Whenever there are strongly curved knives, whether convex or concave, you have to come up with some kind of solution to sharpen the knives.

attached you can see a video in which Hans-Heiner tested the prototypes.

Here is an alternative that should solve these problems.

Set consists of 2 wheels with a radius

The dimensions are

250×30 mm

Bore 12mm (Tormek)

For these wheels you need a spacer for serrated or leather wheels. (in the store)