Author Topic: Let the buyer beware ??  (Read 2144 times)

Online trevinoz

  • Newcastle, N.S.W. Australia.
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Re: Let the buyer beware ??
« Reply #15 on: 03.04. 2011 22:38 »
My two-bob's worth on windings.
The 6V armature is wound with 0.8mm conductors or close enough to 0.032" in the old money.
I wind 12V with 0.7mm which is near 0.028".
The 48W generators are wound with 0.6mm conductors.
By my reckoning there should be no over heating problems with rewound 12V armatures.
I stated elsewhere that I had easily generated 80W at about 2500 generator RPM.
Perhaps some rewinders are skimping on copper?


Offline Dynamo Regulators Mike

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  • Fareham, UK, 1960 A10
    • Dynamo Regulators Ltd
Re: Let the buyer beware ??
« Reply #16 on: 04.04. 2011 10:18 »
Good morning from Fareham near the south coast.

The new Dynamo regulators Belt drive kit is particularly useful for 12 V conversion using the bog standard E3L dynamo. Naturally I recommend use of one of our DVR2 regulators with the kit. 80 W is conservatively available, but it is certainly wise to ensure that the dynamo is in good condition. That is good bearings, well greased, good commutator & brushes (which will last longer due to lower current for given power) and is running true and well balanced (poor balance can be an issue with some rewinds and pattern armatures). Short bursts at higher speeds will not be a problem, but if you use peaks revs a lot  *eek* then the conversion may not be for you. The idea is to increase overall reliability and usability of your 50 plus year old machine.

The kit is as recommended by Steve McFarlane, the originator of the well known SRM Engineering, but who now runs an independent engineering business. The belt is high temperature steel cored polyurethane, from Continental of Germany. This type is extremely unlikely to lose teeth (when correctly fitted naturally) given its 15 mm width and strength, unlike the black rubbery ones.

It is interesting to note that 2 known makes of alternators in 3" dynamo formats will not give more output than the E3L at 12 V. Despite the expense the biggest advantage is the elimination of brushes, but instead adds other mechanical complications. Trouble is the eccentric spindle location in the dynamo does not allow very efficient filling with the essential magnets and pole pieces. Lucas always much maligned but their dynamos are as rugged and efficient as they come IMHO.

Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL