Fine-tuning a Sears Scrollsaw

[Byrocat]

This is one of the more recent models (with a tension adjustment right by the blade and a built-in puffer).

1) How do you know when you don't have enough or too much tension on the blade (beside the obvious ka-ching! as it snaps)? How much flex should there be? 2) I need the blade to be absolutely vertical and at right angles to the worksurface. The blade slopes slightly backwards and to the right. How do you make these adjustments? 3) I also have a project coming up where I need to cut foam and Depron (platic foam that used in meat trays), what is the recommended blade to use so that I don't burn the foam or rip it to shreds?

I'll post the model numbers when I go downstairs next time....

[Rick Cook]

Pluck it and listen to the pitch. The higher the better. Come to that I'm not sure you can snap a blade by over-tensioning it. The rule on blades like that is the tighter they are the better they perform and the longer they last.

Use a machinists square to adjust the blade perfectly vertical. This will probably involve setting the table angle. The backslope may be a characteristic of the design and shouldn't be a problem if it is not too extreme.

--RC

[Nate Perkins]

Lightly pluck the blade, you'll hear the pitch of it increasing with the increased tension. Increase the tension until it makes a pitched ping sound. There shouldn't be any noticeable flex.

You can set the blade to be square to the surface from side to side by tilting the tabletop. From front to back, there usually is no adjustment because the blade doesn't remain perfectly square anyway; it tilts slightly as it rocks.

Sorry, I don't know about that. I'd try the finest blade at the slowest speed setting.

p.s. My scrollsaw is a Delta, but they are all pretty similar.

[mac davis]

we used to cut a LOT of foam for model airplane wings, and the best way we found was a hot wire.. we started with copper wire and a car battery, ended up within a year using some kind of tungsten wire and a power supply.. (i wasn't involved in that part)

Basically, you draw the hot wire through the foam and it cuts it like you used a very good blade on wood.. Run in down a wood straight edge for simple cuts, for curved or repeat work, make a form and follow the contours with the wire...

We learned this when my brother's model company out grew his garage and we asked our foam vender what type of cutter the factory used..

[Ray R]

For cutting foam hot wire as some else mentioned. The most controllable hot wire is nichrome with an adjustable power supply. For cutting foam on a scroll saw I would use a fairly coarse blade to avoid melting the foam. Use a zero clearance insert so the foam does not flex.

[Byrocat]

Actualy, it's sheet Depron (5mm thickness). I've managed to rip strips with no real problem except for making sure that I don't get flutter and my fingers are well away from the blade as I guide ths sheet through.

FYI, here is the link to the thread on RCGroups:

are pictures of my scrollsaw setup and the strips.