A TRACKING SOLAR CONCENTRATOR
THE HUB - FABRICATION continued
Burn a hole through it for the one-inch rod (109) as shown in Figure 13 and Figure 14 Work on a flat surface and be precise about positioning the three pieces. Both ends of the rod should be the same distance above your work surface and it should be dead center in the wheel and pipe piece while not interfering with access to the lug nuts. When you've tacked it and are sure of the quality, weld the three pieces (107), (108) & (109) together. Finally, burn the rod out of the center of the pipe piece so the hub (106) can fit through. This procedure assures that the two pieces of shaft are properly aligned with each other.
Mount the spindle (104), positioning it so that when all parts are assembled the one inch shaft (109) when held in a horizontal position is directly above the center of the plate (101). This is not important for tracking purposes but will reduce the stresses on you support structure by causing the center of gravity of the array to fall in its center. Also, in positioning the spindle, you may have to space it on washers or shims so that the drum will be in position for the chain drive per Figure 14.
Make up the four bushings (110) approximately two inchs long from nominal one inch black pipe. Drill and tap two of them for a couple of 3/8" set screws. Weld the other two into the bearing plates (008) on your mirror array using the newly made wheel and shaft assembly to align and position them. You'll notice the bearing plates (008) seem to be rather non-rigid due to flex in the array. Don't be alarmed, the tail assembly will fix this.
