JT 2-1/2 Spindle Chuch replacement

Norm Dresner · 2006-03-02T14:15:19+00:00

I've got a (roughly) 35 year old AMT (American Machine Tool) bench drill press that's still working wonderfully and although I've thought occasionally of replacing it with a more modern DP with conveniences like a larger table, a ratchet drive on the table and possibly even variable speed, I still can't bring myself to part with this marvelous piece of machinery.BUT ... I'd like to purchase a better chuck. Some of the drilling I do with this beast is in the #70-80 range in both model working and PC board manufacture and while I don't yet have the tool to measure the runout (it's been ordered), I think that I need something with a little better precision, even if a smaller range.HOWEVER ... I don't think I've ever seen any product offered in the last 30 years for a JT#2-1/2. Is it a complete orphan or is something available?TIA Norm

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DoN. Nichols 20 years ago

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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.

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DoN. Nichols 20 years ago

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.

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drillpress 7 years ago

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.

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drillpress 7 years ago

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.

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Chitty 6 years ago

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!

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Chitty 6 years ago

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 Iâve 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!

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