Dominik hat geschrieben:@Jonas: Bin mal auf deinen Magneten von brightspark magnetos gespannt...
Ich auch! Ich vermute, das wird gut werden...
Gestern bekam ich eine Mail von Bill Brown. Der Magnet ist überholt und soll hervorragend funktionieren. Leider komme ich erst ca. Ende Februar dazu, ihn einzubauen. Eventuell kann ich ihn aber vorher schon in Augenschein nehmen.
Mit Bills Einverständnis veröffentliche ich hier mal ein paar Auszüge seiner umfangreichen Mails, denn "We believe in 'demystification' and have a totally open approach to these things." Vielleicht hilft es ja dem einen oder anderen ein wenig weiter.
Bill ist offiziell im Ruhestand und "macht nicht mehr viele Überholarbeiten". Insofern bin ich froh, dass das alles geklappt hat. Jetzt nur noch Daumen drücken, dass der Rückversand aus Frankreich problemlos funktioniert.
Here we go...
"In terms of the job, there were one or two interesting aspects! Most notably the fact that someone had enlarged the contact breaker centre screw thread to M5 from 3BA which meant that the insulator on the inner part of the unit was missing as the larger screw wouldn't pass through it, and of course the fixture on the inside was ruined and had to be remade.
The ruined thread for the dynamo setscrew was quite bad, and I have had to fit a Stud using a helicoil to get a reliable repair. I have made a stainless steel sleeve nut with hex head and a slot to go on the stud, and it will look reasonably close to correct (and be a bit shinier). That was the best I could do there. Studs and nuts are always better into aluminium anyway - I don't know how many of those threads I have seen in a very tired state!
The little earth-wire retaining nut on the end housing I had to make as well, because the standard parts are 2BA and of course all the threads had been taken to M5. I have therefore made a part in stainless steel, with a stainless small screw to retain the wire (if you fit one) in the slotted deep nut. Again, it looks quite good I think, and is very functional.
I assembled the magneto using what looked a brand new set of contacts for the contact breaker from your supply. It was fine cold - but quite appalling when hot. Because, believe it or not, the tungsten tip - the point - on the spring blade became loose with heat and caused all sorts of trouble. That took a while to figure out! I have therefore used the other set of points, the ones that were fitted prevously, and all is well. I wouldn't use the other one, although you could probably fix it with a hammer and punch to rivet it together better.
The spare bits are all ready to send back. Both condensers are in correct working condition.
I have had to make and fit a plunger for the advance and retard so I could test the thing properly - I have left it in there so if your cable will hook into it nicely, you won't have to remove the contact breaker and camplate to refit your one. It's not as pretty probably as an original one, but a 'working fix' so I could test the magneto properly.
If removing the contact breaker, it should be refitted on the shaft with the unit fully to the 'right', in the clockwise sense therefore, to obtain the optimal internal timing. There is wear on the jaw on the end of the armature, which is common but not something one can fix. Bear in mind that the contact breaker centre screw doesn't want to be done up with a HUGE spanner, or the small threaded fastener on the inside can break, which is a Very Bad Thing! 'Nice and firm' is quite good enough. I have used a split locking washer there, as it is more solid than the original bent brass tab washer, which is usually pretty ineffective as a locking device anyway.
In terms of performance . . .
. . . this is a good MO1. It makes 100% of its sparks, advanced, from 110 rpm cold, and from 135 rpm fully retarded. This is better than the Lucas specification. Hot - at 50°C - it works 100% from 135rpm advanced and from 155 rpm retarded. These are all excellent figures. There are 24° of movement on the camplate, which equates to 48° on the crankshaft. This is more than is needed, but about typical for one of these. Given the amount of retard provided, the spark performance when fully retarded is really very good. About half-retard for starting should be plenty."