Graphtec FC7000 MK-2-75 Cutting pressure issue.

[rebelkustoms]

I have a Graphtec FC7000 that has been having a cutting issue lately. It either does not cut well enough to weed easily or it scores the paper causing it to tear off the top layer of backing paper and leave it behind on the letter. I put a fresh blade in a few months ago when i began having the issue, but it still happens. I am doing test cut 2 and adjusting pressure accordingly with each roll change. Any thoughts would be greatly appreciated, this is driving me nuts and dragging down production time. Thanks in advance for your help.
-Tom

 

[bob]

I have a Graphtec FC7000 that has been having a cutting issue lately. It either does not cut well enough to weed easily or it scores the paper causing it to tear off the top layer of backing paper and leave it behind on the letter. I put a fresh blade in a few months ago when i began having the issue, but it still happens. I am doing test cut 2 and adjusting pressure accordingly with each roll change. Any thoughts would be greatly appreciated, this is driving me nuts and dragging down production time. Thanks in advance for your help.
-Tom

Either turn down the pressure or back the blade into the holder a bit. Or some combination.

Note that, at least with the FC-7000, the pressure number is just a number and the only meaning you can ascirbe to it is that the smaller the number the less the pressure and the larger the number the greater the pressure. The actual number doesn't stand for anything other than a point on a non-linear [an exponential curve it would seem but not sure] line from 1 to 45 or wherever. This information was beaten out of a Graphtec engineering weenie after he spent some time hemming and hawing. Way back when you could actually get in touch with them.

 

[rebelkustoms]

I get that bob, thanks for the reply also. I have been through a few machines and I understand mechanically that when you set the blade there is an infinite number of factors like offset and blade depth in the holder that make that cut pressure number just a bookmark, not really a "pressure" per say. Problem is when I turn down 1 step, doesnt weed worth a crap, turn up 1 step, scores the paper and it tears when peeling the backing paper. I am wondering if maybe I need to do a new protection strip? also had my former partner tell me the other day his graphtec had a slurry of cutting problems until he bought a certified graphtec blade, not one of the knockoffs sold by my distributor. Still just checking out my options seeing if anyone has had a similar problem.

 

[bob]

I get that bob, thanks for the reply also. I have been through a few machines and I understand mechanically that when you set the blade there is an infinite number of factors like offset and blade depth in the holder that make that cut pressure number just a bookmark, not really a "pressure" per say. Problem is when I turn down 1 step, doesnt weed worth a crap, turn up 1 step, scores the paper and it tears when peeling the backing paper. I am wondering if maybe I need to do a new protection strip? also had my former partner tell me the other day his graphtec had a slurry of cutting problems until he bought a certified graphtec blade, not one of the knockoffs sold by my distributor. Still just checking out my options seeing if anyone has had a similar problem.

Where to begin...First offset will only affect those points on the cut where the blade must turn. If the offset isn't correct then these points will be either over or under cut, not a smooth transition form one tangent to the next. Offset is nothing more than the distance from the tip of the bade to its axis of rotation and once set, is set and never changes for a particular blade diameter.

Next, typically if your cutting strip were worn you'd expect incomplete cuts, not cutting too deeply.

Lastly, that one pressure setting doesn't weed [which one might assume would be from incomplete cutting] and one step up cuts through the backing there are a couple of things to consider. First being, wait for it, remove the dust cover from your tool carriage and blow the dust and crud out of the blade positions tackle paying particular attention to the blade up/down mechanism. The lubricate the tiny ball bearings in the blade holder with a bit of silicone grease on the end of a toothpick. If this doesn't mitigate your problem then the hyper-sensitivity of the pressure setting would suggest that either the blade exposure or the pressure range or both are wildly wrong. Understanding a little just how this particular plotter works when it comes to blade pressure, it might indicate too much blade exposure and a laminate that's tougher than the vinyl beneath it. This would cause the plotter to finally have enough pressure to punch through the laminate then the excessive blade exposure would drive it though the vinyl and into the backing. Just a theory but it fits the data. If this is the case then you're going to have to walk a delicate balance between pressure and blade exposure with this vinyl/laminate combination to get it to cut properly.

 

[BIG EASY DOES IT]

If you are getting varying results across the width of your material. Cutting strip.

 

[woolly]

Next to the coil actuator is a small encoder strip that measures the depth and keeps it constant dust on this strip will give you as described. Also why a dead flat cutting strip is very important any worn areas will give a light cut. As suggested in previous post