Pneumatic Press

I have been wanting to install a RMC controller on a four post pneumatic press for some time. We use the RMC controllers on our hydraulic presses with great success. I have some doubts on how well I will be able to control the motion due to the characteristics of pneumatics. I have researched on line to see what I could find and have not seen anything on presses that would have a hanging weight.
The typical size of one press has the moving steel platen weight @ 700lbs (2" x 25"x 44.5"). We would raise and lower the platen with a 6" bore cylinder. Time of the move we would like to have in 0.5 to 0.7 seconds. The CV rating on the valve would need to be in the 3cv to 5cv.
We would install a linear transducer for position feedback to the controller mounted in the cylinder and fabricate a manifold and adapter plate to mount the valve directly to the cylinder.
Questions are:

  1. Has anyone seen this implemented on a four post pneumatic press ? If so how well did it perform?
  2. What pneumatic valve recommendations do you have?

I want to set a system up and test it before actually using it on a customers machine. I could test it on a press coming through and see how it performs. I just need a little info to get started.

Thank you for any information you can provide.

Hi ZedIDave!

You are certainly not afraid of challenges! Based on our research here, your application sounds like it will be very difficult. That said, I don’t know that we have tried a press, so there may be a chance that we are erroneously thinking it is difficult. What is the distance of the move?

Myself, I am very interested in hearing whether it works or not. I would suggest that you approach this as a research project and not assume it is absolutely going to work. Of course, you will be able to get motion out of it, the big question is what cycle time can be achieved.

As for pneumatic valve recommedations, I will see if I can get someone else to give that. From what I know, we have found the Woodward HRT valves to perform very well. They are quite expensive. We have tried some other valves that just aren’t worth trying.

Hi Jacob,

Sorry, I thought I included all the info that may be required. For this application we would stroke the cylinder about 5". I am a little leery of how well it could control and if so, what speeds could I see. With the sponginess of pneumatics this is a very gray area for me.
We have used the Woodward valves on our hydraulic platens (27G50). Great valves if you can wait for it. I’m hoping since Woodward acquired this line, maybe this will improve? We currently use either Continental proportional valves(VED08MJ / 07MJ ) or the Woodward servo valves for our hydraulic applications.
I was wanting to try one of these valves for the pneumatic application but it would require making a manifold plate to attach to the pneumatic cylinder on a press that we currently do not have coming through.
I wanted to check to see if a pneumatic press with this control system was even feasible before putting too much time/labor into it. I would like to see what valves you would recommend.