I've just cleaned up this vintage Shopmaster (of Minnesota) Jig Saw, described by the 1955 US Patent 173891
The motor is a 1/15th HP Dayton, with a gear box connecting it to the reciprocating blade mechanism. When I first got it, it was clogged with sawdust and wouldn't run, but with a little cleaning and lubrication of the gear box, and it seems to run fine.
I'm wondering if anyone else has one of these. I am trying to figure out the best technique for installing a new blade. The upper end of the blade mechanism has a spring loaded collar that holds a pinch clamp for the end of the blade which can be tightened by a set-screw. It seems very difficult to tension this collar while installing the blade, so that the collar doesn't hit the upper arm at the top of it's travel. I'd be very interested in talking with anyone who owns and uses one of these, or seeing a photocopy or pdf of the blade-change instructions from a user manual. Aside from the fact that it's aluminum, the saw seems like a pretty solid design once you get the blade tensioned properly. I wouldn't want to do fretsawing with it, but for my use in cutting out the occasional router pattern, it seems like it might be serviceable.
Thanks for any info!
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To try and answer your question - this may not be the proper way to do it, but I get the bottom jaw to the top of the stroke, TDC so to speak, put the blade in the top jaw first, tighten the set screw, then pull it down and insert it in the bottom jaw and tighten. Then bump the switch or cycle it by moving the bottom jaw up and down (if possible)a few times to make sure nothing is hitting.
