2.7. Constructing the Base

Pass the shaft of the handle (j) through the handle (i) and glue it into the hole in the pulley (h). Be careful not to get glue on the handle or it won't turn. I apply the glue to the hole with a paper clip and then push the shaft into the hole.

Pass the bolt (k) through the pulley and washer (l) into the threaded hole in the base (m). The washer goes between the pulley and the base. Tighten the bolt until the pulley is snug but turns freely.

Place an end of the main axle (d) into the main bearing (n). Use a hammer to lightly force the axle into the bearing. The fit should be tight enough that no glue is needed. Place the bearing into the hole at the center of the base. Slip the belt (o) over the axle. When the Dirod is not in use, the belt should be left in this position so it doesn't stretch. When you want to run the Dirod, slip the belt over the pulley.

Then glue the legs (p) into the holes at the corners of the base. Slip the neutral support (e), foil side down, over two of the legs (p) as shown. The leg holes on the neutral support may be tight, so insert the legs gently to avoid cracking the neutral support. If the legs are too tight, you can lightly sand them until they fit snugly. Place all four legs in the holes in the base, passing the main axle through the hole in the neutral support. Then force the disk, rods on top, onto the main axle. The axle should project above the disk about 3/8 inch, placing it just above the tops of the rods. Slip the belt around the pulley and turn it to check that the disk runs true. If not, make slight adjustments to the disk until it does. Adjust the neutral support so that the brushes contact each rod as the disk turns. When the disk runs true and each rod touches each neutral brush, glue the legs to the base, the neutral support to the legs, and the disk to the main axle.

Place a socket (q) at the top of each leg. Do not glue it. The socket will be glued to the corona shield but not the leg. The friction fit it provides will securely attach the corona shield to the legs, but will allow the shield to be removed should the need arise. Place (don't glue) the corona shield (r) on top of the sockets and check that the main axle clears it. If not, either hammer the axle further into the bearing, or file the top of the axle until it does. At this point, the disk should be turning freely, running true, not hitting either the corona shield or the neutral support, and the neutral brushes should contact each rod as it passes. The main axle should not touch the corona shield. When all is running true, remove the corona shield, glue the neutral support to the legs and the disk to the main axle. Let the glue dry overnight before proceeding.