Art's health has been up and down over the last few years. He is home now after a recent stay in a rehab facility and Geoffrey, the original poster in this thread, has been working with and helping Art for years.
Art was a world class competitor for many years. In addition to inventing the fin jig Art also produced an engine testing stand which I believe is what the NAR still uses to certify motors. My understanding is that the Bulgarians as well will be using an Art Rose stand to test the motors of every team at this summer's World Championships. Art was also a pioneer in competition motor development where he was assisted by Estes and others in producing special motors for the World Championships.
As for the fin jig itself, it is simply the finest piece of rocketry equipment you can buy. It's designed to deliver world class precision to people who want to compete at a world class level. It is completely unnecessary for sport rockets. Five out of the six current Junior and Senior members of the U.S. Spacemodeling Altitude team use an Art Rose Fin Jig (one even has a left-handed version of the jig). The sixth may also use a Rose fin jig, I just don't know.
Art Rose's contribution to model rocketry has been truly incredible and his fin jig is just magnificent.
Steve
Photos below are of my daughter using a Rose Fin Jig at NARAM 55 (where she did pretty well :wink
and of Art Rose at the 1990 World Championships in the Ukraine (where he did pretty well :smile
.