I tried one, the Joint Jigger. But i found the slop in the spindle's bushing and the tube clamp's small contact made for wondering angles. My jigger was also not centered. I shimmed the bushing to get better on center but still dislaiked the tube clamp. I see that Stan uses a reinforcing sleeve on the tube. I still have mine although I've not used it in a long while. It was faster then mitering on my 6" Atlas lathe but with more chudder and tooth catching potential.

The only machine mitering that I've used that was really nice was Doug Fattic's mounted on his Bridgeport mill. It uses a collet to hold the tube and is VERY rigid. Andy.