I think the variable speed feature mentioned in another reply, would be a
key feature for this type of work. The scroll (or jigsaw as it's known)
wouldn't neccessarily have to be a top-of-the-line model, any older cast
iron tabletop jigsaw should be more than adequate.
Step pulleys can accomplish speed selection for powering with an AC
induction motor.. I don't care much for high RPM brush-type universal
motors, but they can be adjusted with inexpensive speed controls or a big
variac.
A foot switch might be a very handy feature too.
I dunno if cutting dry is the general practice, but I'd think that a
wax-type cutting lube would be more appropriate, since a liquid would likely
be slippery and possibly create a situation where it would be too easy to
slip and get fingers cut.
Keeping the stock firmly pressed downward against the saw table surface is
an important factor in efficiently cutting your stock. Back-up material is
generally called for, when cutting thin stock. This could be hardboard or
luan ply, and works well when the metal is glued to the back-up material
(for less vertical reaction).
The table insert that surrounds the blade (I forget what it's called) should
have a fairly close fit to the shape of the blade, and be securely mounted
to the table.. not just a loose-fitting drop-in insert.
Very thin stock might be problematic on the jigsaw, and hand sawing might be
required. Maybe someone can describe the old method used to cut intricate
precision fit inlays in wood.. I forget what that's called too.. but I
watched a program about how it's done. There was a fairly long training
program to learn the skill to become artist-level in the procedure.
The worker sat at the saw fixture with his heel on the lever that secures
the work in the vise, and the heel pressure was let up to release the vise
for frequent movement of the work, to change the direction of cutting.
The saw was in a fixture similar to a linear sliding rod, and the work was
held perpendicular to the blade cut.
WB
...............
"Charles A. Sherwood" wrote in message
...
I am starting a clock project made almost entirely of brass plate.
Specifically I am building W.R. Smith's Lyre clock.
I need to saw out patterns in 3/16 brass for the main plates,
80 thou brass for the dial and 60 thou brass for the other parts
such as gear spokes.
I tried roughing out the main 3/16 plates with my 4x6 band saw in
vertical mode and quickly discovered the small throat really limits
the work envelope. It also does not allow me to do inside cuts.
Mr. Smith shows roughing out the plates with a table jig saw and
finishing up with a die filer and belt sander.
I believe a jig saw would not work well on thin stock but work work
well on the thick stock. I am wondering if a good scroll saw would
work on the 3/16 plate.
A bit of web research tells me the top of line scroll saws are
Hegner and Excaliber. Middle of the road in Dewalt and everything
else is lumped together.
So will a good scroll saw cut the 3/16 brass plate in a timely manner?
Do I need a jig saw and a scroll saw?
Looking for advise!!
thanks
chuck
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