The Knowledge - Velocette Owners Club

#3490 I was hoping a modern plastic coating had been found and used. By removable, I mean non
permanent that could be taken off without damage in case the windings needed to be redone. On more
thought.....I should do it the right way....rewound and a new capacitor. I'm planning on total loss battery
arrangement and will be relying on the mag completely.
L #4062 Hi, Does anyone know the procedure for testing Miller Dynamos in situ? Mine is on a
Rudge, but I'm sure Velo's use the same Miller parts.
#4063 From page 74 of the Red Book: "The dynamo can be checked quickly and with very little trouble
by removing the driving belt, and the commutator cover, and pressing the cut-out points together. If the
dynamo does not begin to run as a motor from the battery current there is a fault in it. "This is not a
100% check, as in some circumstances a dynamo with a faulty winding may 'motor,' but by testing in
this way a lot of time can be saved."
#4075 Doug is bang on.. but shorted turns in the field or armature can allow the dynamo to motor but
still not charge. Measure the field resistance - should be 2.5-3 ohms. The armature is best tested with a
'growler' - see an old fashioned motor rewinder in your area. Obviously check all wiring is sound and
that the brushes are in good condition and move freely. Might be worth cleaning up the commutator - if
badly worn trim up in a lathe taking as little off as necessary. My experience with miller setups is that
the dynamo is less likely to be faulty than the regulator.
L #4749 Hi Does anyone know where I can obtain dynamo brushes for my Miller dynamo, mine
are getting low and the spring pressure is becoming ineffective, I don't mind modifying substitute
replacements.
#4750 Dave Lindsley in the UK has them as his part number 404.
L # 4890 I am changing my K-tec regulator +v for a VW 6-v but I'm not sure quite how to go
about changing the dynamo polarity has anybody any idea's how this can be done, I have the
instruction from a N American fishtail from 1985, there is one part missing and that is on the polarity
change of the dynamo. Any advice gratefully accepted.
4892 Bob, You will need to swap the two field-coil wires one for the other. ie the one which is now
grounded goes to the 'live' 'F' lead and vice- versa. When you have done this a motoring test with
correct battery polarity (-ve earth now) should have the dynamo rotating the same way as when driven
by the engine = anti-clockwise at the pulley end.
# 4895 All the answers are contained in an article called "Uprating your dynamo" in the files section of
the group site http://autos.groups.yahoo.com/group/velocette/files/Electrics/Uprating%20you
r%20Dynamo/
# 4898 You are getting some bum info here! Do not reverse field winding connections unless you are
reversing the direction you want to rotate the dynamo. To reverse polarity all you need to do is connect
the required battery teminal to earth, and with a wire on the other terminal, dab it momentarily onto the
'F' (field) terminal of the dynamo. Make sure you have removed the old regulator as the reversed
polarity will destroy it!
# 4907 I know where your coming from re reversing the field connections as far as the old regulator
that was a k-tec that already passed on.
# 4901 In principle it's very easy - just motor the dynamo with the polarity you want. For a lucas-style
dynamo this means connect the F and D wires together, connect them to a charged battery of the
appropriate polarity , and the other end of the battery to the dynamo case. The dynamo should rotate it
the direction it goes on the bike. There's a small complication. Some regulators require the dynamo to
be connected like a Lucas - ie one end of the field coil is permanently earthed, and some require one
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