Lucas C45 dynamo

[jddevel]

OK so not a good day. Dropped my starter motor armature in a bucket of diesel I was using for cleaning purposes and my wife fell of her horse!!!! Anyway am attempting to "dry out" the armature and will see in a couple of days the end result. As a pessimist am now considering that perhaps a new Dynamator Dynamo/Alternator conversion is the way to go. Any advice please?

[i.thomson]

What's the point? Unless you have money to burn, don't care about originality and need to install a huge sound system complete with disco lights you don't need it.
Ian

[antijam]

Agreed, the dynamo is more than adequate for the current demand of everything on the standard car and I for one prefer not to put electronics on a car that never had them.
If you do decide to it would be a good time to swap to negative earth (unless you've already done it). Positive earth Dynamators are available but more expensive, and then you'd have the facility to power your SatNav and charge your phone!

[jddevel]

Ian Not sure I`ve made my point clear. In the event that I`ve "knackered" the existing armature and advice from a restorer of these items is that due to the age of the dynamo it`s likely that the insulation(shellac) has become decayed anyway why pay for a exchange/reconditioned dynamo at £350 plus against a Dynamator Dynamo at around half that price. For originality I`ve had the engine rebuilt, the steering is now a VW and a 5 speed box is being installed and it`s now whilst in pieces a non standard TC colour. I just enjoy the "looks" of the MG cars (have owned one of different models) for nearly 60 years. Originality I leave to others which due to cost of time and investment probably would mean it would unfortunately spend to much time sheltered in my garage. Incidentally I did mean Dynamo not starter.

[Duncan M]

Too bad it fell in diesel fuel. Might be ok. Who is reconditioning these for 350 Pounds? On an exchange basis, if your dynamo was the original one to the car, you will lose the correct date code on the case by going that route. Most difficult part of re-furbishing my dynamo was removing the field coils to replace the (case) insulating paper.

This link has some tests for the armature while it is out... and dry. Scroll down
https://www.electrical4u.com/armature-e ... generator/

[jddevel]

Thank you for the link Duncan. Very helpful. I will say that even on removing the armature on visual inspection I found some small parts of the windings have lost a little shellac insulation covering. This obviously makes me wonder as to the condition of the unseen. Regarding pricing here in the UK the following are examples. Cheers Jan
Brown and Gammon Price including surcharge + VAT: £ 390.00, £120 refund on return of repairable item
jb vintage spares Lucas Dynamo MG TA TB & TC £395.00
Moss TB-TCEL177 £340.70

[antijam]

It may be worth trying Broadway Electrical Services in Grays, Essex (Tel. 01375 372782) for a repair or overhaul. They rebuilt a Starter, Dynamo and Voltage regulator for a Classic rebuild I did a few years ago and did an excellent job at a very reasonable price. I know several other Vintage and Classic owners who swear by them. The contact used to be Rob, but I don't know if he's still there.

[jddevel]

Thanks antijam. If my cleaning drying process fails will try and contact them.

[Steve Simmons]

You should be able to clean it thoroughly with electrical spray cleaner. One can should be more than enough. It's also worth inquiring what a "rebuild" consists of. Some places simply replace the bearing, bushing and brushes and call it done. Others, like a place near me, install a re-wound armature, brand new field coils, etc so it's literally as good as when it was brand new. But the cost isn't cheap, at around $700 USD exchange.

Dynamators seem to work very well, until they don't. Overheating is the usual complaint I hear. Others have used them for years without issue. They give a lot of power, and much better power at idle, but they don't look correct by any means and require some wiring changes, primarily the elimination of the control box. A friend recently put one in his TC, and was talking about opening up the very small vent holes to aid in cooling. Personally I prefer generators for their simplicity and originality.

[Duncan M]

A video that shows the basic refurbishment process on the commutator bars. Gets relevant at around 7 minutes. https://www.youtube.com/watch?v=FyyCG1jHKgU I guess he does not have a lathe.

He uses an Xacto blade to undercut between the bars. The gap between our bars is wider, and you can make a tool from a hacksaw blade, as long as you find one with just the right tooth width. The soldering repair he does would have been done with rosin core solder, I would think.

The important insulation on an armature is when the winding begins, so you cannot see it. It insulates the armature shaft from the winding, electrically. The shellac you can see on the outside is mainly to keep grease and oil from getting into the winding and shorting it out on the armature.

[jddevel]

Now bench tested and runs. Only charging at just over 11 volts but that may be due to running as an electric motor and therefore at insufficient speed to produce the ideal 14 volts.