Help! Problems with Rotary Cutter!
 

I've been using a Martelli rotary cutter for about a year now, been very satisfied with its performance and less fatigue in my hands and wrists. The last couple days, however, I've been having problems when I try to cut on a diagonal -- it's like the blade stops turning, the fabric develops wrinkles in front of the blade and if I continue with the cut it's very jagged. Of course I need to be making diagonal cuts right now for a large set of swap blocks due July 10.

I'm not having this problem with straight cuts; only diagonal ones. I changed the blade about a week ago so it should not be dull.

Any ideas what my problem could be?
Donna D., Hemet, CA

The blades are very thin and come with oil on them that can make them stick together. Could you have perhaps put two on by mistake? That's a common problem with that.

Thanks, Becky, I did think of that (have done it in the past) but I'm pretty sure I've only got one blade in there. A sure tip-off you've got two blades is a tiny little "sliver" of fabric every time you cut, and I'm not getting that.

I would try loosening the screw slightly. Also, starching the fabric helps with diagonal cuts.

Check to make sure you don't have a buildup of lint and fuzz around the screw and washer. I also agree with Prism99, try loosening the screw a little.

Could you have a wonky blade. I got one once. It was out of round.

A blade can be ruined in a blink of an eye ... hit a pin, run into the plastic ruler, etc.
So being a week old, yes it could be ruined.

By chance did you reassemble your rotary cutter wrong?

You said something that gives me a clue - it doesn't happen when you make straight cuts. I don't think it's the blade, I think it's the fabric. You are cutting it on the diagonal, which means bias and stretch. Are you using a ruler? I would make sure you cut only one layer at a time, hold the fabric down with a ruler, and cut slowly.

Also check the board condition... If you normally use the marks on your board to measure and cut you can develop straight ridges and then when going across the borad you could effectively be cutting over a few mountain ranges.

If that isn't the issue, try weighting down the other side of the fabric with a second ruler leaving yourself a channel to cut aling the edge of your main ruler with a second one a few 8ths away to hold the fabric down.

I have found that I have to use certain blades in my Martelli. If I put the Olfa blades in it, it wobbles. If I put Fiskar blades--it works fine. Olfa blades have little Mickey Mouse ears around the center hole & the Martelli/Fiskar blades are simply round. I have also managed to crack a blade and it would push the fabric & simply stop before I discovered it was cracked.