The Home Machinist!

Looking to purchase a 3 or 4 jaw Chuck for a Pratt and Whitney model 1689 bench lathe

wow that's sm..all Small

LIALLEGHENY wrote: ↑Tue Apr 28, 2020 12:22 am wow that's sm..all Small

Here's the specs;
http://qfguides.tripod.com/american_lat ... ecific.htm
http://www.lathes.co.uk/latheparts/page12.html

Thanks for the info. This should help.

Hey, how about some help here?
I read the beginning of this thread when it was posted, and I'm troubled by the D1-2 designation.
The D series of spindles starts at D1-3, so I have to assume that it's not a D type attachment, but simply named a D1-2, likely long before the D series of spindles was introduced to machine tools.

Anyone know? How does this chuck, named D1-2, mount to the machine? Threaded? That's what I expect.

H

Actually, the first reference above does show a D1-2 mount.

Thanks for that, Russ. For what ever reason, I had overlooked that bit of information. Don't claim to be an authority on D spindles, and have never seen one that small, so I was in error in stating that the D series begins with the D1-3.

Now then, that said, it could be that the chuck in question really is a D1-2. I expect it would be exceedingly hard to find, maybe even bordering on the impossible. Were it not for the Monarch EE, the D1-3 isn't all that common.

One thing I can say. The D type spindle is certainly my first choice. In my opinion, it has proven to be a very reliable and fast method of attaching a chuck.

H

Here's a picture of the D1-2 on a Pratt & Whitney lathe


Steve

Harold, when I first saw this post I thought the same thing, there is no D1-2 taper....but I too stand corrected.

There is however something wrong with the chart attached above: http://qfguides.tripod.com/american_lat ... ecific.htm
The chart says the D1-3 taper "B" dia is 2.5", where it is actually 2.125" I had to double check and look at some other charts....and also checked a chuck and faceplate I have.
So I have to ask what would the taper diameter be on the D1-2?

Nyle

Nyle,
I hadn't noticed the error on the chart, but you have to be right, as the difference stated between a D1-3 and a D1-4 is only a few thou. Having operated machines with each of those, I know that's not correct. The D1-3 is noticeably smaller, as must be the D1-2. I'm now used to the D1-4, as that's all I've used for the past 53 years.

I commented on the D type as being favorable. I can still remember running a 48" sliding gap bed lathe at Sperry. It was a LeBlond, and purchased new in 1956, when they were still using the L spindles. The spanner for that spindle was a real handful. The system worked well enough, but it was much slower to install than the D spindles on all the rest of the lathes in the shop.

H