The terms CONTROL and MONITOR are often confused and misunderstood when dealing with press equipment. Presses can be grouped into four main categories, manual, air, hydraulic and electric. Each of these offers a wide range of capability. Controls are used to operate many types of presses. Additionally, feedback may be necessary to provide in-process quality monitoring. When it comes to selecting press equipment and quality needs to be monitored, a selection must be made based on the process capability and complexity (CONTROL), as well as the detail of quality monitoring (MONITOR). The question becomes, what technology is right for your assembly?

A basic hand or pneumatic press can provide varying degrees of control & monitoring. A simple mechanical or electrical device can be applied to ensure that a specific stroke is achieved, a flow or speed control to slow the ram speed down, or a load cell with a monitoring instrument to check peak force.

If your assembly requires true process MONITORING that allows definition of parameters for various critical steps of the process and can be adapted to characteristics of a work piece, a more intelligent press may be needed. At this point, one would have to carefully examine the level of monitoring detail requirements versus the monitoring capability of the equipment selected. Most importantly, what are the consequences and costs if a part is passed and it does not meet quality requirements?

The ability to CONTROL an assembly process is a result of the capability of the press. Can it control the actions of the press, i.e. speed, force & distance? Can it respond to external feedback? The solution may be to use a servo actuated press so you can have a freely programmable system. These solutions should adjust to position, force or both with a high degree of precision. When looking at these systems, ask yourself:

• Do I have pressing parameters that change frequently?
• Is accuracy critical, despite varying forces?
• Is closed loop force control important?
• Does my positioning vary due to part relaxation, tooling compression or system bending?
• Do you need to reach a target based on a force or distance?
• Do you need to maintain an accurate force over a time period or react to a change in slope?
• Is external feedback required to reach a target base?

Press technology has come a long way and there are many questions you need to ask yourself when purchasing a press for you manufacturing requirements. Take some time to ask yourself, or a press expert, what you really need. It may save you time and money in the end.

For more information, visit www.schmidtpresses.com.