although it's
missing
> the
> > "straight" area at the top of the taper. BT 40 seems to have the
> right
> > taper, but a metric drawbar/pullstud thread.
> >
> > Mine is shaped something like this:
> >
> > | | <------ this is the "straight" part
that
> isn't on
> > a CAT40 taper, as far as I can tell...
> > | |
> > / \
> > / \
> > / \
> > / \
> > | |
> > ---------------
> >
> >
> > Can anyone help me out here? I need a decent collet holding chuck
> for this
> > thing to make endmill changes easier and they seem to be far more
> readily
> > available on the surplus market in CAT form rather than NMTB.
> >
> > Thanks!
> >
> Matt
> This subject has been covered a lot on alt.machines.cnc
> The concensus of opinion is that all the 40 series has the same
taper.
> All that differs is the pull stud thread, whether or not it has the
> straight portion and the dimensions of the vee groove and drive peg
> sizes.
> You have correctly listed the NMTB and BT series. The CAT series is
> unique in that it has one large drive dog and one smaller one so
that
> it can locate in the tool changer. For a manual machine you can
> ignore this. So you now have a choice between the two types. If you
> can change drawbars easily you can also use the BT40 series.
>
> John Stevenson.