Retractable Lathe Tool Holder

mickri said:
I don't know what it is about threading that makes people think that they have to make multiple moves faster than the speed of light at the end of the thread they are cutting. All you have to do is disengage the half nuts for imperial threads or stop the motor on metric threads. The tool bit can happily sit there cutting a groove. The groove won't have any affect on the thread. Then you can calmly do what you need to to make another pass.

If all you did was cut threads all day long and having this gizmo would let you cut more threads in a day then by all means get one. Or if you want a cool project to make then make one. Otherwise why spend the money on something that you really don't need.
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I've been (successfully) cutting threads for years, but a quick retracting toolpost would greatly improve my metric threading. I do things a little unconventionally - Make sure you read to 'You have to keep the half-nuts engaged for metric threading - not! . And this seems like a real time saver.
GsT
 
The photo shows a lever locking topslide that can be moved and locked at any angle on the cross slide. It also has a lever operated withdrawal movement that can withdraw the cutting for thread cutting from either an external or internal thread.
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Here is one I found and have used. It works well.

In the post I made a lot of double pics being 2014 and me newer to posting then.

It shows the thing taken apart so someone could make one using the pics. It is only 3 parts and 2 covers.

www.hobby-machinist.com

Can anyone identify this retractable tool post?

I found this retractable tool post. It is for BXA size QCTP. It retracts fine and looks very solid. So simple, just 3 parts beside the two covers. I'll post pics of the actual tool together and then the tool apart. No maker markings on it at all. With the pics someone may be able to make one.
www.hobby-machinist.com www.hobby-machinist.com
 
I’m comfortable single point threading, but I don’t do enough to enhance the process beyond a typical lathe set up. Still a retractable system would be very cool. I like the design from TheShedDweller. The slide is kicked over 30 degrees, so it retracts up that thread flank. Perhaps if threading to a shoulder it gives you a little more time? He publishes a nice set of plans on his project page (and posts on YouTube).
 
How about incorporating a cross feed stop? It's easy to do and costs nothing.
 
I had seen one a while back that used a solenoid for a release. It had a spring retraction that was held in cutting position by a sear. When the solenoid was activated, the sear was pulled back and the cutter retracted by the spring. A microswitch activated the solenoid which eliminated reaction time from the picture, permitting very precise positioning even at higher threading speeds, With a proximity switch or optical switch, repeatability could be to a thousandth.
 
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