Building home made pan/box brake

Any one have any diagrams? I am attempting to build a pan brake to bend

1/8 sheet metal up to 36 inches wide manuelly. Using 4 x 7.3 channel iron and 1/4 x 4 angle. Will use 1/2 x 3 F.B. where needed. Thanks.
Reply to
TomTom1
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1/8" X 36" is going to take you a LOT more than the materials you listed, and 36" bend in 8 gauge is going to be virtually impossible with a manual unit. I don't know of a commercial manual that goes much over 12 gauge.

A 60 ton press brake with proper dies can do it.

Reply to
Steve W.

Manuel, he ees not heere.

Google is your friend:

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Reply to
Larry Jaques

I have a light-weight Chicago finger brake. I use it mostly to bend .062" aluminum, and it can just handle that OK. The brake beam on top is a solid steel 2x4 with some braces welded to it. The platen (main frame) is equally solid, and the folding plate is a huge piece of 3/8 and 1/2" steel.

Remember, this just handles 1/16" aluminum! You want to bend

1/8" steel? You need a brake that weighs something like 2000 Lbs, and is probably hydraulically operated.

A press brake seems to be the modern tool for this kind of work.

Jon

Reply to
Jon Elson

I have a 50 ton press which is 25 inches wide and it will bend 1/4 plate with ease. It only takes 4 tons pressure to bend 1/8 (12 guage plate) I dont want to rebuild my press to accomodate the 36 inch width. Rather rebuild an entire new set up. And yes, 2 men on a 48 inch 12 guage box brake can bend a 36 inch wide piece of 12 guage. :)

Reply to
TomTom1

Just some doodling with numbers by a non-engineer :-). Using your number of

4 tons (8000 lbs.) to bend a 25" wide piece, then it will take 36/25 * 8000 lbs. = 11520 lbs. to bend a 36" wide piece of 1/8" steel. With your 4x7.3 channel mounted vertically so the force is applied to one of the 1.7" wide flanges (in line with the 4" face so the flange itself won't bend), and the ends rigidly supported by your design, a force of 11520 lbs. uniformly distributed will result in a maximum deflection of 0.010". If the ends are simply supported (so they can rotate as the beam deflects) the deflection jumps to 0.053" so reinforcing those ends and making your hinge arrangement as stiff as possible is mandatory. As for 1/4 x 4" angle for the rotating part, it is only 64% as stiff as the C channel so it will deflect 1.56 times as much (so 0.016" if rigidly supported which will be difficult and still allow motion, and 0.083" if simply supported at the ends). All of these deflections are directly proportional to the load force and inversely proportional to the moment of inertia of the beams, so browse a table of channel and angle properties that includes the moment of inertia and see if there is a size you can step up to that makes sense (I used 4.59 for the channel and 2.936 for the angle for moment of inertia).

'Steve W.[_4_ Wrote:

I have a 50 ton press which is 25 inches wide and it will bend 1/4 plate with ease. It only takes 4 tons pressure to bend 1/8 (12 guage plate) I dont want to rebuild my press to accomodate the 36 inch width. Rather rebuild an entire new set up. And yes, 2 men on a 48 inch 12 guage box brake can bend a 36 inch wide piece of 12 guage. :)

Reply to
Carl Ijames

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