Here is the wedge gizzy I use. I saw something similar on another thread. Great minds think alike. Quick and easy to make. I used a scarp piece of nylon and some 1/16" dia. nickel silver pins. Drill the holes a few thousands undersize and hammer the pins in place. Once they are in place hold the gizzy against the disk sander to reduce the length. The pins in my wedges are always 1/8" back from the edge so that is the distance between the pins. Take your wedge material measure back 1/8" inch and drill a hole. Drop it on the gizzy and hold it against the sanding disk. It's easy to sand on an angle to get the wedge shape. Do one side flip it over and do the other. Take a few cuts and sort of sneak up on it. It doesn't get much simpler. The last photo is a completed and installed horn wedge.
Your welcome...
I posted it in butchered blade some time back, for those that dont have a belt sander.
Mine was made to make large and small single pin wedges and double pin wedges.