Broken rod for the pendulum counter weight
  • One of the rods for the pendulum counter weight broke when I tried to flatten the end with a hammer. The inner diameter of the tube was too wide for the rod (or the rod was too thin for the tube), even though I hadn't thinned the rod at all, not even polished it. The tube slipped on to the rod with not resistance at all. So I followed the advice on page 43 of the instructions, where it says: "..., then with a hammer slightly flatten the end." Since the rod was so thin, I had to strike hard several times with the hammer in order to make the end of the rod thicker, and then suddenly the end broke off. So now the rod that should be 55mm is only 50mm long. And I have no spare rods.
    My questions:
    - Should the inner diameter of the tube really be so wide that it easily slips on and off the rod?
    - Will a 50mm rod be long enough, or must I get hold of a new rod?
    - If it must be 55mm, can you (Dave) send me a new rod?
    - I dare not try to flatten the end of the other rod to make it thicker, so can the tube instead be glued to the rod with epoxy or some other glue? Or maybe I can squeeze it thicker in a vise (Schraubstock)?
  • The brass rods are not precision products, so you could have a tight fit as well as a loose fit, depends on the tolerances.
    The point of the counter weight is to keep the pendulum perpendicular, 55 mm is a starting point but you will probably find it will be shorter, but you will first find out when you balance the pendula.
    Of course the 8/4 can also be glued onto the rod.
  • I said I didn't dare to flatten the other rod with a hammer, but now I did it anyway, and it went well. So I will do it with what is left of the first one too. If it proves to be too short, I can just insert a short piece (5 mm) of a rod into the slot first.