printing with guides on a platen

I have a windmill and the other day I noticed that the paper I was using was slipping in between the platen and the lower guides causes my prints to come out on a slant (when it needs to be dead straight) and it was always the same angle.

Can this happen if there is not enough packing in the platen? or is the problem with my lower lay guides? not sitting close enough to the platen??

I hope this all makes sense. I can mock up a diagram if that helps??? :).

Thank you in advance :).

Meaghan

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Hi Meaghan,
Do you have enough margin to not use guides? We rarely used guides - got good straight work without them. Look in the Manual on page 53 No. 2 & 3 for settings/instructions for using or not using guides. Without guides the gripper bar holds the paper in place for printing without releasing it to the guides.
Dick
Btw: Congratulations on the great job you have done on restoring that fine press.

Hi Meaghan,
A few things can happen when working with guides, all of which can be fixed if you listen to Dick’s advice on not using them. But I have always been in the practice of using guides, so here are some possible causes to your problem.

If your paper is too thick, the gripper will not release it completely and this will cause a crooked print (this may also happen it there is something sticky in the gripper). If your tympan is worn, the sheet will not slide down into the guides consistantly. If your guides themselves aren’t adjusted properly under the sheet, the sheet will fall in between them. If your sheet has a curl, it will find itself working its way in between the platen and the guide (in theory, this may also happen if you have too little packing as you described, but I have never experienced it). If you have make-ready affixed to the tympan, the sheet may be catching on it.

All these can cause a crooked print, but these are only the more popular culprits, much stranger things can occur. I’m sure you have realized by now that a large part of printing is problem solving. Experience will hone this skill also.
Bill

Waldwick has some good advice. Try slowing the press down and inching the paper from the gripper down to the guides. Stop the press every inch or so, put your head down there, and try to see what’s going on. The curl of the paper might be causing it to jump a guide. Or it could actually be sitting up on top of a guide instead of down in it. Also, at faster speeds the gripper might sling the paper causing it to behave strangely.

Brad
Vertallee Letterpress

Hi Meagan
I have had a windmill for many years and very seldom do I print with the guide for my work doesn’t require close registering. My work is always good and straight. It’s very simple to disengage the register guide, as explain earlier, the paper is release and fall on the register guide. This is very small guide and if you are having problem with the stock it will fall and print slanted
or crooked. Hope this is helpful.

Hi Meagan,
It’s some 14 years since I operated a windmill, but if my memory is correct, it sounds to me that you are missing a vital part for printing with guides.
At the base of the platen there should be a narrow bar extending about 2/3 width of the platen, it has a flat face and curved edges; on this there should be a small guide about the size of a small finger nail, which is slid onto the bar, and positioned as close as possible to, but allowing for the movement of the guides, this guide rides over the tympan bar, and is slightly higher than the tympan, and thus prevents the sheet from slipping between the tympan and the guides. Hope this helps.

Packing on a windmill controls the leveling of the impression verticaly (to much impression on the bottom = to much packing, not enough impression on the bottom = not enough packing). So packing can’t be the answer, although sometimes I will use small pieces of chipboard in non-image spots to hold out the guide side, mostly when using nickel gauages or when using a counter die or small piece of phonalic board for foiling or embossing.
Bern’s comment is correct for using brass lays. The piece looks like a upside down chrome J with a brass piece to hold it on its own bar (not the guage bar). This device don’t do any good with nickel guages as the edge of the sheet should not be below the platen. Nickel lays can be a real pain to use (I wish my customers would give me the grip and guide space I tell them I need).
It could be that the lay guage bar is not adjusted right. There are 2 stop bolts that control how close the lays can get to the platen and 2 set screws on the blocks that hold the lay guage bars that allow you to move the bar in or out. I normaly use the in and out adjustment to set the nickel lays as close to the packed platen as possible without binding or tearing up the tympan and then the brass lays are right.
As to just using commercial regester I do that when ever I can, but I have never run any press, letterpress or offset, that can regester as good as a windmill. But one thing to remember is that if you adjust the front guide (grip) to far in it can hit the lead edge of the sheet when it moves up into the griper bar and bounce the sheet back.

Do you use Lay pins on your guides? if not there should be small holes on one of your brass guides to slip one of these pins in, this will keep your sheet from slipping.

Hello - sorry for the delay in my response. I have been busy troubleshooting this in my garage at home. Yes I think it was a packing problem not enough of it. Thank you everyone one for your advice. It is good to know I am on the right track when I am working through these little hurdles :).