Job centering issues

[PDQDESIGN]

PLEASE HELP.
I'm setting up jobs for our FOUR COLOR press in an Illustrator template.
OUR PLATE SIZE IS 19.09 X 12
OUR SHEET SIZE IS 17.75 X 12
OUR IMAGE AREA IS 17.25

I seem to be having a difficult time centering my work on the sheet.
I have the dead zone and the gripper ruled out and start my sheet size
directly after the dead zone

When I center work I drag my guide out to 8.875 HALF my sheet size

Our pressman is having to roll the work back at least an 1/8 inch on each job
that needs centering (work and tumbles etc.)

Is there something I'm missing?
ANY ADVISE WOULE BE GREATLY APPRECIATED

 

[DavidMa]

I would think that your problem is not so much your position of the image on the sheet, but the position of the sheet on the plate.

Is the long dimension around the cylinder?

 

[KimSaks]

You say your sheet size is 17.75 and you are centering to 8.875... and coming up approx 1/8" off center.
I think the problem is in your gripper area. Perhaps you're figuring too much or too little for the gripper spec of the press.
When you figure in the gripper area as part of your "dead zone" you still have to include that amount into figuring out the center of the sheet.... not the center of the printable area.

 

[Visualaid]

PLEASE HELP.
I'm setting up jobs for our FOUR COLOR press in an Illustrator template.
OUR PLATE SIZE IS 19.09 X 12
OUR SHEET SIZE IS 17.75 X 12
OUR IMAGE AREA IS 17.25

I seem to be having a difficult time centering my work on the sheet.
I have the dead zone and the gripper ruled out and start my sheet size
directly after the dead zone

When I center work I drag my guide out to 8.875 HALF my sheet size

Our pressman is having to roll the work back at least an 1/8 inch on each job
that needs centering (work and tumbles etc.)

Is there something I'm missing?
ANY ADVISE WOULE BE GREATLY APPRECIATED

Can't you just draw a box the size of the plate minus your gripper, then select your plate box, sheet, and image and center it?

 

[DavidMa]

The OP doesn't mention what press he's working with. It might help if we knew and someone may already have a template that works.