Pneumatic Vs Hydraulic Press Brake

[Huskerz]

I currently own a Diacro 14-48 (17 Ton 48") hydro mechanical press brake AND a Pneuco 35 ton 6 foot up-acting pneumatic press brake. I have not used either, nor any press brake for that matter. I bought them to learn and am considering parting with one due to space constraints and lack of use so far. I would like experienced input on the pros/cons of both machines. I've come to realize neither will probably do all I want - but you have to start somewhere. I work mainly with 18 ga steel, although heavier aluminum is a possibility. I do have a 4' finger brake and 10' apron brake as well. Thanks for any input on which one to keep and why? Or if its worth keeping both? Thanks in advance

 

[Huskerz]

I would appreciate any feedback from anyone who has used a pneumatic press brake vs a more typical hydro mechanical brake? Thanks

 

[kb0thn]

I started with an old leaky Diacro 17-ton hydro mechanical press brake. And made a lot of product with it. Other than the leaks, they are a fine machine.

 

[RC Mech]

Get rid of the pneumatic brake.

 

[kb0thn]

I started with an old leaky Diacro 17-ton hydro mechanical press brake. And made a lot of product with it. Other than the leaks, they are a fine machine.

I should add that with the Diacro you do have an honest 17 tons to do with what you want. We formed short pieces of 1/2" steel and stainless on a regular basis. You just run out of tonnage fast as your parts get long. But that's always the case. My next press brake was 60 tons and we run out of tonnage on it on a regular basis. Next press brake I am looking at is 150 metric ton. I am sure it will run out of tonnage too...

 

[EmGo]

Get rid of the pneumatic brake.

To expand on this for beginners, air compresses while hydraulic oils do not, so anything pneumatic will be less controllable than anything hydraulic.

 

[Strostkovy]

Without knowing more about the pneumatic press brake, I can't make a recommendation. However, if the ram bottoms out on a screw driven travel stop, then it will be more accurate than a hydraulic brake with a mechanical positioning valve, which is rather pressure dependent.

 

[kb0thn]

Without knowing more about the pneumatic press brake, I can't make a recommendation. However, if the ram bottoms out on a screw driven travel stop, then it will be more accurate than a hydraulic brake with a mechanical positioning valve, which is rather pressure dependent.

The Diacro he has is "hydro mechanical". It is a hydraulic rotary motor that drives a cam. There are threaded linkages on the "rams" that set the depth. So it's going to be very similar in accuracy to a mechanical press brake.

 

[Strostkovy]

The Diacro he has is "hydro mechanical". It is a hydraulic rotary motor that drives a cam. There are threaded linkages on the "rams" that set the depth. So it's going to be very similar in accuracy to a mechanical press brake.

That's a fair assessment.

We had one of those at my old job and it was never functional because someone would overload it and break something every time it was fixed.

 

[kb0thn]

That's a fair assessment.

We had one of those at my old job and it was never functional because someone would overload it and break something every time it was fixed.

Maybe I did myself a favor when I put a VFD on mine. It stalled the pump / VFD when it was grossly overloaded.

 

[Strostkovy]

Maybe I did myself a favor when I put a VFD on mine. It stalled the pump / VFD when it was grossly overloaded.

Actually I forgot that the brake they had was a flywheel and clutch style. A hydraulic cam shouldn't have the same issue.

 

[Garwood]

Actually I forgot that the brake they had was a flywheel and clutch style. A hydraulic cam shouldn't have the same issue.

Diacro hydromechanical brakes are the standard good old precision press brake everyone at least starts off with. If you haven't been around them and have sheetmetal experience that's surprising because they are literally everywhere.

 

[Strostkovy]

Diacro hydromechanical brakes are the standard good old precision press brake everyone at least starts off with. If you haven't been around them and have sheetmetal experience that's surprising because they are literally everywhere.

I'm aware of two shops that have them. But they are much older than I am. That same shop I worked for has a 40 ton ballscrew servo press and two lasers from the 90s, which isn't ten years ago anymore. Even the new stuff is old tech at this point.

 

[Garwood]

I'm aware of two shops that have them. But they are much older than I am. That same shop I worked for has a 40 ton ballscrew servo press and two lasers from the 90s, which isn't ten years ago anymore. Even the new stuff is old tech at this point.

Old tech or not Diacros are decent press brakes and are often found with fancy modern programmable backgauges.

 

[Strostkovy]

Old tech or not Diacros are decent press brakes and are often found with fancy modern programmable backgauges.

Oh, yeah, they're decent. My point is servos are just more desirable because of how quickly you can change bend parameters, and there are a lot of old options available more cheaply than there used to be. For a lot of uses I'm sure they are a great fit; I just don't have the luxury of high volume production.

 

[Huskerz]

I appreciate the valuable dialog. It sounds like the Diacro is the better of the two machines overall? Unfortunately I do have some longer parts I'd potentially like to bend that wont' fit on the 4'. Right now they are being made on a very spendy modern press brake (outsourced) and I doubt I could get the accuracy and repeatability on the Pneumatic to make them fold up properly?

 

[townsonkimbrly]

As for the hydro-mechanical press brake, it gives you precise control over bending operations, allowing for consistent results. The 48" bed length gives ample space for bending longer workpieces, and the 17-ton capacity should be sufficient for bending 18 gauge steel and can handle thicker materials like aluminum with care.

But you sholud remember that it might require more setup time compared to the pneumatic press brake due to the nature of its operation.

 

[kb0thn]

I appreciate the valuable dialog. It sounds like the Diacro is the better of the two machines overall? Unfortunately I do have some longer parts I'd potentially like to bend that wont' fit on the 4'. Right now they are being made on a very spendy modern press brake (outsourced) and I doubt I could get the accuracy and repeatability on the Pneumatic to make them fold up properly?

You are going to have to get to be good to be able to replicate what a modern press brake can do. And parts longer than 4' is going to be another big hurdle. Tonnage gets used up quickly on long parts. Crowning becomes a huge issue. Finding a different vendor who can form your 4'+ long parts cheaper probably makes more sense than thinking you are going to save doing those yourself.

Or get a finger brake and you don't have the issues associated with a press brake. But you are much more limited on profiles you can form. But if you can form your profiles on a finger brake, you won't have to spend months or years of your life and thousands or tens of thousands of dollars on tooling.

 

[snowshooze]

I currently own a Diacro 14-48 (17 Ton 48") hydro mechanical press brake AND a Pneuco 35 ton 6 foot up-acting pneumatic press brake. I have not used either, nor any press brake for that matter. I bought them to learn and am considering parting with one due to space constraints and lack of use so far. I would like experienced input on the pros/cons of both machines. I've come to realize neither will probably do all I want - but you have to start somewhere. I work mainly with 18 ga steel, although heavier aluminum is a possibility. I do have a 4' finger brake and 10' apron brake as well. Thanks for any input on which one to keep and why? Or if its worth keeping both? Thanks in advance

First;
I could use that finger brake.
Now, pneumatic... straight to air cylinder, or does it go to an air motor driving an acme screw?
If with screw... not a big difference. If straight to cylinder, huge difference.
Hydraulic and air-motor driven screw are equal. One requires a compressor, the other a pump.
Other than that, it is just noise.

 

[snowshooze]

The Diacro he has is "hydro mechanical". It is a hydraulic rotary motor that drives a cam. There are threaded linkages on the "rams" that set the depth. So it's going to be very similar in accuracy to a mechanical press brake.

Gotta be good.