My experimental carrier for an Agni, in the photo attached.
This was made from copper water pipes, bent to shape and hard wired to the bus bars, the purpose is dual, one to take current to the tip of the brush and secondly to cool the whole system, as a heatsink. The brushes are PMG 132 , which offer greater contact area than a rectangular brush does, these match the commutator better and are physically stronger and slower wearing. The copper brush carrier tubes carry current right up as close to the commutator as possible. That is shown by the older brush at the front of the four... That one is being used to measure the tube to commutator clearance, it has no spring, just a half melted pigtail on it. The others are good brushes. The back sides of the brushes measure 4.5 mm wide instead of the 2 mm of the rectangular originals, that should give you an idea of scale of the tube to commutator gap. I made the tubes tight and then ground them to their final planes and clearances.
There are two temperature sensors on it, one for each polarity during bench tests and one for the bike and one for the rider during actual operation. The only other improvement that comes to mind, would have been to use an old car door central locking actuator, to provide an "on the fly" advance function, like an overdrive.
The copper carrier tubes are potted into the old carrier using "Dynasteel" a high temperature epoxy putty, that can take 260°C and live and the copper can take far, far more, the original Bakelite is useless. If this one melts, burns and smokes, then something is really wrong... since it can take the heat of being soldered.
Cheers,
Cam
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Topic: What I would call a "High Amperage, Racing, pmg 132 brush carrier" for an Agni (Read 2479 times)