Need Help Summa S140 T series vinyl tracking

[2ny]

Hi.
We have a Summa plotter S140 T series that has some issues with the vinyl tracking on fullwidth vinyl media. The plotter has 4 tracking wheels where the 2 innermost are optional to use.
When I load a roll with vinyl 1260mm width, and want to plot a file from Flexi I always click "show me" to check if the vinyl is going straight and that the vinyl will be ok. However -on this width our plotter have some tracking issues, and I can not find any fault of mine to explain this issue. When the plotter returns to the start point after rolling out maybe about 2 meters of vinyl, the vinyl buckles on both the outermost tracking wheels. (picture) We use a lot of halfsize rolls, so this problem has been a minor pain. However we have been using more fullwidth vinyls lately, and this is getting more and more irritating. I can not find any issues with the wheels or any other obvious fault with the vinyl, so I hope maybe the forum could give me a tip or two... I have seen that Summa plotters are getting praise on the web for the accuracy on the tracking and such, but this sucks.

Best regards
Tony

 

[FrankW]

Could be the pinch rollers anyway. Or do you work with reduced pressure on the pinch rollers? Be shure to lower the middle pinch rollers too.

Have a look on the back of your media after tracking. You should see the tracks left by the grit rollers. Compare it with the picture attached to this post. Shows it good or bad tracking?

 

[jayhawksigns]

Another question I would have is this colored media or something you are cutting after printing?

I see this on ours on some print media, usually when I probably ran it through the printer a little too hot.

 

[Bly]

Pretty sure it's the media.
It happens to us on some media with thinner backing paper.
Bring the rollers in a little if you can.

 

[gabagoo]

I have seen this on my summa d140 . The culprit for me is that the roller has to be lined up on the little metal roller beneath it and sometimes when loading vinyl they can get moved slightly without you noticing it, then the buckles happen. You might also try slowing the plotter down

 

[jayhawksigns]

I have seen this on my summa d140 . The culprit for me is that the roller has to be lined up on the little metal roller beneath it and sometimes when loading vinyl they can get moved slightly without you noticing it, then the buckles happen. You might also try slowing the plotter down

Forgot about that one, I know it scans to check that the rollers are aligned, but there is some wiggle room where it can be off and not catch it.

 

[2ny]

Hi.
Thanks for the replys. I have checked the tracking on the media backside, after I have done a 4 meters pull-through of the media. (I have a slightly less bulging than my initial picture btw.) Inspection of the backside shows that one side have an evenly pattern up to 20cm from the start edge, and the other about 80cm from the edge. (The middle rollers does not leave so much marks that I can inspect them.)
I have payed attention to the exact placement of the pinchrollers, and I am using all 4 on this width of media. I also use quite a slow setting on the velocity - 200mm/sec, and have tried several other speeds.
I use Oracal 751 vinyl wich have a backing paper that is very similar to many other suppliers in the backing media about 130-140 g/cm2.
I checked the pressure of the pinch rollers with a paper inserted between the pinch rollers and the media, and find that the outermost wheels have a significantly higher pressure on them than the 2 in the middle. I suspect this is as it should be. I will try to do some more tests and pay close attention to the factors that may have effect on the issue.

Best regards
Tony

 

[Snydo]

Use the media guide flanges with 751 and it will feed much straighter than without.

 

[2ny]

Use the media guide flanges with 751 and it will feed much straighter than without.

We do not have any media guide flanges on this plotter -unless I with my school english is misunderstanding something. There are the usual guidance marks on the leveler side of the plotter, but thats it. However; I have no problem getting the media to go straight enough to keep inside the grip of the pinchrollers. Its the end result of back-and-forth rolling of the media that creates the problem with bulging of the media towards the outermost pinchrollers.

edit; Ahh.. it just dawned on me -and my school english that you mean those end pieces you stick in the media core and that rests in the adjustable rings on the plotter. Of course, these I often use when plotting with large/full media and such, but not always on smaller rolls. Come to think of it, I may not have used these when I have had the most trouble with the vinyl bulging. Maybe the tighter pull of the media out of the rolls are creating enough difference back-and-forth, so I really should use the flanges every time I want to plot things that are longer than what you can roll out of the media in one go before starting to plot. Phuh... what a sentence
I will investigate some and post a report. Have a nice weekend all.

Best regards
Tony

 

[Split76]

Forgot about that one, I know it scans to check that the rollers are aligned, but there is some wiggle room where it can be off and not catch it.

Exactly. If the roller is just a bit off, it does that and cutters doesnt notice it.