Once you find new brushes, the alternator comutator needs to be fixed up for best performance.
The comutator (the round coppery thing, for Margo) has axial grooves in it. The grooves "close up" during normal use, reducing the performance of the unit.
Make a purpose built tool from an old hacksaw blade, and scrape a "chamfer" along both sides of each segment - just enough to remove the overhang which forms naturally. DO NOT SCRATCH THE OPERATING SUR
!.
Put the shaft in a lathe, if possible, or rig up something with an electric drill so you can rotate the unit at high speed. Using FINE (1200) emery cloth, polish the surface of the comutator to remove any blemishes which may have formed during normal use.
Treat the whole thing until it is a uniform copper colour.
Repeat the chamfer process, but ONLY ENOUGH TO REMOVE THE SHARP EDGE YOU HAVE JUST CREATED.
Blow the unit thoroughly with compressed air to clean.
Fit new brushes.
Off you go.
I give thanks to my apprentice training officer, Mr Roy Candy, for teaching this process to me in 1972
The comutator (the round coppery thing, for Margo) has axial grooves in it. The grooves "close up" during normal use, reducing the performance of the unit.
Make a purpose built tool from an old hacksaw blade, and scrape a "chamfer" along both sides of each segment - just enough to remove the overhang which forms naturally. DO NOT SCRATCH THE OPERATING SUR
!.Put the shaft in a lathe, if possible, or rig up something with an electric drill so you can rotate the unit at high speed. Using FINE (1200) emery cloth, polish the surface of the comutator to remove any blemishes which may have formed during normal use.
Treat the whole thing until it is a uniform copper colour.
Repeat the chamfer process, but ONLY ENOUGH TO REMOVE THE SHARP EDGE YOU HAVE JUST CREATED.
Blow the unit thoroughly with compressed air to clean.
Fit new brushes.
Off you go.
I give thanks to my apprentice training officer, Mr Roy Candy, for teaching this process to me in 1972
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