Help with spindle nose thread

[brino]

Wow, there really is almost no useful info out there about this machine......

I found one small hint in this thread:
http://www.chaski.org/homemachinist/viewtopic.php?t=89005

Post #3 gives a link to a machine tool service company that may have some info.
It is probably worth writing them a note on their "Contact Us" page asking your spindle spec.

-brino

 

[RandyWilson]

The lathes.co.uk link above has a link to their store where they sell the manuals for these lathes.

 

[DAT510]

This subject is something I've chased for a while regarding my Jet 1024p lathe. The one published constant appears to be an 8 TPI tread. The Diameter is a different beast. Depending on the MFG I've found it listed as both MM and Inch. This is the first I've seen at around 2.5" or 65mm.

Attached is what if found listed in a number of different manuals:

Grizzly

Shenwai

Tida

Jet 1024, 1236 PY

 

[Varmint204]

Well at least they were consistent in there inconsistency. I have a 2 1/4" that I miss ordered. any Idea on how to bore and thread this without a chuck? or am I missing a more obvious solution.

 

[RJSakowski]

You said in the first post that you had a blank plate. You could mount that plate on the spindle and clamp your back plate to it. If you were careful in doing so, You could drill three or four holes through both and bolt them together. Jus make sure that you miss the locations for the chuck mounting holes.

As many have suggested before, it is wise to have a stub thread that you can use for a test fit. This is a catch 22 situation for you though. You could conceivably do this by mounting the stub between centers. You will need some sort of a drive dog and will need to mount the blank plate to drive the dog. You can remove the stub and the plate for appropriate test fits. Because you are running between centers, this will not affect accuracy when remounting for another pass. Using pitch wires to measure pitch diameter would also be of value. .072 diameter is the recommended wire size. You can make some makeshift wires from any suitable wire. Drill bits can be used. You can measure pitch diameter with a single wire although the math is a little more complcated.

 

[jcp]

Thanks for the replys, as far as I can tell it indeed looks like 3mm thread pitch. Are back plates available or will I have to make my own? As to the model it has a tag that says KING no model number. What little i have dug up it appears to be L850B, I could be wrong about that.

Do you have a 3.0 mm pitch gage and a 8 tpi pitch gage? Which one fits the spindle correctly?


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[Varmint204]

Do you have a 3.0 mm pitch gage and a 8 tpi pitch gage? Which one fits the spindle correctly?


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These are some of the things on my shoping list.

 

[RandyWilson]

Lay a steel ruler on the threads aligned with the spindle axle. Put 0 directly on the peak of the first fully formed thread from the headstock. If the 1/2" mark falls directly on top of the third thread, 6tpi. If it falls directly on the fourth, 8tpi. If it falls just beyond the third thread it would be 4.0. If it falls past the fourth thread, it's 3.0.

 

[NortonDommi]

Get a decent set of thread gauges in Imperial,(both 60 & 55 degree angles). and a set of Metric gauges. You are just wasting your time without them. I have a friend who keeps sending me inquiries about "what thread is this?" Sends a picture with notes on whatever the brand name on a part is and a 'guesstamate' of the diameter. Over 20 years I have been telling him to buy some thread gauges and a verynear at the least.
63.8 mm sounds right for a 64 mm thread as male threads are always slightly under the nominal size unless there is a special reason. I think JCP is right.

#Here is a handy chart from Maryland Metrics:

 

[Varmint204]

Thanks for all the help. I will get a set of guages asap. And put this to rest once and for all. Looking the chart (thanks NotonDommi) I am pretty sure it is 64 x 3 mm. Now to see if anyone makes any thing for these spindles.