Anyone make a jig to sharpen Turbo Till blades on a bench? How many times can they be sharpened before they should be replaced? (I'm sure it says in the manual).

Couple months ago I bought some used turbo blades at an auction. They are not worn out by any means. Still have the original cutting edge, just dull.

The blades currently on our Turbo are about the same size and dullness. They have been sharpened once and probably have another season or 2 left before they need replaced. Figured I would sharpen the blades I bought and swap them out.

If that doesn't work the neighbor wants to buy them and build one of those disc conversions that don't work.