I read an interview with David Chandler in THUMBzine, in which he mentioned having discovered the ideal length of tape to make loop cassettes. I emailed him, and here's the info he kindly provided me with!back to the cementimental indexI reproduce it here for the edification of all, so get looping!
UPDATE 26 Nov 2014: Zalhietzli on the Maniacs Only forum was kind enough to diagram some alternate designs for a loop cassette, using extra capstains stuck in weird places:
Hey, I looked at the numbers: they are 235mm and 372mm. The longer one is tricky to figure out the way to thread it: you have to make the top of the loop go under one of the reels and then over and the loop goes around the other reel if that makes sense.... kind of a pulley-looking threading... one of the reels is just a corner around which both sides of the loop come together and over to actually loop around the other reel, er.... maybe I can draw it
_______ /____ \ //O \ O | || \_/ / \________ o___________o ^ <head>that is the longer one, the shorter one just goes up and around the reels, snug...David