MT#3 x MT#2 Adapter Mods

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platypus20
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Location: camillus, ny (syracuse)

MT#3 x MT#2 Adapter Mods

Post by platypus20 » Sun Oct 17, 2010 9:28 pm

With the new lathe, the tailstock on the Atlas was MT#2, but on the Jet it is MT#3. For the time being, because of budgetary restraints, I'd using all of the tailstock tooling I have, thats all MT#2. So I took a MT#3 x MT#2 tanged adapter, and cut it down to work in the Jet tailstock. I cut it so it ejects out of the tailstock about an 1/8" before the tailstock quill is fully retracted. Not real hard job, but at this time a necessary.


1 - the before and after
2 - another view
3 - in the tailstock


jack
Attachments
3x2 mt adapter 009x.jpg
3x2 mt adapter 006x.jpg
3x2 mt adapter 002x.jpg
jack

randyc
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Re: MT#3 x MT#2 Adapter Mods

Post by randyc » Sun Oct 17, 2010 9:47 pm

Hey Jack, that's a neat "before/after" photo trick !

Rosco-P
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Re: MT#3 x MT#2 Adapter Mods

Post by Rosco-P » Mon Oct 18, 2010 12:42 pm

I understand the Jet tailstock ram is MT3, the Atlas was MT2. But why was it necessary to shorten the tang on the adapter? Was the length of the tang causing to eject (prematurely), before the TS barrel retracted fully or nearly so? Wouldn't this be an indication that the Jet TS screw was too long?

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platypus20
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Re: MT#3 x MT#2 Adapter Mods

Post by platypus20 » Mon Oct 18, 2010 3:40 pm

Rosco-P wrote:I understand the Jet tailstock ram is MT3, the Atlas was MT2. But why was it necessary to shorten the tang on the adapter? Was the length of the tang causing to eject (prematurely), before the TS barrel retracted fully or nearly so? Wouldn't this be an indication that the Jet TS screw was too long?
No, the Jet screw is the right length, its the added length of the tanged adapter that causes it to eject to early. The adapter tang causes the total length of usable TS quill travel to be cut down to about 2" of travel. The modification was quite necessary to get the full TS quill travel.


jack
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Rosco-P
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Re: MT#3 x MT#2 Adapter Mods

Post by Rosco-P » Wed Oct 20, 2010 11:54 am

Does Jet allude to this in the manual for the machine and offer adapters such as the one you modified? Seems like you would encounter this problem with every MT3 shank drill as well. The tang dimensions on MT tooling is standard and has been for about a hundred years. Sorry, I can't believe the reduced quill travel is a design "feature". I'd be on the phone to Jet.

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platypus20
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Re: MT#3 x MT#2 Adapter Mods

Post by platypus20 » Wed Oct 20, 2010 7:27 pm

I just ran a MT#3 arbor and drill chuck, in and out of the tailstock, and it is fine.



jack
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