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.)

[old_toolmaker]

mklotz,

Nice idea for making a small spider for the spindle. I never thought about doing that! Thanks for posting!

[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

[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

[Paul Jones]

jjr2001,
I have been using TurboCAD since the early 1990's and wish they had kept it simple. There are now more special features and multiple ways for doing the same functions. Unless you are using TurbCAD everyday it is difficult to start up from where you left off. There used to be a wonderful website at www3.turbocadcommunity.com for help but it disappeared in September 2017.
Paul

[jjr2001]

jjr2001,
I have been using TurboCAD since the early 1990's and wish they had kept it simple. There are now more special features and multiple ways for doing the same functions. Unless you are using TurbCAD everyday it is difficult to start up from where you left off. There used to be a wonderful website at www3.turbocadcommunity.com for help but it disappeared in September 2017.
Paul

Hi Paul, the evolution of add more stuff just continues. I do remember www3.turbocadcommunity.com and miss its demise. I have Turbocad V21 and that is where I stop. I do not use 25% of the features but I like the tools I have become accustomed to. I do not care for the new pay per month or yearly subscription craze. Everyone wants to be the phone company. I prefer to buy once and use it as long as I like it.

Reminds me of the free Google Sketchup. I learned how to make detailed airframe parts for RC models and then they stabbed us in the back, sold it to Trimble and now it is a subscription...I do have an old copy and can use it if I have to but just don't want to put more effort in something that you cannot buy. I remember enough of it to be dangerous!

I think Win10 will be my last operating system for the same reasoning. It does everything I need it to and I own it on several machines....

Cheers, JR

[old_toolmaker]

Hi Jr,

I used CadKey and then Key Creator for years. Every year another $$$$ to pay to stay current with unneeded upgrades. I’m not opposed to learning but for a hobby there are limits.