Output size differs from file size!

[annette]

I'm at a loss. I'm using Rasterlink for a Mimaki printer and I have never encountered this problem before. I've printed two banners that are supposed to be 191" but the finished size is only 184". I am designing in Corel and have to export the file to scale and size it up in the rip software like I've done a thousand times before. I double and triple checked the size because it has to be exact to fit in the space. I also gave the stitcher a detailed diagram which they followed so it's not their fault.

I went back and checked the size in the queue and it says the right size on the screen. Has anyone had this problem before? Any idea how it happened and how to fix the problem?

 

[FrankW]

It could happen with roll printers that the output sizes don’t match, often seen with thicker banners. You should calculate the factor and resize the file in the RIP.

 

[P Wagner]

I'm at a loss. I'm using Rasterlink for a Mimaki printer and I have never encountered this problem before. I've printed two banners that are supposed to be 191" but the finished size is only 184". I am designing in Corel and have to export the file to scale and size it up in the rip software like I've done a thousand times before. I double and triple checked the size because it has to be exact to fit in the space. I also gave the stitcher a detailed diagram which they followed so it's not their fault.

I went back and checked the size in the queue and it says the right size on the screen. Has anyone had this problem before? Any idea how it happened and how to fix the problem?

It is not at all unusual that there could be size deviations between the file size and printed output size, most commonly in the media feed axis. This can occur with any roll feed printer.

Most RIPs have a compensation function to automatically correct this (corrections are based on the specific media and print mode being used). For example, Onyx Media Manager has a tool called Scale Adjust, and SAI has a tool called Output Size Compensation. You input the two values (file size and printed size) and the software will calculate a scale adjustment to correct.

 

[Stacey K]

Shot in the dark here. This happened to me a few times. Really got my goat...somehow I had changed the percentage to like 94% instead of 100%. This is Flexi but maybe you have something similar...

 

[JBurton]

Shot in the dark here. This happened to me a few times. Really got my goat...somehow I had changed the percentage to like 94% instead of 100%. This is Flexi but maybe you have something similar...

View attachment 165884

Oh cripes, I've seen this problem on a plotter tons of times, but I hate flexi even more if they have a scale function that's as easily ignored as the one in the plotter. In onyx its on a tab that is dedicated to job dimensions, therefore not somewhere you'd find yourself unless you need the dimensions changed.

I think OP's problem was not properly calibrated feed advance like Pwagner and frank said.

 

[GaSouthpaw]

I'm with PWagner in thinking it's a media feed issue. It's been 20+ years since I ran a Mimaki, so I couldn't begin to tell you how to correct it, other than most printers have a way to calibrate the feed for various materials. I would definitely check that if you're certain the output is correct.

 

[annette]

It could happen with roll printers that the output sizes don’t match, often seen with thicker banners. You should calculate the factor and resize the file in the RIP.

Do you think this is because the roll is so heavy and the pinch rollers can't handle the weight? I'm wondering if I babysit it and make sure there is always slack in the roll will that solve the problem?

Or is there a way to tell the printer that I'm using heavier weight material so the software compensates.

I should mention that precision is key with this project. I need the size to be exact. I'm even printing guides to show the stitcher exactly where to place each grommet so the banner fits the in space where it is to be installed.

Even if I calculate the factor to compensate for the error, how can I trust that it will print it six inches short like it did the first time and not longer or shorter?

 

[Solventinkjet]

Are you sure there isn't some transparent object that is being scaled up with the banner and throwing off the total size in Rasterlink?

 

[annette]

Are you sure there isn't some transparent object that is being scaled up with the banner and throwing off the total size in Rasterlink?

I thought that might be the issue so I checked and there's nothing.

 

[P Wagner]

Even if I calculate the factor to compensate for the error, how can I trust that it will print it six inches short like it did the first time and not longer or shorter?

Scale corrections are specific to the media print used, along with the print mode being used.

If the printer is not producing consistent scale results on the media/ print mode, there is no way for software to correct for random scale behavior. As stated in the original post, you printed 2x with consistent scale results for each. Based on that result, the scale adjustment would be 1.0381

 

[BigNate]

.... a simple check that will tell if this is the rollers or a digital problem - make 2 prints and see if they are the same size. If there is a physical problem (the media slipping in the rollers) it is incredibly unlikely that the error is repeatable with any kind of precision - so if the problem is the medial slipping in the rollers, then the prints will both be the wrong size, but you should be able to see a difference between them (maybe 1 is 184" and the other 185") - but if the error was digital, then the prints would off by the same amount on every print.... unless you have slippage as well as a digital scaling issue.

 

[Josh Kuper]

Where do you find the, i'm not seeing it anywhere. My window perfs have always come up short (vertically), width are correct (horizontally)

SAI has a tool called Output Size Compensation

 

[FrankW]

Do you think this is because the roll is so heavy and the pinch rollers can't handle the weight? I'm wondering if I babysit it and make sure there is always slack in the roll will that solve the problem?

The pinch rollers can handle the weight. It is that the motor needs different power for moving different weight of media. Always slack the roll would help, but compensating the size deviation in the Rip would too.

 

[Josh Kuper]

Im using an HP latex, I can't relax the roll like I can on a Roland. I have the 50/50 perf substrate loaded as the profile so I would think it would know how heavy the roll is

 

[balstestrat]

Im using an HP latex, I can't relax the roll like I can on a Roland. I have the 50/50 perf substrate loaded as the profile so I would think it would know how heavy the roll is

The printer has no idea about how heavy the roll is. However you can lower the roll tension if you'd like to.

 

[Josh Kuper]

I don't see how thats possible on my HP latex 115, the roll loads and is tight

 

[balstestrat]

I don't see how thats possible on my HP latex 115, the roll loads and is tight

You go edit the printmode and there is a setting for roll tension. More details in user guide.

 

[Fechin]

I've sometimes noticed on very long prints that a length discrepancy happens. Though I found setting the length to 101.7% worked, but that was my printer and this 3.7% difference. It might be the feed rate or tension, but a little math can adjust it.

 

[Eric H]

I'm having a similar problem also but my prints are too long. I've done similar jobs just a few weeks ago that were fine. Same setup corel 2023 rasterlink 7 mimaki jv160-300plus. I had print cut files (that actually cut fine) that needed to line up to to cut vinyl and it was about an inch too long over a 6' print. I did a 12" box and it was about an 1/8" too long, scan direction was right on.