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Ignition contact breaker points

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MikeN:
I need to make the contact breakers for my Bentley BR2.  I've made most of the assembly that fits inside the dummy magnetos.
What should I make the actual contact part out of? The finished contact discs about 3mm diameter.
The book says the author used contacts from an old dish washing machine relay.
I have removed the contacts from an old relay that I found which are about the right size and can be adapted but they are quite soft.
Do contacts have to be hard?
Thanks

cwelkie:
If you know someone with a tig welder you might try using a couple thin slices of electrode rod.  I've done that successfully on my Anzani engine.  I don't recall exactly which rod I used (don't think it matters much).  The slices were cut off using a circular cutoff tool in a moto-tool on the lathe tool post.  Could also be done by hand in a vise with practice and a way to catch the little bits when they come off.

MikeN:
I own a tig welder! (I was once a coded welder).
Thanks, I'll give it a try.

gbritnell:
With electronic model ignitions you don't have to use Tungsten.  The points aren't subject to high current as with conventional battery/coil ignitions. If you use Tungsten silver solder a long enough piece so you can hold or fixture it then cut it off with a small diamond cut-off disc. After cutting off polish the surface with a diamond honing stick.

MikeN:

--- Quote from: gbritnell on January 18, 2026, 03:06:19 PM ---With electronic model ignitions you don't have to use Tungsten.  The points aren't subject to high current as with conventional battery/coil ignitions. If you use Tungsten silver solder a long enough piece so you can hold or fixture it then cut it off with a small diamond cut-off disc. After cutting off polish the surface with a diamond honing stick.

--- End quote ---

Just spent an hour cutting slices of tungsten off with a thin cut off disc. It turns out that it doesn't matter how many sheets of white kitchen paper you put down to catch them, they all ping off and disappear. The only way is to catch them in your hand. And they come off hot!

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