Loss of precision

[Peter Martins]

Hi we are cutting a sheets of printed circular images on a summa s160t

Media about 54"
Diameter of circles about 50mm

We're losing tracking as it proceeds through the print- the cut circle is moving away from the printed circle. It's about 3mm out along an axis about 45 degrees.

We professionally fix a lot of designjet printers. So not afraid to tackle it. Though we have not much experiance.

We are not sure where to go with it.
Suspects are
1) motors
2) encoders
3) pinch wheels
4) y axis spindle wear
5) belts
6) wear somewhere (where?) In the system.

Don't think its Media.

Before we start trying all those things and working through the list though there may be some help here.

Thanks for reading.
Bristol inkjet ltd

 

[MikePro]

i have the same problem when I exceed ~4ft of print&cuts. I believe it is the drag of the material going through the plotter that works its way out of alignment as you progress through batches of cuts.

I've done longer batches by only exporting half of the page, flipping the sheet and rescan&export the other half, or thirds, or lines at a time. Its a bit more work but saves a TON of material since more gaps between prints & more barcodes = more media wasted, not to mention saving more of the prints that you would have thrown-away for miscuts.

posted this in another similiar thread. figured i'd copy here as well.