JT 2 1/2 arbor

wa5cab said:
Unfortunately, it would appear that Jacobs quit making chucks to fit a 2-1/2JT sometime prior to 1961.
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The JT6 being so close to the obsolete JT 2 1/2, fitting a JT6 chuck on the spindle is certainly worth a try.
If the fit is not acceptable to you then it should be easy to lap the spindle nose until you are happy with it.
It would not be hard to imagine that the spindle nose could already be 'modified' to JT6 dimensions and the info plate was never corrected accordingly.
 
Tozguy said:
It is not clear to me exactly what is missing and what you are looking for.
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The arbor is missing. There was one person in-between me and the original owner. When the drill was given to my friend, the original owner said he was keeping the arbor because "it is special".

I am looking for a JT 2 1/2 arbor (the other end can be JT 33 or whatever; something common) so I can get a drill chuck in it and use it.

I modified my original post to hopefully clarify.
 
Tozguy said:
If the fit is not acceptable to you then it should be easy to lap the spindle nose until you are happy with it.
Click to expand...

I've kind of assumed I would have to go this route, but before I do I was hoping maybe someone had one of these old drills laying around broken/unused and could salvage an arbor from it.
 
martik777 said:
Mine is also a 2 1/2,made in 1985, I replaced it with a keyless JT6, seems to work ok
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I almost missed this comment. Did you do any lapping or anything else to modify it? Or did it just work right off the bat?
 
schmidty13 said:
I am looking for a JT 2 1/2 arbor (the other end can be JT 33 or whatever; something common) so I can get a drill chuck in it and use it.
Click to expand...

Never seen or heard of such an animal.

If the spindle nose on your drill press is a male 2 1/2JT then just buy a drill chuck with a female 6JT mount.
The chuck will slip right on to the spindle, no need for an arbor of any kind.
The difference between the tapers of 2 1/2JT and 6JT is .0013'' per side (.0026'' combined) and the nose of the 2 1/2JT will be tight in the 6JT socket of the drill chuck. This is where you have to determine how well the taper mount holds the chuck and take it from there.

If the spindle nose has a female 2 1/2JT socket then you will probably have to start with a Morse taper arbor (MT2) and modify it to fit your spindle.

or am I missing something?
 
There's another option here: cut your losses, get rid of that DP, and buy another. Since it was given to you
you you have nothing in it, and it seems clear at this point why it was free. CL is usually full of inexpensive Chinese
and older American DP's at low cost. An older Craftsman or Delta DP would, in the long run be a good choice.
Or, you could find a bench top Chinese DP with the same column diameter and turn it into a floor model.
 
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schmidty13 said:
I almost missed this comment. Did you do any lapping or anything else to modify it? Or did it just work right off the bat?
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iirc it just fit as is but as others have said you could lap it in. I was the original owner of the DP so it wasn't modified
 
Is the spindle male or female? (I'm confused...)
If I can remember when I get out in the shop today I'll dig around in my box of old DP items.
 
It's female. Which the more I think about it, confuses me, too. So, it originally had an arbor that was JT 2 1/2 male in the spindle, to JT (something) in a chuck? From what I've seen, there are no JT to JT arbors.

:dunno:
 
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