CAT 40 with a Drawbar for Deckel FP3

[alcro1998]

I am looking to adopt a new 40 taper system for my Deckel FP3. I am not a fan of the Deckel system and do not plan on using the low profile Deckel collets. I also have no Deckel tooling.

Cat 40 tooling seems to be very cheap and readily available compared to all of the other 40 taper holders. I could easily make a new drawbar for cat 40 but is the cat 40 system ok to use with a drawbar? I will also make a new dog drive ring and my machine did not come with any. I am aware that there are Deckel studs available for cat 40 but I'd prefer to just use normal Cat 40 holders with no added cost.

Thanks for the future replies

-Chris

 

[sneebot]

Shouldn't have any problem at all using Cat 40 holders with a drawbar. I would port over part of the Deckel drawbar design and put a flange right above your drawbar threads such that the drawbar has to be insert from below instead of above-- this will 'eject' the holders when you loosen the drawbar.

 

[alcro1998]

Shouldn't have any problem at all using Cat 40 holders with a drawbar. I would port over part of the Deckel drawbar design and put a flange right above your drawbar threads such that the drawbar has to be insert from below instead of above-- this will 'eject' the holders when you loosen the drawbar.

Really good idea! I was already planning on using the top part of the Deckel drawbar that screws off but did not think to add a flange on the bottom.

 

[AlfaGTA]

Horizontal drawbar will be slightly more complex. On the FP3 the rear Allen socket exits the horizontal ram at the rear and is in a fixed linear position.
To compensate for the horizontal quill travel the drawbar must telescope relative to the end wrench socket while maintaining drive to tighten the
drawbar in the tool holder. Might wish to check your parts manual

Original Deckel direct mounting collets have the advantage of saving the valuable limited head room in the "Z" on these machines. Plus the short distance from the support of the spindle bearings gives a very rigid setup.
I would personally opt for a combination setup...allowing for use of both original style tooling and your CAT 40 holders.

Cheers Ross

 

[alcro1998]

Horizontal drawbar will be slightly more complex. On the FP3 the rear Allen socket exits the horizontal ram at the rear and is in a fixed linear position.
To compensate for the horizontal quill travel the drawbar must telescope relative to the end wrench socket while maintaining drive to tighten the
drawbar in the tool holder. Might wish to check your parts manual

Original Deckel direct mounting collets have the advantage of saving the valuable limited head room in the "Z" on these machines. Plus the short distance from the support of the spindle bearings gives a very rigid setup.
I would personally opt for a combination setup...allowing for use of both original style tooling and your CAT 40 holders.

Cheers Ross

Yeah I kinda forgot about the horizontal spindle. I did notice how when using the quill the back socket did not move in or out.

I’ll look at the parts manual or remove the drawbar and see how it work.

It might be good to have some Deckel studs on hand and use cat 40 for the vertical spindle and the Deckel setup for the horizontal. I don’t think I’ll use the horizontal setup a ton but I know it’ll come in handy. I was very surprised when I got the machine and the guy showed me how it had a horizontal quill. Did not expect that.

 

[Chris999]

What about BT40? Pull studs readily available for the Deckel drawbar and they're just as plentiful as CAT40.

 

[Halcohead]

Using a drawbar with CAT40 isn't ideal since the taper can be distorted excessively if the drawbar threads are overtightened. With pullstuds this isn't a big deal since they're only torqued once, but the variable torque of a drawbar can be an issue every tool change.

If you do make a drawbar for just CAT40, I agree with retaining the self-ejecting feature. Per the above thread, it's a good idea to relieve the threads so that the drawbar engages with the threads deeper in the taper, and not the top threads. See the bottom of this page for a bit more detail: https://www.techniksusa.com/downloads/catalogs/Retention_Knobs_Catalog.pdf

But also, you can just buy pullstuds to directly adapt CT40 to deckel's drawbar with no modifications: https://www.singer-werkzeugmaschine...11-zoll-inch-z-b-fur-deckel-frasmaschine.html

Personally I decided to make my own pullstuds for CT40, but if I had known about the singer pullstuds I would've bought 20 of those and been happy. Here's the thread where I went through this: https://www.practicalmachinist.com/forum/threads/bringing-home-an-fp3l.341781/page-2

A few additional things:

Deckel drawbars are an annoying, small metric square drive, mine was already a bit rounded, and the proper wrench was hard to find. So I made an adapter with a 12mm square on the inside and a 3/4" hex on the outside, which allows me to use the same 3/4" wrench that fits my strap clamps and the Kurt vise screw. The adapter is slit across the corner of the hex and square and clamped to the drawbar where it lives permanently, so the drawbar behaves like it has a 3/4" hex on it. Very convenient just like a bridgeport; one wrench for everything (except the horizontal drawbar which remains a 10mm allen key. Maybe I'll adapt that to 3/4" hex next).

Whether or not you make your own drawbar, you'll also want a drive key adapter. I made mine identical to TeryK's in this thread: https://www.practicalmachinist.com/forum/threads/making-a-cat40-ring-adapter-for-my-fp1.312271/

 

[sneebot]

On this machine the horizontal drawbar should have a replaceable 'end'. The end unscrews and allows you to swap in different threaded ends without changing the entire drawbar.

You'll have to make a tool to remove the existing 'end'.

 

[ShotgunRob]

Alcro, I have quite a few mill sk40 tool holders and collet holders. I bought them at an auction with other items and I believe they were used on Deckel equipment. GEWFA and Ortielb brand. I don't own a mill, just a lathe, and haven't figured out what to do with them. If you are interested, PM me and I can send you pics. I have attached the GEWFA catalog page of one of the collet holders item number 05-006-002.