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Two paths to the same end
Tailstock Tool Holder
© Frank Ford, 2008; Photos by FF

Here's another little project - one, like so many others, that I'd been planning to do someday. It's a simple tailstock (Morse Taper #2) holder for tools that might otherwise be expected to be used on a turret lathe. Some time ago I made one that fits the majority of those tools I use which have 5/8" shanks, but wouldn't you know it, I've ended up with some others that are 3/4" shank tools, including my absolute favorite, a Slater Rotary Broach.

A bit over two and a half years ago, when I'd made my first version of this tool, I had the "foresight" to make up a batch of MT2 blanks for future use.  Now, I use the quotes for a good reason because I'm not only lacking in foresight, but hindsight as well.  You'll get a better sense of that when/if you follow this article through to the end.

OK, without any more fanfare, here are five of the blanks I'd had leftover from the previous project:

I'd bought a number of short pieces of 1144 steel from an eBay vendor and made some up with MT2 ends - just for this kind of occasion.

Since then I acquired a Hardinge MT2 taper 5C collet holder:

So, without any difficulty, I mounted one of my MT2 blanks, and drove it home with a lead mallet:

After turning the end to a trifle under 9/16, I threaded it to 9/16-18:

Over on the mill, I drilled a piece of cold rolled steel I'd roughed out to size:

And tapped it to fit the threaded end of my previous effort:

Here, I simply put the mill into low speed and let it feed the tap downward, reversing when it went deep enough.

At the other end of the block, I drilled a slightly undersize hole for a 9/16" diameter cotter, after spending some time calculating the appropriate spacing:

And I finished the hole with a 9/16" reamer:

Here's a short section of 9/16" diameter O-1 drill rod I'm inserting in the hole:

It will be the cotter, after a few more operations.

With the block screwed onto the threaded section of my MT2 adapter piece, I used a small C-clamp to keep the cotter in place as I finished the diameter of the hole, first, truing up the hole with a boring bar:

I had to be careful with RPMs to keep the vibration to a minimum.

Drilling by steps, until I came close to the required 3/4" diameter hole:

Because of the long work overhang, I didn't feel confident about boring the entire job for fear of deflection.

Now that I was very close to final diameter, I used the boring bar to once again true up the hole, working slowly:

Final dimensioning of the hole with a 3/4" reamer:

Pushing out the cotter piece, I could see I had a nice fit:

With the cotter held in a collet, I parted it in half:

I center drilled the outer ends of both cotter halves:

Drilled and tapped the threaded end:


Drilled the other half for screw clearance:

   

And, counterbored for the cap screw:

Each half took a turn in the heat of the propane torch:

And got a dunk in oil:

This his how they looked after an hour at 400 degrees in my kitchen oven:

We won't talk about how the kitchen smelled for the next few hours. . .

This is the finished cotter, with its nice black baked finish:

I set the tool holder in the mill vise at what I thought looked like an attractive angle, and milled away a bit of it:

After milling the angle, I finished off all the surfaces and corners with a 220 grit belt on my sander:

All done, and ready for work:

But that's not all - read on:

AFTER I'd done this project, assembled the photos and written most of it, I chanced to look in my file of future article photos, and I found. . .

. . .a full set of pictures I'd taken while making my first tailstock tool holder, the one for 5/8" tools.

Now, I've said for years that one of the many reasons I photograph and write about my work (mostly guitar repair,  you know) is to help me smooth out process, improve my work, and help me remember how I learned and did things.

Well, let's look at how I made that holder two and a half  years ago:

I'd wanted a longer shaft on this one, so when I threaded the end, I simply gripped it in a round collet:

Besides, I hadn't found the MT2 collet on eBay at that point.

OK, what's this?

Hmm, looks like I chose to grip the block eccentrically in the four jaw chuck so I could bore the tool hole:

What was I doing here?

Oh, yeah, I tapped all the way through the holder for the threads to hold it on the shaft, and then finished the bore out to 5/8" for the section that would hold the tool shank.  I used a hand tap, supported by the tailstock for alignment.  By now I've forgotten how I finished the bore to 5/8".  I think I did it right in place after running the tap through, rather than mounting it on the shaft as I did for the 3/4" tool holder.  That may explain the slightly more than .005" runout I measured on the holder when mounted on the shaft, gripped in a collet.  I hadn't measured the runout before - it just occurred to me to do it today.  Regardless, there's enough flexibility with the long shaft that I doubt the rounout will be an issue.  At least it hasn't been so far.

Over on the mill, I drilled for the cotter, and finished the hole with an end mill, not having an appropriate diameter reamer at the ready:

Then, I cut the angle on the block - if I recall correctly, I was still "designing" this as I went:

OK, cotter time.  First I drilled the end of a piece of O-1 (or was it W-1?) drill rod for screw clearance at the end:

I don't remember why I drilled the rod at this stage, but, then I hardly remember this morning's breakfast, if  you know what I mean.

Then, to align my cut, I ran a 5/8" end mill down into the tool holder while it was supported by the drill rod held in the mill vise:

When I was convinced I had the holder sitting vertical, I figured my alignment would be good enough, so I moved the X-axis until the cotter was flush with the surface of the tool holder block.

Then, after removing the block, I made a single plunge cut with the end mill to contour the gripping surface of the cotter:

This looks familiar - parting the cotter with the same 3/32" cutoff tool I used this week:

And, the same counterbore:

Again, hand tapping the cotter:

After heat treating, it looks just like the other cotter:

After finishing on the belt sander, the tool was ready for work:

And, work it has.  I've used it with a Hardinge turret knurling tool to make over 700 Jack-the-Gripper tools, so far.

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