The Cobra magbot pendulum Started building a new magbot pendulum after my attempt to make a magbot spinner failed. Parts that will be used for the stand: -wooden base (from an old amplifier) -copper pipe -brass fittings Parts used for the electronic circuit: -coil(from a VCR) -3300 uF and 1000uF cap -100K resistors -pn2222n and 2n3906 transistor -red LED -4100 type diode -solar cell Step 1: I built the circuit according to the picture(a very good description in the junkbots book,so no need for me to repeat that here). Normally I would test it first on the breadboard but in this case I took the chance that it would work,and it did.The coil was not soldered on yet. Step 2: I started soldering the pieces of copper pipe and brass fittings together to form the stand. Step 3: I Prepared the wooden base for the copper pipe.There was already one hole in the piece of wood but this was too big for the 12 mm pipe so I had to use a brass socket.Then I drilled the other hole with a flat wood bit.Between these holes I drilled a 22mm,shallower,hole for the coil to fit in so it is flush with the surface of the wood.I then drilled two small holes inside this hole for the ends of the coil to go through(these will run on the underside of the base to the rest of the circuit which will be housed inside an alumin(i)um box.
Step 4: The electronic circuit is housed in an aluminium case out of an old radio. I riveted a piece of copper and brass sheet metal on this to keep the co-bra theme going.A hole was drilled for the LED to go through,then the solar cell glued on top.A big brass screw was then used to fix the housing on the stand.
Step5: The pendulum was made from a piece of metal wire out of an old radio and two brass parts, super glued together.