Retracting tool holder

[pdentrem]

I purchased the Hemingway Tools kit for the Retracting Tool Holder. What you receive are excellent drawings plus the article originally done by the designer G. Thomas, and all the blank steel components as well as the screws, drill blanks for pins etc. Naturally the screws are British thread, not Imperial nor Metric. Since I do not have the taps to thread for these, I replaced them with regular 6x32, 8x32, and 10x24 hardware. I used a knob and handle shaft that I had on hand, instead of cutting a steel ball for the knob.
Total time to finish the build was about 10 hrs. As I did the milling on a light mill I had to take more time than if I had used the BP at work. I have included some pics of the completed holder, before I do the metal treatment to complete the job. I set it up to be used in a Phase II/Aloris clone holder. There is enough meat to cut a vertical dovetail to fit the tool post directly, I would do that if I did this again.
Next week I will beadblast the outer surfaces and do a Phosphate coating to protect the metal.

 

[billinecin]

Very nice. I think I need one of those!

Bill

 

[pdentrem]

Yes I have his site on the short favorites list. I have looked at that dog clutch setup. Once I finish a few other projects that will be looked at more seriously.

 

[pdentrem]

Here is the completed holder after the metal was beadblasted and phos coated and pins installed and the handle clocked for full movement.

 

[gmcken]

Great work This is on my to make list

 

[brino]

Great project.
Thanks for sharing!
-brino

 

[higgite]

pdentrem,

If you’re still following this thread, how has the tool worked out for you? Have you used it much? What size machine(s) have you used it on? I keep waffling back and forth between ordering one of those for threading or making a pivoting tool holder.

Tom

 

[larry4406]

Nice looking tool!

I am a total newbie to machining. What exactly does this do and what are its advantages?

 

[brino]

What exactly does this do and what are its advantages?

Hi @larry4406 ,
The retractable tool holder is mostly used when single-point thread cutting on the lathe. Threads are too deep to be cut in one pass, and so require you to make several passes each taking off a little material. Normally, with a regular tool holder you would make one pass (right to left) and then have to turn either the cross slide or compound slide to retract the threading tool so that the tool does not contact the work piece, then move the carriage back to the start, then advance the tools back to where it was plus the depth of the new depth of cut (DOC).

With the retractable tool holder you use that lever to retract the tool back so that it will not contact the work when you move the carriage back to the start. When back to the start use the lever again to put the tool right back to the previous depth, then advance the tool a little for the new DOC.

It means you do not need to remember or write down the original dial setting while thinking about the order of operations and trying to remember what thread-dial line to re-engage the carriage feed.

-brino

 

[larry4406]

Brino - that makes perfect sense. Thank you. Quite clever.