MT1 Tool Extractor..Sherline or Small Lathe..Prints

[jjr2001]

I had been using the old method of placing a 3/4-16 nut on the spindle prior to installing the MT1 tool holder.
Sherline 2000 Mill MT1 Tool Extractor
However I have been known to forget to put the nut on prior to installing the tool.

So I checked the spindle diameter and found it to be close to the diameter for threading to 7/16-20.
I used a spiral machine tap and it threaded to 3/4" deep without any problems. The back end of
the spindle is not all that hard. I wanted at least 1/2 inch of thread engagement for the extractor.

Next I needed an "extraction tool" to push the taper out of the spindle and came up with this:

Two were made. One for short MT1 adapters and one for Long MT1 adapters.
Both were made using standard grade 5 bolts and plated steel rods.
Bolts were faced and drilled on the lathe using the brass adapter and lock nut with a .250" hole .500" deep.
Next the rods were cleaned up and turned to .330".
Then one end of each rod was turned to .250".
All that remains was to solder the two pieces while holding them in alignment in the lathe.
Threads were chased with a standard threading die to clean them up.

Presto, I now have a way to remove MT1 tools without ever pounding on my Sherline lathe or mill.
This method may work on Taig or other bench top tools.

Cheers, JR

[mklotz]

The inertia type, e.g....

Lathe spindle tools

are typically termed "knockout bars" so I guess that makes your version a "screwout bar". On second hand, that doesn't sound like something one would say in polite company so better to stick with "extraction tool" which only ignites images of dentists.

Now that you have the left end of the spindle threaded, you might want to think about making a steady for those cases where you're turning long items with a lot of stick out. Beyond the risk of bending into a thrasher, long items inside the spindle can vibrate and rattle which can be distracting. Perhaps it's not as much a problem on smaller lathes as it is on the larger ones.

My version is nothing more than an aluminum faceplate-like device that threads onto the existing male threads on the left end of the spindle. Three slotted "jaws" (actually Unimat milling clamps) bolt on the faceplate and keep the workpiece roughly centered so it doesn't vibrate. (A separate wooden rod with various sized holes bolts to an adjacent table and prevents whipping on those rare occasions when I turn long stuff.)

[jjr2001]

Thanks Marv, Good idea for a steady or spyder device for the spindle. It would be easy to buy a few extra 7/16-20 x 1/2" long bolts and just drill them out to the desired diameter for thin rods...

Cheers, JR

[DIYer]

Thanks jjr2001! We've added your MT1 Tool Extractor to our Lathe Accessories category,
as well as to your builder page: jjr2001's Homemade Tools. Your receipt:

MT1 Tool Extractor by jjr2001

tags: lathe, extractor

[old_toolmaker]

jjr2001,

Nice work and certainly solves your dilemma. I have used brass tipped knock out bars in lathes for years but they can cause a jarring force to equipment which is not necessarily a good thing and is better avoided if possible. I have an adjustable backstop for my lathe spindle which can be used as an MT extractor when needed.
Thanks for posting this!

[old_toolmaker]

jjr2001,

I looked at your drawing. May I ask what CAD program you use?

[jjr2001]

Thanks for your comments Dick, I have dabbled with a lot of cad pgms including Autocad, Inkscape, Sketchup, and Alibre.
I find that TurboCad (once you get the hang of it) is extremely versatile with more functions that I will ever learn.
I now use TurboCad for all of my 2D drawings. After years of working with it I find it "easy"..

Cheers, JR

[old_toolmaker]

Thanks, JR!
I am currently trying Libre Cad.
I think I will get along well with it but as with anything new, there will be a learning curve.

[jjr2001]

Libre Cad is a great 2D program and you can find a lot of tutorials and examples on youtube.
I have learned almost everything I know about Turbocad from the tube!

Cheers, JR

[old_toolmaker]

Hi jjr2001,

Thanks for the YouTube tip. I continue to read and practice, but I don’t often think of using the Tube.