GTO 52 Swing arm problem

[Bounty105]

I have a 1983 single color GTO52 the swing arm grippers damage the grip edge of the sheet. Is this a general wear problem or is there any adjustment I can make to rectify this? So far it has not affected registration, but it is progressively getting worse to the point where the edge of the sheet tears slightly when the swing arm grippers transfer to the impression cylinder grippers, this is ok on jobs that get trimmed after print, but its no good for finished size jobs like envelopes. I have attempted some adjustments such as feed table height and the rod that adjusts how much the swing arm grippers open, but to no avail?
Any advice would be great, thanks.
Paul

 

[GazKL440]

everything greased and oiled etc? GTOs are pretty bulletproof but will wear out with lack of slippery stuff.. could be the solenoid that operates the miss feed dam but that generally throws registration issues first.. put a few drops of oil in the top of the front lays could help where they rotate on the shaft. and have a look at the cylinder gripper pads may be worn out.. cant think of anything else of top of head..

 

[rbailleu]

time for a service call. the swing gripper gets a lot of water drips. you probably have a bearing going out. although they usually just stop grabing the sheet tightly.

 

[otherthoughts]

Does decreasing the gripper bite by retarding the head-stops help?

OT

 

[rbailleu]

are you sure its the swing gripper that is doing the damage.

 

[Bounty105]

To be honest Im not entirely sure its the falt of the swingarm grippers, but I do know when turning the machine over by hand and watching the sheet go through slowly I can see (and hear) the impression cylinder grippers grab and pull the sheet just before it has been entirely cleared by the swingarm grippers thus causing the small tear in the stock on the edges where the swingarm grippers held.

 

[rbailleu]

this could very well just be a timing issue. If the impression grippers are opening too soon or too far then the could be doing the damage before the actual gripping. does the dinged paper go up or down.

 

[Al Ferrari]

I think you have the poor timing consequences backwards. Opening too soon after the transfer, leads to miss register. Opening late after the transfer, is what would cause tearing.

Al

 

[Al Ferrari]

Taking this further, if the problem has worsen over time, there is certainly wear involved. Two possibilities are the swing gripper opening cam, or the cam follower. I would try to check for slight play in the cam follower.

Al