New acquisition!

[JPG]

Ditto Ed.

I am surprised it looked that good with that 'pile' of sawdust.

[pieceseeker]

Ditto Ed.

I am surprised it looked that good with that 'pile' of sawdust.

Yea, I was happy to see that much air. Replaced the original leather piston seal with new leather (meant to re-sole dance shoes...shhhh,.don't tell the wife). It fit a bit tighter, had to keep working it and sanding the sides of the leather to make an acceptable fit.

Hoping to hear from SS jigsaw owners to compare results.

Most of the old jigsaws I see on craigs list are of the Magna variety. I'm still curious about the absence of check balls and springs on my jigsaw. Wondering whether it was a design change after the SS label.

[BuckeyeDennis]

This is an air pump test. Threw the jigsaw together last night in order to run this test before final assembly and cleanup.

http://www.youtube.com/watch?v=y8Rp_5GG ... e=youtu.be

Looks good to me. I think that I may be the only guy on this forum to ever buy a SS (Magna, actually) jigsaw that was already in good working order. Yours blows dust just as well as mine does.

But yours does look more stable than mine, which came on a Power Stand. Score one more reason to take JPG's advice and use the jigsaw, when the occasional need arises, on the right aux mount of the SS.

[pieceseeker]

Looks good to me. I think that I may be the only guy on this forum to ever buy a SS (Magna, actually) jigsaw that was already in good working order. Yours blows dust just as well as mine does.

But yours does look more stable than mine, which came on a Power Stand. Score one more reason to take JPG's advice and use the jigsaw, when the occasional need arises, on the right aux mount of the SS.

Well, mine came on a pwr stand also, but have vibration problem due to pulleys being wobbly.

I believe the problem is the weak die-cast aluminum pulleys it came with. The jigsaw pulley is a single pulley and the hub has a steel slotted insert. See previous posts on that. It won't tighten down straight with the shaft.

Bought another pulley with a fixed bore (die-cast also), it did great initially. But by the time I adjusted, tighten and retighten the hub, it too was soon wobbly. Don't think I was overtightening, but maybe.

Anyway, I have a cast iron fixed bore pulley coming today and a variable pitch pulley for the motor shaft that is also cast iron. Will see if they can stay and run true with the shafts.

If I strike out this time, I'll probably just give up on using the pwr stand for any of the SPT's.

[pieceseeker]

During more testing with the jigsaw, I see a possible partial solution to the plugging of the air bleed hole in the crankcase.

http://www.youtube.com/watch?v=NAQLcmn0OqU

I propose shaping and gluing a small dust shield or hood that is open on the bottom over the air bleed hole.

It wouldn't need to be large, could be made of wood or plastic, just something to cover it from the cascading sawdust while cutting.

I think it would have to help somewhat, what do you think?

[JPG]

During more testing with the jigsaw, I see a possible partial solution to the plugging of the air bleed hole in the crankcase.

http://www.youtube.com/watch?v=NAQLcmn0OqU

I propose shaping and gluing a small dust shield or hood that is open on the bottom over the air bleed hole.

It wouldn't need to be large, could be made of wood or plastic, just something to cover it from the cascading sawdust while cutting.

I think it would have to help somewhat, what do you think?

Gotta be an improvement if cutting dust makes it plug. Since it has been demonstrated that air goes in/out of that hole when operating, keeping dust away should help.

If we be paranoid, glue a balloon over the hole.

[billmayo]

I just drilled a bigger vent hole in the jig saws I sold. You could see the hole much easlier to see if it was getting plugged. I did not believe that sawdust and crud would plug the bigger hole or work it way into the housing. Air gap vents were all too big that I could find at the time. I found all the jig saws I got into my shop had a plugged vent hole and the housing gasket always seeps/leaked oil.

[pieceseeker]

My questions remain about this air bleed hole, where it is and why its so small.

I presented several senarios on why, earlier in this thread.

Was it simply a manufacturing cost consideration?

If a bigger hole that wouldn't plug is all it would take, it shouldn't cost more to drill a bigger hole at time of production.

Is it a law of physics involved in the design?
Does it have something to do with lubricating the upper bearing? If the small hole holds back very minute ocillating pressures, is that helping the lubricating oil reach into the upper bearing?

If that is so, then a bigger hole would defeat that purpose.

Obviously, the hole has to be at a high point. It can't be on top, sawdust would certainly pour in.

Location of the hole is really not in question for me. But why not shroud it?

Yes, it needs to be accessible for cleaning eventually.

It would just be nice to know the real reasons behind the design, be they genius.... or simply a miserly cost decision.....maybe a little of both?


Maybe Peter, with his clear plexiglass cover on his jigsaw, could shoot a video of it running and post on youtube!

[BuckeyeDennis]

My questions remain about this air bleed hole, where it is and why its so small.

I presented several senarios on why, earlier in this thread.

Was it simply a manufacturing cost consideration?

If a bigger hole that wouldn't plug is all it would take, it shouldn't cost more to drill a bigger hole at time of production.

Is it a law of physics involved in the design?
Does it have something to do with lubricating the upper bearing? If the small hole holds back very minute ocillating pressures, is that helping the lubricating oil reach into the upper bearing?

If that is so, then a bigger hole would defeat that purpose.

Obviously, the hole has to be at a high point. It can't be on top, sawdust would certainly pour in.

Location of the hole is really not in question for me. But why not shroud it?

Yes, it needs to be accessible for cleaning eventually.

It would just be nice to know the real reasons behind the design, be they genius.... or simply a miserly cost decision.....maybe a little of both?


Maybe Peter, with his clear plexiglass cover on his jigsaw, could shoot a video of it running and post on youtube!

I have a version of the jigsaw manual that gives a clue. Here's the relevant text:

Dirt and fine sawdust will plug the small breather hole at the front of the lower housing. Check frequently and clean with a fine wire or pin.
Store jigsaw in such a position that oil will not drain out breather hole. A wall bracket with two holes for mounting tubes is ideal for holding jigsaw when not in use.

So I've gotta believe that the hole was sized large enough for the required air passage, but kept as small as practical in order to minimize nuisance leakage when the jigsaw is improperly stored. Especially as it is more expensive to drill a tiny hole like this.

These days, one could address both problems by making the hole large enough to prevent clogging, and then affixing a Gore membrane vent to the hole. These are low-cost devices from the maker of Gore-Tex fabrics. They allow air to pass freely, but block water and/or oil, depending on the membrane type. My company uses them to prevent air-pressure differentials across the gaskets of sealed electronics enclosures. The ones we use are self-adhesive, about the size and shape of a notebook-paper hole reinforcer. You just stick them to the inside of the enclosure, over top of the vent hole. Now I'm wondering if sawdust would eventually clog the vent, or if the combination of the filter's oil-repellant fibers and the reciprocating airflow would conspire to keep it clean.

[pieceseeker]

Your points are well taken, I've read that passage in my manual.

I was just thinking of improving on an existing design.

A cheap temporary cure for the sawdust falling over the air bleed would be to just stick a post-it note above the hole.

At least it would deflect what falls over the hole and wouldn't require any work.

Maybe I'm being too picky. These machines are not designed to be maintenance free.

There's got to be some satisfaction from knowing everything about a machine, what fails, what adjustments to make and how to make them in order for it to run like a sewing machine.

Then and only then will you be "one with the machine, master of the machine and nature"
http://www.youtube.com/watch?v=jmQNBSQmXCE