Printing Press Motor / Drive Synchronization Problems

I do not know the system it self but I could pinpoint some aspects which are general.

You have two synchro problems : the speed and the angular position.

Usually the systems work with a master and slaves subsystems and the phases are corrected between slaves and master. If you get problems it means that the control loops have not same dynamics and have not same response when errors are detected.

It could be possible that installed powers/torques are not every where sufficient to accelerate components to the right speed in a short time and errors are due to the time constant of the control loop+mechanical connected components.

It could also be possible that the initial positions are too far from the correct one (settings) and lead to a long time required for compensation.

Those are as mentioned ONLY general thoughts.

Hope it will help.

Being a former Pressman I love these kind of challenges. I would first ask if it is always the same cylinders that are not coming up to speed? My first guess would be the encoders or whatever you have reading cylinder rpm, for some reason I am thinking signal strength. Have you requested a new set of plates? Could be the registration is out on the digital plate processor to the point the system is having problems compensating. Intriguing, the more I think of possible issues the more variables seem to creep in, hard to make a good suggestion without seeing the operation. Personally i would start by eliminating all the external possibilities first, could be the press is fine.

Don't need a really good mechanic do you. I am looking for something new so I don't have to return to cubical land Not a great place for a creative mechanical person who really doesn't want to test software.

Sorry for the shamless plug, but if I don't do it...

I'm afraid your problem can't be resolved distantly in no way unless by skilled service man from factory. I had been maintaining the printing press equipment some years ago. Needless to say I virtually lived there. A ton of reasons could cause a problem. What total counter shows? If there more than 5-10 mln, maybe the time has come to readjust your equipment. Is authorized service out of reach?

It's so unlikely the controller is the cause, none the less try turn off not only motors but all controllers/electronics for program resetting (more than 5 min). Sometimes it helps. Have you any means to readjust encoder(s) set up for you machine?

Check out all your sensors (especially photo). Wipe their optics surface out of paper's dust. If there are some assemblies like boss-cam-follower - check them how tight ones bolted and so on.

Has your machine test (slow motion or even handled) mode to observe when and how all sensors LED are switching.

It's not clear how was up the trouble - abruptly or gradually (during relatively long operating time)? Have been there another significant accidents?

All mechanical, electrical assemblies and parts should be checked and revised out with full attention.