[loldmopar]

Howdy,

A few years ago, me and my father were cleaning out his uncles tool shop and we acquired an old metal lathe. It has some retrofitting done to it since I'm guessing from the looks it was once used in a manufacturing plant with the turning power coming from a source overhead (see pics). After getting it back to my dad's basement I started messing around with it to see how it worked (I dabble with metalwork, don't know a ton). I realized it did not have a chuck on it, but have no idea what kind of chuck would go on it. I looked on ENCO.com but obviously there are numerous different kinds of chuck mounts . Please take a look at the attached pictures to help me out. Any information about the lathe and what I can get to be able to use it would be appreciated.

Thank you,

luke

[mfgbydesign]

collet closer missing. Yours appears to have a small spindle bore which makes me think it takes a front closer (no draw bar thru the spindle.
Take a look at this page for a couple examples of front collet closers:
http://www.lathe.com/catalogs/AC-210.htm
Figure out what the taper is in the nose. If no taper might be a push style, like W&S #1 which is also shown in the catalog.

[Geof]

Those old machines had a flange screwed onto the thread and the chuck bolted onto this. Scroll down the page on this link and you will see them:

LittleMachineShop.com - Lathe Chucks and Adapters

If you cannot find one that matches the thread on your lathe you may have to get someone to make one.

[loldmopar]

Take a look at the attached picture, I have marked out the measurements for the threads. Since I am new at this, I didn't know what else to measure. I'm guessing I need a 1-1/2" 6 thread adapter. or should I get the 8 thread and screw it on as far as it can go? What size chuck should I get? 3 or 4 jaw?

Thanks for the help!

L

[juergenwt]

You need the exact thread inside your adapter, It can be slightly loose but the 1.500 dia is for locating and should be a good fit. Measure it and get a adapter that will be no more than .0002 to .0005 over size. Also the back of your adapter should square and running true with the 1.500 dia. The 1.500 and the back is where you locate. Shop around for a chuck (3 jaw) with a 11/2 - 6 adapter plate. Make sure it is 6 threads per inch.

Ps.: Go back to your uncles shop and look. There has to be a chuck somewhere.

[mfgbydesign]

If the thread pitch is 3/32 then the Threads Per Inch (TPI) is 32/3; it doesn't measure up. Make a measurement across several threads with a dial caliper at either the crest or root and divide by the number of threads measured for the pitch. Take the pitch and invert it for the TPI.

It also looks like there may be a shoulder the chuck or adapter plate might seat against, but I agree with prior post get the 1.5000 dia as close a slip fit as possible. Again, look for that chuck or collet closer; on my Logan they screw right on.

[Geof]

If it is indeed six threads per inch you are a bit out of luck because there is nothing listed on that page I linked to. You can get un-threaded adapters but then you have the problem of getting a good measurement so someone can do the thread.

Having a really good fitting thread is not critical because the alignment does come from the 1.500" diameter and the adapter butts up against the shoulder at the end of this diameter.

Also the trueness (?) of both the 1.5" diameter and the bore of the adapter to its face is not critical because the normal practise is to screw the adapter tightly on and then machine the face and the boss the chuck locates on in position.

Incidentally if you get this machine running don't get any idea to drive it with a three phase motor. With three phase you can reverse the motor immediately from forward rotation and if you do this with a screwed on chuck it can unscrew and you finish cradling a rapidly spinning chuck in your hands.

[loldmopar]

I measured the threads again, and since the threads do not extend a full inch to measure TPI, I measured a half inch and doubled it. Came out to have 6 threads in a half inch crest to crest. so that would be 12 Threads Per Inch?

[Geof]

Just wondering. Does the picture show how you measured and counted crest to crest? This is five threads in 1/2" or 10tpi

[loldmopar]

Yes that is how I counted, so it is 10 TPI?

[Geof]

If it is 1-1/2-10tpi it still does not match anything in the link.

One way to confirm the 10 tpi is to get a 3/4" NC bolt which is 10tpi and see if the threads match. One inch NC is 8tpi.

[loldmopar]

I went back to measure and turns out I was wrong about the OD of the threads, It is actually 1-1/8". does that mean its rounded to 1" or is it something that is totally rare and i'll need someone to make me an adapter?

[Geof]

Okay if the thread is 1-1/8 you are getting closer. A 1-1/8" diameter National Fine thread is 12 tpi. Maybe I have lead you wrong with my little picture about measuring threads because if it is 12tpi then it could be 1-1/8 National Fine.

You could get a 9/16 National Fine bolt which is 12 tpi to confirm the tpi or get a 1-1/8 National Fine nut and see if it will fit.

If it is a standard National Fine thread you should be able to get an adapter made without too much trouble.

[mfgbydesign]

found some "1.1/8x12" Myford chuck adapters on ebay. When I bought a Logan I joined a group on Yahoo. You might try something similar once you identify the lathe.