There are many different methods that woodworkers use to sharpen their blades. I happen to like the use of sandpaper with a jig, which gives me good results. I already had the granite slab and the sandpaper because I use them to sharpen my jointer blades, with a different jig that I made.
I sized the width at least 6” between the wheels, so that it’s wide enough to easily straddle the 4 ½” wide self-adhesive sandpaper that I use.
To make the jig frame, I glued the sides to the back with a half lap joint. I used a long ¼” screw through the entire width of the frame, to tighten the pivot board to the correct angle, needed for sharpening.
My chisels all have the same angle on the blade. So when I drilled and tapped the holes for the chisels, in the ½” aluminum square bar, I drilled the holes at the same angle that the bar would be at.
For the screw holes for the flat chisel blades, those holes were drilled straight into the bar.
The “training wheels” on this jig are 7/8” shower door wheels. I drilled and tapped the wood for the 8-32 screw that fits the wheel.
To sharpen the blades, I’ve been using 100, 180, 320 grit and 50 micron sandpaper. (see JOINTER BLADE SHARPENER JIG)