For what its worth I had the O'Donnel jig set up on a six inch grinder and also a Tru-Grind jig set up on a 8 inch Record Power grinder both fitted with whith white wheels, and still struggled to replicate my sharpening angles every time. I took the plunge invested in the Robert Sorby Pro-edge. Absolutley worth every penny to me, my turning has improved, less time spent sharpening tools and the tools are so much sharper than before and replicating angles is so easy. In hindsight I wish Id bought one first instead of the other two jigs and grinders which are now standing redundant in the corner of my shed.