What's new
What's new

Can You ID this 4" Chuck Backplate? Has Hollow Shank? From a Grinding Machine?

morsetaper2

Diamond
Joined
Jul 2, 2002
Location
Gaithersburg, MD USA
This backplate came attached to a Buck 4" lathe chuck. I removed the 4" chuck to a 5C back so I won't have to break down the 5C collet closer to do an operation in a chuck.

The OD of the shank is 1.250, the ID is .870 (thru). Can anyone ID what type of machine would take this shanked backplate? Would it be some sort of grinding machine?

I don't have any use for it. If someone wanted to make a backplate for a 1-1/2 inch +/- spindle this could be a good start.

If someone can ID where this came from so I could better target a possible buyer and get this off my workbench.

Thanks in advance for any help.

http://home.comcast.net/~morsetaper2/FS/4_in_shanked_backplate_4.jpg
http://home.comcast.net/~morsetaper2/FS/4_in_shanked_backplate_2.jpg
http://home.comcast.net/~morsetaper2/FS/4_in_shanked_backplate_3.jpg


4_in_shanked_backplate_1.jpg
 
Last edited:
I would venture to say someone was grabbing it in a larger three jaw chuck , to avoid changeing the chuck , for a quicky small job. A handy thing to have around.
Dave [acme thread]
 
I have bought several Buck 4" Ajust-Tru chucks on eBay that were mounted on the KO Lee taper shank backs for a sensitive work head. It would be easy enough to turn the taper to a convenient straight diameter or cut it off and put a thread into the remaining plate. I kept the taper shank adapters, but have not yet needed to modify one. I don't recall ever measuring the taper, but I suppose it is a big B&S.

Larry
 
I have bought several Buck 4" Ajust-Tru chucks on eBay that were mounted on the KO Lee taper shank backs for a sensitive work head. It would be easy enough to turn the taper to a convenient straight diameter or cut it off and put a thread into the remaining plate. I kept the taper shank adapters, but have not yet needed to modify one. I don't recall ever measuring the taper, but I suppose it is a big B&S.

Larry

Larry, I believe they were BS#11 tapers. The one I have is straight shank.
 
Yes. I was thinking someone modified the one you have. Larry

Looking at the 2nd linked photo the end of the shank (at about 2 o'clock) has a number stamped into the face between the OD & ID. Which leads me to believe it hasn't been modified, because care was taken to get it on that face between the OD & ID. But again, my guess. I'm pretty sure a BS#11 taper would be longer than the 2" shank.
 
I was in the shop and took a quick look, with no written notes, at three Buck 4" back plates I have. Two shanks are tapered, one larger than the other, and both have I.D. a bit over 1 inch. I suppose one of them is 11 B&S. Then I have a 1.25 straight shank with .88 I. D. That one has marks showing the cylindrical and flat faces were ground on an O. D. grinder, so it was meant for a precision application, probably not for holding in a big chuck. The taper shanks have bores too large to cut them down to 1.25 O. D. for gripping in a big chuck, but they could be made into larger straight shanks.

The question of what the 1.25 shank was meant to fit is still open. I could hold it in a Jacobs Rubberflex collet chuck, a Hardinge Sjogren 2J collet chuck or a Burnerd Multigrip collet chuck or even in a Hardinge Cataract No. 6 lathe with 6C collets. But I suspect there is another answer.

Anyway, there are at least two existing 1.25 straight shank adapters.

Larry
 








 
Back
Top