Guess I will have to go and do one Gadge, I have done a lot of them and everyone works perfectly, I will take some pics as I go.I use a half round file so that it gives a slight leading edge for the pawls to slip into. Probably would work ok with a square edge file but I haven't tried it. The half round gives me a square edge for the pawl to hit against. As I said I have not had one that didn't work perfectly every time. The slots I'm cutting are probably less than half a mm deep
