Help ID collet - Cincinnati Grinder work head - similar to R8 but much larger

S

simpsonrl

Plastic

Joined

Dec 8, 2020

• Dec 8, 2020

• #1

Hi All,

I have what I believe is a Cincinnati No 2 work head. The published info I can find shows that it should have NMTB 50 taper. the work head has a draw bar with what appears to be a 1 inch 8 TPI male threads. There is a collet in the work head that fits 1-1/2" dia stock. this collet does not have a 50 taper, so there must be an adapter in the work head to adapt from 50 taper to what ever this is. I will look when I get back home.

Any idea what this collet is?

- female 1x8 threads
- 6 inches overall length
- 1-3/4" body diameter
- 2 inch large end of taper dia
- shape similar to R8, but much bigger

I have a crude drawing, but can't figure out how to attach it???

thanks for the help

added the pic. Note the threads are internal (it is just a poor drawing)

 

J

jdavi581

Hot Rolled

Joined

May 27, 2011

Location

Marathon City WI, USA

• Dec 13, 2020

• #2

Mine came with some similar sized Hendey collets, but external threads


Sent from my iPhone using Tapatalk

 

S

simpsonrl

Plastic

Joined

Dec 8, 2020

• Dec 14, 2020

• #3

When I was back this weekend, I looked closer and there is indeed an adapter. But no markings on anything. I added a few pics to see it that helps over my crappy drawing. I have searched all of the collet types I can find and the dimensions and don't find anything like this and only a very few this large. Thanks for looking

 

J

jdavi581

Hot Rolled

Joined

May 27, 2011

Location

Marathon City WI, USA

• Dec 14, 2020

• #4

My guess is someone used an existing collet, made a stub to fit in the internal thread, to adapt to the draw bar, and adapted the NMTB to the outside of the collet. I have 2 workheads, one does the NMTB on one end and 6H Hendey on the other. The other older workhead is a jarno taper, with a Cincinnati adapter to a smaller Jarno, with a homemade adapter to MT 4.
I would look at the end of the gripping end of the collet and see if something exists, as the other end with the coarse threads appears to be homemade. By the looks of the outside adapter, you could likely use the NMTB by removing this adapter and using an endmill holder.
Joe


Sent from my iPhone using Tapatalk

 

S

simpsonrl

Plastic

Joined

Dec 8, 2020

• Dec 15, 2020

• #5

Thanks jdavi, It did not occur to me that the last couple of inches might be an adapter that someone made. I will look more closely at this when I get back.

Any idea what the collet is? I tried searching for collets with the 1.75" dia body and a length of approx 4 inches and still could not find anything that looked right.

thanks again

 

J

jdavi581

Hot Rolled

Joined

May 27, 2011

Location

Marathon City WI, USA

• Dec 15, 2020

• #6

I am traveling, right now, but I have a cheat sheet that has a lot of collets and their dimensions. Hardinge I believe made the sheets and will make them if needed. It is a handy reference for this.
Joe


Sent from my iPhone using Tapatalk

 

J

jdavi581

Hot Rolled

Joined

May 27, 2011

Location

Marathon City WI, USA

• Dec 15, 2020

• #7

Collets

 

sfriedberg

Diamond

Joined

Oct 14, 2010

Location

Oregon, USA

• Dec 15, 2020

• #8

Tools-N-Gizmos (whose owner is looking to sell out) has a huge list of collet and taper specs. Here's the page for "C-ish" style collets.

 

S

simpsonrl

Plastic

Joined

Dec 8, 2020

• Dec 16, 2020

• #9

Thanks Guys, I have run across those references in my searching. I was looking for something with a body diameter of 1.750". So far I have not found anything.

I will keep looking. If anything comes to mind, let me know.

Appreciated..

 

sfriedberg

Diamond

Joined

Oct 14, 2010

Location

Oregon, USA

• Dec 21, 2020

• #10

Looks like 2J is too small, and 3J and 16C are too big. Yet it seems really unlikely this is some shop-made one-off.

 

Last edited: Dec 22, 2020

S

simpsonrl

Plastic

Joined

Dec 8, 2020

• Dec 22, 2020

• #11

Agreed. I can see maybe cutting the tail end off to put the threaded insert in. But not turning down the OD. And then you would have to custom make the adapter in the chuck also...

The adapter has some markings, very faint and hard to read. but looks like a part number and address??

Markings are:

24300 1073868
COILING ARBORS PA 19914
BUSHINGS PB 44088

part of it almost look like a city in Pennsylvania and zip code. But searching, I could not make any sense of it.