Chris Schwarz's Blog

From the Island of Misfit Tools

Here in America we will put a motor on just about anything. Picnic tables. Ice cream cones. Scissors.

And yet, it was still a surprise when I stumbled on a motorized coping saw for sale on eBay. And no thanks to the two beers inside me at the time, I ended up buying the saw. It arrived yesterday. It is a curious creature.

Patented in 1941 by Albert J. Dremel (yes, the namesake of Dremel), the Dremel Moto-Saw is a remarkable if commercially unsuccessful piece of engineering. After reading the patent application (check it out on Google Patents), I was impressed by its ingenuity.

Like a traditional coping saw, the blade is held in tension with a spring action. The heel of the blade (the part by the handle) is on an armature that looks and works like a diving board at the swimming pool. The armature is attached to the frame of the saw at one end and juts out over a big electromagnet in the handle.

Plug the saw in and pull the trigger and the armature moves quickly back and forth as it is attracted to and repulsed by the electromagnet.

You can even vary the stroke of the saw by turning a knob that adjusts the position of the armature, just like you would adjust the springiness of a diving board.

How does it work? Well I plugged it in, pulled the trigger and the Moto-Saw made a noise like a gaggle of angry bees being shorn by an electric razor. This is normal.

The armature indeed moved rapidly in and out. I was ready to be impressed.

The only thing stopping me was the fact that this saw came with no blade. And standard coping saw blades won’t work. I’m guessing that this saw uses pin blades that have about 2-1/4″ to 2-3/8″ of blade between the pins.

I started making my own blades this morning, but I’m going to need a 3/64″ drill bit and some punches first. So I’ll put that on the list for my next trip to the hardware store.

Now before you dismiss this saw as a piece of war-era lunacy, take a look at this 2007 patent from the Robert Bosch corporation (yes, that Robert Bosch).

- Christopher Schwarz

28 thoughts on “From the Island of Misfit Tools

  1. Al Goldstein

    Chris, I also found one of these saws at a garage sale. Sears makes blades that will fit it. Craftsman Pin-end Scroll Saw Hobby Blades 929445. It really works.

  2. James Watriss

    I’m not going to buy any motorized chisels until I find a good one with a laser guide.

    And even then, it better have a rubberized grip so that I can tell for sure that it’s actually a professional grade tool. I’m not interested in buying a stripped down consumer grade knock-off model, that’s actually intended for home improvement weekend warriors.

    I know I sound like a snob, but I’m just not interested in buying any more gimmicky, crappy tools.

    : )

  3. Andrew Gieselman

    Chris

    If you compare your photo of the Moto-Saw to some of the others that have sold on eBay, it looks like your’s may have a bent blade bracket. I notice that there are blades available for the Dremel Moto-Shop (a bench top motorized scroll saw) that are 3 inches long, and I wonder if these would also work in your contraption if you straighten out the bracket. Here’s a link to a photo of a "near mint in original box" moto-saw;
    http://cgi.ebay.com/ws/eBayISAPI.dll?VISuperSize&item=350301161850

  4. www.google.com/accounts/o8/id?id=AItOawmfXvwMdrS5WtBBs_pQ0_3_nBCgFWUehQM

    My Dad got one of these for me when, because of shop class, I asked for a coping saw. Typical to his generation, power was better. Because the vibration was hand and arm numbing for me, I used it once or twice and abandoned it. My Dad died about a year ago and I was cleaning out his workshop and cubby holes and there it was, in the original box and probably unused for forty years. I was surprised to see that it was a Dremel. I brought it home with me and plugged it in and the nerve numbing vibration brought back the memories of why I stopped woodworking when I was a pre-teen.

  5. Bruce Jackson

    Electric chisels? Well, I had to go out into the shop and … yep, there it is: a Ryobi electric carving chisel set used to make replacement filigrees for antique cuckoo clocks before it was passed on to me.

  6. Stan Suther

    I hope you didn’t pay much for it! I just threw one of these away last week. My father or grandfather accumulated it in their shop years ago. Of course, there were no blades around, and I think I plugged it in once and got a nice flash from a short in it. Got too many "projects" around already to keep it, and I’m trying to quit using electrons anyway.

  7. Steve

    What I find most disturbing about this is your apparent familiarity with all things motorized. Imagining the existence of a motorized ice cream cone is bad enough, but to actually find one for sale…

    I guess this could be the power woodworker’s version of Rule 34.

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