MORE force needed with a brand new blade

Not familiar with your plotter, but they all have the same issues..
Is your blade holder tight in the machine?
Is your cutting strip, tore up?
Same brand & degree of blade?
Could have the blade been dropped and chipped the edge?

 

Did you set the blade exposure to be the same as previous? if the blade isn't as far out as before it will take more "force" to cut than previous but its just a reduced blade depth.

 

Like others have said. Make sure the blade holder is tight. Manually adjust the amount of the blade that comes out of the holder. If alot of the blade is exposed you can have very minimal force... not enough blade exposure and you have to set the force high.

 

Sounds like a cutting strip issue to me. You even wrote that you are cutting hard enough to cut through the backing paper. Which means you are cutting into the strip at that point. Maybe your strip just needs to be switched. We run our blades all day everyday cutting all sorts of materials. We replace the blade maybe every 6 months. You might have your blade out to far. My vinyl is always at a 17-18 pressure.

 

Like Big Easy above, we cut vinyl (single layer) at 17-18 and laminated at 24-25 on our FC8600.
I too think that the blade might have been out too far before changing it to the new one.

 

Might also check to see if your carriage is still tight on the track it slides across.
If it is loose it would cause cutting issues.

 

as long time graphtec user have 4 on site i have found around 14 -15 brand new then settles about 17 for months to come for polymeric 3 less for cast. i gave up with oe blades years ago after a couple of iffy ones i can accept a 1 in 10 iffy one when they are really cheap but not at oe prices.

 

Have you tried another blade? I've had them blunt straight out of a new box. It was genuine Summa.

 

Did you keep the old blade? If so put it back in and see if you can turn the fore back down to 13. That should give you a better idea if it's the blade or something on the cutter. Also, you had said that when increasing the pressure over time with the old blade you started cutting through the paper. If that is the case your cutting strip is probably compromised. Even if you can't really see a cut it could be there and opening a little under the pressure of the blade and effecting the cut.

 

Off topic, but what does everyone use as a guide to setting the blade?
I have always used the visualization of the blade sticking out the thickness of 5-7 sheets of notebook paper.

 

I just eyeball it

 

That seems thick to me. We move to where the blade is basically flush with the holder. If you rub your finger it will change the direction of the blade but it will not cut you. You can barely feel it. I'm thinking more 1 sheet of paper. 7 sheets of paper feels like a bump when you put them on top of the table. A lot of this also depends on your cutting strip.

 

Always found this weird with cutters. Surely there should just be a way to set them all exactly the same. So if I take one out, the new one I put in is the exact same but a bit sharper

 

On a Graphtec the manual says to set the blade flush with the holder and then turn the screw handle a certain number of marks, with each mark a mil.

 

As far as the cut off blade, mine gets loose all the time, I just tighten the thumb screw back up when I start hearing it clack.
On the blade itself, is the ring around the knife holder slipped under the finger of the blade clamp? I had a guy who could never remember to back that screw out enough to get the lip under the holder after swapping the pen out, so he'd run some vinyl and most of it would not weed, all to realize the knife holder had been pushed up while cutting. and it always happened on a 10' run of 48" 3m translucent! It makes me sick to think about throwing that away.
But we run ours at 17 for cast vinyl, ~24 for laminated stuff, and brushed aluminum vinyl always cuts like garbage, through the paper every 15".