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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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