# Crude Threading Stop for the PM1236



## rdfoster (Aug 29, 2013)

After hearing from Tom and Mrpete brag about the threading capabilities of the Hardinge lathe I decided to try to get my PM1236 to do a similar thing. I know it is crude but it works "sort of". It is not real accurate in stopping on a thousandth of an inch but it's close. It takes a little work to figure out how to set it. But as you can see it enabled me to thread almost to a shoulder.

Bob


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## Ray C (Aug 29, 2013)

Hi Bob,

I was just thinking about you.  Where you been?  Anyhow, nice little mod there.  I've thought about doing something similar but then designed a air pneumatic system that kicks the half-nut out when the carriage hits an adjustable air valve.  -Just haven't gotten around to making it.... You know how that goes.

Keeps us apprised on how yours is working out and thanks for showing...


Ray


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## churchjw (Aug 30, 2013)

Ray did you post how your system works?  I love this idea but on my lathe you have to disengage the half nut to get it to stops so I don't think Bob's setup would work on mine but I love the idea. I have done some inside threads to a shoulder and even on my slowest speed its hard to stop at the right place. 

Thanks for posting this Bob its a great idea. :thinking::thinking:

Jeff


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## rdfoster (Aug 30, 2013)

Ray: I've been on vacation in Montana, Wyoming and South Dakota. Glad to be back in the shop. It's pretty cool down there even when the outside temp is in the high nineties. It's supposed to get to 99 today.
I'm working on a cheap and dirty method of sharpening end mills. 

BoG


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## Ray C (Aug 30, 2013)

Jeff,

I have it all sketched-out on paper in a file in the shop.  I measured how much torque it take to operate the half nut lever and calculated the air pressures and orifice sizes needed to effect proper actuation.  I also started to sketch the triggering valve (it needs to be discrete and not continuous) then it occurred to me such things are probably commercially available.  I haven't gotten around to shopping/pricing things.  It's a really simple design that has a pressure switch mounted in a carriage-stop along with a pneumatic operating rod to pop the lever.  It also needs a manual pressure bypass switch to allow the operator to reset the halfnut.


LOL:  The reason I started this design was because I too had a bunch of sleeves with inside threads...  -Necessity:  The mother of invention...

Ray





churchjw said:


> Ray did you post how your system works? I love this idea but on my lathe you have to disengage the half nut to get it to stops so I don't think Bob's setup would work on mine but I love the idea. I have done some inside threads to a shoulder and even on my slowest speed its hard to stop at the right place.
> 
> Thanks for posting this Bob its a great idea. :thinking::thinking:
> 
> Jeff


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