Heidelberg Windmill - Vertical Bouncing Issue

Hey all, I could use some help here. I’m foiling a job on a Heidelberg 10x15 and I’m getting some vertical movement that I’ve never seen before. I’ve been scouring this site trying to find answers and with your help on previous posts I’ve made a LOT of adjustments on this old beauty. But alas I’m still getting the same issue. What it seems like to me is that the lay gauges aren’t rising to the same height every time. I’d get 5-10 sheets that register perfectly, then it bounces vertically about a millimeter or two every sheet after that, never exactly the same, it’s not every other sheet. I have no sheet pinching that I can find. The issue happens even when I hand feed sheets and manually rotate the flywheel. Also might be helpful to note: I’m working with a 2 up foil die and the image appears to be bouncing evenly for both images.
I’ve been working on this for five days now and I’m about ready to rip my hair out… Any ideas or tips you can offer are greatly appreciated!


Log in to reply   4 replies so far

Be sure that the bushings that the spindle (the shaft which holds the guide bar assembly, and which passes through the casting under the platen have plenty of oil and work freely. If dirt is caked, remove it. If you work the guide assembly with the knob on the left side, the entire apparatus should move without any sort of a hitch. use this opportunity to make certain that there is no place where the guide(s) might be brushing anything. Remember also that the guide assembly and spindle are easily bent, and even a slight bend will interfere with your press’s register. Also, get any paper dust and crud picked out of the side guide assembly — lots of troubles occur because the area has a good deal of paper dust.

Thanks for your suggestions Frank, the lay spindle was indeed sticking. I’m pretty confident the spindle is a little bent. But I’ve done a several jobs without issue since the possible incident. I’ve shimmed the bolts on the feed side bracket and that has allowed the spindle to move freely again. I’ve replaced the tension spring on the knob unit. The slide spring wasn’t bringing the spindle all the way back into position so I clamped the spindle behind the spring to give it more tension. I thought maybe it was a timing issue between the side guide and the grippers, but I’ve adjusted the grubscrew on the lay spindle and the timing is at least back in line with all our other functioning windmills. I’ve cleaned the guide bar, replaced the guide bar. I’ve replaced a gripper arm. All to no avail. I feel like if it was the bend in the spindle the results would be more consistent and I wouldn’t have 5-10 sheets in a row without movement. Though, these beasts can be pretty mysterious like that.


Hi, I’ve run windmills for years, and I’ve learned to start with the simplest things first. I would check is for loose tape first off. We would tape down our phenolic board, and sometimes a piece would be loose and catch the edge of the sheet, or transfer to the grippers and cause register problems. Make sure your guides are smooth and clean.
Of course, you’ve checked to make sure the paper standard is all the way over to the stop for brass guides (you are running brass guides right?) If it’s not all the way over, it makes sense that as the press picks up speed you would have misregister.
These types of errors are very common.
Good luck!

Hi bppayne, thanks for your suggestions, I did start with the simple things, testing for paper pinching, cleaned the gauges and bar, I cleaned the side guide assembly made sure everything was well lubricated and moving easily. Watched for sheet bounce, adjusted the paper standard (which was out of whack and is back in the correct location for brass guides and flowing smoothly.) I even wrapped parts of the feed table with anti-static tinsel. It was very festive, but not very helpful.

I’ve got a few ideas bubbling in my brain after a weekend of stewing. Fingers crossed!