Here's a little video on how to sharpen your knives and plates for your grinder.
Many years ago I was at Michlitch Spokane Spice Company picking up some supplies. A couple of guys came in with their dad's grinder plates and knives and asked how much to sharpen them, I can't recall but it was ridiculous and they said they couldn't afford that.
So I followed them outside and told them to get a piece of glass plate about 1/4" thick and to use the sandpaper. They didn't think that it would work and I said trust me. I gave them my phone number and to try it and to call me with the results. They called a few days later and couldn't believe how easy it was.
Anyway, I hope this will help some of the guys out there. It's got a bit of B.S. in it but it's good information.
Enjoy!
https://www.youtube.com/watch?v=xp7UKCMrv-o