Cutting sheet steel

I've got some .035 4130 that I have to cut elevon ribs from. 2 inch on
one end, 3/8ths on the other and about 16" long (each one is a different
length). The small end fits against a run of tube, the thick end against
the elevon spar. Both ends have to be shaped appropriately. The sides
of the long runs need to be perfectly straight. I've seen a lot of
options on how to cut aluminum, but the info on steel seems to be more
limited. Here's where I'm at so far.

A shear big and strong enough to handle the job is currently out of my
budget. (though, I keep hearing that the economy is coming back around)

Harbor Freight has a $35 cutting tool that can handle the job according
to the advertised specs. It sorta, kinda looks like an angle grinder,
except that it has a short arm and a reciprocating tooth out one side.
I figure I can drill a 3/8" hole, clamp a 2x4 to each side of the sheet
as guides, and just make a run with the cutter. Anyone have experience
with these things? Do they leave a clean edge?

Another option is to pay a machine shop. If I can find a good shop, I'm
sure to get quality work, but I can't say that I did it and I won't have
a tool afterward. I'm saving that as a last resort.

Are there any better options?

--
http://www.ernest.isa-geek.org/
"Ignorance is mankinds normal state,
alleviated by information and experience."
Veeduber

..035 isn't that thick and 'perfectly straight' is relative but the average
nibbler will be close to its limit.

One of the most commonly used tools in my shop is the throatless shear.

First thing I would do is make up an accurate pattern showing the centers of
any holes plus at least two tooling holes. I'd lay that out with at least a
sixteenth outside the finish line and do all the drilling in the flat. Then
whack them into APPROXIMATE size with the throatless shear, phasor (ie, plasma
cutter), bandsaw or abrasive disk. Once cut the edges have to be treated so
the pieces will lie flat against each other. They they get bolted together
using the tooling holes.

Now I've got a steel BAR about three-eights thick by 16" long, which should be
pretty easy to bring to finished size using a file, disk grinder, belt sander
or whatever..

I think you'll find that uniformity will have a higher priority than absolute
dimensional accuracy.

-R.S.Hoover

On 25 Nov 2003 03:32:49 GMT, (Veeduber) wrote:

.035 isn't that thick and 'perfectly straight' is relative but the average
nibbler will be close to its limit.

One of the most commonly used tools in my shop is the throatless shear.

First thing I would do is make up an accurate pattern showing the centers of
any holes plus at least two tooling holes. I'd lay that out with at least a
sixteenth outside the finish line and do all the drilling in the flat. Then
whack them into APPROXIMATE size with the throatless shear, phasor (ie, plasma

Just a comment on the plasma torch. I had one here for a while when
we were building the shop. It didn't take long before I could cut one
of those sheets of painted barn metal without scorching the paint. If
the paint started to show signs of heating you knew you were moving
too slow (and this was one of those little self contained units with a
turbine compressor.) Those things are nice...plus they'll cut just
about anything unlike a torch.

I had ordered a much larger one, but they tried to talk me into the
little one. It wasn't big enough for the 1/2 inch thick plate and
even thicker I beams I was cutting so I used the torch. After wearing
out one tip, I let them have it back, but by then I couldn't justify
the big one.

You'll have to fix the return add due to dumb virus checkers, not spam
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair?)
www.rogerhalstead.com

cutter), bandsaw or abrasive disk. Once cut the edges have to be treated so
the pieces will lie flat against each other. They they get bolted together
using the tooling holes.

Now I've got a steel BAR about three-eights thick by 16" long, which should be
pretty easy to bring to finished size using a file, disk grinder, belt sander
or whatever..

I think you'll find that uniformity will have a higher priority than absolute
dimensional accuracy.

-R.S.Hoover

In article ,
Ernest Christley wrote:

I've got some .035 4130 that I have to cut elevon ribs from. 2 inch on
one end, 3/8ths on the other and about 16" long (each one is a different
length). The small end fits against a run of tube, the thick end against
the elevon spar. Both ends have to be shaped appropriately. The sides
of the long runs need to be perfectly straight. I've seen a lot of
options on how to cut aluminum, but the info on steel seems to be more
limited. Here's where I'm at so far.

A shear big and strong enough to handle the job is currently out of my
budget. (though, I keep hearing that the economy is coming back around)

Harbor Freight has a $35 cutting tool that can handle the job according
to the advertised specs. It sorta, kinda looks like an angle grinder,
except that it has a short arm and a reciprocating tooth out one side.
I figure I can drill a 3/8" hole, clamp a 2x4 to each side of the sheet
as guides, and just make a run with the cutter. Anyone have experience
with these things? Do they leave a clean edge?

Another option is to pay a machine shop. If I can find a good shop, I'm
sure to get quality work, but I can't say that I did it and I won't have
a tool afterward. I'm saving that as a last resort.

Are there any better options?

I have a very large pair of sheet metal shears thet I have use to cut
..032 4130. It takes a lot of effort, but is doable.

Save yourself a lot of aggravation. Do not buy anything from "Harbor
Fright". All they sell is junk and it never works like they say. You would
have a lot more fun throwing the money in your toilet and watching it swirl
around as you flush.


Harbor Freight has a $35 cutting tool that can handle the job according
to the advertised specs. It sorta, kinda looks like an angle grinder,
except that it has a short arm and a reciprocating tooth out one side.
I figure I can drill a 3/8" hole, clamp a 2x4 to each side of the sheet
as guides, and just make a run with the cutter. Anyone have experience
with these things? Do they leave a clean edge?

If this is a one time project and you do not see the need for a proper shear in
your future, find someone near you with a shear, pay them to cut the ribs for
you. Or, if they will allow, use their shear to cut the ribs. We let locals
use our shear now and then.

Kevin

Since most builders only need to cut a batch of sheet steel occasionally,
why not try a water jet cutting service. A friend here in Perth was
rebuilding a car and had a new steel firewall made up from a CAD drawing at
very reasonable cost. There are plenty of service providers in the USA -
have a look at http://www.precisioncuttingservice.com/ in Savanna GA for
example.

One local company here in Perth has done many instrument panels out of sheet
aluminum.

Phil Maley
Perth Australia

For lists of waterjet job shops in the USA or International visit the
following link:

http://www.waterjets.org/waterjet_jobshops.html
http://www.waterjets.org/internation..._jobshops.html

Or, call OMAX Corporation to ask for specific shops in your area:

http://www.omax.com (or 253 872 2300 or 800 838 0343)

- Carl



"Phil" philatwotechdotcomdotau wrote in message ...
Since most builders only need to cut a batch of sheet steel occasionally,
why not try a water jet cutting service. A friend here in Perth was
rebuilding a car and had a new steel firewall made up from a CAD drawing at
very reasonable cost. There are plenty of service providers in the USA -
have a look at http://www.precisioncuttingservice.com/ in Savanna GA for
example.

One local company here in Perth has done many instrument panels out of sheet
aluminum.

Phil Maley
Perth Australia

"Jimmy Galvin" wrote in message
...
Save yourself a lot of aggravation. Do not buy anything from "Harbor
Fright". All they sell is junk and it never works like they say. You would
have a lot more fun throwing the money in your toilet and watching it
swirl
around as you flush.


Harbor Freight has a $35 cutting tool that can handle the job according
to the advertised specs. It sorta, kinda looks like an angle grinder,
except that it has a short arm and a reciprocating tooth out one side.
I figure I can drill a 3/8" hole, clamp a 2x4 to each side of the sheet
as guides, and just make a run with the cutter. Anyone have experience
with these things? Do they leave a clean edge?

I think it is pretty obvious from the prices that the stuff you get from
Harbor Freight is not "top of the line". That said, I have bought a lot of
stuff from them that works just fine. My air powered pop rivet gun has
built 3 airplanes so far. I only paid $39.00 for it. My band saw has cut
anything I have need to cut on 3 airplanes. The snowmobile casters that I
bought from them hold my Pulsar just fine and allow me to put it in the T
hangar, behind the pole, and still fit my Waco in too.

It is a bit of an overstatement to say that nothing Harbor Freight sells
works.

Rick Pellicciotti

You have stated a valid view point.

I have been in construction all of my life. I made a living using tools. I
am not satisfied with less than top of the line tools because they make life
soooooo much easier. An example would be I use Milwaukee drills. I would not
walk across the hall to get a free Master Mechanic drill. I don't care for
their quality but if you are satisfied with their products then that's fine.
I think it is pretty obvious from the prices that the stuff you get from
Harbor Freight is not "top of the line". That said, I have bought a lot
of
stuff from them that works just fine. My air powered pop rivet gun has
built 3 airplanes so far. I only paid $39.00 for it. My band saw has cut
anything I have need to cut on 3 airplanes. The snowmobile casters that I
bought from them hold my Pulsar just fine and allow me to put it in the T
hangar, behind the pole, and still fit my Waco in too.

It is a bit of an overstatement to say that nothing Harbor Freight sells
works.

Rick Pellicciotti