The Home Machinist!

Howdy all. I recently purchased a 1240P jet lathe from the late 70s.

It did not come with a 5c collet adapter so I've been trying to assemble one. I purchased a 5mt to 5c sleeve from ebay but it doesn't seem to fit properly. In this photo you can see the adapter inserted into the spindle.

The lathe came with a 5mt to 3mt adapter, it can be seen in the photo above on the board and here in the spindle.

As you can see the 5mt to 3mt adapter fits fine in the spindle, its large end is 1.75". The collet sleeve I bought from ebay has only a 1.625" large end.
I measured the taper on the 5mt/3mt sleeve that came with the lathe and I'm pretty sure the spindle has a 5mt taper.
Does anyone know where I can find a 5c collet sleeve that will fit this lathe?
Thanks very much for any help.
I know I could make one but I'm not very good with hardening and grinding.
Dan

Dan I've sorta been looking for the same thing I would try machining my 5MT-3MT sleeve but I'm not too sure how hard it is and I'd rather have both.
Best bet, if it's available from Grizzly would be "Grizzly Adapter part# is P4026001 for $29.50 (MT5-OD x 5C-ID"
JFK seems to offer all kinds of MT5-5C sleeves but they mention the "guide line" which seems to refer to the depth into the taper. Imagine, if you can, a #5MT about a foot long, Depending where along that 12" your #5mt in your lathe spindlke falls governs the guide line dia.
http://www.jfkprecisionproducts.com/colletadapters.htm.
Gotta go, I'll be checking back, could you maybe call Grizzly about that part? At $29.95 it would work for me.
Steve

Thanks for the info. I just ordered one from Grizzly, hopefully it will fit properly.
Dan

stevec wrote:Dan I've sorta been looking for the same thing I would try machining my 5MT-3MT sleeve but I'm not too sure how hard it is and I'd rather have both.
Best bet, if it's available from Grizzly would be "Grizzly Adapter part# is P4026001 for $29.50 (MT5-OD x 5C-ID"
JFK seems to offer all kinds of MT5-5C sleeves but they mention the "guide line" which seems to refer to the depth into the taper. Imagine, if you can, a #5MT about a foot long, Depending where along that 12" your #5mt in your lathe spindlke falls governs the guide line dia.
P4026001 om/colletadapters.htm.
Gotta go, I'll be checking back, could you maybe call Grizzly about that part? At $29.95 it would work for me.
Steve

Great Dan! I'll be watching, meantime I may inquire if Buzy Bee can supply one up here in Canukistan.

A MT-5 taper is 1.748 at the nominal big end, so the ebay adapter is wrong, maybe its a Jarno taper, which would be a #13, suitable for what I don't know. A least thats the only taper that works out close to your measurement.

I had a 1981 or 1983 Jet 1236...don't remember which year but I think it was a 1981. It had a MT-5 taper in the spindle. Below is the spec sheet and it looks to me like your's has a MT-4 taper. There are some deviations though as mine has a #2 tailstock taper and not the MT-3 as the spec shows.




This is the Jet I had:


Charlie

I ended up getting a sleeve from Grizzly. It fits. Didn't cost much on upside, the downside is that it is not hardened. The torque arresting pin barely protrudes into the bore, and the outside taper where the pin is had to be ground down before I could put it in the lathe. If I find it has excessive run out I'll regrind the 5c taper. If I still can't it to work I may buy one from these folks,
http://www.jfkprecisionproducts.com/colletadapters.htm
Dan

Mine looks nearly identical to that lathe. It has a 1.5" bore and 40" center distance. It is definitely a 5mt bore.
Dan

Charlie W. wrote:I had a 1981 or 1983 Jet 1236...don't remember which year but I think it was a 1981. It had a MT-5 taper in the spindle. Below is the spec sheet and it looks to me like your's has a MT-4 taper. There are some deviations though as mine has a #2 tailstock taper and not the MT-3 as the spec shows.




This is the Jet I had:


Charlie

The Grizzly adaptor has now gone up from US$29.50 to US$122.50. No longer an economical solution.

Check ebay. At one point there were several sources with the 5C -Morse adapters. There is a guage line so measuring the diameter of the entrance to your taper will help you select from morse adapters with varying nominal sizes.

shars or cdco

not always the best quality, but if you need something to get going