Roland SP-540i print head questions

[Sam On Maui]

We have a Roland SP-540i and it's been working pretty well over the years. That said, the original operator left a long time ago so I'm having to work with it. As such, I was wondering about a few things:

The black portion of the first KC head seems to take a beating. How long should one of these heads last?

While we try to keep our media as flat as possible and use the appropriate head height it seems that on vinyl it'll sometimes hit the edge of the media once in a while. Likewise, despite our best efforts, banner material (particularly 54") can buckle up during a job and cause a head hit. The previous operator only had two pinch rollers (inside and outside edges) because the center rollers would affect print quality. We do have a take-up reel which in theory helps pull the media evenly.

Any thoughts or advice? I looked through our (admittedly thin) manual and didn't see best practices guide nor any sort of expectation of how long parts should last or how often they should be replaced. Our digital printers all have life expectancies as part of their part specs, but I didn't see anything like that for the Roland. There are no Roland techs here to ask.

We replaced our KC head about this time last year and there's some streaking whenever Black is used. It's a little frustrating!

 

[Terry01]

The suctions fans will be full of dust and lint, and your suction pressures will be down. Also make sure to always use the media edge guide clamps.

 

[damonCA21]

Do you use the media clamps? These are designed to keep the vinyl flat in the area the head passes over, so is important to use them and also make sure they are laying nice and flat so there is no chance of the head catching them.
How long a head lasts doesn't really have any answer. It depends on how much printing is done, how well the machine is maintained, if it gets any head strikes etc..

 

[Sam On Maui]

The suctions fans will be full of dust and lint, and your suction pressures will be down. Also make sure to always use the media edge guide clamps.

Oh jeez. I'm assuming cleaning those out will be a non-trivial project?

Do you use the media clamps? These are designed to keep the vinyl flat in the area the head passes over, so is important to use them and also make sure they are laying nice and flat so there is no chance of the head catching them.
How long a head lasts doesn't really have any answer. It depends on how much printing is done, how well the machine is maintained, if it gets any head strikes etc..

We stopped using them because one got very subtly bent out of shape and scratched the heads. The tech who helped us (now retired) told us to get rid of them. I guess we'll need to look into how to replace them! O_O

 

[damonCA21]

As long as the clamps are straight then they won't cause any problems, and they are better for keeping the vinyl flat rather than just relying on the suction

 

[Jim Hancock]

You can find media clamps here - https://dgastore.rolanddga.com/ or you can try Ebay. If you can get the short ones, you will be less likely to crash the sheet cutter by forgetting to remove the clamps when sheet cutting.

Check the condition and orientation of your pinch rollers. The outside rollers are tapered, while the middle rollers are flat. The outside rollers have a dot on one side. This dot goes towards the outside.

As far as banner material and other heavy media, instead of laying the roll on top of the two rollers, remove the front one and run the back one through the core of the media. This will reduce the pulling resistance immensely and puts less strain on the feed motor, as an additional benefit.

 

[Sam On Maui]

The suctions fans will be full of dust and lint, and your suction pressures will be down. Also make sure to always use the media edge guide clamps.

How do you clean those? I don't see a fan intake or exhaust?

 

[Terry01]

How do you clean those? I don't see a fan intake or exhaust?

Remove the panel below the post driers.. The two fans are inside there. The Intakes are the holes in the platen.

 

[Sam On Maui]

I'll see if I can find that in our diagrams. I'm quite afraid of killing something somehow.

Did just order new media clamps, and we've gotten new pinch rollers. Oh, next week will be fun >_>

 

[MrDav3C]

Your middle pinch rollers shouldn't cause issues with print quality provided they are in good condition and your heaters are the right temp for the media.

Definitely use the media clamps for heavier print media like banner, but also definitely remove them for any contour cutting to prevent them from damaging the blade.

We also found reducing the heater temps for banners stopped the media from buckling.

Totally agree with the other posts regarding cleaning out the fans to improve suction, when our technician cleaned these during an overdue regular service the difference was like night & day!

As a guide, when the printer is initialised and the pinch rollers are down, between the efforts from the fans and pinch rollers you shouldn't be able to move the media by pulling it.

We had an SP540V for about 15 years and only needed to replace the print heads twice, I guess we were extremely lucky and doubt they will last quite this long in our new printer but obviously if you are having a lot of head crashes then these will damage the print heads.

Another thing to consider are the inks you are using, some 3rd party inks are notorious for ruining printers!

 

[Jim Hancock]

Where the middle pinch rollers can cause "print quality" issues is on softer or thicker media, such as banner, when the roller creates a very tiny impression in the media, which shows up as a visible vertical line the width of the pinch roller. This is caused by a tiny difference in the distance between the printhead and the media, resulting in a tiny misalignment of the bi-directional alignment in that area. It will be most visible solid color areas, a slightly more grainy look. You see the same kind of anomaly when you have slight rippling of the media. You won't see this if you print uni-directional, but then that kills printing speed.

To help minimize rippling, especially with heavy media rolls, such as banner, do the following:
1. Remove the front media holder shaft in the back of the printer.
2. Insert the rear media holder shaft through the core of the media, place the doughnuts to prevent sideways shifting of the role.
3. Use the felt friction lock on the roller.
This will reduce the pulling force needed by the printer greatly, usually resulting in virtually eliminating media rippling.

As to your black head issues, head crashes when the head is moving from the home position will crash into the black channel first. The other factor is the DX4 heads on Rolands have a tendency for the black channel to start to act up first, likely due to the pigments in the black ink being tougher on the DX4 heads.

 

[Sam On Maui]

Totally agree with the other posts regarding cleaning out the fans to improve suction, when our technician cleaned these during an overdue regular service the difference was like night & day!

I'll have to go find a tutorial or three first, thank you.

Another thing to consider are the inks you are using, some 3rd party inks are notorious for ruining printers!

We're just using Roland ink. I'm boring

As to your black head issues, head crashes when the head is moving from the home position will crash into the black channel first. The other factor is the DX4 heads on Rolands have a tendency for the black channel to start to act up first, likely due to the pigments in the black ink being tougher on the DX4 heads.

Good to know!