Roller Peels up vinyl while cutting

[cdavis 0]

Hi

I have had this cutter MH-MK2-28" for about 2 months.  Initially, this unit worked fine. While cutting some letters (which I had cut before) today, the roller started to grab and roll up the vinyl on it while cutting.  It then caused the roll to stop rolling and basically fouled up the last cut as the material did not roll any more.   I live in a dry environment, so could it be static on the rollers from movement lifting the material off the backing? I guess I could try to set the rollers to predict where it might pick up a thin point of the cut, but I believe you should not have to do that as it would be trial and error, wasting material to get it set.  Material being cut-Oracal 751C.

My blade set up from the start: I have the blade depth set to cut the material without cutting into the backing, cutting the material by hand before I put the blade holder on the machine.  Once on the machine, I had to set the pressure up to 290 to get it to cut through the vinyl with a light scoring on the backing.  I had to get that high with the pressure,  as the blade was not cutting through on some lines of the cutting run while I was testing it during set it up.  At 290, it just cuts through the vinyl with a light scoring of the backing.  

Thank in advance for the help.

Chris

[Dakotagrafx 7,297]

you must be using 3 rollers?  with 2 a roller wouldn't be near there.  see if the rubber roller has any adhesive on it

[haumana 1,220]

check the quality of your offset, to make sure that it's not causing any tails that are lifting off the backing when it's cutting.

check your pinch rollers, if they happen to be extra sticky or something.

if you have 3 rollers, you can scoot one to the side and just not use it (unless your vinyl is tenting in the middle), then just use 2 pinch rollers - equal distance from the edge of your vinyl - about an inch to an inch and half from the edge.

[cdavis 0]

Hi

I checked the rollers for adhesive and they are good.  I like the suggestion for moving 1 roller off, it is the center roller doing it.  I thought it was needed since the job is 24" across.

Haumana, please educate me on the quality of offset and how to properly set it.  I set it at .25 mm as recommended for the 45' blade, but it does seem at the tight corners (V shaped) like at the "Y" in the photo and the "N" (also in the photo) the part to be weeded looks crinkled up.  Would a different offset help that?   and if so, what direction should I try.

Thanks for the help.

Chris

[haumana 1,220]

Off set can/will vary from machine to machine - It takes a little time to find the 'sweet spot.'   Sometimes if the offset is too high, then it creates these little tags at the close of the cut, and that can stick out once in a while, which the blade holder and/or pinch roller can potentially pick up.

Make sure your blade holder is clean, inside and out. If there is any debris in the shaft where the blade goes it, it could cause the blade not to turn as easily, and that could cause a rough cut or not cut at all - depending if the blade was able to turn or not. The outside of the blade holder would mostly be where the blade pokes out of the shaft. I often times get tiny bits of vinyl that sticks to it, that could also possible cause some lifting on the edge of a rough cut.

If the 24" is lifting in the center, then you will have not choice but to use the 3rd roller, but if you can run the job with just the 2, then that's the way to go.

Practice, practice, practice

[cdavis 0]

Thanks Haumana, very helpful information.

[darcshadow 1,626]

If you look closely at other points/corners on your cut are they lifted? My guess would be the point of that A was lifted enough that the sticky side was exposed and it stuck to the roller.

Not having the correct blade depth can cause the vinyl to lift. 

[cdavis 0]

Darcshadow-Yes, those corners seem to be slightly crumpled as a result of the cut.

Also, as I am in the learning phase of vinyl cutting, is it when the blade cuts too deep that it can lift the vinyl too?

Thanks

[haumana 1,220]

Cutting too deep could be a function of too much blade exposure and/or too much force.

Dial in the right amount of blade depth first and foremost, then move on to force.

Ideally, you want the blade to cut through the vinyl and adhesive, but not into the backing. It is okay if the backing has slight indentation, but not if it's been cut into.