I'd look at www.GolfSmith.com and look in their clubemaking section and search on "carbon shafts" They have them in both 0.335" and 0.370" tip diamaters and 0.575", 0.600" and 0.605" butt diamaters. I'm thinking with one of each cut in the right places you could make them "nest" together. I'm guessing that your student is attempting to make a club similar to the Divinick, http://www.divnickgolf.com/telescopic/index.html.

I would think that by using existing carbon shafts from almost any application, golf or otherwise, the finished product would not have any desireable "feel" to it as the flex, kickpoint and general frequency of the shaft.

Just my thoughts,

Rich