BT40 holders in CAT40 machine? does it work...

[RedGTZ]

Hi guys!

I already have a machine over here (Torqcut22) that is completely tooled in BT40 and I'm now looking at buying another (TC4G) but this one is equiped with the CAT40 spindle. I know the CAT and BT holder slots are different but if I'm right, the BT slots are larger. taper angle is the same... I heard that the BT40 would fit in there... is that true?

Will I be able to use the BT40's in the Cat40 spindle?

if no, can the machine or holder be easily modified to fit both?

Thanks for your time and help!

[DareBee]

This was discussed at great length within the last 6 mo. please do a search.

[Geof]

CT40 vs. BT40 spindle's and tooling?

Another MINIMILL post

[RedGTZ]

Thanks for the links

[gus]

http://www.cnczone.com/vb...d.php?t=163087

I recently did the opposite.
If my reading is right, you want to put BT in the cat machine? You will need new fingers in the spindle, and all new toolchanger segments[22 at ~35 bucks a piece] and then whatever pull studs are called for that combo, which I do not know if they are the same. Bridgeport used a different spindle whenever they fitted CAT to a machine[at least on the 1000 series] and it could also be fitted back to BT, but the stock BT spindle never had CAT......

[RedGTZ]

Thanks for the input.

The fingers would need to be changed for sure in the carousel. Tool change height should not be a big issue since we can chage the tool change height parameters if needed. For the pull studs, I'm pretty sure I would ba able to work it out, if nothing exist I would make them... since the threads in the CT are Standard and Bt are Metrics...

[DareBee]

If I were you I would definitely standardize the 2 machines or get a machine with BT and forget about the CAT machine.
We all know tooling is WAY to expensive not to share.
If your changer is umbrella type all you will need to change is the pocket clips. Pull studs should be readily available and your TC height will NOT change as the OAL tool length still matches the taper to drawbar lenght.

[gus]

The tool change height does not change ONLY because Bridgeport made their fingers at different groove heights to allow it to remain the same. The taper etc has nothing to do with it. Also you must check the clearance between the drawbar and the tool release mechanism, which is going to change to some degree with different grippers and pull studs. The pull studs I called out in my other post allow it to remain unchanged, but that may not be true in his machine.

[DareBee]

Then Fadal and many others has done the same as well.
IMO the (40) taper does have something to do with it because when the drawbar pulls the tool tight into the spindle it seats on that taper and the drawbar is pulling on the knob of the stud.
If that length varies than the tool will not seat and be tensioned properly.
The drawbar/spindle in my Fadal will work with both BT and CAT with NO changes (as will most machines). The problem is the toolchangers and the clips are usually swappable if you wish to change styles (umbrella type anyway). You can always load the spindle by hand and not need to change anything.

[gus]

Since you cannot use the same pull studs, then you must change something. the length of the taper is different, and the thread is different, so you must change pull studs. once you change pull studs, then the fit into the spindle IS different. The tool umbrella is NOT related to this. The difference in length is something like .150. You must check your clearances to make sure that you chose the right pull stud if your machine does not list a direct swap

There is no reason I can see why someone could not have made a tool carousel that was either or IOW, flip it upside down and it is BT Actually the bridgeport, I think, you could mix carousel segments as they appear identical, but I haven't checked.

[DareBee]

We must be talking about different things.

I am only talking about the part of the holder that physically goes inside the spindle. The BT tool is faced off a little shorter causing the pull stud to have a little longer flange - but ALL datum dimensions including the length to the end of the stud are identical.

If you are using the correct pull studs dimension A & B (attached sketch) will be the same whether CAT or BT.

[gus]

Well, let's see, the length of the taper is different, and the position of the flange is different, so unless your machine manual says 'use this pull stud for CAT and this for BT' you are going to have to do some figuring, are you not? since this is NOT the case on a Bridgeport as the OP has, it is not 'quite' that easy.

Those dimensions seem straightforward, but try measuring them in the machine....

In the case like I went through, where there is not any factory called out pull stud, you have to do the math and find a stud that looks right[ the cat needs ~.15 shorter pull stud] and then put it in the machine and see if all the clearances are what they should be. In the OP's situation, I think there is a factory pull stud to bring a CAT machine back to BT, once he changes the drawbar fingers. There might be one to use without changing the drawbar fingers, but he will have to figure that out.