When I put in a new blade and then run over a pin and nick it. Oh yes, I have done this. I save the old blades and put them into an old cutter and use on paper.
Seriously, when I can't cut through 4 layers comfortably, that is when I replace. I've noticed since I now use the Martelli Ergo, I do not replace blades nearly as often, I think it has to do with the angle I use when cutting. With the straight cutters, I always seem to catch the blade on the ruler edge. I know I am weird. grin

LOL....I do the same thing!!!!

I resharpen mine too. I usually change them when start skipping. I seem to go thru quickly with paperpiecing, it dulls them a little quicker. When I purchase them it is usually when they are 40 or 50% off. But am so happy and Thanks you to the person that recommended the carpet Rotary blades. Mine came yesterday and they fit the Olfa Wonderfully.
Judy

Two things that are hard on rotary cutters, paper and polyester fleece and other synthetics. I try to remember to replace the blade if I have been cutting fleece. I use fleece for some of my quilt backings and find when I cut the cotton it makes a mess; skips, rolls the fabric along. Change often in that case.

When my blade becomes dull I sharpen it with a rotary sharpener. Love my sharpener. I have not purchased blades in at least 4 years, in fact it's probably longer then that since I am still using the ones that came with the cutter. I do a lot of cutting of batting and trimming quilts and have cut maybe 6 full to queen size tops out. The trick to using the sharpener is to always turn the sharpener clockwise as I'm sharpening the blade. (Trick my father always used when sharpening his knives, axes, etc.)

The little blue sharpener I bought did not work very well. My son even sharpened a few blades for me, then said this thing is a waste of money. Now I go to Harbpr Freight Tools and buy 100 in a box for 15.00. They are called "carpet cutter" replacement blades and fit my 45mm rotary cutter. (They do not fit the 65mm). Now I change blades more often and end up with less frustration over skips!

When my blade starts getting dull, I turn it over and add a drop of oil. A tip I read on this board. Also I clean the built up of lint brushed out. I had a sharpner and was not pleased with it. Even had DH sharpen the blades and was still not please. Has anyone ever set them out to be sharpen? I used to see ads for that service it the quilting mags.

Just watch Harbor Freight for quality. My husband used to buy a lot of his tools, etc. from them and found sometimes they weren't first quality. He got a bunch of screws and half of them weren't usable do to bad threading. I guess you get what you pay for.

My husband use to purchase tools from them too and the 2 he bought were sub-standard. However, these blades are not actually made by them, they just sell them. They can also be purchased at a local hardware store here in our town. Same blades. I have never had any trouble with them at all and I am about half way through the box!

I ordered one from Nancy's Notions and I haven't had any luck sharpening blades.