This one is a wierd one, and it's definitely a machine fault, but I wanted to see if anyone else has experienced anything like it. It actually started as three seemingly unrelated problems that now seem to be very much related.
The first issue we had was that after the printer had been on for a while, say, half a day, there would be a noticeable lag in the responsiveness of the control panel. Most obviously, when you are selecting a media that you've just loaded, there is literally a 5 second lag after you confirm the media type before it allows you to open the window to slide the edge holders. As in, you press the buttin to confirm, and it takes 5 seconds for it to change the colour of the button, acknowledging that you've pressed it. Often you're not sure if you actually did press it, so you do it 3 or more times just to be safe, and it still just bums around for a while, thinking. If you restart the printer, the control panel goes back to being quick and responsive. Somewhat annoying, but alone, no big issue.
The second issue is that we'd had print alignment issues, like the passes are stepped slightly incorrect, the sort of thing you'd expect from a grubby encoder strip, or just the heads needing alignment. After cleaning the encoder strip and doing alignments, it's exactly the same. Restart the printer, and it is perfect. Which made me think that it was related to the above processing lag, in that there's a software glitch. It's happened multipe times, sometimes as bad a stepping a good 10mm sideways over 50mm of print length. This is a bit more worrying of course than just a slow menu.
The last one was a *****. We'd had the machine for 6 months (bought it new). Out of the blue, we had two medias that had always printer perfectly, all of a sudden getting head strikes on one side. We looked at every possible cause, like too much heat causing it to ripple, like the takeup reel not being loaded straight (alternating between loading it up before printing, then during printing, then not using the takeup at all), a thousand other things. One media was a textured SAV fabric-based wall graphic, so you could understand a bit of stretch, but the other was a film for pull-up banners - no stretch at all and we'd used maybe 10 rolls of it to that point with no issues. We couldn't find what was causing it. The strange thing was that it always got ripples on one side of the media. Not the same side every time, sometimes on the right, sometimes on the left, but once it started it would stay down that side. The strikes were occurring after the media had passed the edge holders, as it'd be there that the ripples in the media would hit the head as it passed over. In the end, with no cause found, we'd resorted to manually gaffer-taping the metal edge holders from our L28500 below the standard ones, meaning the media's edge was held down all the way to where the media disappeared behind the window in to the curing unit.
Just yesterday it all came together. Printing a poster that was only 1000 x 700mm, one of the workshop guys brought it back to me and said it's not straight, it doesn't fit the frame. We measured it, and sure enough one edge was 8mm shorter than the opposite edge. Thinking the guy had trimmed it wrong (I never make mistakes of course, it couldn't be the file...), I asked to see the scrap, and sure enough he'd cut it to the exact crop marks. And looking closer at the print, there was a definite alignment issue on one side. Here's the kicker though - the alignment issue wasn't on the scan axis, it was on the feed. One side of the media had fed 8mm more then the other, over just 700mm of print length.
Here are the pics:
As you can see, scan axis is pretty good. But you can definitely see inconsistencies in the feed axis, especially with the blue on yellow, where the top of the pic has okay alignment but the bottom is way out. Restarted the printer, printed it again (same file from the rip, just dragged back up and hit print again), and it's perfect.
So this has me thinking that it's all related. For some reason, after the printer has been on for a while, it starts having brain farts and glitching. Maybe it has something to do with how it comes out of sleep mode??? How a software glitch could cause one side of the media to feed at a different rate to the other I don't know. I would have thought for sure that the rate that the rollers move the media would be locked. And it can't be a mechanical issue, like the media is somehow slipping, otherwise why would simply restarting the printer fix it?
Anyone else ever seen anything like this?
The first issue we had was that after the printer had been on for a while, say, half a day, there would be a noticeable lag in the responsiveness of the control panel. Most obviously, when you are selecting a media that you've just loaded, there is literally a 5 second lag after you confirm the media type before it allows you to open the window to slide the edge holders. As in, you press the buttin to confirm, and it takes 5 seconds for it to change the colour of the button, acknowledging that you've pressed it. Often you're not sure if you actually did press it, so you do it 3 or more times just to be safe, and it still just bums around for a while, thinking. If you restart the printer, the control panel goes back to being quick and responsive. Somewhat annoying, but alone, no big issue.
The second issue is that we'd had print alignment issues, like the passes are stepped slightly incorrect, the sort of thing you'd expect from a grubby encoder strip, or just the heads needing alignment. After cleaning the encoder strip and doing alignments, it's exactly the same. Restart the printer, and it is perfect. Which made me think that it was related to the above processing lag, in that there's a software glitch. It's happened multipe times, sometimes as bad a stepping a good 10mm sideways over 50mm of print length. This is a bit more worrying of course than just a slow menu.
The last one was a *****. We'd had the machine for 6 months (bought it new). Out of the blue, we had two medias that had always printer perfectly, all of a sudden getting head strikes on one side. We looked at every possible cause, like too much heat causing it to ripple, like the takeup reel not being loaded straight (alternating between loading it up before printing, then during printing, then not using the takeup at all), a thousand other things. One media was a textured SAV fabric-based wall graphic, so you could understand a bit of stretch, but the other was a film for pull-up banners - no stretch at all and we'd used maybe 10 rolls of it to that point with no issues. We couldn't find what was causing it. The strange thing was that it always got ripples on one side of the media. Not the same side every time, sometimes on the right, sometimes on the left, but once it started it would stay down that side. The strikes were occurring after the media had passed the edge holders, as it'd be there that the ripples in the media would hit the head as it passed over. In the end, with no cause found, we'd resorted to manually gaffer-taping the metal edge holders from our L28500 below the standard ones, meaning the media's edge was held down all the way to where the media disappeared behind the window in to the curing unit.
Just yesterday it all came together. Printing a poster that was only 1000 x 700mm, one of the workshop guys brought it back to me and said it's not straight, it doesn't fit the frame. We measured it, and sure enough one edge was 8mm shorter than the opposite edge. Thinking the guy had trimmed it wrong (I never make mistakes of course, it couldn't be the file...), I asked to see the scrap, and sure enough he'd cut it to the exact crop marks. And looking closer at the print, there was a definite alignment issue on one side. Here's the kicker though - the alignment issue wasn't on the scan axis, it was on the feed. One side of the media had fed 8mm more then the other, over just 700mm of print length.
Here are the pics:
As you can see, scan axis is pretty good. But you can definitely see inconsistencies in the feed axis, especially with the blue on yellow, where the top of the pic has okay alignment but the bottom is way out. Restarted the printer, printed it again (same file from the rip, just dragged back up and hit print again), and it's perfect.
So this has me thinking that it's all related. For some reason, after the printer has been on for a while, it starts having brain farts and glitching. Maybe it has something to do with how it comes out of sleep mode??? How a software glitch could cause one side of the media to feed at a different rate to the other I don't know. I would have thought for sure that the rate that the rollers move the media would be locked. And it can't be a mechanical issue, like the media is somehow slipping, otherwise why would simply restarting the printer fix it?
Anyone else ever seen anything like this?