help! mutoh prints longer panels than sent

[chrismccray]

having trouble with my mutoh 1604 printing panels longer than the file is saying they will be. my 500mm distance check is reading 500mm before AND after i print. my pf disc is clean, i did the distance adjust check with onyx to see if they were being sent with the correct scale. everything looks fine and we still can't figure it out. on a 10 foot panel, im growing about a half inch. any suggestions?

 

[bob]

having trouble with my mutoh 1604 printing panels longer than the file is saying they will be. my 500mm distance check is reading 500mm before AND after i print. my pf disc is clean, i did the distance adjust check with onyx to see if they were being sent with the correct scale. everything looks fine and we still can't figure it out. on a 10 foot panel, im growing about a half inch. any suggestions?

.5" in 120" is one part in 240. Reasonable accuracy when friction feeding this sort of media off of rolls of varying widths, weights, and surface characteristics.

A 500mm test is ~20". An proportional error of 1 in 240 at 20" would be about .083 of an inch. 8 thousandths of an inch is a fat 1/16". Even at that, it should be detectable.

I don't know what how Onyx works, but with Flexi you can enter any two figures in the distance compensation dialog. Measure the exact variation in the larger panel you're actually printing and then enter the expected length of that panel and the actual length produced. A test panel doesn't have to be an actual test panel, your can use anything you with which know the actual length. The longer, the more accurate.

If you must enter some constant, like 500mm, merely scale the compensation required with a simple bit of algebra...

X/standard_test_length=actual_length/expected_length

Solving for X...X=actual_length*standard_test_length/expected_length

Just make sure that all of the measurements are in the same units.

Note that setting the distance compensation for one media may or may not carry over to other medias. My printer feeds vinyl somewhat differently than banner media. If the difference is really wild, have a setup for each different media type.

 

[chrismccray]

hey bob, thanks for the reply.yeah, my boss is an engineer so he caculated most of that stuff you described already. its been a frustrating issue because it really only gets noticed when we do vehicle wraps, and even with that, not until we unspool the prints and/or laminate them. so sometimes we dont know it ran long until the job is basically done. it is the first version of the valuejet 1604 and has been running like a champ for 5 years (even though this issue has been haunting us from the start), so we're looking at buying a new one and keeping this one as a backup.

have you heard of any issues like this with the new mutohs? or do you know if it is pretty common for printers alike?
what printers do you use and how long have you been digital?

 

[bob]

...have you heard of any issues like this with the new mutohs? or do you know if it is pretty common for printers alike?
what printers do you use and how long have you been digital?

It's a characteristic of any and all devices that feed any sort of media. That's why there's a way to perform compensation adjustments in both X and Y on most all machines.

Any particular mechanical device's concept of an inch will vary from any other machine's. Moreover any physical interpretation of an inch will necessarily be in error. Compound the built in error with the vagaries of feeding media and you have built-in inaccuracy. That's why there's feed compensation adjustments.

You can mitigate this bit of graphical anarchy by setting up your output such that a bit of error in size can more easily be accommodated by the design.

It's there, it's unavoidable, you have to deal with it.

 

[chrismccray]

well put. indeed.

 

[Stealth Ryder]

It's a characteristic of any and all devices that feed any sort of media. That's why there's a way to perform compensation adjustments in both X and Y on most all machines.

Any particular mechanical device's concept of an inch will vary from any other machine's. Moreover any physical interpretation of an inch will necessarily be in error. Compound the built in error with the vagaries of feeding media and you have built-in inaccuracy. That's why there's feed compensation adjustments.

You can mitigate this bit of graphical anarchy by setting up your output such that a bit of error in size can more easily be accommodated by the design.

It's there, it's unavoidable, you have to deal with it.

Very well put Sir......