Larry,
I use the Oneway Wolverine system which is similar.
I made some sizing "blocks" from 3/4 inch MDF. They are for the common angles of 40, 45 and 50 degrees. The blocks allow you to be the same distance away as the wheel wears.
40 degree is 5 1/2 inchs wide
45 degree is 5 3/4 inchs wide
50 degree is 6 1/4 inchs wide
The correct block sets the pocket distance from the wheel. You put your bowl gouge in the fingernail jig and allow the tip to stick out 2 inchs. Each time you sharpen, do 2 inchs out. You can drill a hole in a scrap to get this each time. Set the leg to 23 degrees.
Wear a full mask face shield. Two worst times are start-up and shut down for wheel to destabilize and fracture violently...
The jig is held, not the handle. The jig puts you in the correct orientation, you must guide it. Less time on the tip, as it's the thinnest part. Do one side, then the other, then a pass all the way around to blend it together. Do Not keep going all the way around every time or you will have a bird beak. Oh! Those pretty sparks are tool steel you'll never use, so a very gentle hand. Just a real light kiss... Pressure is bad...
Of Course this is all easy if you have a friend nearby who can show you. Otherwise, take it easy and be safe.
