Roland RF-640 Shortening Prints

[MetatronZero]

Wondering if anyone has any insight into this issue I've been having. Randomly, our Roland RF-640 started printing 1/8"-1/2" too short on longer prints. I'm using Versaworks 6.21.1, and my files are showing at the right size in the software, but when we get them on the table they're somehow short. This has only been affecting some prints, and I'm not totally sure why some are affected and not others. Mainly happening when printing onto gloss banner material

 

[Joe House]

Have you done the feed calibration on the banner material that you're having the most problem with?
Also some banner material trends to stick to itself, so try unrolling the material before the printer has to pull it. Same thing if a full roll is too heavy for the printer.
Have you replaced your pinch wheels lately? Or cleaned the grit wheels? They may be slipping.

Good luck

 

[MetatronZero]

Have you done the feed calibration on the banner material that you're having the most problem with?
Also some banner material trends to stick to itself, so try unrolling the material before the printer has to pull it. Same thing if a full roll is too heavy for the printer.
Have you replaced your pinch wheels lately? Or cleaned the grit wheels? They may be slipping.

Good luck

Thanks a ton, these tips seem to have solved my woes.
Total newbie stuff I know, I've only got a few months of experience running these printers and there's a lot I don't know.