C&P Cutter Keeps Angling Paper
I recently bought a 23” C&P manual cutter. I’m currently cutting a job that is on 220# Lettra. Every time I cut they come out angled and messes up my stack and comes out wonky.
I just bought a new blade and I’ve had it clamped down tight. When I cut, the back stack come outs out great where it meets the blade, nice and straight, but the front stack keeps angling. I especially can’t do more than 3 sheets of paper at a time or the difference from the bottom paper is super extreme from the top paper.
The only thing I can think of is the blade angle is wrong or I’m not strong/fast enough for the manual cutter. I have noticed that the paper angles with the angle of the blade (see photos), that’s why I figured the blade angle is too obtuse. If this is the case, is there something I can do to fix that? Please let me know your thoughts and suggestions. Thanks in advance!
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It looks to be that your cutter is doing just exactly what it should do.
The paper under the clamp is the finished size paper. The paper in front of the blade is the scrap. It may be that it is a large scrap and is used again for another cut piece.
The blade is not like a kitchen knife nor is it like a shear. It is made and sharpened at that angle for a purpose. As the back or straight side of the blade makes the proper cut, the front side pushes the paper away. If your blade is set square in the cutter, is sharp, and the clamp is down tight, you will get a square cut.
Jog your scrap (front stack) and see if it is square. It should be.
Lettra is a soft paper and you cannot cut a large stack satisfactorily. With a good sharp blade and tightly clamped,
you should be able to do 25-50 sheets.
Remember to never try to get a finished cut from the paper in front of the blade.
There are a couple things that could also cause the lettra you are trimming even behind the knife to kind of angle forward too. In front of the knife, I agree with inky. But you can see pile tilt even with a sharp blade and a pretty strong clamp.
It isn’t a common practice amongst people with manual cutters, but you can’t expect a finished edge without doing a rough cut and then finish cut. I can’t completely explain why but the case is made that when running thick stock like lettra or 4 ply museum board etc through a guillotine, the pile will usually pull forward if you’re cutting more than around 1/2” or so off.
So you could use a 2 part cut to get around this-
The rough cut splits apart pieces, and then the finish cut takes off just a little bit more and should be over the crop marks or to the final desired dimension.
You lose a little paper but it’s worth it to have a better edge, even behind the knife.
If you want to test this theory, split apart a bunch of sheets the way you already have, and then take a couple out of the pile, then move the back gauge forward about 1/16-1/32”. Enough to just shave a bit more off.
Re-clamp and cut. Then take a couple pieces out and compare the rough cut edge to the shave cut edge.
Its a little distinction but an important one if you want to do fine work with a cutter; laying out and planning the jobs that are to come out of sheets and/or planning the layout of a series of cuts should add at least 1/8-3/16” between pieces, for this reason, and allow you to shave both sides of a cut from the pieces split out.
Good luck with your cutting.
Inky – thanks for letting me know this. I’ve already got a job printed with prints 6 up on a sheet, so both sides need to be accurate. I’ll just have to get it finished somewhere else.
Haven – thanks for those numbers, I’ll definitely keep that in mind for future cuts.