320 Gripper Bar Sheet Guide Studs—Bent?

I’m (still) refurbishing a Vandercook 320, and I’ve started attacking the gripper bar. I have it all apart and clean enough to handle, but I have noticed that the studs that hold and adjust the sheet guides seem to be a little off-square.

It looks somewhat like the result of crashing the guides (several times), but before I try to straighten them I was wondering if anyone could provide any insight as to whether these might be like this by design.

Even if it is by design, they are not all at the same angle.

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Eric Holub
Editor
3 years ago

My recollection from re-timing my 325 cylinder is that the gripper bar is not at dead top when at rest; rather it is the face of the cylinder that the gripper bar sits against which is positioned at 0 degrees or 12 o’clock, so the gripper bar is slightly forward.

Paul Moxon, Moderator
Admin
3 years ago

I didn’t know that. Thanks, Kevin. Very happy to learn something new.

This may only be applicable to the 320/325 series. Certainly not the SP and Universal series or the Nos. 3 and 4, 15-21 … I will investigate.

Paul Moxon, Moderator
Admin
3 years ago

You may only be off by one or two teeth. For the benefit of other 320 owners, I’ll describe how to retime the impression cylinder.

Timing or indexing means choosing which tooth on the cylinder will contact the end tooth on the cylinder rack (track) so that the gripper heads are parallel to the feed board. (The side of the tooth may have been marked, but that often is not the case.) Mistimed cylinders cause the grippers to bend paper and gripper heads may smash type high material in the bed.

To commence:
– Obtain an engine hoist *
– Conscript two strong friends as spotters
– Roll the carriage forward 3/4 of the way down the bed
– align hoist at the end of the press
– attach ratchet straps to the carriage and hoist, cinch enough to support but not lift the carriage
– Remove the bumper blocks
– Roll the carriage forward until the cylinder gears clear the racks
– Rotate the cylinder as needed in the stationary carriage
– Push the carriage back onto the racks until the gears engage with the racks, shift carriage laterally if needed
– Return carriage to feed board
– Repeat as needed until the timing is correct

*This is required because of the weight of the carriage. Also, the cylinder racks (tracks) are a single piece on each side, which means that the cylinder can only be rotated in the carriage once the cylinder gears clear the racks near the end of the bed. A forklift set level with the bed bearers can be substituted.

Other models, e.g. the No. 4, later Universals, and later SP20 have sectional racks that can be removed to allow retiming in the middle of the bed.

Paul Moxon, Moderator
Admin
3 years ago

These studs are bent. The manual Sheet No. 52 shows that the studs are perpendicular to the body of the gripper bar.
The front end of the feed board is at an angle. The gripper bar is 90° to the feed board end.

Studs are swedged into the gripper bar from the backside. A machinist could install new studs. NA Graphics may have replacements (LR-76). I think that they are the same part as the stud for No. 4 (CR-266). The latter is 2″ long and the threaded end is 1/4-28.

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