I have a problem with sticky grippers on my SP-15. Everything was working fine, then they became stiffer and stiffer until they didn’t want to open at all. As far as I can tell the foot pedal assembly is fine. I’ve taken apart the gripper assembly, cleaned and lubricated it. While it seems to work now, it doesn’t work as smoothly as it should. I’ve been using AGS powdered white lubricant in lieu of graphite. Are there any other lubricants I should use? Or any other reasons why this is happening? Thanks so much!
I had a duh moment.
The position of the cams regulate the distance the gripper pins rise, not the smoothness of the action.
Thanks Paul & Daniel for the advice.
Have done as instructed and it’s still sticking. It’s like the pins want to go up when the pedal is pressed, but they catch somewhat halfway before they rise. They are also sticky at the end of the bed when they’re supposed to release the paper.
We’re cleaning and lubricating the pins and holes again, but if that doesn’t help should we try to adjust the cams?
When you had the gripper bar off the press did you lubricate the cams that engage the grippers inside of the cylinder? A dab of lithium grease on those things makes a huge difference if the grease that was there is dried out or you cleaned it all off when you rebuilt the gripper bar.
The Arm Letterpress
You probably need to clean crud from around the hole in the cylinder in which that the push rod passes through. Build up mostly occurs on the outer backside.
If this doesn’t help, then remove the gripper bar from the press and test each pin, by pushing up from the bottom with your hand, for how smoothly it slides in the hole. If there is resistance then maybe the hole is still dirty or a pin maybe bent (unlikely).