Designing a Hydraulic Press Brake (1 Viewer)

[GLTHFJ60]

After seeing @Mieser 's custom made hydraulic press brake, I thought that would be a fun design and build project. I looked at all the pics he had in his build thread and set out designing one.

Requirements:
60" bed
Laminated, removable finger dies (upper and lower)
Bottom-up press design (lower dies move up towards the top dies)
Bend capacity up to 24" of 1/4" plate, 36" 3/16, full width for all smaller gauges
Removable upper die guide
Tensioning bar in the center of the upper die guide
Lower die guide to move on fabricated "machine ways" to help ensure alignment to upper die

Specifics on the current design below.

Definitions:
- Upper Die Guide: Red, holds upper dies, has tensioning rod
- Lower Die Guide: Orange, holds lower dies, rides on ways, pushed up by bottle jacks
- Main Frame: Gray, holds upper and lower guides, provides platform for bottle jacks
- Dual 20t bottle jacks

Upper die guide materials:
- Angled uprights are 2x2x1/8 tubing
- Horizontal section is 1x5" solid bar sunk into a section of 2x2x1/4 tubing
- Gussets and die holders made of 1/4" plate
- Bolted to frame with 4 1/2" bolts
- Tensioning rod made out of 1/2" machine all thread (or ACME thread if cost effective)

Lower die guide materials:
- 1x1/2 solid bar to form channel for dies
- 2x4x1/4 main rail
- 2x2x1/4 lower rail
- 3/4" plates to distribute pressure from bottle jacks
- ~1"x~1/2" rails ("ways") to slide along main frame "ways"

Main Frame:
- Uprights and legs are 2x2x1/4 wall
- 2x6x1/4 bottle jack platform
- 2x4x1/4 bottle jack platform support
- 1x1 solid bar "ways"

Looking for thoughts and input on this design. I'd like to integrate as many features as are useful. If you see something I should do differently, please post up your suggestions!!

Working on the following components now:

1. Metal Rolling dies (think sheet metal roller)
2. Flip-up infeed/outfeed tables
3. Casters instead of feet (need to find a caster model I like in the 3D warehouse)

 

[GLTHFJ60]

Thinking this will be a more reliable, and easier to fabricate, mechanism to keep the lower die guide in line with the frame:

 

[Mieser]

Hello. I'll get you some more pics and that video soon.

Don't over think it.

You don't really need any fancy guides. I added a few brass 1/4-20 set screws with lock nuts on both the sliding points and where the upper die pins onto the frame. This let's me take the slop out of the assembly and align everything.

Make sure the top die truss can be removed. Mine pins in place using trailer hitch tubing material.

Make sure you can preload the upper truss for deflection.

If you want to bend thick material on a wide bed you will probably need some tie bars that lock the upper truss to the bottom framework.

 

[Mieser]

The beam for the bottom of the rams would be better/stronger if the 2nd piece of material was upright. All you need it is a small plate to keep the ram from tipping over.

 

[Mieser]

Also. Remember this is a press brake not a sheetmetal brake. The bend radius will typically be set by a combination of the upper die AND an air bending spring back component unless you are going to bottom the dies.

You may not get super crisp bends in sheetmetal like material for better or worse.

 

[Mieser]

If you design you dies like mine, don't forget that you need a little room at the ends for the nuts that pinch things together with the all thread. This can change the overall width you need for the bed/truss.

 

[Mieser]

The tensioning jack screw needs to be pretty thick in diameter to prevent it from bowing. 1/2 inch thread probably isn't large enough. Mine is like 3/4 threads I think.

 

[Mieser]

It would be better if the upper truss came off easily. Mine collapses by slacking the tension screw and pulling the top pin. . This is handy for bending things over the top of the truss, like a 3 bend box.

 

[GLTHFJ60]

You don't really need any fancy guides. I added a few brass 1/4-20 set screws with lock nuts on both the sliding points and where the upper die pins onto the frame. This let's me take the slop out of the assembly and align everything.

10-4. Do you have any issues with misalignment as the lower die moves up or does it retain it's alignment reliably with those brass dogpoints?

The beam for the bottom of the rams would be better/stronger if the 2nd piece of material was upright. All you need it is a small plate to keep the ram from tipping over.

Need clarification. The beam for the bottom of the rams, what I'd call the bottle jack platform, is a 2x6 and a 2x4 in a T formation. You're saying two 2x6s in a "II" formation (upright, next to each other) would be stronger?

If you want to bend thick material on a wide bed you will probably need some tie bars that lock the upper truss to the bottom framework.

Metal straps that go from the bolts down to the main frame uprights? It will already be bolted in place, or are you saying that four bolts (two per side) is not enough? Imagine bolts going where there are currently just holes.

The tensioning jack screw needs to be pretty thick in diameter to prevent it from bowing. 1/2 inch thread probably isn't large enough. Mine is like 3/4 threads I think.

10-4. Will upsize to 3/4" or 1" threaded rod.

It would be better if the upper truss came off easily. Mine collapses by slacking the tension screw and pulling the top pin. . This is handy for bending things over the top of the truss, like a 3 bend box.

That makes a lot of sense for lighter duty bends. I didn't think of that before. I'll change that truss design to incorporate that as well.

Thanks for your input

 

[Mieser]

10-4. Do you have any issues with misalignment as the lower die moves up or does it retain it's alignment reliably with those brass dogpoints?

Need clarification. The beam for the bottom of the rams, what I'd call the bottle jack platform, is a 2x6 and a 2x4 in a T formation. You're saying two 2x6s in a "II" formation (upright, next to each other) would be stronger?

Metal straps that go from the bolts down to the main frame uprights? It will already be bolted in place, or are you saying that four bolts (two per side) is not enough? Imagine bolts going where there are currently just holes.

That makes a lot of sense for lighter duty bends. I didn't think of that before. I'll change that truss design to incorporate that as well.

Thanks for your input

No issues with alignment at all. I was able to dial in things pretty easy.

For the bottom beam, overall height is generally your friend. My bottom structure is 2x4x1/4 box stacked on top of each other long ways to form an 8" tall x 2" wide beam. I just have some round discs for the ram bases to sit on. The tops of the ram piston pad sit in some small sections of round tubing.

In general, I designed my machine to be made out of 1 stick of 2x4x1/4 and one stick of 2x2x1/4. I bought a long section of receiver adapter tubing on Amazon, that gave me enough to make the top truss attachments along with the sliding legs.

We need pics....





















I hope that helps.

 

[GLTHFJ60]

I see said the blind man.

Thank you sir, that helps a lot

 

[Mieser]

Any progress with your model or building?

 

[GLTHFJ60]

Yup, implemented your suggestions. Still some more design work to do, specifically for the sheetmetal rollers, then will need to make parts lists.

Upper die guide changed to attach via a single 3/4" bolt (per side) to the main frame with a section of 2 1/2x 2 1/2x 1/4 tubing. Changed tensioning rod to 1/4" plates that are attached with 3/4" bolts.

Lower die guide changed to index off of the main frame with 1/4" plates and brass bolts like you did on yours.

Bottle jack platform changed to be two vertical 2x4s with a 1/4" plate platform for each jack to sit on.

 

[Mieser]

Looking good.

I would increase the length of the tubing for the upper die attachment. Make it as long as the main upper rib is tall. If you look close on mine you can see another set of the brass set screws. These help align the top die to the bottom as there is slop between the two tubes. These done slide so they don't wear. I used these more than the bottom die ones for alignment.

 

[GLTHFJ60]

I would increase the length of the tubing for the upper die attachment. Make it as long as the main upper rib is tall.

10-4, good idea. Should have thought of that myself.

If you look close on mine you can see another set of the brass set screws. These help align the top die to the bottom as there is slop between the two tubes. These don't slide so they don't wear. I used these more than the bottom die ones for alignment.

Question about that. Do you need to bolt the upper die guide to the frame or can you use shear pins, like hitch pins or wire lock pins? Would make assembly and disassembly easier.

 

[GLTHFJ60]

Updated upper die guide.

 

[Mieser]

I think a pin would be ok.

What are the extra strap/material at the top of the upper die truss? Anything you can do to eliminate welding the better. That will prevent warping and keep the upper die straighter.

 

[GLTHFJ60]

I think a pin would be ok.

What are the extra strap/material at the top of the upper die truss? Anything you can do to eliminate welding the better. That will prevent warping and keep the upper die straighter.

That's a 2x2x.25 bar that the 1x5" plate is slotted into, then welded to, to add extra rigidity to the upper die. Not needed?

 

[GLTHFJ60]

Second set of dies for this press. Sheet metal roller for making curves. These conveyor rollers from McMaster have a 1,100# capacity each, so I'm thinking this will be perfect for rolling sheetmetal for replicating curves, like FJ40 rear quarter skins and the like.

 

[Mieser]

That's a 2x2x.25 bar that the 1x5" plate is slotted into, then welded to, to add extra rigidity to the upper die. Not needed?

Not needed. The vertical height is buying you the most strength in that beam. The welding will just pull/bend it. I'd delete.

I would up size the hardware used to hold the truss on also. I did 1/2 inch grade 8. If I do something stupid like max out the jacks using too narrow a bottom die width I can bend them. I would go up to 5/8

On the rolling die. Rolling is a pretty different process, you need force to turn the die also. I would just use pipe/tube and see if you could find a radius that works after spring back. Make the bottom dies have a few different width positions to allow using different dia upper dis vs the bend angle you want.....likely a max 90.