Question LEC-300 Test Print and Relative Humidity

[Josh F.]

The Roland LEC-300 is pretty much just the SP-300 but with UV ink and white and gloss capabilities.

I've been pulling my hair out trying to get to the bottom of why my black is printing the way it is. I'll start off by saying this machine doesn't get regular use and it's normal for it to sit idle (but powered on) for a month or two at a time. However, this last quarter of the year it has been getting use at least once a month. Back in August it printed great, a few missing jets in the test print but the printed result always looked fine. Then as it got colder and drier I noticed the test prints start to decline to the point where I am now. Black lines now print "hairy" and you can notice banding in the black. The things I have tried to solve the quality issue:

-Numerous manual cleanings
-16 hour head soak
-Cap top replacement
-Wiper replacement
-Wiper scraper cleaning
-Cleaned the encoder strip

None of those things changed the test print in any way. The only notable change from August until now has been the humidity change in our building. The relative humidity in the room that this machine is in is currently at 26%. I've seen it as low as 17%. Would relative humidity play such a large role in print quality or am I going to have to start looking at a replacement head?

Some background: I've no formal training on Rolands. The responsibility of this one was kind of just given to me after the last person quit a few years ago but if there is a youtube video on how to do something I can probably figure it out.

 

[Josh F.]

Just to follow up: Increasing the room's RH to average about 40% hasn't done anything to help the print.

I did notice, however, that the cap tops are not draining well - if at all. I'm going to order a set of syringes to see if I can pull anything out of anywhere between the cap tops and the drain. Maybe that will help get some nozzles back but I doubt it. I'm kind of at a loss at what my next steps should be for troubleshooting. I'd like to get a tech in to take a look at the machine, but it doesn't get a whole lot of work so my boss is reluctant to spend the money on one. And from reading on this forum I do realize that I will likely need to replace the print head. But that will be an even harder sell to my boss. So until then I am open to any suggestions as to what I could do to try to get some of those nozzles back or straighten them out.

 

[Zoogee World]

I would say replace the cap tops first, they should be replaced every 6 months, but if being rarely used, then yearly would be fine.

 

[Josh F.]

Thanks for the response. I replaced the cap tops about a month ago. So if there is a buildup anywhere in the lines it's going to be somewhere around the pump. I'm also confused as to why ink would build up considering this uses UV ink and all of the tubing is black.

 

[Zoogee World]

Could be due to lack of use, I've heard UV printers need to be used on a regular basis to stay in top shape. But I just noticed the nozzle test and there is a bit of deflection in some of those nozzles, my guess is that is at least part of the problem. Have you adjusted the alignment recently to see if that helps any, or try different profiles. From seeing that print, it's looking like a head would likely be needed, but you could try to do a 48 hour soak and see if that helps anything.

 

[Josh F.]

Well, I just finished a 22 hour soak. Though, I did read on a different forum that heads need to soak for 48 hours so I guess I could give that a shot over the weekend.

I have not done any of the bi-direction adjustments recently, no. I did need to do some cutting adjustments last week though, so it may not hurt to try print adjustments. As far as any alignment done in the service mode: I don't even know how to get into service mode.

 

[Zoogee World]

Typically depending on how bad the nozzle deflection is you can play around with the adjustments to minimize the banding, that looks to be the biggest issue you have, I also notice a little overspray, which is probably from the deflecting nozzles. But you may be able to minimize by reducing print speed and increase heat settings (If UV has that ability), maybe even trying different print profiles. I don't have a UV printer only Eco-Sol, but I know Roland's are very similar in function in all the different formats.

 

[rjssigns]

The LEC needs constant use, no way around it if you don't want to tear your hair out. Daily runs are key. We had one in the lab and if it was used regularly it was okay. Ended up with a second functioning unit from a local business. Both ended up being recycled after the flatbed was installed.

 

[dreko]

So far our LEC-300 has been smooth... we don't often print to it, but we do make sure we keep the maintenance up as much as possible. You can bump up the printing quality (passes) to help eliminate those banding lines, as well as printing uni-directional. Are you happening to print at a very fast/low quality setting? In my experience this mode becomes a stress test for the printer... Our room's humidity levels are somewhat low as well

 

[Josh F.]

To be honest, that test print doesn't really do justice to the quality that it can print. That cyan banding is pretty nonexistent in real world application and the only real noticeable quality issue is the black over spray. I attached a pic of something fresh off the printer this morning - no adjustments from when I ran that test print last week. I personally think the quality is outstanding (the dithering in the yellow and pixelization of the background is intentional)....except for the black. Really quite disappointing.

I almost exclusively run it on high quality, uni-directional unless print time becomes a factor. I tried messing with the print speed but I didn't really see any improvements in the quality of the black. Sounds like my syringes will be coming in tomorrow so I'll post an update then if pulling ink through the cap tops helps anything.

 

[dreko]

Our white nozzle started spraying somewhat like that black... the Roland tech replaced the damper, problem solved. They didn't even need to replace the damper filter, as he pulled ink back through it... he said it would be fine, but because he was already there, had the part,etc...
he went ahead and replaced the damper filter. Maybe this is your solution??

 

[Josh F.]

Drawing from the cap tops with a syringe cleared up my draining issue from earlier but it hasn't done anything to help with the black nozzles unfortunately. When I first started drawing with the syringe I was pulling a lot of bubbles so I kept drawing slow and steady until I didn't see any anymore. After I closed everything back up I ran 3 medium clean cycles and then the test print and yeah, nothing new.

Kind of an off the wall question: if you look on youtube you can find any number of videos advertising head cleaning solutions. From reading this forum I gather at best they don't work and at worst they damage your print head. But, there are videos of people using a syringe to push cleaning solution through the head to clear out nozzles. I don't want to attempt that directly, but *in theory*, wouldn't pulling ink through the cap top with a syringe be doing a similar action? Basically just forcing flow through the nozzles, right? If that is true then is there some merit in just continuing to try to draw ink through the cap tops?

Thanks all for the help so far.