Dynamator refurbishment

[Stuart Giles]

Testing at this point revealed that the rotor winding was open circuit (was this the same Dynamator that Stuart had a go at?). Oh poo.

Well done for finding and fixing the faulty rotor. Happy to confirm that all the left over Dynamator bits from the repair that I did are still lingering in my workshop somewhere  

It looks like the Dynamator I repaired using the rotor from a donated 'dead' unit has failed again, and I hope to have the unit back here in the workshop over the  next week or two. I will have a look to see if it's the rotor I replaced that has failed or whether it is some other fault this time. The other components are fairly generic so should be fixable if the regulator or such has let out the magic smoke.

Have said car and and Dynamator here now. A quick check showed  no 12v on the field/excitor connection, further poking about revealed that the ignition/charge warning lamp had blown. Simple fix, I thought; new bulb, still no charge, booger! stripping down the unit I repaired last year with a donated rotor from another dead Dynamator, revealed this bizarre fault...

Yes, that really is the stator, welded to the rotor; the whole lot has been spinning in the case, as can be seen in the rear of the photo.

Didn't need too much force in my hydraulic press to part the rotor from the stator, it appears that the epoxy which the stator has been pugged in with, has turned to crumb (it's all over the inside of the Alty) and this loose crumb has been responsible for a kind of friction welding of the whole stator to the rotor. As neither the car's owner nor myself have experienced a great deal  of reliability with the Dynamator setup , I have built up a permanent magnet alternative as described here.

The above was the wierdest Alty fault I have ever come across, not least because there is no sign of overheating on any of the alty components. However, the permanent magnet version I have built will hopefully be more reliable, and I have an improved version in development at the moment.