Announcement

Collapse
No announcement yet.

40 taper versus cat 40

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 40 taper versus cat 40

    Can anyone explain the differences, so that I will know if the mill i just bought uses one or the other. I was told it was one thing, and now being told it is the other. Inquiring minds just want to know. I have a few toolholders that are supposed to go with the machine, but I haven't picked up the machine yet to tell if they fit it. Thanks, David from jax
    A serious accident is one that money can't fix.

  • #2
    The taper, whether it is 30, 40, or 50, is the same whether it is CAT or NMTB. CAT tooling is used in CNC machine tools. CAT tooling is designed to, and uses a retention knob, not a drawbar, to hold the tooling in the machine's spindle. If you look at CAT vs. NMTB shanked tooling, you will notice there is a pilot which leads up to the taper on NMTB tooling. That pilot is not on CAT tooling. CAT and NMTB tooling cannot be interchanged. If your machine requires CAT type tooling, be sure of which retention knob yor machine uses. There are many different ones. Use the wrong one and it will be a bad day. MSC can help select the correct knob if you are not sure which one you need. Knobs do wear out an need replacement depending upon frequency of use.

    [This message has been edited by ERBenoit (edited 08-05-2004).]

    [This message has been edited by ERBenoit (edited 08-05-2004).]
    Paying Attention Is Not That Expensive.

    Comment


    • #3
      Either will work, the Cat 40 has a V flange for automatic tool selectors to grab onto and a different retaining knob.
      If it is a manual machine with a threaded drawbar, it is probably NMTB. Cat or BT flange can be used by making adaptors or different drawbars.
      Jim H.

      Comment


      • #4
        I'm rasslin' with that very problem. The tapers themselves are exactly the same but the retention configuration and the flange details vary.

        I recently bought a small universal milling head I plan to use on my planer. I recently bought off eBay a set of cheap shell mill adaptors with a BT 40 taper. This is like the Cat but it has a 16 - 2 metric thread instead of the 5/8- 11 Unified. Since this is my first tooling purchase in this formfactor it's easy to let it drive subsequent tooling purchases - all BT for example in order to standardize.

        I like the 1" shorter taper outline of these V flange spindle tooling units. The storage can be shallower and it's easier to handle the shorter taper in cramped conditions, etc. I still haven't decided. Most likely I will go with the MMT form factor and make some threaded extentions that convert the BT or Cat or whatever tool to MMT.

        The only practical difference in MMT, Cat and BT in manual tool change machines is the drawbar - and that some styles of the BT and Cat end mill holders can't accept double ended endmills. This is easy for me to handle in the universal milling head I have to work with. The drawbar is 10" long and easy to change; its only a petty PITA to swap them as I move from tool to tool. I will need to face about 1/4" off the short tapers to get adequate thread depth in the conversion adaptor but that's a small issue.

        CNC is a different deal. Not much flexibility. You have to have the tooling your CNC machine requires. CNC machine with their sensitive automatic tool changers have to have the unique tooling specified including the exactly the right retention knobs. The wrong tooling leads to very expensive busted parts, ruined work, dropped tools, and long delays waiting for or making replacements.

        If you have more than one CNC machine it makes sense to settle on a shop standard for spindle tooling so that all machines can share it.

        This is no small consideration. It takes $5000 to $10,000 for a functional set of spindle tooling to equip a machining center; more as the tooling form factor gets larger. The spindle tooling alone can approach 30% of the new machine cost. If you have four CNC machining centers sharing tooling a fifth would more than likely get along on the existing inventory plus a set of endmill holders aand a few other items.

        For that reason the first CNC machining center acquisition is the the one that drives future purchases so think strategically about that spindle tooling decision.

        [This message has been edited by Forrest Addy (edited 08-05-2004).]

        Comment


        • #5
          This is a photo of some of the tooling I got with it.



          David from jax
          A serious accident is one that money can't fix.

          Comment


          • #6
            This is what I just bought.



            Wonder if they can be modified to fit? It has a tool changer, but you remove the tool by hand, when pushing the release... so no drawbar.
            David from jax
            A serious accident is one that money can't fix.

            Comment


            • #7
              The tooling in your pictures, (what you got with it) since I see no retention knobs, and the tooling has a pilot before the taper, it LOOKS like NMTB shanked tooling. Does all of the tooling that you have, (what you got with it), have that groove on the pilot? I will try to find out if, though I do not beleive it is, the BT type of tooling. BT type of tooling is similar to CAT tooling where a retention knob is used, and there is no pilot leading up to the taper. What you bought is definately NMTB shanked tooling. Notice that what you bought does not have the groove on the pilot that appears to be on all of the tooling that you got with it. That groove may be essential. Could be from the early days of tool changers where it was not automatic, yet required no wrenches etc. to change holders. All of the NMTB shanked tooling I use in manual machines, does not have that groove on the pilot. None of the NMTB shanked tooling that I have bought has that groove on the pilot. If you push a release lever or button to release the tooling from the spindle, the machine probably has a pneumatic/mechanical drawbar. I have a three axis CNC mill at work, where the tooling is changed by hand also, that uses a Kurt pneumatic/mechanical drawbar with NMTB shanked tooling. Is there an air fitting? What make of mill is it? How old is it? Does it have a manual?

              [This message has been edited by ERBenoit (edited 08-05-2004).]
              Paying Attention Is Not That Expensive.

              Comment


              • #8
                1983 Maho 600P horizontal milling machine with a vertical head.
                No air connection, so it must be a mechanical drawbar.
                The top piece with the groove and two flats on it will unscrew if you take a wrench to it. (I just figured that out)
                There is a manual, but it seems to be in la la land for the moment. They are still looking.
                The V groove around the widest part of the holder is present on all of the tooling except for the arbor that fits the overarm.It has no V groove, kind of like the ones I just bought off ebay. Since the arbor is for the horizontal only, I wonder if it has different requirements.
                I will be glad to get my hands on the manual, and the machine at home, so I can really get confused.
                Thanks again for all of your help.
                David from jax



                [This message has been edited by sandman2234 (edited 08-05-2004).]
                A serious accident is one that money can't fix.

                Comment


                • #9
                  That's definately 40 NMTB... You don't want to use Cat40 if for no other reason that those threads are not meant for constant assembly/dissassembly but rather a retention knob. BT40 stuff is a fortune and has a much smaller selection than Cat40, which is probably the cheapest of all the 40 taper tooling because it is the most widely used. The CAT system was invented by Catepillar Tractor in the 1970's hence the name, BTW. Keep an eye on Ebay, they have tooling on all the time including double endmill holders.

                  HTRN
                  EGO partum , proinde EGO sum

                  Comment


                  • #10
                    If the top part, what I am calling the pilot can be removed, then I would tend to think that it is some sort of retention knob. However, it does not look like anything I have seen as far as retention knobs go. It could also be an adapter used in CAT or BT tooling to catch the drawbar with sufficient threads as NMTB shanked tooling does. I have not seen an adapter commercialy availiable, then again I have not had to look for them. Not that they do not exist.
                    Paying Attention Is Not That Expensive.

                    Comment


                    • #11
                      The tooling that came with the mill appears to be CAT V flange. The V groove in the flange is distinctive of that tooling. The end appears to have a joint at the top of the taper that looks removable.
                      The purchased tooling is NMTB 40 taper tooling. The plain flange ant solid pilot is the tip off there.
                      BT 40 will have a V flange similar to the CAT V, but the flange is much thicker.
                      Jim H.

                      Comment


                      • #12
                        Sheesh David, why don't you ask these questions on the Deckel Maho forum where folks would immediately tell you the scoop on these holders ?

                        What you have are Deckel retention knobs mounted to CAT 40 toolholders, which, amazingly enough, have exactly the same diameter dimensions as the "neck" on standard NMTBA 40 tooling. So, you can, if you like simply turn that groove present in the neck of standard tooling, or use the knobs in CAT tooling.

                        You have no drawbar because you (should) have a hydraulic "drawbar", which is actually 3 "fingers" that grip that groove. The fingers are held by a very strong spring, such that the hydraulics actually serve to release the grip rather than hold it.

                        Comment


                        • #13
                          Had kind of forgotten about that Maho forumn on the other board. Last time I was there, nobody had posted anything for 4 days.
                          Thanks for the help.
                          David from jax
                          A serious accident is one that money can't fix.

                          Comment

                          Working...
                          X