I have not found any articles detailing the secrets of these dynamos. Does anyone have good information they could impart about how to check and adjust these? I have two, neither of which works at present, and the brush housing casting is differently anchored in the slotted holes. I hesitate to change anything without sound information on what I should be doing.
Do these differ much from the DEL? is the 3rd brush adjustable?
With two ball races care is necessary that not preloaded or constrained.
For those familair with more common 2 pole devices the 4 pole can be puzzling, with main brushes at 90 deg. And armature not wound 1 to 2 to 3 but 1 to mid to 2 etc whch complicates tests with an ohmmeter.
The modest output best taken from the no load ammeter charge; balancing lamps is only applicable with original wattage bulbs.
Bob.I'm no dynamo expert but my rebuilt CAV dynamo was capable of producing 27 amps unregulated.The third brush is adjustable and the bearing located in the aluminium die cast brush end can slide in the housing.
This light aluminium casting is usually cracked,or the bearing dia oversize.
May 24, 2017 - 5:26AM
Re: Magneto type CAV dynamo
Thanks A i S.
That output is surprising but, in the modern jargon, “not sustainable”!
I have done all my own car work on various troublesome makes over the decades. I have no trade background but managed to avoid many of the provoked failures in which many “professionals” seem to specialise.
But I did manage to ruin a bearing on a DEL dynamo....
Thanks to all who have contributed to this thread. I got enough information to determine that both my dynamos were beyond a quick fix for our trip to France next week. I dipped my hand in my pocket and bought a tested working dynamo.