Roland, Ink Starvation or What?

[RocketBanner]

I have had problems for 2 years with the black output on my Roland SC545-EX. Here's the scenario: I start printing a banner with full bleed black, it starts fine but after a couple of feet a slight over spray starts, it eventually gets worse, then the print starts to go bad, I can see that not all the ink that should be laid down is, I pause the printer for 30 seconds and restart the job, it starts fine then goes bad again, I cancel the print and do a quick test print, there are several dropouts on the black, I lower the capping station and look at the caps, there is residual ink in the black cap top. i do a cleaning on the Head group containing the black head then another test print and all looks good. The scenario I just described happened today after I installed a new black head, new black dampers (the small stock ones) and 6 new cap tops and full alignment of the heads. Mind you though, this has been going on for a couple of years, on 3 different heads to date. I have been getting by by 1. slowing the print head speed and 2. pausing the printer when it gets bad enough 3. praying people don't order full bleed black banners. I am running Solaris inks now but this happened just as bad for the last 2 years on OEM inks. I think it's ink starvation but why? and how to fix? thoughts please?

 

[artbot]

is it both side of the black head? or just one side. i'd definitely do a damper swap to see if the issue follows the dampers. i'm pretty sure it will. also, have you reverse flushed the black lines? if not, set the cleaning cart, fill a syringe and aggressively force the solution into the cart (you'll hear a rush of bubbles when the line is clean). the needle can trap neoprene from a cartridge, or a fragment of paper that will only come out going toward the cart.

also one sign of a clogged line is when pulling with a syringe at the damper, the membrane will stay concaved for and extended amount of time. you might want to do this to each of your black dampers. one may relax, the other may stay concave. do the concave one first. one other thing to look for if this does not fix it is a kink in your black in line.

 

[RocketBanner]

I don't think it's the dampers I have changed them so many of them my head spins. I put 2 brand new ones on yesterday with the head change. I think your on the right track when you talk about a clogged line. I was trying to pull ink into the damper with my syringe after the head change, to prime it you know, It was very stubborn, the damper stayed concave and eventually let ink in but it was not a normal flow. I was concerned about a clogged line so I put a cleaning fluid cartridge in and disconnected the damper then did several strong pulls and push backs of cleaning fluid through the lines. I did it enough that the fluid eventually ran clear and the pulls got easier. I put the ink cartridge back in and installed yet another damper and went to prime it but again it was very difficult to pull ink into the damper. Curious I returned the heads to their capping stations and tried to pull ink through the cap tube, it was very difficult. It happens like this with both sides of the head, but the left side much worse than the right. Thanks for you input, keep it coming.

 

[Jack Knight1979]

This has plagued my roland 745 since day one. Regardless of OEM or aftermarket inks.

It's a constant battle, but I've had this problem licked for a few years now.

First thing is to use large screen dampers. (ebay or solventinkonline) I do not get drop on on eight pass or more, but on heavy coverage jobs doing four pass or less I get drop out pretty quickly.

The solution is to go into service mode, turn periodic cleaning on. Set the interval to around 20. You'll have to adjust it your needs. The interval is based on the thermistor of the head and has no bearing on time til cleaning, etc. I have to adjust my interval depending on ambient temp and humidity levels. I'll adjust every couple months or so.

The most important thing is to adjust the level of cleaning to light.

A light cleaning primes the heads and wipes the head surface. It doesn't pull much ink through and is a very fast cleaning which prevents the weird dry line in the banner. You may still have a faint line, but it's not noticeable, and way better than a horrible looking black banner with tons of drop out.

When doing jobs on higher pass or light coverage, go into the regular menu and turn off periodic cleaning.

This will fix your problem.

This was something I tried years ago and was glad I discovered it. Haven't looked back since.

 

[RocketBanner]

Damper size?

Thanks for that. Will these larger dampers fit under the damper bar alright?

 

[artbot]

you don't really need the bar if they won't fit. i tossed mine long ago. along the with the head raising lever. just too much stuff in the way. when i mentioned "damper swap" that's not meaning replacing them as a fix. ....it's a diagnostic procedure. you keep the dampers hooked to the lines the way they presently are, then stick them on different manifold nipples to prove or disprove if you have flow or leaks at that damper or flow or leaks at the vacuum attempting to pull from the damper. so you are "crossing lines" you can swap the two black dampers to two magenta nipples, or rotate the two black dampers on the single black head. all do isolate what is going on. if the black suddenly start working at the magenta position, then that would mean that you don't have good vacuum at the black head, etc. it's one of the first thing to do when eliminating a drop out issue. there's also cap top swaps, and pump tube swaps, all capable of isolating the issue.

 

[Jack Knight1979]

I hear you on the bar Artbot. I still use it. I've had dampers lift off the head manifold.

The large screen dampers are the same height as the normal dampers they have a larger screen to allow a larger volume of ink to pass.

I'm not talking about the BIG dampers (aj 1000) that have double the ink capacity. You can use them, but they could lift on you. That is a bad day.

Just buy the large screen dampers. Same overall dimensions as the OEM dampers. Not the AJ100 double bladder dampers.

 

[RocketBanner]

Thanks Artbot, good trouble shooting tips, I'll let you know how it goes.

Jack...I have been using the periodic cleaning for the last 2 days and it works but really slows production. I am waiting on the new dampers.

 

[Jack Knight1979]

Adjust the interval further apart and make sure you are on a light clean. A normal clean takes forever. Light clean takes my machine about 20 seconds.

The factory settings for periodic cleaning is a normal cleaning which is a huge waste of ink and time.

[QUOTE =RocketBanner;987452]Thanks Artbot, good trouble shooting tips, I'll let you know how it goes.

Jack...I have been using the periodic cleaning for the last 2 days and it works but really slows production. I am waiting on the new dampers.[/QUOTE]

 

[RocketBanner]

yes, I did set the cleaning to light as per your original post but it takes my machine 60 seconds to complete a light cleaning. I have the interval adjusted to 3.5, this works well. It's really not slowing production that much when you consider the alternative...It was a great suggestion.

I have the large dampers arriving today from China, $4.00US as well as 2 spare heads and other various parts. Regarding the dampers, I want to switch to the large dampers but you stated you had some dislodge before...ouch. I know you mentioned to use large screen dampers (which are the same size as the small dampers) but I am going to be in possession of the big ones later today and would like to give them a try, how likely is it they will come off and ruin my day?

Artbot....you've not had any trouble with the large dampers coming off?

 

[Jack Knight1979]

If the o-ring is wet with ink or the manifold has ink, the dampers have a tendency to lift off the head manifold. If you're not around when this happens you're head if firing w.out ink = blown head/headboard.

I would rig up some kind of fastener to ensure they stay down.

 

[mcglockers]

This has plagued my roland 745 since day one. Regardless of OEM or aftermarket inks.

It's a constant battle, but I've had this problem licked for a few years now.

First thing is to use large screen dampers. (ebay or solventinkonline) I do not get drop on on eight pass or more, but on heavy coverage jobs doing four pass or less I get drop out pretty quickly.

The solution is to go into service mode, turn periodic cleaning on. Set the interval to around 20. You'll have to adjust it your needs. The interval is based on the thermistor of the head and has no bearing on time til cleaning, etc. I have to adjust my interval depending on ambient temp and humidity levels. I'll adjust every couple months or so.

The most important thing is to adjust the level of cleaning to light.

A light cleaning primes the heads and wipes the head surface. It doesn't pull much ink through and is a very fast cleaning which prevents the weird dry line in the banner. You may still have a faint line, but it's not noticeable, and way better than a horrible looking black banner with tons of drop out.

When doing jobs on higher pass or light coverage, go into the regular menu and turn off periodic cleaning.

This will fix your problem.

This was something I tried years ago and was glad I discovered it. Haven't looked back since.

Hi there,

I have an AJ-740 which has been problematic from the word go. Various suggestions have been static on the media and humidity etc but I only seem to have a problem with magenta dropping out. All other colours seem to behave fine.

Recently this has been happening:



Magenta goes for about three passes before it starts dropping out. I've been using the machine for about 3/4 years and I've usually been able to play around enough to get it back on track but this is above my head now.



Can any of you help? Or suggest possible solutions/parts that may need replacing.

Cheers!

 

[J Hill Designs]

drain line is probably plugged at least somewhat below the magenta cap

 

[mark in tx]

Last resort would be replacing all the O-rings in the ink lines.