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).
-----
Regards,
Carl Ijames
"TomTom1" wrote in message ...
'Steve W.[_4_ Wrote:
;2965798']TomTom1 wrote:-
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.
-
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.
--
Steve W.
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.
--
TomTom1