View Single Post
  #7   Report Post  
Posted to rec.crafts.metalworking
Stanley Schaefer Stanley Schaefer is offline
external usenet poster
 
Posts: 269
Default Sheet metal nibbler vs. shears

On Dec 31 2011, 2:43*pm, "Steve B" wrote:
I have noticed there are two types of cutters for sheet metal. *One a
nibbler, one a shear.

The one nibbler I see apparently cuts out small pieces, almost circles, and
imagine that would be for very fine work. *The other "nibbler" has two
blades that are about 3/4" long that go up and down, pinching and shearing
the metal.

The third is a shear, much like a pair of electrified scissors.

A brief description of each and its use would be appreciated. *When it comes
down to it, I will probably need all three for various stuff.

And lastly, I see some run on air. *If one has a good compressor, is there
any important differences between the electric and air models?

This is going to run a few bucks, so wanted to ask first.

And is buying refurbished worth the savings or not? *Problems later vs: new?

Steve


Just depends on what you want to cut and to what accuracy. I've got
the pneumatic nibbler that cuts the little partial circular nibbles,
like the other poster said, they're nasty sharp. Takes quite a hole
if you want to start in the middle of a panel. The other nibblers I
have are hand-powered, good for small stuff like the electronic
chassis and circuit boards they were designed for, not so great for
roofing sheets. You can follow a line quite closely with those, the
handle is under the work surface and you can see the punch very
easily. They will cut to a sharp corner. Any of the nibbler types
need to have sufficient material allowed for when laying out for
filing, the cut tends to be ragged. Punch sets can be had for both
types, you just have to dig around to find them. The small hand
nibblers only take a 1/4" hole to start in the center of a workpiece.

The electric shears I'm familiar with can do the job, but like hand
shears, they'll distort the material edge while doing it. People tend
to crowd the limits of what they can handle, leading to busted blades
and sometimes busted innards. Blades sets, when obtainable, tend to
be a little expensive. I see a lot of the shears in the pawn shops
with one blade gone, good luck finding a replacement. Every OEM has
its own design.

I don't do a lot of compound curved sheetmetal work, if I did, a set
of the rotary wheel shears would be nice, I believe the formal name
for those is "Beverly", you see them used a lot for aircraft work and
making custom car body parts. Only worth it if you do a lot of it and
can take the tool cost off the taxes.

For a lot of things, the fastest way is to get out the angle grinder,
equip it with a thin metal cutting blade and go to it freehand. I
had a brand of wheel called "Razorblade", were like super Dremel
cutoff wheels on steroids. Just about that thin, too, but stood up
better. I bought what that weld shop had on hand, haven't found them
anywhere else. I've got a "shoe" for the 4 1/2", looks like the base
for a Skil saw and works the same way. Kind of a pain to put on, so
not really worth messing with except for long cuts. It does keep the
spark tail down. Fewer holes in shirt and pants.

Stan