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Old 07-25-2007, 05:33 PM
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KurtB KurtB is offline
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Default The Hobo Holder - Part II

After the mammoth original coin collet thread, I decided to finally get off my rear and get a design done which will do the job I originally intended. Rather than hog all of Steve's bandwidth, I made a web page with all the gory details.

I've had a machinist hobby site for years, and I've always recorded my projects in this manner, so if you're not into machine work, it'll be rather dry. But it does show the detail and care that goes into such a simple device.

In a nutshell, it uses two pieces of tool steel, sandwiched together. A steel pin at the bottom forms a fulcrum. At the top, a recess is precision bored to hold only the rim of the nickel. Finally, a hole in the side near the top carries the clamping screw, which is a shoulder bolt. The very last operation is the removal of 0.010" of material from the faces of the blocks where they meet in the middle. This gives the holder clearance so that when the screw is tightened, the holder bears on the coin, rather than on itself.

Apart:



And together with a nickel installed:



Some initial tests showed that the holder grips a large range of nickels, which can vary almost 0.010" in dameter. I tried some real intense cuts with my Palmcontrol at full blast, and with each cut gouging out a huge strip of metal, and it appears that the holder is doing what it is designed to do.

I'm going to get one or two of these out to some Hobo people, and if all is well, I'll crank a few out. These are pretty labor intensive and will not be as cheap as I had hoped. Thank you for being patient with me... I know I really whipped up this whole concept and haven't done diddly with it.
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