http://www.forrestrace.com/standard-grinder-3/

Knife sharpening on a standard Bench Grinder?
I would like to start grinding knives to earn a bit extra money. Being a former abattior worker I have experience in it but don’t know whether I can adapt a standard 205mm Bench Grinder to do a good job. The wheel we used at work ran backwards and was approximately 400mm diam. Anyone able to help?
Sharpening? On a bench grinder?
They make cardboard wheels for bench grinders just for that purpose.
But the knives were no sharper than what I can do with a soft arkansas stone, a ceramic rod, and leather.
Several links to paper wheels for bench grinder sharpening googled up. Below is one.
http://users.ameritech.net/knives/paper.htm
Model 555 SRI Spin & Relief Reel Grinder