Mutoh 661UF Alignment / Color Issues

[Bigdawg]

Since I'm here anyway... having some issues with a new piece of equipment. We have a Mutoh 661UF that we are just now starting to utilize regularly with the VerteLith RIP. We print mostly onto acrylic. We've noticed that if we start a run of signs and don't finish them the same day, the color is off when we pick back up later. Enough that it is noticeable. Any thoughts from those that have used it a while?
Secondly, we print on paper first to align the sign and place the acrylic EXACTLY where that paper is, but then when we print the raised graphics and braille, the alignment on the sign is shifted. What are we doing wrong?
Any help is appreciated!
Now back to reading a couple of years of back posts...

 

[Solventinkjet]

Here's a free course on using Verilith: https://mutoh.thinkific.com/courses/vertelith

If you scroll to the bottom, there's also a free add on about braille. Might help!

 

[White Haus]

We have a Mimaki UV-LED printer and the color shift is huge over time. You may have checked already and maybe it's not the case but just thought I'd mention it, try comparing colors 30ish minutes later and see if they match the previous day's prints. (I'm not even sure if this is across the board with LED printers or just Mimaki, but I was shocked when I realized how much it shifts after printing/curing)
Can't really comment on the alignment part as I'm not familiar with those printers at all.

 

[Bigdawg]

Thanks for the link and the input.
White Haus - the color shift is from the same job file - just additional prints of what we did the day before. Even after curing they are different colors.
Stacy

 

[JBurton]

Secondly, we print on paper first to align the sign and place the acrylic EXACTLY where that paper is, but then when we print the raised graphics and braille, the alignment on the sign is shifted.

Is the shift consistent? I'd imagine not, otherwise you would be offsetting your placement print to accommodate the offset. Is it consistently different between substrate thicknesses? If not, it could be something like the vacuum table setting at an angle, or the mechanism controlling printhead height could be bent/crooked, but the latter seems like it would cause many more issues. My money is that the print bed is somehow dislodged from where it needs to sit.
How do you like the printer otherwise? I had been eyeing a braille printer, but with the way my interaction with direct color systems went, I back peddled pretty quickly.