Freeride
Well-Known Member
I've wanted to add a press brake to my home shop for quite a while. I've been watching craigslist and ebay and gone and checked out several used machinery dealers but haven't seen anything that would work. Everything was either huge and antiquated, or small and still very expensive. The small press brake inserts for shop presses are neat, but they don't offer interchangeable tooling or have provisions for setting depth stops for repeat bends.
So now I'm planning on building my own. I'm modeling the design after the Iroquois press brakes like the one below. The design allows for a lot of tonnage in a smaller brake. It also will be designed to accept standard press brake tooling. I have lots of fab & mechanical experience, but this is my first hydraulic project, so comments are appreciated!
General specs are 36" tooling length, 31 ton, 7" travel.
I'm planning on using this 4" bore, 14" stroke double acting ram. With the 2:1 mechanical advantage of the press, it will give me 7" of max tooling travel.
http://www.northerntool.com/shop/tools/product_200309393_200309393
With a 2:1 mechanical advantage and 2500 psi working pressure, it should push a little over 31 tons. I used this calculator:
http://www.baumhydraulics.com/calculators/cyl_calc.htm
For a pump, I'm using this Haldex 2 stage unit. The first stage is 11 gpm at 650 psi. The second stage puts out 2.9 gpm at 2500 psi. That pump should net me a cycle time of around 7 seconds. Although I plan on being able to adjust the up stroke so that I'm not always using the full throw of the ram. Practical cycle time should be around 3-4 seconds. This calculator is great.
http://www.baumhydraulics.com/calculators/cyl_speed.htm
http://www.northerntool.com/shop/tools/product_200321051_200321051
This 5hp 230V single phase motor should push the pump just fine. The formula I used is this: (GPM x PSI) / (1714 x 85% efficiency)
http://www.northerntool.com/shop/tools/product_200381912_200381912
I still need to find a coupler for the motor & pump.
For a resevoir, I'm looking at this unit. It's a 12 gallon. The info I found online recommends at least 1 gallon of resevoir to every GPM that the pump outputs.
http://www.northerntool.com/shop/tools/product_200466866_200466866
The control valve I'm a little fuzzy on. The press I'm building is basically a hydraulic log splitter in concept. Just arranged differently. I'd prefer a foot pedal actuator, but I haven't found any great options there. These hand valves for log splitters seem like they'd work fine. This should allow me to hold the handle down in the down cycle, and then it should auto-retract the cylinder.
http://www.northerntool.com/shop/tools/product_472_472
For the lower stroke stop, I'm looking for one of these. I still need to source it.
This basic filter setup looks like it should work fine.
http://www.northerntool.com/shop/tools/product_200466914_200466914
The main body and upper punch holder will be 1" thick steel. I might use my plasma table and cut 1/2" steel and then bolt/weld the pieces together laminated to make 1". I'm still working on the mechanical modeling and will post up renderings in the next few days.
So now I'm planning on building my own. I'm modeling the design after the Iroquois press brakes like the one below. The design allows for a lot of tonnage in a smaller brake. It also will be designed to accept standard press brake tooling. I have lots of fab & mechanical experience, but this is my first hydraulic project, so comments are appreciated!
General specs are 36" tooling length, 31 ton, 7" travel.
I'm planning on using this 4" bore, 14" stroke double acting ram. With the 2:1 mechanical advantage of the press, it will give me 7" of max tooling travel.
http://www.northerntool.com/shop/tools/product_200309393_200309393
With a 2:1 mechanical advantage and 2500 psi working pressure, it should push a little over 31 tons. I used this calculator:
http://www.baumhydraulics.com/calculators/cyl_calc.htm
For a pump, I'm using this Haldex 2 stage unit. The first stage is 11 gpm at 650 psi. The second stage puts out 2.9 gpm at 2500 psi. That pump should net me a cycle time of around 7 seconds. Although I plan on being able to adjust the up stroke so that I'm not always using the full throw of the ram. Practical cycle time should be around 3-4 seconds. This calculator is great.
http://www.baumhydraulics.com/calculators/cyl_speed.htm
http://www.northerntool.com/shop/tools/product_200321051_200321051
This 5hp 230V single phase motor should push the pump just fine. The formula I used is this: (GPM x PSI) / (1714 x 85% efficiency)
http://www.northerntool.com/shop/tools/product_200381912_200381912
I still need to find a coupler for the motor & pump.
For a resevoir, I'm looking at this unit. It's a 12 gallon. The info I found online recommends at least 1 gallon of resevoir to every GPM that the pump outputs.
http://www.northerntool.com/shop/tools/product_200466866_200466866
The control valve I'm a little fuzzy on. The press I'm building is basically a hydraulic log splitter in concept. Just arranged differently. I'd prefer a foot pedal actuator, but I haven't found any great options there. These hand valves for log splitters seem like they'd work fine. This should allow me to hold the handle down in the down cycle, and then it should auto-retract the cylinder.
http://www.northerntool.com/shop/tools/product_472_472
For the lower stroke stop, I'm looking for one of these. I still need to source it.
This basic filter setup looks like it should work fine.
http://www.northerntool.com/shop/tools/product_200466914_200466914
The main body and upper punch holder will be 1" thick steel. I might use my plasma table and cut 1/2" steel and then bolt/weld the pieces together laminated to make 1". I'm still working on the mechanical modeling and will post up renderings in the next few days.
