Model 288 Rod sticking

Published by Drew Davis on


We are using the PLC to send a signal for a very short time so we can control how hard we stamp the part. We have measured the wave form and it appears the signal is good. Could you maybe take a look at the components we are using with your stamper and approve that they are acceptable. Could you think of anything that could be causing the first hit to be softer and not hit the part then after that it is fine. The problem seems to appear if the system sits for a while.



CMT Recommends using our valve packs.


I can say you need at least 1. CV (volume is most important) and your air line to the valve I would suggest ½” and the air line from the valve to the marker not to excess 3’ and be 3/8

Air requirements

It sounds like your return air after the first hit provides a little resistance. Which is helping as your advance air has a moment to build and make the ram more of a snap action. When you cycle it the first time you might be losing a tiny amount of time as the ram is more sluggish and not accelerating.


You might need to adjust your dwell time to overcome the inefficiency of the valve system.


PLC set time and actual are always different. Logic scan time of the PLC, solenoid reaction, spool shifting, then add the air volume/speed to fill all the hoses chambers and build desired pressure can add to the equation.