On 19 Jan 2017 03:10:11 GMT, "DoN. Nichols"
wrote:

On 2017-01-18, Bob Engelhardt wrote:
On 1/18/2017 8:39 AM, Howard Beel wrote:
I bought a hand held nibbler that has a 1/4" capacity (mild steel) on ebay
back in the day when they were cheap. I made an adaptor to attach a couple
of 1" linear bearings to the nibbler, kinda looks like a radial arm saw

[ ... ]

I have a nibbler that won't get anywhere near 1/4". Just to be sure
that it's the same thing - a "nibbler" cuts by punching crescent-shaped
chips, yes?

Depends. My first nibbler was hand powered, made by Adel, and
sold for making cutouts in sheet metal to make instrument panels and the
like. That one cuts rectangular pieces -- 1/4" wide and something like
1/8" or perhaps 3/64" "long". Nominal thickness limit is 16 Ga in
steel, IIRC, but by filing a flat on the side of the screw which acts as
the stop, it can go a bit thicker in aluminum.

http://adelnibbler.com/

It can be started in a hole in the sheet metal, so you don't
have to start at an edge. Back when I used one regularly, I would drill
a hole (lagest bit I had at the time was a 5/16 S&D bit with a 1/4"
shank to fit the hand held electric drill, and then use a tapered reamer
to enlarge the hole to where the tool would fit through. Accroding to
the on-line instructions from the site above, it needed 7/6" as a
starting hole, and I usually went up to the 1/2" diameter of the tapered
reamer.

My God -- the price has increased. $49.95. I seem to remember
paying something like $7.00 for one. :-)

Later nibblers which I have acquired are air-powered tolls which
make the crescent shaped punchings. (Nasty sharp ones, BTW). I would be
careful using them in areas where you are likely to drive, as I can see
the crescents working their way through a tire.

There is also another tool -- once available as a hand powered
tool, now electric or air powered, which is a three-fingered shear --
the middle finger gones into a drilled hole, and shears on both sides of
that against the other two fingers. That produces a coil of metal, and
is best for cutting straight or gently curved lines. I've used one
air-powered one cutting against a bit of angle iron C-clamped to sheet
aluminum to get it down to the dimensions which my 24" DiAcro shear will
accept.

Your setup sounds interesting - any chance of your putting up some
pictures? I thought that I had the idea until you mentioned the 8'
sheet & I don't see how that would work.

With the crescent or the double-shear styles I can do that
against a angle-iron guide. The old Adel would tire my hand and make
reach rather difficult for an 8' cut. (Or, even a 4' cut for stock
4'x8' sheet metal.

Enjoy,
DoN.
I'm certain I paid less than $7.00 for mine when I bought it from
Allied Radio around 65 years ago,I still have it and use it
occasionaly. I think the toughest job I ever used it for was to cut an
8+ inch hole in the stainless steel lid from a commercial washing
machine to make a single burner, "in counter" stove for my home
brewery. I had blisters when I completed that little project!