Windmill roller lifting
So recently I noticed the rollers weren’t inking a part of the plate. After recalibrating the rollers, swapping rollers, turning rollers and anything else I could think of over and over with no difference I hand rolled the press and discovered that the delivery side roller arm pops the top roller away from the rails when exactly half way up the plate, or when the roller arm is perfectly horizontal. When my engineer was here for another problem he looked at it and gave it a little tap, some extra oil and after a quick roll through it seemed fixed. Since I wasn’t using ink for a week I didn’t realise until today that it didn’t fix it. A gently hammer tap does knock it back in but 2-3 runs through later and it’s back again.
Does anyone know what causes this and how to fix it? In the pics you can see that it sits bout 1-2mm off the rail for about an inch I think, some sheets were missing ink for about 1.5 inches.
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Looking at your photos I wondered if your roller diameter matches the trucks? From picture 6041 it looks smaller. If it is that could be an issue.
Check the plunger that holds the rollers to the arm, to be sure it is sliding freely, and that the spring is as strong as the other side. If there is a bit of dirt or a burr on the plunger rod it could bind enough to cause the problem — like perhaps at some time someone grabbed the outer end with a pair of pliers that raised a burr.
Bob
Frank Hemmings, I thought that you were right until I took a closer look at that picture. The roller and the truck are the same size but the reflections on the roller make it look smaller.
The rollers have been fine for years, this is only a recent issue.
Bob, the plunger does move freely but I’m not sure where I would see a burr? Just on the back end where the bolt is?
Or inside the arm (meaning it has to be pulled apart)?
The part you are calling a plunger is the roller carriage spindle. Do the rollers “skip” while they are on their way up only, or in both directions? I’m thinking it happens only on the “up” travel, after the roller spindles have been extended at the bottom of their travel.
Inadequate lubrication of the roller carriage spindle could cause what you’ve described. Be sure your oil gun is getting oil into both of the ball oilers on the roller carriage arm.
As suggested by Bob, there could also be an obstruction in the carriage assembly (dirt, metal shaving?).
Michael
I agree with Michael, wash with blanket wash, the area clean and generously oil.
Maintaining your press is important.
There is a third oil point on both arms. This is a felt pad that is accessed through the hole in each arm—toward the lower roller arm daily oil point. With the arms up, but not quite top dead center, you should be able to see the recess where this felt pad is.
This oils a guide block, that is also the spring support (part T0706). Oil this vigorously to start and see if it fixes your problem. This is normally a yellow oil point, so it doesn’t require constant attention. The red oilers are where the roller rods pass through the cast iron arms, and must be oiled daily.
Thanks everyone. I do oil religiously. And slowly to be sure I don’t miss one, but I will double check to see if I’m missing something. I didn’t know about a felt pad, but I do oil the two nipples and in the holes (which seem to be directing oil onto the spring).
But to answer your question Michael, the arm ‘skips’ in both upward and downward directions.
So I discovered the felt pad. Thanks Mike!
But it didn’t change the problem. I super oiled, manually agitated the spindle and then ran for a while but when I got down low I realise both rollers are lifting, although the lower is less which is why I didn’t notice it before but it explains the large area with no ink coverage.
I can’t see an obstruction so I guess I’ll get the engineer back for another poke around. He’s a whizz at fixing things but Heidelbergs are not his forte so I’ll pass on your knowledge to see if it helps him find the problem this time.
Just FYI for anybody else with this issue. One thing I forgot to mention, is that when the rollers are off the roller carriage spindle never fully retracted. A gentle hammer tap got it to pull in, but it would come back out after a few runs. That is what caused the rollers to lift away from the rail.
A super good dose of WD40 with a few hours for it sink in, some manual flexing of the spring. Rotating the hexagon screw at the back of the carriage arm (it rotates the journal box when rollers are not on, so remember to straighten it back up). A 10 min run with rollers on. So far so good. Then removing the rollers, the carriage spindle snapped back in 100%.
So thank you all for your help and suggestions. I’m looking forward to some nice and even inking again. And no more headaches.
Remember WD40 is not a lubricant. Put some real lubricant on that roller carriage spindle. I don’t know if it has lubrication points, but if it does those are worth checking.