Are there ever used grinders for sale? Where does one find them?

bladeforums.com

Good place to start.

One of our members here who is a very accomplished knife maker built his own and had his brother weld it up for him. You might look into doing the same. You can download a set of plans for the exact model for around $20.00. The place that sells those plans is USA Knifemaker.

Try and find a motor locally as shipping costs are high for heavy motors. You need a TEFC motor that is at least 1.5 horsepower, and 2 horsepower would be better yet. Look on Ebay for good deals on larger contact wheels, but understand that wherever you buy one its not going to be cheap, even if its used.