CNC Taper Question

ISO20, ISO30, HSK63, HSK100, BT30, BT40, CAT30, CAT40, CAT50... Name a few yourself if you can as I'm sure there are a few others.

What are the most common here in the US? I'm thinking the CATxx series but I'm still learning about these buggers.

Context: This is going to start sounding like an ad, but that is NOT my intention as you can see from the history of my posts here in this group... We are going to start selling lower cost, high quality aggregate heads if I can solve some of the adapter issues. I'm right at the threshold of doing so but the choice now exists as to how we will solve this best.

My challenge at this time is choosing the top adapter / taper choices to be made available in the first year when we will be selling for less as a semi-beta test of the product, etc. After we have reached a high confidence level, we will offer 'em all but charge more.

Figuring out the most likely and reliable tapers to offer now is my goal.

Thoughts?

Regards, Joe Agro, Jr. (800) 871-5022

01.908.542.0244 Automatic / Pneumatic Drills:
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Spindle Drills:
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Tapping:
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Site:
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V8013-R

/{[(P.s. Also posted in alt.machines.cnc) but not via this message so as to limit crosstalk.)]}\

Reply to
Joe AutoDrill
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You forgot the NMTB series: 30, 40, 50. Then I have a BT45 machine that I have made custom pull studs so I can use CAT45 tooling also.

Unless you're in large machines, CAT40 is by far the most common on recent equipment.

Karl

Reply to
Karl Townsend

What's that? Standards are so nice -- and there's so many to choose from, too.

Reply to
Tim Wescott

Well ... FWIW my old CNC Bridgeport BOSS-3 (Series I) uses the NMTB 30 taper in a quick-change spindle, and my non-CNC Nichols horizontal mill uses the NMTB 40 taper. This is a flat flange with just two square notches at 180 degrees separation around the flange, and no V-groove. The flange is thinner than the CAT and BT flanges in the same size.

Now all of the 30-taper ones have the same physical taper, but differences in the flange and the draw screws or studs. The Bridgeport quick-change spindle *requires* the NMTB flange -- no way to make the CAT or BT series work in there. I'm not sure where the ISO falls in this list.

O.K. It looks as though it is the NMTB specified in metric units, except that I can't find enough detail of the flange. The threads for the drawstuds or drawbars are metric instead of the inch threads on the US standards.

For the Nichols horizontal mill, there is no real sensitivity to the flange dimensions, as long as there is room to accept the cap screw heads which fit into the notches. However, I've had to make studs on the end of the taper to accept the normal drawscrew.

Are you talking about the mounting of the drilling head to the machine, or the tools to the drilling head? If the mounting of the head, probably go for the CAT or BT flange and offer a choice of drawstud to fit the customer's machine. They normally seem to be held in with a rather tough Loctite, so better to offer the taper bare and let them install the proper stud and Loctite it in place. That way, your bearings won't be subjected to the heat needed to break down the Loctite if someone needs to change to a different drawstud.

Oh yes -- there is also another style (I forget the name) which has a standard 30 or 40 (or maybe even 50) taper with a rounded groove milled into the side of the taper (at right angles to the axis) which allows the taper to be held in with a cam in the spindle. I *think* that this groove can be present in other sockets of the same taper without harm.

I presume that your heads will not be installed by a quick-change turret, but rather by hand.

I hope that this is some help.

Good Luck, DoN.

Reply to
DoN. Nichols

We are indeed talking about the mounting of the head to the machine.

We offer adapters now, but they are manually loaded in design. I'm working toward the automatic tool changer variety at this time - which opens op a whole new playing field for us.

See above. :)

Absolutely! Thank you (and everyone else) for the info.

Reply to
Joe AutoDrill

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