Trouble with a 325 Trip Mechanism

I have a 325, serial #6086, and I’m having trouble with the trip mechanism.  The pedal is completely unresponsive.  It would seem that there was a problem with a spring or the spring link, but it seems to be at least connected fine.  It’s not “snapping back” to create the tension one needs to raise the grippers, but according to the diagram, all the connections are correct. . . .  When i push the gripper trip lever from the other side, they go up just fine.  I’m not sure how to access the push rod to see if the problems is there.  I’m also thinking that maybe the spring has lost it’s tension?

Any help would be most appreciated.

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Eric Holub
10 years ago

That does not seem right. The grippers should not open as you move away from the feed table. Both 325G and 325A models have the same cam to raise the grippers as they return to the feed table, and close onto the sheet until it is released aafter the print stroke. No point in them opening as they leave.
I wonder if your cylinder has been removed at some time and replaced out of alignment. The correct rest position has at absolute top the division between cylinder and tympan clamp.
What holds the cylinder at rest position (sorry I don’t have the parts list here) is the gripper trip cam. The grippers raise as the LR-9 roller moves over it, then falls behind it. It is the spring tenson on the gripper trip cam that holds the cylinder at rest. Broken spring there will let the cam slip out of action, and so no automaatic gropper action and no positive rest.

Eric Holub
10 years ago

Do the grippers raise and close automatically as you return the cylinder to the feed table? They should. If neither auto or pedal gripper use is functional, maybe the problem is later in the linkages.
In addition to regularly replacing the NRS-24 spring, I also had to replace the LR-4 pin and LR-9 roller in the NR-175 roller rod before I had normal gripper action. And the LR-4 pins in the LS-64 gripper trip lever have to be tightened when they start to work their way out. The shoulder of the pin is larger diameter than the thread and when the gripper trip lever is riding on the smaller threaded section the motion is reduced.
My parts diagrams don’t show any of the hidden gripper linkages under the bed, except for sheet 50A which only shows the parts for the automatic gripper trip.

Eric Holub
10 years ago

The spring that controls the trip wedge on my 325G breaks regularly. I have to form a new tip and reattach it. The original spring was too aged and weak to do the job (which is both to lift the grippers AND hold the carriage at the rest position), but the new spring from the hardware store was a bit too stiff and hard to re-form, so it fatigues and breaks with use.
As always, follow the linkages, and test their functionality. They may be there, but are they actually working?

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