One day I really hope to own an awesome belt grinder but, until that day, I’m using files, a jig, and a shed-load of elbow grease. The jig I have made is 100% inspired by the fantastic work and knowledge sharing of Aaron Gough (Gough Custom Knives). I take no credit for the basic concept of the jig albeit I have worked my own variation on the Gough jig.
The principle is that I start grinding with the file rod positioned in the top file guide hole and file until I reach just off the blade centre line; once reached I move down a hole and repeat. As I progress down the file guide holes the bevel angle becomes shallower and the primary bevel pushes up towards the spine.