Epson Stylus Pro 9900 Sheet fed back up issue?

[rande]

I have tried everything to get this to back up.
It may be off at the bottom then at the top exactly on.
I've had it be on on the bottom and off on the top. (it happens more)
It's been on, on one side and off on the other?
I'm using the Epson Driver. I've tried settings on the printer and in the software.
I've tried moving the other side manually; that thru it off on the top?
I don't see any place to adjust.
I've tried the setting the heads; the procedure in the book.
I have been chasing this for weeks.
Anyone know how this is done.
We have GMG color, but at the moment can't run to the 9900.
Any help, any ideas would be appreciated.

thanks

 

[Al Ferrari]

I don't believe that model prints both sides on the same pass, so you are re-feeding the cut sheet for the second side. Is that correct?

Are you getting a simple front/back misalignment, or is there an out of squareness problem also?

Al

 

[rande]

I don't think its a misalignment, I'm lining up right along the line and seems to be tracking right along it. On the printed sheet it gets back on track by the time it gets to the top.
In therory it should straighten itself out I thought. But it doesn't in the beginning for most of them.
We have squared off the paper, that doesn't seem to have done anything.

Seems like its skewing, but the only setting I see for that is off/on and I've
done both with no difference.

 

[Al Ferrari]

You did not confirm my guess that you are re feeding the stock in order to print the 2nd side.

When you say you "have squared off the paper" does that apply to the printing of the 1st side?

Al

 

[rande]

Yes, we're feeding it back thru.
We have cut the paper down to square it off. They don't come exactly square.

 

[Al Ferrari]

OK.
I suggest you try assuming that the lead edge white alignment line on the printer is slightly crooked. Proceed by aligning to the "bottom" of that line on the right and to the "top" of that line on the left. Do it exactly the same way for the second pass. Does that lead to any useful information?

Al

 

[rande]

I'll give it a shot.

 

[Al Ferrari]

Here is an idea for testing squareness of the printed image without having to print both sides:

Create a large format page test file with just a full height vertical rule centered, and a full width horizontal rule also centered. Print this normally and try folding it exactly along one of the rules. then, punch a /4 inch round hole (or cut a square one) at one end of the other perpendicular rule and examine the folded sheet carefully on a light table. Do the two ends of the folded over rule line up???

Al