JT 2-1/2 Spindle Chuch replacement

According to Norm Dresner :

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That I find amazing. What brand of 1/2" drill chuck is it which closes down to grip a #75 drill bit?.

Can you check whether it will grip a #80?

If it does not, you can go for the sensitive adaptor (either the one in the eBay auction to which I pointed, or another similar one) which will also give you more control and feel in feeding the drill bit.

I've done down to #70 in the tailstock of my small lathe -- an Emco-Maier Compact-5/CNC, with a 0-1/8th Albrecht chuck on a #1 MT arbor. And that worked well enough in 12L14 steel -- but I kept worrying about the lack of feel that the leadscrew gave me with that tiny a drill bit, so I was *very* careful.

Good Luck, DoN.

Reply to
DoN. Nichols
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That is actually quite similar to many of the sensitive drill presses to be found on eBay currently.

I agree that feel is an important consideration with such tiny drill bits.

Enjoy, DoN.

Reply to
DoN. Nichols

According to Norm Dresner :

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O.K. That could be what they used -- though Lord only knows why they would mark that on the machine, when there is a Morse taper socket in the spindle to allow you to change arbors for whatever size your favorite drill chuck happens to take.

Enjoy, DoN.

Reply to
DoN. Nichols

replying to Norm Dresner, drillpress wrote: I also have a JT 2 1/2 Chuck on a Columbia 515 drill press made in Taiwan. I compared the taper dimensions with the published Jacobs taper dimensions and found that it was likely consistant with a current Jacobs 6 taper. I purchased a new Jacobs 6 chuck and it fit perfectly. I have no idea how that conversion can be explained.

Reply to
drillpress

replying to Norm Dresner, drillpress wrote: I also have a JT 2 1/2 Chuck on a Columbia 515 drill press made in Taiwan. I compared the taper dimensions with the published Jacobs taper dimensions and found that it was likely consistant with a current Jacobs 6 taper. I purchased a new Jacobs 6 chuck and it fit perfectly. I have no idea how that conversion can be explained.

Reply to
drillpress

replying to drillpress, Chitty wrote: Looking for info on a JT 2 1/2 taper drill chuck also. Mine is a similar Taiwan marketed in North America. The Jacobs 2 1/2 taper is its very own taper but used widely in the era on Japanese configuration but appears to be no longer available these days. The JT

6 is close but a different bird. Anyone have any luck? The spindle on my machine is a one piece unit with the lower end being a male JT 2 1/2 that is intended to mount the appropriate chuck directly to the spindle without the typical double ended arbor between the spindle and chuck. Only option I?ve found is to pull the spindle and hope a machinist can convert the spindle without error to a modern available taper. Share your info please!
Reply to
Chitty

replying to drillpress, Chitty wrote: Looking for info on a JT 2 1/2 taper drill chuck also. Mine is a similar Taiwan marketed in North America. The Jacobs 2 1/2 taper is its very own taper but used widely in the era on Japanese configuration but appears to be no longer available these days. The JT 6 is close but a different bird. Anyone have any luck? The spindle on my machine is a one piece unit with the lower end being a male JT 2 1/2 that is intended to mount the appropriate chuck directly to the spindle without the typical double ended arbor between the spindle and chuck. Only option I’ve found is to pull the spindle and hope a machinist can convert the spindle without error to a modern available taper. Share your info please!

Reply to
Chitty

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