Bob - probably because that's what it is

The Joy Stick was a Noel Rozelle design and produced in three sizes for 0.049, 0.25 and 0.60 engines. He called them Joy Stick, Super Joy Stick & Super Duper Joy Stick respectively.

The 0.049 version was published in the April 1975 issue of RCM and the 0.60 one in the February 1981 issue. They may have also been produced as kits - I don't know.

These shots are the 0.60 & 0.049 versions.

Ray