Hi, I am needing to saw 5 slits in the interior of a large (10"x10")
sheet of 14 gauge copper. It will become a box and I need to cold
connect some features with tabs. How does one hold the metall, insert
the blade, put tension on the frame and clamp in the blade w/o
breaking the blades? I broke 2 already trying to do this. 2 of us
worked on the metal: put bricks on the metal to hold steady on back
end, c-clamped boards on each side of the metal, and still I broke
blades just trying to feed themup thru the drilled holes and push
down on the frame. Any other suggestions… please thanks,
.... and still I broke blades just trying to feed themup thru the
drilled holes and push down on the frame. Any other suggestions..
please thanks,
Tricky, in part because those very deep saw frames are not only a
bit clumsy in general, but also more flexible, which also puts
additonal risk on the blade while sawing.
But try this. Instead of holding the sheet horizontally, instead
brace the saw frame top against the bench pin or bench, much as one
might ordinarily do, putting pressure on it via your breastbone,
leaving hands free. That’s the traditional means of inserting and
tensioning a blade, and still perhaps the most solid and least likely
to slip, even with the deep frame. Insert the top end of the blade
first. Now hold the sheet vertically, and you can thread the blade
through the hole. Gravity will help hold the sheet vertical, so all
you must do is keep it from moving up and down too much. If the holes
are so small as to be a tight fit for the blade, you might have to
use a slightly larger drill hole too. With the sheet positioned right
up agaist the top clamp, if it’s not too small a blade, you should be
able to support at least some of the weight of the sheet on the blade
(there should be no space between the sheet and the clamp when you do
this, or you will break the blade.) This should allow you to insert
the blade in the lower clamp. Tensioning is done just by leaning in
on the saw frame handle. Once that’s done, and still keeping the
frame down tight on the sheet, you should now be able to reposition
the sheet to the horizontal sawing position. I suspect your problem
is trying to insert the blade with the saw frame held in the normal
sawing position. Hard to hold it steady, and tension the blade all
at the same time, and if the frame twists just a little, there goes
the blade.
Once you’ve got the sheet in the horizontal sawing position and the
saw frame held properly, sawing should be not too different from any
other time, beyond the cumbersome size of both frame and sheet.
While sitting facing my bench pin, I secure the blade at the top of
the saw frame, rest the top of the frame in the bench pin, hold my
sheet vertically, thread the blade while the saw is resting in the
bench pin and then apply pressure to the frame with my chest and
secure the bottom of the blade in the frame. I’m careful while moving
the sheet into sawing position to not allow any pressure on the
blade.
You might want to try one of Lee Marshall’s “Knew Concepts” saws.
(The red aluminum ones) There’s a deep 8" frame that’s easily the
most rigid deep frame available. (Short of his 8" titanium frame…)
The nice thing about it is that it tensions by way of a screw knob,
so you don’t have to worry about trying to hold things straight
while you try to crush the frame at the same time. Just connect the
blade ends, and dial in your tension. Quick and simple.
Full disclosure: Lee’s a friend, so I’m not entirely impartial.