Follow up - press brake
Bob Engelhardt
press brake (how to eliminate deflection of the die & the limit of force
on hyd. jack).
I am pleased to report that with the mod to the die & using more force
on the jack, I have bent 20" of 14 ga steel. That size is surely the
limit though - I used a 3' piece of pipe as a jack handle & put some
weight on it. The pressure relief never went off, though.
Thanks again,
Bob
Bob La Londe
news:hhjhi...@news5.newsguy.com...
I use a 12 ton air over hydraulic in my press. I've bent lots of stuff in
it, although I have to be honest. In no way could you call it braking.
LOL. Its more like mashing and hoping.
Jim Wilkins
>...
> I use a 12 ton air over hydraulic in my press. I've bent lots of stuff in
> it, although I have to be honest. In no way could you call it braking.
> LOL. Its more like mashing and hoping.
Here's what I use:
http://www.toolplanet.com/product/TD-Industrial-Sheet-Metal-Form-Bender-and-Bending-Brake/brakes-benders
I got it from Harbor Freight, Central Machinery 36477. The maximum
width is 105mm or about 4.12"
jsw
Denis G.
On this topic, I was wondering if there are any guidelines for scoring
sheetmetal to help make bends. Obviously you can get sharper bends
with less force, but you pay some price in strength. It seems that
most of the bends that I need, I'd rather have a well formed sharp
bend and I'm not as concerned about the strength. Another problem
might be in controlling the depth of the score.
I've looked on-line, but haven't found much on this topic. Most
people working with sheetmetal probably have the right equipment to
begin with and don't need to be concerned with scoring.
Steve W.
Scoring ANY item to be bent is a VERY bad idea. You are already going to
stress the area when you bend it. Scoring it will only make that MUCH
worse. Likely to the point that the material will shear instead of bend.
Sharp bends are also dangerous bends. Because they are sharp they lose
quite a bit of strength and they also pose a striking hazard.
But it's your choice.
--
Steve W.
cavelamb
I hear that, Bob.
That's the way I did my ailerons.
You never quite know what yer gonna get...
Richard
Bob La Londe
news:75e9c95d-d6b6-4532...@35g2000yqa.googlegroups.com...
I have been experimenting with getting sharp straight lines in aluminum that
way. Lengths you would normally only butt up at the correct angle and weld.
I have needed some support angles with other than 90 deg. So far just done
this with .125 5052. I make a half depth cut with my table saw, Bend with
the cut to the inside, and the brush and weld along the inside of the bend.
Narrow pieces do not seem to bend easily. Maybe its just the lack of
gripping material, but I do not think so. After its cut I'll clamp heavier
stock and clamp it to a table. Then I hand bend to angle. It's a little
tricky. You have to bend to the correct angle the first time because it
work hardens instantly, and further attempts to bend your angle distort the
legs. For acute angles down to about 70 degrees I have had success by
taking one and a half passes with a standard carbide blade. For 90 degrees
or more a single pass is adequate. Of course thicker material would need a
wider cut. You get really elegantly sharp, smooth, and straight corner
edges this way. Much sharper than with a brake. I just can not bring
myself to trust it for anything critical. I've been trying to work up the
nerve (and figure out the logistics) to try this on a larger scale for the
chines and pad edges on an aluminum fishing boat. Something with a profile
normally only found in glass boats. I'll probably never do it. Mostly
because I would hate to waste that much aluminum. Well, that and I do not
have a 20 foot cast iron table to use for clamping and bending it on. LOL.
Anyway, I suppose that the technique would work with other metals, but again
I would be fearful of trusting it. The cut needs to be a substantial
percentage of the thickness of the material to have the desired affect.
With the aluminum I have found it needs to be about 60% -70% of thickness to
work well and give the aesthetically nice outer finish. It also needs to
be jigged up and supported along the cut with some good planning.
Bob La Londe
news:hhlc2e$fpa$1...@news.eternal-september.org...
Anyway, in my case the weld is what gives it all its strength. The cut and
fold is strictly for shape and positioning. You could get the same
functional piece by welding two pieces together. The weld does go down very
nicely as there is no place for air contamination from the back side.
Obviously if you can not deal with a weld on the inside of your bend this
would be a poor choice of techniques, and as atleast one other has said may
be a poor choice of techniques anyway.
Bob Engelhardt
> I use a 12 ton air over hydraulic in my press. I've bent lots of stuff
> in it, although I have to be honest. In no way could you call it
> braking. LOL. Its more like mashing and hoping.
Maybe I'm easy, but I'm pleased with the bends that I get in my
hydraulic-press-as-press-brake. Here's a pic of that bend of 20" piece
of 14 ga:
http://home.comcast.net/~bobengelhardt/PressBrakeBend.jpg
Bob
Bob La Londe
Very nice