I have been helping to get a recently-acquired Vandercook-4 up-and-running for a commercial digital printer new to the medium. The press was shipped from the UK, after having been reconditioned in advance of the sale. All looked to be in good working order, except the grippers. They did not move when the pedal was depressed.
Following the guidelines in the manual and also watching an instructional video from Penland, I dismantled, thoroughly cleaned and lubricated all parts with graphite powder, and reassembled it. Frustratingly, the grippers still will not open.
My colleague consulted the vendor, but did not receive any response.
What should I try next?
This is helpful. It did occur to me that this connection could be the source of the problem.
The press is situated in a tight space in an active shop, so the more involved repair would prove difficult. For now, adding the hand-release attachment sounds to be the best solution. Thank you!
This issue has been discussed before. It may be that the linkage from the pedal to the gripper opener cam disconnected. To repair it remove the carriage from the press bed then separate the bed from the cabinet using an engine hoist or jacks and blocks.
The workaround is to install this hand gripper lever:
http://danielmellis.com/fabrication/vandercook-no-3-gripper-lever/