JV3 160s head strike problem

[Alan_F]

Hello
i have just bought my first printer an old one i know but i got to start somewhere.

everything with it is fine but i am getting head strikes, i think it is something to do with the heat settings for the media but i not sure.

i am using SS2 compatible inks and Ritrama Rijet 100 i have the correct profile installed, and my printer has had the big wiper modification or something i am told, so the carriage is permanently in the high position.

I have had to learn from scratch over this last 3 weeks since i got it, i was running 35 degrees pre and print heat, and in fine mode it works great, not one head strike but its painfully slow even in Bilateral print mode.

If i set everything the same but go into standard print mode i seem to be getting head strikes after its printed about 18 inch on a four ft wide piece of vinyl the head strikes are roughly at 18" x 32" across the width, as if the media is buckling after its come off the print platen and onto the start of the cold round platen on the front if yo uknow what i mean.

only thing i can think is that because of the print forward speed being greater the heaters aren't correct and either the vinyls too hot or cooling down to quick.

Any advice would be much appreciated

Al

 

[Morkel]

Hello
i have just bought my first printer an old one i know but i got to start somewhere.

everything with it is fine but i am getting head strikes, i think it is something to do with the heat settings for the media but i not sure.

i am using SS2 compatible inks and Ritrama Rijet 100 i have the correct profile installed, and my printer has had the big wiper modification or something i am told, so the carriage is permanently in the high position.

I have had to learn from scratch over this last 3 weeks since i got it, i was running 35 degrees pre and print heat, and in fine mode it works great, not one head strike but its painfully slow even in Bilateral print mode.

If i set everything the same but go into standard print mode i seem to be getting head strikes after its printed about 18 inch on a four ft wide piece of vinyl the head strikes are roughly at 18" x 32" across the width, as if the media is buckling after its come off the print platen and onto the start of the cold round platen on the front if yo uknow what i mean.

only thing i can think is that because of the print forward speed being greater the heaters aren't correct and either the vinyls too hot or cooling down to quick.

Any advice would be much appreciated

Al

Hey Al,

This is a great printer to start out with - it's the second one I ever had and I loved it. Only got rid of it about 6 months ago and that was because we had no more room (bought a HP 360).

As you'll find as you move forward, there's potentially 20 explanations for every issue. You'll start to identify them through experience. I'm not sure how experienced you are with printers (and as it's out of warranty you won't have any free technical support I assume) so here are some explanations I can offer:

* Have you checked the vacuum settings? If the media is sucking down really well everywhere else, and only lifting up in a certain spot, it could be an issue with some of the vacuum holes.

* Are you using Rasterlink as your RIP (Rasterlink is the one that Mimaki supplies with the printer here in Australia)? If so, just check that when you change the quality setting that the heat settings don't change automatically. With a faster speed, it will actually need more heat to cure, so it's not unusual for the heat settings to be higher by default on a faster setting. It would need a LOT of heat for it to buckle enough to hit the heads on the high-head setting, but you never know.

* Is the media brand new or has it been sitting around for a while? If it's old, it can have moisture in the liner, meaning it's potentially expanded, which will be exacerbated with heat, causing ripples.

There are heaps more but these are what I'd look at first. If possible, are you able to take a photo and upload it here?

Thanks!

 

[Alan_F]

Thanks for your reply Morkel,

glad i have found someone to help that's owned one of these machines, it really has been daunting these past 4 weeks, and now i know why every trade printer i have met say "people think you just hit "print."

One problem like you said was old stock, and yes i am using some part rolls that i got from my supplier cheap, maybe this is the problem, i did try running at 35/35 pre and print heat (degrees C) and it was fine for a time but then i started noticing the buckling and have dropped it down now to 30/32 pre/print and it seems a lot better, it was like it was buckling though to the front of the head, like about an inch back from the first print pass, and it would usually start about 9 or 10 inch into the print.

The vinyl i am using is Ritrama R100 which is only a 3 to 5 year vinyl, how do i go on when using the more expensive 5 to 7 and wrap vinyls, these being thinner will they need more or less heat?

Most of the time it is printing fine with only a couple of blocked nozzles on the Lc which i have tried to get out but wont come back using a strong clean.

One other issue is cleaning on these machines, someone an another forum mentioned you could take the heads out for cleaning, a bit fiddly i now, making sure everything is fully powered down etc and that the carriage can somehow be tipped back to get at the heads to keep them properly clean at the back, rather than keep taking the side off to clean them.


sorry for all the question and i'm sure i'll be asking a lot more.

Al.

ps it's round 2 later with the cold roll laminator i bought last week, but.... that's another story.

 

[Alan_F]

here's a photo

 

[Morkel]

No probs Al, happy to help where I can.

Did you look in to the vacuum settings? It was rare that we had head strike problems on SAV, and even then it was old monomeric (1-2 yr) vinyls that had cheap liners, ie, paper-based ones that'd absorb moisture and swell up (despite having air-con and dehumidifiers on 24-7). I would be very surprised to see this happening on a polymeric unless the vacuum is set to off or low.

Can I ask what # of passes you're using on that media? I'm used to the low-sheen appearance of latex ink now, but even so that ink looks very wet. It might be the photo. It's not smudging at all when you touch it after a good 30 seconds or so? From memory, and I do know that every machine & environment is different, if I were using 30 - 35 degrees I would only be running it at 10 or 12 pass mode. If it's on 6 or 8 pass I'd have them cranked up to 40 degrees. And all of these were for uni-direction (personal preference, long story). Which is again why I don't think it's necessarily excess heat causing the rippling, moreso vacuum. Rule of thumb too was to have the pre and print heater the same temp, with the drying heater up to 10 degrees hotter for better drying. For example, as 12 pass I would have had set up as roughly 32, 32, 40 degrees (pre, print, post), something like that.

You're really going to need to experiment with heater settings - too cold and the ink won't cure and will get wetness/spreading - too hot and you get heat banding, particularly on large areas of flat mid-tone colour. If I can work out how to attach my old test swatch I'll do that - it's got swatches and test patterns to test if the inks aren't bleeding from not enough heat, some really dark swatches to make sure that amount of coverage can cure properly, and then some larger patches of mid-range colours to test heat banding. It's tedious, but if you use that test print to hit a Goldilocks (not too hot, not too cold) on each of the swatches, then you should be pretty comfortable in printing 95% of the jobs you'll encounter. But you'll need to do it for each of your speed settings, for each of your medias.

For your higher quality, thinner medias (like some car wraps, but also some translucent SAVs), I particularly found the heat banding was a problem. The appearance would suggest that the media was rippling parallel to the length of the media and causing light & dark spots, but it's not, the media sits perfectly flat and it's just one of those weird things that large format printers do. The way to reduce it is to obviously reduce the heat, meaning you'll have to run it at a higher pass mode (eg, 12-16 pass instead of 10) so it cures enough.

It's all a balancing act. Like you said, "just print it". Which is why we made this sticker, to remind the sales reps:

Test print file (if it works):

Thanks,
Michael

 

[Morkel]

PS, looking again at your photo, I'm convinced that it's not running hot enough / printing too fast for the heat settings. Theoretically if the ink was staying wet it could cause those ripples. Do you have a higher res version of the pic? I can't be sure, but it looks like you can see indications of each print head pass, ie, the stepping of each pass, and it looks like maybe 6 or 8 pass? If I'm seeing that, either your advance settings are way out, or the ink is just way way too wet. If you want to print that fast, you'll have to do some trials with temperatures closer to 40 degrees [40,40,50] (maybe 45 [45,45,50] if you're doing it bi-direction).

 

[Alan_F]

thanks for that Morkel

a couple of things how can i check the vacuum or turn it up, and also you mention post heat i dont think i have a post heater, just pre and print.

im getting closer to working the damn thing out, and think that it may be like you said a bit of dampness in the liner.

the head strikes are happening if ive only got about 2ft pulled through the printer, if i drag about 3ft through it seems ok and obviously if i set it on the bottom roller its fine once ive worked the media comp out, which i'm getting used to now.

i'll get there, but what a learnnig curve... ps ive got a skip full of waste vinyl but at least now i ain't throwing as much away.

Al

 

[gabagoo]

I keep my heat at 45 / 40 with good 90 lb backing paper vinyls... What software are you printing with?

 

[MikePro]

funky media & heat settings are most likely the culprit.
and if you're head-striking already, I would STOP doing what you're doing and run some long nozzle-washes to clear-up any gummed-up printhead nozzles before they become permanent deflections.
(I kept my printheads at the high-setting for 8 years, as well. no reason to dial it down unless you're having ghosting issues printing on paper-thin media.)

when I operated my JV3160, to help reduce rippling when it was an issue, I would pre-feed enough material to strap to the take-up reel.
the weight of the vinyl waterfalling-down off the printer, paired with the tug of the take-up, was always enough to help flatten-out the ripples while printing.

Ritrama is nice, and cheap, but there are plenty of 3M/Oracal/Arlon options that I had never had issues with printing/longevity.
All non-cast Ritrama products I've used, have failed long before other calendared products I've used or turned crunchy while sitting on the shelf for too-long.
Their new high-performance & wrapping vinyls, however, are pretty awesome.

 

[Morkel]

thanks for that Morkel

a couple of things how can i check the vacuum or turn it up, and also you mention post heat i dont think i have a post heater, just pre and print.

im getting closer to working the damn thing out, and think that it may be like you said a bit of dampness in the liner.

the head strikes are happening if ive only got about 2ft pulled through the printer, if i drag about 3ft through it seems ok and obviously if i set it on the bottom roller its fine once ive worked the media comp out, which i'm getting used to now.

i'll get there, but what a learnnig curve... ps ive got a skip full of waste vinyl but at least now i ain't throwing as much away.

Al

What rip are you using? We had ours through Rasterlink, and then through Onyx, and both had the 3 heating settings (pre, print, and post), and vacuum settings easily viewable/adjustable.

And by the sounds of that, yeah, if it's only effectively the outer layer of the roll that ripples, it's moisture in the liner. Attaching it to the take-up roller is a good idea for tension. Because we didn't want to waste a full 1200mm-odd (4 foot) every time we loaded a media, we taped a scrap piece of banner to the take-up (permanently) and then just pulled that tight and taped it to the media coming out of the printer. You can then feed out the media as much or as little as you want and it still keeps tension. Just make sure the banner has minimal stretch and you pull it taught before you tape it so there's no skew. Pic attached:

 

[SignDeeJay]

Thank you for this Thread

I just happened to stumble across this thread, and it was very helpful thank you to everyone who commented/ the original post.

-DeeJay