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PreWarCar Workshop: An exploding dynamo

Amilcar dynamo_explodedWhen you start up your beloved vintage machine and the ampere-meter reads a steep discharge, something might be going on with your charging device (when equipped!). In this case, I wanted to check the status of this dynamo and took of the brush cover to see what I would find.

Well, if you find what you see in the picture on the right, something did fail. In my case, the commutator had come loose and ground the inside of the dynamo to small pieces. The whole thing was crushed on the inside, no usable parts were left. Note that it was still turning and when the engine ran, it was still grinding and eating away more of the inside of this unit.
Amilcar dynamo

Since these units proved hard to find, and when found, owners warned us for how fragile they are and that this seems to happen more often, we chose a different way.

The idea we used came from Andrew Mitchell Automotive Engineering from South Australia. It seems that in Amilcar dynamo_partsAustralia, Amilcars (from which this unit came) have long had generator problems. They adapted Model-T generators to fit the Amilcar with success. The difference between this article and Andrew Mitchell's idea is that we use the original Amilcar housing (they do use the same Kubota dynamo as I did).

The new dynamo's housing is turned to size, the shaft is made new to fit and the Amilcar dynamo_finishedwires are connected to the original terminals. The old bearings are renewed and used in their original locations. This unit doesn't have the radiator-fan attachment on the back but if that was present, it could still be used in this setup. From the outside, it looks completely original. Under the dashboard of the car, a new regulator is mounted out of sight and the whole setup functions again like normal!

Please view the photo album here:

Note: on the new Google Photo's album, the comments are "more hidden". Click on the photo and find my comment in the top-right corner of the page.

Article written by Jos van Genugten.

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#3 2017-01-05 21:39
The bearings that were installed were roller bearings, I have no reason to assume these aren't original to this unit.

As for cooling: there is ventilation in the housing through 8 holes around the house, the Kubota unit doesn't use forced cooling and doesn't get very warm by itself, so I expect no problems from this.
#2 2017-01-05 10:52
Do you have no cooling problems?
#1 2017-01-04 20:23
Are the original equipment(O.E.M.) bearings, needle instead of roller(or ball)?

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