As has been said before, Tom is a hobbyist . Tom doesn't make 0r market a voltage regulator . I believe that Toms favorite voltage regulator is the Nurex voltage regulator that takes the place of the third brush. Tom doesn't own the Nurex regulator anymore than I own the Fun Projects voltage regulator . I have used the Fun Projects 6 and 12 volt voltage regulators and have never had a problem with either . In my experience and opinion , one of the better features of the Fun Projects voltage regulators is that they don't use the often troublesome cut out ... Cut outs can often be repaired but I would rather use a system with no points to stick and kill the battery . A cut out with a diode installed doesn't give voltage regulation . When A diode is used , it allows the generator to charge at whatever rate that the third adjustable brush is set for and there is no points to stick , as can often happen with A stock cut out . Fun Projects offers voltage regulators in six , eight and twelve volt versions . The Nurex voltage regulator only works on a six volt system .
What Keith True says in post # 19 is right on !!! People trying to re polarize the generator with the regulator in place , damages the voltage regulator . I can easily see how failing to follow instructions would upset the maker to the point that he would need to charge a fee to repair the regulator .