I own the TimberTuff chainsaw chain sharpener that I picked up at Blain's Farm & Fleet. Works great. Others have compared it to the Northern Industrial Bench- or Wall-Mount Chain Grinder. I must say it looks identical. I paid $109.99 for the TimberTuff, saving $30. The Northern Industrial model, right now, is on sale for $89.99. I just wanted to pass this on to anyone in the forums who might be looking for a new chain grinder.
http://www.northerntool.com/shop/tools/product_200327449_200327449
http://www.northerntool.com/shop/tools/product_200327449_200327449