Originally posted by Jim Riser:
I put the "little gray cells" to work on this
Didn't realize you were a Poirot fan :)
A Snapple bottle! You can almost put your hand down into that. I want my coin vise to fit down through a 5/8" diameter bottle neck.
Yes, a Snapple bottle is pretty big. But for most readers of the forum, the mods to the original design that I mentioned will allow them to get a coin in a bottle after a trip to Lowe's or Home Depot, and an afternoon in the basement, if they are reasonably handy and have a reasonable set of home tools. After doing so, however, they can judge for theirself, based on their skills, tool collection, and desire, how far they want to go. With most projects like this, the first time you do it is a prototype anyway -- why not do it in such a way as to guarantee some level of success? Then start optimizing via better raw materials, better design, more complicated fabrications, etc. Tell most people that they've got to start hardening steel, and have access to a milling machine, and they'll go learn a new version of Triumph instead.
The largest diameter bottle neck that a half dollar will go into is about 1/2 the diameter of the coin (30 mm/2, or 15 mm) (assuming you only bend the coin one time). The biggest cross section of the parts I used is about 26 mm, and a couple of mm of the corners could be ground down on a bench grinder (again, commonly available tools. . . ) with no loss of strength or utility. A Snapple bottle neck has a minimum I.D. of about 29 mm. Obviously, "impossibility" is not maximized with my particular example. If a slightly smaller necked bottle is easily available, use it. If you have access to 3/4" wide steel bar stock rather than 1", use it, and you can do an even smaller bottle.
The long tube is machined from medium wall stainless steel.
I tried screwing SS tubing into the top piece of the vise. Worked fine, until I started squeezing the coin, and it stripped out. It turned out that when I threaded the tubing, it cut threads deeply into the tube, and significantly reduced the wall thickness. I suppose I could have rounded up some tubing with a thicker wall, but it was easier to get pipe nipples.
Bill, do my modifications to the Eng coin vise make sense to you? By making the pieces from round stock, I can get maximum thicknesses of steel for the vise parts for the size of bottle hole.
Absolutely. If I were trying to get the absolute largest coin into the absolute smallest necked bottle, these (or something very much like them) are the steps I'd take. But my original goal was to get a coin into a bottle soon, with minimal time spent making the tools. Next time, I'll start optimizing. (And one of my goals is to come up with a design that can be assembled in the bottle much quicker. That design will most likely not be simply an optimized Eng vise, but something altogether different.)
But from our email discussions, and from seeing your work, I know that "quick and dirty" isn't good enough for you. A Jim Riser product will certainly be better, in just about any respect, than a Bill Mullins product. And that's okay. We do what we do for different reasons. As my skills and my shop grow, I'll get to your level of sophistication, and I'll want to improve my vise.
My idea is to use a flexible sheft with a magnetized cut off allen wrench in the end.
I thought about magnetizing, adhesives, glue, rubber cement, post-it glue dots, double sticky tape, and other ideas. But in the spirit of KISS, it was easier to slightly deform the end of the allen wrench by banging on it with a hammer. Now the sockets in the bolts will "press fit" onto the wrench, and will stay on it well enough to start threading into the bottom of the vise, but will still pull off when I'm done. (I put the bolts onto the wrench outside the bottle, rather than inside). I don't usually advocate such rough treatment of tools, but the wrench in this case is dedicated to a particular task.
Note: I wasn't able to buy a long enough allen wrench at the local hardware store, or Home Depot. They are available mail order, but I found some at a local electronics supply house. And I didn't use one with a flexible shaft -- wasn't necessary.
I'm thinking the next "impossible bottle" will have a padlock in it. It's looking like the limiting factor will be the width of the shackle -- I can't dissasemble (surreptitiously or not) to a size smaller than that. Although once I get the lock into the bottle, and reassembled and locked, it'll be too big to come out.