I’ve had it in mind to make a bolster plate for an old Famco #3 arbor press, so I’d been keeping my eyes open for some appropriate steel stock. I was therefore pleased when I found some 9″ x 3/4″ thick cut-outs in the surplus bin at one of the local steel suppliers. Of course the stock sat around for a while, but recently I set out to make the bolster plate. My initial thought was to weld the two disks together, but bolting them seemed to me a better solution. With the disks securely bolted together, I rough-sawed the slots, then cleaned them up in the mill. The edge and top didn’t really need to be done, but why not? Besides, it gave me an opportunity to use the little face mill I’d made the arbor for (though the resulting surface finish did leave a bit to be desired). Regardless, the old arbor press is now as good as new!
Some time back I got a small face mill in a box of other tools at an auction. Since the taper shank was incorrect for my milling machine, a new arbor would be required. I had a chunk of tool steel that was about the right size, so with a little lathe and mill work I made a new arbor. In retrospect I should have planned the drive lugs a little differently as the welds don’t look all that great, but the arbor is serviceable.
Early on I made a stupid mistake by not properly engaging the collet in its nut before tightening it—the result being an end mill and collet very tightly held by the chuck and no way to remove it. Mistakes like this are pitfall of learning on my own, but also an opportunity to learn and to make tools to solve a problem. The solution I came up with was to make a split-collar to engage the ejector lip of the collet, and then a separate nut to apply force against the split-collar. An indexing head with a 6-jaw chuck held the split-collar firmly against the collet and resisted the turning force applied to the nut. After a moment the collet and end mill was freed and a valuable lesson was learned.
An SK40 collet chuck is an adapter which fits into the ISO 40 taper spindle of a milling machine, which in turn uses a collet to firmly grip an end mill. This particular collet chuck is less common in that it uses the S20x2 “buttress” thread used by Deckel milling machines. The collets themselves are similar to the TG series of collets. All of which is to say: if I couldn’t get this apart without damaging anything, I would have a very expensive mistake on my hands.