I'm repairing a Rapidor hacksaw that's been neglected for a few years. I don't know what model it is, but the blade is 14" x 1" and several of the castings have numbers like '3XM3' or '3XM4' on them.
It's in surprisingly good condition under the dirt and leaves (nothing really seized up) but I'm confused about the dashpot mechanism.
The dashpot itself is straightforward - a piston with holes in it, and a spring-loaded washer to shut the holes as the piston is pushed into the dashpot. But there's a length of 1/4" rod screwed into the piston that runs parallel to the square shaft. It's about 6" long, has a short knurled length, then just stops, bent and ragged.
The main cam that drives the saw also has some wear, as though a cam-follower once rode on it. There's an empty boss in the base casting, directly under the edge of this cam. I suspect there's something missing here, perhaps a hydraulic lifter that's connected in some way with that 1/4" rod. Anyone know how it's supposed to work ? It's a long while since I last used a well-maintained one.
Another puzzle is the vice : when it's tightened, the jaws are pulled together nicely. But when the crank is loosened, the thread doesn't drive the jaws apart : instead, the crank winds out of the front jaw and a tap on the end is needed to move the jaws apart. Is this right, or should there be a pin somewhere to keep the crank in place ?