On 2009-02-07, Searcher7 wrote:

[ ... ]

I've been staying out of your threads for a while, because I was
working on getting carpel tunnel syndrome just from the typing to *you*.

But -- I feel that I *have* to speak up here.

For the cutting gang saw I figured I'd have to build a jig of some
sort. The metal("Beryllium Copper" or Phosphor
Bronze) to be cut into these strips will be anywhere between .005"
and .015" thick.(Whatever I can find cheaply).

*Don't* even consider using BeCu (Beryllium Copper) in your
apartment (which is where you were working last I knew), or even in a
normal shop without specialized air and coolant control.

BeCu can result in serious lung damage -- starting about ten
years or so after you work with it. Slitting saws would produce fine
particles which could become airborne. Even the zero-loss techniques
generate a bit of this. The Phosphor Bronze, however, is quite safe to
work with.

I thought I'd make a channel that would be the same width as whatever
the standard width metal coil I'd slide under the gang saw. The idea
would be to score the metal enough so that I can easily break off the
strips. I'm assuming the saw would rotate against the direction of the
work, and that multiple passes may be necessary.

What is the minimum length which you need? With the slitting
saws (special milling cutters with spacers on an arbor), the best way
that I can think of is double sided tape holding it to a sacrificial
metal plate, and a stack of milling cutters on an arbor with spacers to
put them the right distance apart. You can't work with things as thin
as you want to use without some kind of control such as that from double
sided tape. The maximum length will be determined by the travel of the
horizontal mill's table. (And I personally don't think that you can get
even a small one upstairs to your apartment. The small Nichols
production mill which I have weighs about 1100 pounds, and needs three
phase power.

However -- an earlier suggestion which you just tossed away
would really be the better way to do it.

Two shafts containing alternate small and large diameter disks
of hardened steel. The upper shaft will have the large disc where the
lower shaft has the small one and vice versa. The thickness of the
disks is the width which you wish for the metal strips. The two are
geared to rotate opposite directions, so they pull in on one side, and
press out on the other. This acts as a large number of scissors,
cutting the thin metal into many strips at once. I can tell you about
one on a small scale made to trim Kroy labels down to a desired width
from wider tape which is feed through the printing machine.

The one I have is rather old, so I don't know whether the model
number is still valid, but go to a quality graphic arts supply store and
look for a "Kroy Tape Trimmer" part number "1335000". It was made to
work with older Kroy machines, but I use it with an electronic label
maker from Kory.

As long as the grooving saw can make grooves in the material(wood or
plastic) those strips would fit in, visual accuracy is really what
this comes down to.

This suggests that you design the strips to match the width of
standard milling cutters (the wheels which stack on arbors, not end
mills for a vertical mill). The cutters are expensive, and you'll have
to buy a number of them to stack on the arbor. The cutters are
available in a number of standard thicknesses, and better to get those
than to try to modify some to get a non-standard dimension.

It'll be tedious work, but I guess I'd have to progressively grind
down the thickness of the metal bushings between each saw until I get
to the proper spacing needed.

They are available (for milling arbors) in a number of
thicknesses, including made of shim stock. Determine the needed
spacing, and find out what the minimum number of sheets of standard shim
stock thicknesses will be to build up the thickness you need. There are
punches to cut the OD and the ID with the keyway from shim stock of
reasonable thicknesses.

If I can buy enough of these saws and find a way to fit them together
in a group as large as 30, I guess the biggest issue would then be
sharpening them when needed. I have a mini lathe. (And a mini mill
that needs to be fixed).

What material are you planning to cut? If glass epoxy, you'll
need carbide to avoid needing to re-sharpen ever pass or two. Many
other plastics will last for a long time.

And since these cutters all need to be the same diameter for it
to work properly, don't expect to be able to sharpen them and keep such
consistency -- unless you also invest in a tool and cutter grinder, and
work on all of the cutters in a single batch.

Go to some web site like MSC and look for the prices of the
milling cutters and slitting saws. I forget what the width you wanted
is, but a 3/16" (0.1875") wide cutter costs $49.41 *each*, and 5/32"
(0.1563") cost $98.21 *each*.

The thinner slitting saws appear to be mostly carbide these
days, and go for well over $200.00 each.

I figure a gang saw like this would be an easier option than some sort
of indexing jig with stops where I'd have to make passes for every
parallel cut. But correct me if I'm wrong. (I doubt that would be as
accurate).

It is not going to work well with material as thin as you plan,
unless you double-sided tape to a sacrificial plate for each run.

Anyway, I was hoping to get a handle on the materials I'd need to
build something like this. And I'm still open to ideas

I'm dropping back out of the thread now.

Good Luck,
DoN.

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