Another little timesaver Click
the small pics for the big shots
Knurled Nuts for Tool Holders
© Frank Ford, 2010; Photos by FF
I use a lot of quick change holders to avoid spending time readjusting center height or overhang, particularly with carbide insert tools. I do find myself readjusting the height of a number of holders - for example, parting tool holders. Whenever I regrind or touchup the cutting edge, it lowers the center height, so I have to readjust for that. One weekend a while ago, it was time for a small fun project, and this one came to mind.
It's a bunch of knurled screws to fit the holders I expect to readjust from time to time.
Starting with 1" diameter 360 brass rod, I plunged in my form tool to make rounded beads along about three inches:
You may notice that I didn't form a completely round bead. Since I would be displace a fair bit of brass when I did the knurling, there was no need to go quite that deep with the cut.
Here's that form tool:
I'd made the tool a couple of years ago by running an end mill into the end of a 1/4" square piece of O-1 steel at a ten degree angle, to provide relief for the cutting edge. I heated it until it was nonmagnetic, quenched in oil, and tempered in the kitchen oven at 400F for an hour.
Then I used my widest parting tool to reduce the diameter between each of the beads:
In came my rope knurling tool:
And then a skinny parting tool to cut off the nut blanks:
Now, I know I could have drilled and threaded several at a time before parting them off, but I'd just acquired a bunch of inexpensive soft jaws for my mill vise, so I decided to use the mill for drilling and tapping this time:
Clamping a spacer in the vise, I cut a shallow recess with a 1" end mill:
Then, it was quick and easy work to clamp the parts and drill:
And, tap under power, simply hitting the reversing switch when the tap broke through:
My holders are Aloris, Phase II, and unnamed Chinese, so I made some for each, namely 10 x 1 metric and 3/8-24.
Instead of lock or keyed washers, I chose to go with some UHMW polyethylene I had, turning it to diameter, drilling and parting:
Now, sporting brass nuts and classy red washers, my holders are easy to adjust without tools:
That's my shop-made tool height setter in the photo above.
And as always, there are some cool leftovers for future projects or more holders:
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