What is this mystery tool?

Over at Cool Tools, Bill Potter asks, "I came across this contraption in my dad’s tool collection after he passed away. He was an electrical engineer/computer science guy, so I’m pretty sure it had nothing to do with his work. Any ideas?"

Contraption in My Dad’s Tool Collection


  1. Wild guess here but,

    Tube cutter?

    It kinda reminds me of a device I saw once that was used for scoring and cutting through metal tubes of pinky diameter or less. I think it was used in bullet manufacturing?

    1. The device in the picture has about a 3″ diameter ring and the whole thing is 14″ long.  It also lacks any obvious cutting mechanism in the tube part.  It seems to me that the ring was just to attach it to something sturdy while you did whatever it is that the business end was for. 

      The spring loaded plate thing caught my attention, I’m guessing that plate is the primary function of the device and everything else is just to let you position it however you want.  I have absolutely no idea what it is for though. 

      1. Yeah, I’m on a phone, so I can’t get a super good look at the thing. The ring part was what caught my eye the most. It looks to me like a levering handle, so I assumed that there could be a scoring blade on the other end, and the clamp might have a way to turn whatever’s in the mechanism.

        But yes I see what you pointed out, and I’m at a total loss

    1.  No regular clamp, I believe that is a inter-war Peters Perfect Pecker Pointer.  Collectors will pay more for one of these than a Stanley #55 plane

  2. its a blade guide.    you clamp it to a machine,  lathe, mill, etc,   then the spring helps you position and guide the tool.    to me?  it looks like a sharpening jig for chisels or other flat cutters.

    1. I would like to agree with you in stating it’s for a lathe, but I don’t think that’s it. It’s clearly meant to hold something in a specific position, but not too specific as the springs would allow for some movement. Perhaps a replicator for a lathe?

      1. you’d be hard pressed to find a ~3″ piece of tubing to clamp that thing to on a lathe. i think it’s much more likely for a drill press, or maybe a vertical mill on a similar piece of tubing.

        as there is no moving connection between the tubing clamp point and the sliding clamp point, i don’t think this is a replicator for a lathe. 

  3. Definitely an attachment for a big machine tool.

    It looks like it would fit a woodworking tool rather than a metal working tool.

    Try researching Shopsmith, as they made such a machine.

  4. I would go with some sort of sharpening jig, or perhaps a polishing/grinding setup.

    The main big black knob is some sort of adjustment for cut rate.  The loop on the back left is not very sturdy.  It wouldn’t hold the whole thing. It could be for holding cutting oil, or a water drip.

    The main thing that I can’t figure out is the pair of knobs facing right.  I would expect that the blade would be attached there, except that the screws have springs behind them.  They are design to clamp something that is not very hard.

  5. This thing looks incredibly familiar, but I can’t place it. 

    This looks an awful lot like a drill press setup my gather used to have. The main body with all its knobs would attach to a base with several narrow metal bars attached to a heavy base, one of them sprocketed, in a couple of different orientations. A handle would plug in somewhere in the contraption. The drill, usually corded, would get screwed into the large metal ring projecting from the side. But It’d have to be fairly old, and the drill fairly small for a ring of that size and shape to securely hold the drill in place. 

    I’d think the jig attachment suggestions would be closer to the truth. And many drill presses have a support pole at the back that would fit nicely into that ring, and about that distance from the bit.

  6. It has the quality of things produced in the seventies or thereabouts. Not very well made. Not very good at the job it is meant for. Designed mostly to sell to hobbyists but not much pressure to make it any good. It looks to me like an attachment made by shopcraft or craftsmen to help sharpen chisels perhaps on a drill press with a special grinding bit. Useless junk tried once and shelved. The marketplace was full of this sort of junk back then and this is one of the attitude problems baby boomers identified as in need of improvement which leads to such things as artisanal coffee and iPhones. Products that actually deliver on the promise. It used to be nearly impossible to find quality goods in the American marketplace.

      1. Today it would be made by LeeValley or Veritas. It would feature brass and rosewood parts, come in a special wooden box and cost $450. But it would work.

        1. Or it would be made in China for Harbor Freight, cost four bucks, and break on the third use. 

  7. This is definitely a plane/chisel sharpening jig. It most likely clamps onto a bench grinder. It’s also not current production, or it would show up in searches.

    Search google images for “sharpening jig ex cond” and you’ll see a picture of an identical unit sold in England recently.

  8. Sharpening jig (As mentioned).

    Would have slotted onto some form of grinder/drill-press (With grinder attachment).

    Put plane blade/chisel into jig.  Turn on grinder slide it backwards and forwards in the jig.  Exact angle is held for the blade.  Issue with this jig was it only really worked if you had a new wheel on the grinder.  As the wheel wore down, you’d start to get different angles on your blade and quality degraded.

    Good idea, but sometimes it’s just better to work out how to do it yourself with a stone.

  9. reminds me a lot of this (I inherited one once): http://www.abra-electronics.com/product_images/k/511/220__42832_zoom.jpg

  10. It’s a device for sharpening wits. Note the decoy wrist-clamp for fooling hipsters into thinking it’s an iPhone holder… nobody wants a hipster with a sharp wit!

  11. Over on kk.org there’s a guy who says it’s a mount for a lens for a projector, and he sounds like he knows what he’s talking about.

  12. It’s a sharpening jig. Here’s a more modern equivalent, you can see the obvious parallels:

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