Work and turn on Windmill: need clarification
I want to try to make my next set of plates as a work and turn job and need some clarification. printing on a windmill.
1.) I’m going to make a plate with the front and back of the design on one plate like this:
{front design} {back design}
2.) I have to align my plate so it prints exactly center on the paper.
3.) After I print side one like this:
A
1 2
B
4.) I feed the paper for side two like this:
A
2 1
B
Am I missing something?
I can’t seem to figure out the diagrams you have laid out in (3) but if you have a (front)(back) plate laid out, you will need to flip your pile and register to the opposite corner of the first run when running through again. I’m assuming you’re running with guides.
This will mean you have to have extremely square paper, it has to be extremely consistent in size and there has to be a margin all around that is the exact same size.
in step #3, I was using A/B to represent the top/bottom of the paper and 1/2 to represent left and right.
Are you printing with guides? It will really just mean registering from the opposite corner between the two runs, printing on the other side of course.
Yes, the print will need to be dead centre and the stock will all need to be very precise.
Yes, with guides.
is there a preferred method besides work and turn to make side #2 registration more simple?
Yep, just print from 2 separate plates.
I’ve been printing from two separate plates. All the work and turn talk made me think it may be better.
I usually think of work and turn as two sides of a sheet printed at the same time, then the sheet is turned over and the same image printed on the back. To achieve the effect you want the images should be foot to foot, so the heads are on opposite ends of the sheet (assuming you want the front and back heads on the same edge in the finished piece). Then you feed the sheet by one end for side one, and by the opposite end for side two, or by one edge, and flip the sheet so you feed by the same edge for the second side, as you may have shown it.
Work and turn is really only effective for long runs where you save on setup and cut running time in half, but for short runs you might be better off just running one side and the the second side on a single sheet.
If your diagram is showing A and B as the top and bottom sheet edge and 1 and 2 as the copy, I think if you run it as you show it you’ll have page 1 backed up by page 1 and page 2 backed up by page 2. These formats are tricky. Best to make up a dummy and do a dry run to work out the method you want to use.
Bob
Bob:
I think your description is more like a work and tumble layout where you will be switching gripper side on the sheets.
Casmit’s layout is a work and turn layout where you keep the same gripper side but switch the side guide side.
Either way it is true that you would have to cut the stock accurately. On most cylinder presses and the Kluge you have the option to switch the side guide to the opposite side so that in a work and turn layout you will still be guiding to the same sides as the first printing. That option is not available on the Windmill.
John Henry
As I understand it, a work and turn is a job with a common head (gripper) with the guide being swapped when the sheet is turned over—so only one side guide. A Windmill is about the only platen I know that cannot run this.
A tumble is a job with a common guide side, but with different grippers (1st side head, second side foot). This requires accurately cut stock in the head/foot dimension and the form must be centered.
A work and whirl is a job where the stock is turned 180 degrees between passes, so the finish sheet has two guide/grip corners on opposing corners of the sheet. The form must be centered in both side to side and head/foot positions.
I think it is simpler to run a job as a sheetwise form on a Windmill. It would take a very large sized run to make me consider trying a different method.
so when running sheetwise, you maintain the same gripper edge and flip the paper.
Since the windmill only has one side register, you would have to print dead center on the paper (only on gripper edge side) or move the plate for side #2 up or down to compensate for different paper margins…
I’m working on a bleed design and I need front and back registration to be dead on.
If you’re printing from photopolymer, just make sure you have a generous margin at the top and the bottom (30+ pts) and you’ll be able to adjust the plate accordingly. The gripper edge will remain consistent.