Okay, I want a real cad-cut guru. None of these folks like that Frog dude!

[Frog]

Cereally folks. What's up with this?
Note the crazy "O's and "C" in the top exampleof this Siser Easyweed. Even with the rough scan it should display quite well the contrast to the good one on the bottom.
Thing is, this problem, on my buddy's old Mimaki is not consistent. Blade is pretty new, and these bad ones were after good ones, and before more good ones with no changes in settings!

[Inkworks]

Looks like too much blade pressure to me. That can cause the blade to catch on the backing and wrinkle a bit causing distortion in letters. I've seen it when switching from cad cut back to sign vinyl and not lowering the blade pressure back down.

It can also be cause by a big full roll of material on the machine and not pulling enough off to pre-feed the size of the image area. As the machine tries to pull material off a big heavy roll the feed can slip a bit.

[royster13]

In addition to what Jon said, too many marks in cutting strip maybe?.....

[Frog]

Inkworks, my rolls are never bigger than ten yards. Is that big? It's happened on fives as well.
And the inconsistency of this problem is because for whatever reason, the drag on the roll increases and decreases on its own?

Royster, a marked up cutting strip problem shouldn't come and go, should it?

[Homer]

check  lateral belt tension on your cutter. things like this tend to happen when it gets loose.

[Chadwick]

What Inkworks said. *and others*

Maybe a feeder issue perhaps?
Gunk on the rails the head travels on?

.02 for troubleshooting.

[Inkworks]

Inkworks, my rolls are never bigger than ten yards. Is that big?

Nope, that's not big, I was think like full rolls ~50 yards.

Is the backing cut most of the way through? or just barely marked?

[Frog]

Inkworks, my rolls are never bigger than ten yards. Is that big?

Nope, that's not big, I was think like full rolls ~50 yards.

Is the backing cut most of the way through? or just barely marked?

Barely marked (if at all), as I assume is correct.
btw, when he tries to duplicate the problem, he can't, but I am going to have him read this thread. (He'll have to sneak it though as his wife has laid down the law about industry forums since he closed his shop lol! Somewhere, she got the crazy impression that many of us get a little addicted and spend far too much time)

This is a lot like the persistent squeak that disappears at the mechanic's.

[Homer]

Another thought Frogger, have him check the blade holder itself. sometimes the blade is fine, but the device it goes into gets ovalized or may not be seated correctly in the holder on the machine. it may appear tight but shift after a few cuts.

Also, I would check to see if there is slippage between the pressure rollers. we had an instance where vinyl was wrapped around the roller  -don't know how it happened- but it made the vinyl skew a little. . .

[blue moon]

that looks like your whole right side is hanging which would indicate a feed problem (from somebody who knows just about nothing about cutters, so sorry if I am off).

pierre

[Sbrem]

Another thought Frogger, have him check the blade holder itself. sometimes the blade is fine, but the device it goes into gets ovalized or may not be seated correctly in the holder on the machine. it may appear tight but shift after a few cuts.

Also, I would check to see if there is slippage between the pressure rollers. we had an instance where vinyl was wrapped around the roller  -don't know how it happened- but it made the vinyl skew a little. . .

I had to replace my blade holder earlier this year because the inside had worn down so much, I couldn't add enough pressure to make it cut. That's a bit extreme, but maybe this is an early sign of that.

Steve

[Inkworks]

Intermittent problems are the bane of the troubleshooter. Sounds like your pressure is fine, and you're not letting the machine feed off a 20lb roll, so I'd look for something in the machine that is worn, loose or out of spec. Check the roller feeders, belts and cogs that there isn't something (vinyl weedlette, dirt, chunky peanut butter etc.) stuck on one and that everything is clean and snug.

[IntegrityShirts]

Try moving your grit rollers in narrower on the material and recut. If it still ovals then move the design up about 2" from the edge of the roll.  Material can scrunch inward on the rollers as it feeds up to the beginning when you load it. Narrowing the grit rollers solves this.

If that doesn't work post a video of you loading and cutting a small design.

[Frog]

Just to make it all a little bit clearer, here's a pic of the entire layout that was cut.
To further muddy the waters, he cut me two of these pages, and only one messed up, and only in the indicated area.
I typically lay out 14" on my 15" rolls to give room for the feed.

btw, so far, you guys have given me a few things to suggest for examination.

[Inkworks]

 From first glance, it looks like that would be the first area to be cut, it could be a bit of lack of tension between the feed rollers. Does your cutter cut the centre of the letters first, then come back and do the outsides? that's where mine (Graphtech) will show up as a problem, particularly if I try to let it feed off a big heavy roll, or if the substrate isn't laying 100% flat between the two feed rollers. It will usually go flat during the run, effectively skewing the "registration"

As shown by your original picture the problem is very temporary during the run. I'd guess there was some slack in the material, it cut the centre of those problem letters, flattened out and cut the rest skewed slightly from the centres of those letters.