lightly used 2 year old Graphtech 8600 inconsistent

[SfSD]

I have a digital print and cut that is causing me some problems. I have an inconsistent cut. That is parts are cut correctly and other parts are path-ed correctly, but do not cut through. It is like the bad parts are scratched in the right path, but not cut.

I thought it was the right side, but it tends to float around, sometimes it is in the middle and the 2 sides are ok, sometimes it is a word or part of a word. Always, a large part is cut correctly and all path-ed correctly, but some is not cut through – it is scratched where there should be a cut If I increase the pressure, I can cut right through the release liner in parts, and still have the problem in other parts.

I guess the knife is not cutting, so it must be “floating” on the surface. (Bad down force?)

It is a run of the mill job, graphics on a van. The material is Arlon 4500 LX with a matching laminate. The letters are a little bigger than 2” (Nothing special in the materials, colors or designs). The file driving the work might have a problem, but I can not find any issue. The letters on the right, left, top and bottom and pretty much the same (left and right panels of the van say the same thing)

I have switched blades a couple of times and am using a 60 degree new blade. I have adjusted the down force and can cut right through the material. So I seem to have down force, speed and depth of cut control.

Any ideas or areas I have not checked?????

 

[GAC05]

I only know the basics.
I'd check the tool holder - make sure there is no vinyl stuck to the bottom or up in the hole the blade sticks out of.
Check to see that the blade swivels smoothly - small drop of light machine oil in the hole.
Check to make sure the holder is not worn out (not likely on a 2yr old machine unless you have been cutting reflective, paint mask or thick ATV vinyl/laminate).
If it all looks good take a look at the cutting strip to see if it has been scored or grooved by the knife.
If that all looks good you could try cleaning the rails the carriage rides on.
If you don't run into any problems with all that set up a basic cut file and test the cut with some simple squares and circles that repeat all the way across cutting width to see if it might be a problem with the original cut file.
With the material you are cutting I think I would be using a standard 45 deg blade over the 60.

wayne k
guam usa

 

[Dennis422]

Something must be loose on your blade holder.
Also, see if your cutter is on the flat floor.

But I think that there must be something loose or stuck in or on blade holder.

 

[BIG EASY DOES IT]

Do all your pinch rollers have the same down force on the back? If one of them got knocked up or down it could be getting messed up this way. I would be more inclined to leans towards the broken cutting strip especially if you have been testing cutting all the way through the material. We try to do all our tests on the very right edge so if we do go through to the strip it is not in an area where we normally cut.