Need Help Inconsistent Print Lengths

[Garrett T.]

I am having an issue printing wall murals were each panel of the murals are coming out at slightly different lengths (usually about a quarter inch per 10 feet of vinyl).

I am using a Roland Versa Express RF-640. the issue seems to be persisting across all materials, we have tried Phototex Wall Paper, Photo paper, and Avery Cast Vinyl. It hasn't been an issue with the Cast because our installers can stretch and work the material, but with the Phototex, there is no give at all. I have checked and confirmed the artwork both before loading it into Versaworks, and after loading it into versaworks, and the panels of the murals should be the same size.
We had a tech come out to check on the printer, and he told me that amount of drift is "within margin of error" for the machine, but with a material that doesn't stretch on install like the Phototex, that's not good enough. has anyone else run into this issue before, or have any advice?

 

[victor bogdanov]

official spec:

"Error of less than ±0.3percent of distance traveled, or ±0.3 mm, whichever is greater"

so over a 10ft panel .36" is within spec


Will always be a problem unless you get a better/newer printer

 

[jcskikus]

I've always experienced that problem since printing long prints over 3' from back in 2003 with my first eco-solvent Roland! 8' banner would print 95.25". It's expected as per specs, so I'd compensate for it by making the print 97".

 

[guillermo]

I still have a Roland, RE640, and printing great, but that issue, I found out that is the feed calibration, if the print is short, increase the feed calibration for about .5%, try it and increase it as needed, I have done up to .15% if the calibration is too much, you will create banding) when you do a test print, check with a magnifier if the gap between the first print/scan is the same as when it prints the second print/scan, (hope I explained well) print head moves 2 times for a test print, I am talking about that gap; also, a big difference is when you print on a new roll, compared to a print from the middle of the roll and the end of the roll, it will be a difference, when the roll is new, it is heavy, the feed motor is working harder to pull the material compared to the end of the material, when I print on a new roll, I manually unwind the material, that way, there is not weight to be pull by that small feed motor.