I have an index mill with , I believe EZ change #30 collets?. (You can turn the collet holder with a spanner wrench to remove or install tooling). I would like to use MT drills in the mill. What is the best way to do this. I assume there is some type of adaptor.I believe I have up to 3/4 or 1 in. collets. Thanks for your help. Newby Bob
There's three flavors of 30 taper that I know of: CAT30, BT30, and NMTB30. You need to find which one you have. Or something else entirely, maybe. All three have adaptors to Morse 1,2,3,4,5. I have some NMTB30 to Morse 3 to sell.
The NMTB-30 has a flat flange just past the gauge line (the largest diameter on the taper), with a pair of notches 180 degrees apart.
The CAT-30 has a much thicker flange, with a V-shaped groove in the edge, which is used by the automatic tool changing turret.
I think that the BT-30 is similar to the CAT-30, but with some dimensional differences.
All three have the same taper dimensions, and differ in the flange dimensions and in the method used to pull them into the spindle. The NMTB-30 uses either a drawbar which threads into the back of it to pull it in, or a rotating collar with a pair of tabs which pass through the notches, then rotate and pull down on the flange to hold it.
The CAT-30, and the BT-30 both have studs threaded into the back of the taper which are gripped by some form of hook or collet, and which pull the taper up into the spindle's female taper.
The thread for the studs seems to be different from that for the NMTB-30 -- at least based on the differences I find in the various
40-taper equivalents which I use in my Nichols mill via a drawbar.
If you don't have a tool changing turret on your machine, this increases the chance that it is the NMTB-30.
If it uses a threaded drawbar, you should be able to make any of the above work -- but that would not be a quick-change, so it is unlikely here, I think.
Note that there is another kind of quick-change tool which also uses the 30 designation, but instead of having a flange with two notches
180 degrees apart, it instead has two ears 180 degrees apart -- sort of it has metal where the others have notches, and nothing where the others have metal.