Cutting sheet steel

[Ernest Christley]

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

[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

[Orval Fairbairn]

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.

[Jimmy Galvin]

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?
>

[KJKimball]

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

[Rick Pellicciotti]

"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

[Holger Stephan]

On Tue, 25 Nov 2003 06:53:47 +0000, Jimmy Galvin wrote:

> 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.

Sometimes it is not what you get that matters but you make out of it:

http://www.mini-lathe.com

That said, a lot of tools at Harbor Freight work just fine without such
refinement. Some do not, so asking around may make sense.

- Holger

[Jimmy Galvin]

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
>
>

[O-ring Seals]

On Tue, 25 Nov 2003 03:04:45 GMT, Ernest Christley
> wrote:

>I've got some .035 4130 that I have to cut elevon ribs from.
>
>Are there any better options?
>
>--
>http://www.ernest.isa-geek.org/
>"Ignorance is mankinds normal state,
> alleviated by information and experience."
> Veeduber
>

Veedubber,

One of the easiest ways to cut sheet 4130 is with a band saw. Use an
old metal cutting blade installed upside down (the teeth pointing up).
Run the saw at normal speed and feed in the material. Keep the
pressure up and it will go (melt) through like you are cutting butter.
Don't pause though, it is not so easy to get started again. Some have
also used the back side of the blade for this purpose with success.

O-ring Seals

[Roger Halstead]

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
>

[Phil]

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

[Veeduber]

>One of the easiest ways to cut sheet 4130 is with a band saw. Use an
>old metal cutting blade installed upside down (the teeth pointing up).
>Run the saw at normal speed and feed in the material. Keep the
>pressure up and it will go (melt) through like you are cutting butter.
>Don't pause though, it is not so easy to get started again. Some have
>also used the back side of the blade for this purpose with success.
>
>O-ring Seals
>
---------------------------------------------------

Dear O-ring (and the Group),

I believe you'll find there's a bit more to it than that :-)

First off, the 'normal speed' you're referring to is for a woodworking bandsaw.
The down-side is that most woodworking bandsaws are fitted with a rubber
'tire' on their driver- & idler-wheels. Friction cutting steel (which is what
you're doing) will destroy the tire on the driver-wheel in short order.
Bandsaw tires are moderately expensive and can be hellishly difficult to
replace on some saws.

Metal-cutting bandsaws do not use tires. The wheels are sizes so that the
teeth overhang the edge of the wheel, not only for cooling but for clearing the
swarf.

You can set-up a metal cutting bandsaw for friction cutting if you have the
proper ratio pulleys (ie, increase the blade speed).

The popularity of this method hinged largely on the builder's ability to splice
their own blades because the original idea was to use common steel strapping.
Operated at high speed -- and cutting relatively thin stock -- the stuff does
in fact cut like butter, with a very attractive displace of sparks, too :-)
But the strapping was rapidly consumed and unless you were a dab hand at
splicing, ideally with a Do-All type butt-welder, there was no long-term
advantage over regular cutting.

All of this came about due to the difficulty of cutting relatively hard steel
in thinner gauges, which loves to strip the teeth off anything. .035 4130, you
can do pretty well using a regular bi-metallic 32T blade by simply rigging the
work to feed 'downhill' so that two teeth are in contact with the work.

I've responded to your message because it appeared to be addressed to me, even
though I was not the person who posted the original question. Someone else has
already offered the most practical solution, which is to track down a
stomp-shear and just whack those puppies out. But the fellow posting the
question implied he not only wanted to make the part but that he wanted to
acquire the tool, learn to use it, and make the parts himself. In that light I
thought telling him to buy a shear might be a bit much :-) ...but did mention
several other methods & tools for producing the parts. I think I even
mentioned bandsawing but I assumed he would know I meant with a metal-cutting
bandsaw.

Friction cutting is kind of fun but if your only means of splicing a blade is
to taper the piece and use hard solder, I think you'll find you can't use
strapping. Too thin; the splice fails due to the heat. And if you can't use
strapping I don't see much sense in ruining a good blade, unless you're trying
to cut 6xxx stock or a leaf spring or something like that and friction cutting
is your only option. Personally, I'd just whip out my phasor, give them
Klingons hell :-)

-R.S.Hoover

[Ernest Christley]

Jimmy Galvin wrote:
> 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?
>>
>
>
>
>

That does sound like a good time, but the HF tools will have to do for
me. I know they're junk for the most part. I also know that they're
cheap. When the most likely failure mode is, "It rusted into a single
solid mass", then it's hard to justify spending what it cost for
professional grade tools. I count on the HF tools not falling apart
until I'm done with the few times I need it.

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

[Rich S.]

"Ernest Christley" > wrote in message
om...
> >
> >>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?
>
> That does sound like a good time, but the HF tools will have to do for
> me. I know they're junk for the most part. I also know that they're
> cheap. When the most likely failure mode is, "It rusted into a single
> solid mass", then it's hard to justify spending what it cost for
> professional grade tools. I count on the HF tools not falling apart
> until I'm done with the few times I need it.

I stopped by the HF tool retail outlet in Tacoma today to buy a set of five
jeweler's loupe's (2x, 3x, 5x, 7x, & 10x) for $2.99. Noticed they had the
electric shear tool on sale for $29.99.

Rich S.

[Veeduber]

Regarding HF tools:

Cheap goods will always drive quality goods out of the market place, a fact
pointed out by Adam Smith more than 200 years ago.

Once the quality goods have been driven out, the price of the cheap goods will
then rise to the point where you will be paying high prices for junk. The
number of everyday examples that illustrate this point are too numerous to
mention but some examples all should appreciate are clothing, light bulbs and
automobiles.

In a dollar-oriented society there appears to be no easy solution for this
economic fact of life.

-R.S.Hoover

[- Barnyard BOb -]

>Regarding HF tools:
>
>Cheap goods will always drive quality goods out of the market place, a fact
>pointed out by Adam Smith more than 200 years ago.
>
>Once the quality goods have been driven out, the price of the cheap goods will
>then rise to the point where you will be paying high prices for junk. The
>number of everyday examples that illustrate this point are too numerous to
>mention but some examples all should appreciate are clothing, light bulbs and
>automobiles.
>
>In a dollar-oriented society there appears to be no easy solution for this
>economic fact of life.
>
>-R.S.Hoover
++++++++++++++++++++

Having a 'down' day?

If I understand you correctly...
today's cars are junk as compared
to decades ago?

Crummy brakes, steering, handling and
lousey gas mileage is what I remember
from those 'good old days'. Ditto for early
washing machines, tube TV's, ad nauseum.

The only thing that sticks with me about
Adam Smith is that he's dead and dead right
about self interest as the "invisible hand" that
guides the most efficient use of resources
as a consequence of economic freedom.

What that means to me in plain english is --
I buy some junk... and lotsa' good stuff.

I have faith in the 'common' man and his
choices in a free market system over the
long haul.

YMMV.

Barnyard BOb - practitioner of self interest

[O-ring Seals]

On 26 Nov 2003 02:52:25 GMT, (Veeduber) wrote:

Thanks RS for the additional information. Sorry, the post was not
intended for you that is just how it came out in the thread. In my
experience, and I have been doing this technique off and on for over
20 years, is that it has not harmed the tires on my old Craftsman wood
cutting band saw. I am not advocating using a "good" blade for this.
Many of us have sufficient old dull blades around for this purpose. I
tend to wear out blades rather than break them.

O-ring
--------------------------------------------------
>
>Dear O-ring (and the Group),
>
>I believe you'll find there's a bit more to it than that :-)
>
>First off, the 'normal speed' you're referring to is for a woodworking bandsaw.
> The down-side is that most woodworking bandsaws are fitted with a rubber
>'tire' on their driver- & idler-wheels. Friction cutting steel (which is what
>you're doing) will destroy the tire on the driver-wheel in short order.
>Bandsaw tires are moderately expensive and can be hellishly difficult to
>replace on some saws.
>
>Metal-cutting bandsaws do not use tires. The wheels are sizes so that the
>teeth overhang the edge of the wheel, not only for cooling but for clearing the
>swarf.
>
>You can set-up a metal cutting bandsaw for friction cutting if you have the
>proper ratio pulleys (ie, increase the blade speed).
>
>The popularity of this method hinged largely on the builder's ability to splice
>their own blades because the original idea was to use common steel strapping.
>Operated at high speed -- and cutting relatively thin stock -- the stuff does
>in fact cut like butter, with a very attractive displace of sparks, too :-)
>But the strapping was rapidly consumed and unless you were a dab hand at
>splicing, ideally with a Do-All type butt-welder, there was no long-term
>advantage over regular cutting.
>
>All of this came about due to the difficulty of cutting relatively hard steel
>in thinner gauges, which loves to strip the teeth off anything. .035 4130, you
>can do pretty well using a regular bi-metallic 32T blade by simply rigging the
>work to feed 'downhill' so that two teeth are in contact with the work.
>
>I've responded to your message because it appeared to be addressed to me, even
>though I was not the person who posted the original question. Someone else has
>already offered the most practical solution, which is to track down a
>stomp-shear and just whack those puppies out. But the fellow posting the
>question implied he not only wanted to make the part but that he wanted to
>acquire the tool, learn to use it, and make the parts himself. In that light I
>thought telling him to buy a shear might be a bit much :-) ...but did mention
>several other methods & tools for producing the parts. I think I even
>mentioned bandsawing but I assumed he would know I meant with a metal-cutting
>bandsaw.
>
>Friction cutting is kind of fun but if your only means of splicing a blade is
>to taper the piece and use hard solder, I think you'll find you can't use
>strapping. Too thin; the splice fails due to the heat. And if you can't use
>strapping I don't see much sense in ruining a good blade, unless you're trying
>to cut 6xxx stock or a leaf spring or something like that and friction cutting
>is your only option. Personally, I'd just whip out my phasor, give them
>Klingons hell :-)
>
>-R.S.Hoover

[Whunicut]

<snipped>
>Operated at high speed -- and cutting relatively thin stock -- the stuff does
>in fact cut like butter, with a very attractive displace of sparks, too :-)
<snipped>

As a Tool&Die shop owner for many years, I have friction-sawed a lot of
different materials and it is the only way to go when cutting stainless steel.

Your post was excellent and I would like to add one thing;
ASAP Aircraft Co., years ago, had some small, flat parts laser cut. Later, the
edges of the parts began showing small cracks caused by the intense heat of the
laser and they stopped using that method of cutting.
Friction sawing also produces heat. In fact, it melts the material.
I dont know if this would be a problem or not but I think I would normalize the
parts. Just to be on the safe side.

Warren

[Carl Olsen]

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/international_waterjet_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

[Dan Thomas]

(Veeduber) wrote in message >...
> >One of the easiest ways to cut sheet 4130 is with a band saw. Use an
> >old metal cutting blade installed upside down (the teeth pointing up).
> >Run the saw at normal speed and feed in the material. Keep the
> >pressure up and it will go (melt) through like you are cutting butter.
> >Don't pause though, it is not so easy to get started again. Some have
> >also used the back side of the blade for this purpose with success.
> >
> >O-ring Seals
> >
> ---------------------------------------------------
>
> Dear O-ring (and the Group),
>
> I believe you'll find there's a bit more to it than that :-)
>
> First off, the 'normal speed' you're referring to is for a woodworking bandsaw.
> The down-side is that most woodworking bandsaws are fitted with a rubber
> 'tire' on their driver- & idler-wheels. Friction cutting steel (which is what
> you're doing) will destroy the tire on the driver-wheel in short order.
> Bandsaw tires are moderately expensive and can be hellishly difficult to
> replace on some saws.
>
> Metal-cutting bandsaws do not use tires. The wheels are sizes so that the
> teeth overhang the edge of the wheel, not only for cooling but for clearing the
> swarf.
>
> You can set-up a metal cutting bandsaw for friction cutting if you have the
> proper ratio pulleys (ie, increase the blade speed).
>
> The popularity of this method hinged largely on the builder's ability to splice
> their own blades because the original idea was to use common steel strapping.
> Operated at high speed -- and cutting relatively thin stock -- the stuff does
> in fact cut like butter, with a very attractive displace of sparks, too :-)
> But the strapping was rapidly consumed and unless you were a dab hand at
> splicing, ideally with a Do-All type butt-welder, there was no long-term
> advantage over regular cutting.
>
> All of this came about due to the difficulty of cutting relatively hard steel
> in thinner gauges, which loves to strip the teeth off anything. .035 4130, you
> can do pretty well using a regular bi-metallic 32T blade by simply rigging the
> work to feed 'downhill' so that two teeth are in contact with the work.


I used to cut 4130 using the bandsaw method, with a 1/2" bimetal
blade installed the right way, and just letting the teeth round off
the first time I used it. It would cut rather nicely, and didn't hurt
the rubber tire. Keeping the cut straight was the biggest hassle.
There's a German-made friction-cutting tool designed to cut sheet
of all sorts using a steel wheel that doesn't spin but instead
oscillates at a fairly high frequency in an arc of about 20 degrees or
so. I saw it demonstrated on aluminum, steel and even stainless steel.
Really noisy, but a really clean cut, too. No chips. When the section
of the disc doing the work gets a bit dull, you loosen the screw and
rotate it a bit to a sharper section. I am trying to remember the
name, but can't. It was a big hit at our aircraft engineer's symposium
a couple of years ago. Not cheap, but well worth the cost if you're
doing much cutting.
Friction welding of aluminum aircraft skin was presented there,
too, though not demonstrated. Skins are butted together and a
high-speed carbide bit with a flat end and one raised tit are run over
the joint under pressure, the metal heats and fuses, and the alloy is
not affected so strength isn't hurt at all. I don't know how. You get
a flush, seamless joint with far less hassle than riveting. Also very
expensive. I think Airbus is using it on the A380, maybe.

Dan

Dan

[Orval Fairbairn]

In article >,
(Dan Thomas) wrote:

> (Veeduber) wrote in message
> >...
> > >One of the easiest ways to cut sheet 4130 is with a band saw. Use an
> > >old metal cutting blade installed upside down (the teeth pointing up).
> > >Run the saw at normal speed and feed in the material. Keep the
> > >pressure up and it will go (melt) through like you are cutting butter.
> > >Don't pause though, it is not so easy to get started again. Some have
> > >also used the back side of the blade for this purpose with success.
> > >
> > >O-ring Seals
> > >
> > ---------------------------------------------------
> >
> > Dear O-ring (and the Group),
> >
> > I believe you'll find there's a bit more to it than that :-)
> >
> > First off, the 'normal speed' you're referring to is for a woodworking
> > bandsaw.
> > The down-side is that most woodworking bandsaws are fitted with a rubber
> > 'tire' on their driver- & idler-wheels. Friction cutting steel (which is
> > what
> > you're doing) will destroy the tire on the driver-wheel in short order.
> > Bandsaw tires are moderately expensive and can be hellishly difficult to
> > replace on some saws.
> >
> > Metal-cutting bandsaws do not use tires. The wheels are sizes so that the
> > teeth overhang the edge of the wheel, not only for cooling but for clearing
> > the
> > swarf.
> >
> > You can set-up a metal cutting bandsaw for friction cutting if you have the
> > proper ratio pulleys (ie, increase the blade speed).
> >
> > The popularity of this method hinged largely on the builder's ability to
> > splice
> > their own blades because the original idea was to use common steel
> > strapping.
> > Operated at high speed -- and cutting relatively thin stock -- the stuff
> > does
> > in fact cut like butter, with a very attractive displace of sparks, too :-)
> > But the strapping was rapidly consumed and unless you were a dab hand at
> > splicing, ideally with a Do-All type butt-welder, there was no long-term
> > advantage over regular cutting.
> >
> > All of this came about due to the difficulty of cutting relatively hard
> > steel
> > in thinner gauges, which loves to strip the teeth off anything. .035 4130,
> > you
> > can do pretty well using a regular bi-metallic 32T blade by simply rigging
> > the
> > work to feed 'downhill' so that two teeth are in contact with the work.
>
>
> I used to cut 4130 using the bandsaw method, with a 1/2" bimetal
> blade installed the right way, and just letting the teeth round off
> the first time I used it. It would cut rather nicely, and didn't hurt
> the rubber tire. Keeping the cut straight was the biggest hassle.
> There's a German-made friction-cutting tool designed to cut sheet
> of all sorts using a steel wheel that doesn't spin but instead
> oscillates at a fairly high frequency in an arc of about 20 degrees or
> so. I saw it demonstrated on aluminum, steel and even stainless steel.
> Really noisy, but a really clean cut, too. No chips. When the section
> of the disc doing the work gets a bit dull, you loosen the screw and
> rotate it a bit to a sharper section. I am trying to remember the
> name, but can't. It was a big hit at our aircraft engineer's symposium
> a couple of years ago. Not cheap, but well worth the cost if you're
> doing much cutting.
> Friction welding of aluminum aircraft skin was presented there,
> too, though not demonstrated. Skins are butted together and a
> high-speed carbide bit with a flat end and one raised tit are run over
> the joint under pressure, the metal heats and fuses, and the alloy is
> not affected so strength isn't hurt at all. I don't know how. You get
> a flush, seamless joint with far less hassle than riveting. Also very
> expensive. I think Airbus is using it on the A380, maybe.
>
> Dan
>
> Dan

I would think that the seam would lose a lot of its basic heat treat
strength, due to the melting/recrystallization.

[Aardvark]

Orval Fairbairn wrote:
> In article >,
> (Dan Thomas) wrote:
>
>
(Veeduber) wrote in message
>...
>>
>>>>One of the easiest ways to cut sheet 4130 is with a band saw. Use an
>>>>old metal cutting blade installed upside down (the teeth pointing up).
>>>>Run the saw at normal speed and feed in the material. Keep the
>>>>pressure up and it will go (melt) through like you are cutting butter.
>>>>Don't pause though, it is not so easy to get started again. Some have
>>>>also used the back side of the blade for this purpose with success.
>>>>
>>>>O-ring Seals
>>>>
>>>
>>>---------------------------------------------------
>>>
>>>Dear O-ring (and the Group),
>>>
>>>I believe you'll find there's a bit more to it than that :-)
>>>
>>>First off, the 'normal speed' you're referring to is for a woodworking
>>>bandsaw.
>>> The down-side is that most woodworking bandsaws are fitted with a rubber
>>>'tire' on their driver- & idler-wheels. Friction cutting steel (which is
>>>what
>>>you're doing) will destroy the tire on the driver-wheel in short order.
>>>Bandsaw tires are moderately expensive and can be hellishly difficult to
>>>replace on some saws.
>>>
>>>Metal-cutting bandsaws do not use tires. The wheels are sizes so that the
>>>teeth overhang the edge of the wheel, not only for cooling but for clearing
>>>the
>>>swarf.
>>>
>>>You can set-up a metal cutting bandsaw for friction cutting if you have the
>>>proper ratio pulleys (ie, increase the blade speed).
>>>
>>>The popularity of this method hinged largely on the builder's ability to
>>>splice
>>>their own blades because the original idea was to use common steel
>>>strapping.
>>>Operated at high speed -- and cutting relatively thin stock -- the stuff
>>>does
>>>in fact cut like butter, with a very attractive displace of sparks, too :-)
>>>But the strapping was rapidly consumed and unless you were a dab hand at
>>>splicing, ideally with a Do-All type butt-welder, there was no long-term
>>>advantage over regular cutting.
>>>
>>>All of this came about due to the difficulty of cutting relatively hard
>>>steel
>>>in thinner gauges, which loves to strip the teeth off anything. .035 4130,
>>>you
>>>can do pretty well using a regular bi-metallic 32T blade by simply rigging
>>>the
>>>work to feed 'downhill' so that two teeth are in contact with the work.
>>
>>
>> I used to cut 4130 using the bandsaw method, with a 1/2" bimetal
>>blade installed the right way, and just letting the teeth round off
>>the first time I used it. It would cut rather nicely, and didn't hurt
>>the rubber tire. Keeping the cut straight was the biggest hassle.
>> There's a German-made friction-cutting tool designed to cut sheet
>>of all sorts using a steel wheel that doesn't spin but instead
>>oscillates at a fairly high frequency in an arc of about 20 degrees or
>>so. I saw it demonstrated on aluminum, steel and even stainless steel.
>>Really noisy, but a really clean cut, too. No chips. When the section
>>of the disc doing the work gets a bit dull, you loosen the screw and
>>rotate it a bit to a sharper section. I am trying to remember the
>>name, but can't. It was a big hit at our aircraft engineer's symposium
>>a couple of years ago. Not cheap, but well worth the cost if you're
>>doing much cutting.
>> Friction welding of aluminum aircraft skin was presented there,
>>too, though not demonstrated. Skins are butted together and a
>>high-speed carbide bit with a flat end and one raised tit are run over
>>the joint under pressure, the metal heats and fuses, and the alloy is
>>not affected so strength isn't hurt at all. I don't know how. You get
>>a flush, seamless joint with far less hassle than riveting. Also very
>>expensive. I think Airbus is using it on the A380, maybe.
>>
>> Dan
>>
>> Dan
>
>
> I would think that the seam would lose a lot of its basic heat treat
> strength, due to the melting/recrystallization.

A PDF on stir/friction welding from NASA.gov
http://makeashorterlink.com/?E472217A6


ww

[David Johnson]

I have purchased a number of items from Harbor Freight, and have
generally been satisfied with them. No question about these things
competing with top of the line merchandise, but for items that I
only use occasionally they are good enough. Two items that come to
mind are an angle grinder for $20 and an electric hoist for $60.

I'd suggest that you visit the store and decide which items you
would want to buy. Then if you are not in a hurry, get on their
mailing list and wait for what you want to come up on sale.
Sooner or later just about everything they sell is offered at
big discounts - often 50%.

David Johnson

[David Johnson]

I'll second the opinion about the quality of modern cars. I have
been astonished by the almost trouble free experience I've had with
my '92 T-Bird (bought new). At 11 years and 135K miles, it still
has the original belts, hoses, ignition wires, etc. Two of the
original tires went 77K miles. The only repair needed was the
"idle" servomotor that went out at a few years ago (the car ran
fine, but "idle" was about 1800 rpm).

David Johnson

[Blueskies]

"Aardvark" > wrote in message ...
> Orval Fairbairn wrote:
> > In article >,
> > (Dan Thomas) wrote:
> >
> >
<snip>> >>
> >> I used to cut 4130 using the bandsaw method, with a 1/2" bimetal
> >>blade installed the right way, and just letting the teeth round off
> >>the first time I used it. It would cut rather nicely, and didn't hurt
> >>the rubber tire. Keeping the cut straight was the biggest hassle.
> >> There's a German-made friction-cutting tool designed to cut sheet
> >>of all sorts using a steel wheel that doesn't spin but instead
> >>oscillates at a fairly high frequency in an arc of about 20 degrees or
> >>so. I saw it demonstrated on aluminum, steel and even stainless steel.
> >>Really noisy, but a really clean cut, too. No chips. When the section
> >>of the disc doing the work gets a bit dull, you loosen the screw and
> >>rotate it a bit to a sharper section. I am trying to remember the
> >>name, but can't. It was a big hit at our aircraft engineer's symposium
> >>a couple of years ago. Not cheap, but well worth the cost if you're
> >>doing much cutting.
> >> Friction welding of aluminum aircraft skin was presented there,
> >>too, though not demonstrated. Skins are butted together and a
> >>high-speed carbide bit with a flat end and one raised tit are run over
> >>the joint under pressure, the metal heats and fuses, and the alloy is
> >>not affected so strength isn't hurt at all. I don't know how. You get
> >>a flush, seamless joint with far less hassle than riveting. Also very
> >>expensive. I think Airbus is using it on the A380, maybe.
> >>
> >> Dan
> >>
> >> Dan
> >
> >
> > I would think that the seam would lose a lot of its basic heat treat
> > strength, due to the melting/recrystallization.
>
> A PDF on stir/friction welding from NASA.gov
> http://makeashorterlink.com/?E472217A6
>
>
> ww
>

The Eclipse 500 is using a patented stir weld process...

--
Dan D.

[Dan Thomas]

Aardvark > wrote in message >...
> Orval Fairbairn wrote:
> >
> >
> > I would think that the seam would lose a lot of its basic heat treat
> > strength, due to the melting/recrystallization.
>
> A PDF on stir/friction welding from NASA.gov
> http://makeashorterlink.com/?E472217A6
>
>
> ww


That's the process. The metal, as they say, does not actually melt,
just plasticizes, and doesn't lose its strength.


Dan

[Ernest Christley]

It appears that my previous thank you note didn't get through. Maybe
it's a appropriate, 'cause now I get to thank everyone on Thanksgiving.
The generosity of members of this list is boundless. I actually had
several people volunteer to cut the sheet for me. I declined those
offers because of the shipping cost and difficulty of communication (and
I really do want to keep the 'I built that' element as much as possible).

I have an inlaw that has access to a portable plasma torch. I'm going
to get the sheet laid out and get up with him. I had actually forgotten
all about this particular resource until someone here mentioned it.
However, I'm still of the mind to hold back at least one piece so that I
can give that friction cutting method a try. Just 'cause I LIKE to see
sparks flying.

Beyond that, I've had dozens of occasions to recieve excellent
information from this newsgroup, both as direct responses to questions
I've posed and in responses to others...even from old curmudgeons(sp?)
like Barnyard Bob. Regardless of the amount of bickering and
namecalling, I firmly believe that everyone here has the goal of
building/help build the safest possible airplane at the least expense of
time, effort, and dollars. When I come flying into Sun'n'Fun or Oskosh
in a few years, you can all rest assured that you had a hand in getting
me there.

Thank you.

(PS - If I crash and burn on test flight, then it's all on my head.)

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

[Olen Goodwin]

I used a table saw and later a radial arm saw with abrasive cutting wheels
from the local lumberyard/hardware. Works just like cutting wood, but
noisier and smellier. Be careful cover the wood table (if the saw table
isn't metal) with a sheet of metal or the sparks will cause charring. I've
cut up to .120 4130 this way and it works fine.

I wouldn't use this method for huge projects, since the grit is messy and
hard on the saw if you don't clean it well, but for the occasional part, it
worked well, cutting straight lines and fairly quickly.

"Ernest Christley" > wrote in message
. com...
> 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
>

[Dan Thomas]

Ernest Christley > wrote in message >...
> I have an inlaw that has access to a portable plasma torch. I'm going
> to get the sheet laid out and get up with him. I had actually forgotten
> all about this particular resource until someone here mentioned it.
> However, I'm still of the mind to hold back at least one piece so that I
> can give that friction cutting method a try. Just 'cause I LIKE to see
> sparks flying.

Might be a good idea to cut one piece with the plasma torch,
another with a saw, clean and polish the edges of both, then bend them
to see what the crack resistance is like. Plasma heat is big-time hot
and might drive lots of carbon (from slag) into the edge of the steel
and make it brittle. If so, it would be wise to cut a little oversize
and grind to final size.
I spent many hours cutting all sorts of metals with a plasma
torch some years ago. What a great time-saver. Of course, these were
feed-mill parts, not airplane parts, and nobody cared what happened to
the edges of mild steel.
I understand that the plasma flame is hotter than the surface of
the sun, which is something like 10,000°F. The interior of the sun, of
course, is much hotter than that.


Dan