going to be making home made pressbrake, jack sizes?

[brendan_h]

think i am going to make it about 400mm long maybe 500mm depending what i got lying around.

just need to know what size tonage jacks should i use? looking to bend anything up to 8mm over the 400-500mm though it probably wouldnt be likely i would need to do this but i would like to have the capabilty there.
just for using around the home making stuff up. i would say mainly 3-5mm steel, aluminium ect
just a side note would a pressbrake be able to bend 1-1.6mm stainless sheet?

and what spacing do the bottom dies need to be?

[aametalmaster]

The rule for the bottom die is 8 times the thickness of the metal you want to bend for the width of the vee...Bob
http://www.accurpress.com/#loadCalculator bottom left side for a calculator.
http://www.americanmachinetools.com/pressure_table.htm

[Diverdude]

Do a little "Reasearch", look on some of the tol web sites for ideas. I know a few have 20 and 40 ton shop presses and the web sites probably have a few dimensions. I built mine using a 20 ton jack. havent built the press brake yet, material still sitting in the corner. Go big on the header over the jack, I have 2 pices of 6" channel on mine and I've had it bow a little when pressing a stuck bearing

[m.k.swelding]

a twenty ton jack I would think would be just right.

[brendan_h]

going by the calculator i think maybe a 30-40t jack would be good though may go for a 20t.

also because of the different thickness i want to bend the bottom dies need to be adjustable? what would i use for dies? i was thinking some 25x25 heavy RHS or maybe even solid?

[aametalmaster]

going by the calculator i think maybe a 30-40t jack would be good though may go for a 20t.

also because of the different thickness i want to bend the bottom dies need to be adjustable? what would i use for dies? i was thinking some 25x25 heavy RHS or maybe even solid?

You could use heavy flatbar with bolts and a thick spacer in between and let the flatbar ears stick up. Or you can use thick angle placed on its point and re enforce the sides with flat...Bob

[aametalmaster]

Sort of like this...Bob

[brendan_h]

how deep do the dies need to be? i like the idear of the flat bar.

[aametalmaster]

Depends how thick the metal is for the depth. You don't want to hit bottom before you are at 90 degrees...Bob

[brendan_h]

best to cut out a holl then?

plan so far is

150x5mm flat bar as the base and starting point with a cut out section where the dies will go.

bottom dies thinking some 25x12 flat bar welded in so the flat bar is lying flat. will only give 12mm befor it bottoms out however i will be cutting a hole out of the base to allow the extra room. ill put some legs on the plate

for the frame to hold the jack still deciding what do use there. thinking maybe come C cection (150 x50)

would be better not to cut the base but i need to know what sort of depth bending 8mm steel will need with a die opening of 80mm