Anyone know anything about magnetos?

[Dieselman 63]

Today I bought this for $12, didn’t know what it was at the time of purchase but I thought if anything its a cool desk ornament.

Anyway, I gave it a rough clean up and I’m curious as to what it could be off (era wise - it’s obviously off an engine), how to test it, and ultimately whether I can make it spark.

Do people buy still use these?

 

[Wallace]

 

[selectedgrub]

Anyway, I gave it a rough clean up

It's beautiful.

 

[frank horton]

magnetos always seem to go for a fair amount up here........think u should find an old engine to put it on then use the whole thing as a desk ornimink......hahaha

 

[Wendelspanswick]

My physics teacher had one on his desk with a fly wheel on one end.
Miscreants were forced to join hands and hold onto the bare HT lead while he spun the fly wheel, providing punishment and educating you at the same time!!!
You'd never get away with it nowadays.

 

[Gareth J]

It is, quite clearly, the firing mechanism for the potato cannon you are about to build.

 

[Scruffywelder]

Sounds cheap to me!

Looks to be missing the screws out of the horseshoe magnet?

Could be one that's been raided for spares as BTH stuff has been tricky to find for a long time.

Test it by:

1. Stick a length of HT lead in the Bakelite bit on the drive side (IIRC you just twist the cable round to screw it onto the terminal),
2. Strip back a wee bit of the other end of the HT lead,
3. Clamp the mag to a table,
4. Hold the exposed end of the HT lead about 1/8" from the mag casing,
5. Flick the drive round as hard as you can (usually clockwise),

If it won't blow a spark across across an 1/8" gap when cold then it's probably dead/dying.

Nice thing to have as a desk ornament/paperweight even if it doesn't work.

 

[Scruffywelder]

My physics teacher had one on his desk with a fly wheel on one end.
Miscreants were forced to join hands and hold onto the bare HT lead while he spun the fly wheel, providing punishment and educating you at the same time!!!
You'd never get away with it nowadays.

To me that nicely fills the definition of "Educate, entertain (the rest of the class, anyway) and inform"

He should have been given a job with the Beeb!

 

[Scruffywelder]

It is, quite clearly, the firing mechanism for the potato cannon you are about to build.

Steampunk collaboration with @selectedgrub perhaps...

 

[Seadog]

It is probably a 1930s motorbike mag, type M I believe. It could be quite sought after by the vintage motorcycle fraternity.

 

[gordon stephenson]

50 years ago my mates mother got a new gas cooker, Bill her husband being an electrical fitter, mounted a magneto to the side of the hob with a HT lead tuning to a probe, She was over the moon, Turn on the gas and spin the little flywheel and she had self igniting burners, How many blokes would get away with bolting a maggy onto anything these days.

 

[Dieselman 63]

Sounds cheap to me!

Looks to be missing the screws out of the horseshoe magnet?

Could be one that's been raided for spares as BTH stuff has been tricky to find for a long time.

Test it by:

1. Stick a length of HT lead in the Bakelite bit on the drive side (IIRC you just twist the cable round to screw it onto the terminal),
2. Strip back a wee bit of the other end of the HT lead,
3. Clamp the mag to a table,
4. Hold the exposed end of the HT lead about 1/8" from the mag casing,
5. Flick the drive round as hard as you can (usually clockwise),

If it won't blow a spark across across an 1/8" gap when cold then it's probably dead/dying.

Nice thing to have as a desk ornament/paperweight even if it doesn't work.

The screws are there - they had just been awaiting sanding back, someone had had a go getting them off with a coin by the looks of things!

The Bakelite bit is broken - I could probably resculpt this with epoxy though.

I’ll try that out tomorrow. I originally bought it to steal the big eclipse magnet but it’s not very powerful at all so I’ll leave it as is. Thanks for the very informative reply!

 

[slim_boy_fat]

but I thought if anything its a cool desk ornament.

I'm pretty sure @Parm could come up with some ideas, after we saw his brilliant lamp.

 

[Ton-up]

When I did my apprenticeship there was a story, which they swore was true, about a guy who used to spend ages in the loo smoking and reading mags. The lads got fed up with him and one of them banged a couple of nails through the loo seat, filed them flat, ran a couple of leads out the wall to his motorbike magneto and when the guy went in the loo for ages, went out and kicked it over. You can imagine the result.
(and before you say, I didn't spend ages in the loo, so it was to scare me!!)

 

[Parm]

I'm pretty sure @Parm could come up with some ideas, after we saw his brilliant lamp.

I’ve got another idea for a lamp. I’ve also got all the parts.

Just waiting to find some time now

 

[Seadog]

I originally bought it to steal the big eclipse magnet but it’s not very powerful

They lose their magnetism quite quickly when removed from the body of the magneto. They can be remagnetised though.

 

[graffian]

Yes people still use old mags, I have a couple of bikes and they have mags. I have a BTH mag on one bike. I would happily given $12 for it, I have a sunbeam that needs a mag; as it happens I bought an almost complete Lucas M01 for £12 just before christmas!

As long as they are all there they can always be rebuilt or if not complete used for parts.
As long as you can feel some mag strength[the flux change], you have a gap on the points and the armature isn't shorted
it's usually possible to get a spark.
You take the pickup off and put something metal, touching the body, close to the slip ring and it should spark when you turn it
over. They should spark when turned over slowly. best put the mag down as if the metal bit isn't earthed you will probably drop
the mag if it bites you.
Putting out a spark doesn't mean it's any good to use, but it meant the bike breakers would buy them as working mags.

 

[wristpin]

Sounds cheap to me!

Looks to be missing the screws out of the horseshoe magnet?

Could be one that's been raided for spares as BTH stuff has been tricky to find for a long time.

Test it by:

1. Stick a length of HT lead in the Bakelite bit on the drive side (IIRC you just twist the cable round to screw it onto the terminal),
2. Strip back a wee bit of the other end of the HT lead,
3. Clamp the mag to a table,
4. Hold the exposed end of the HT lead about 1/8" from the mag casing,
5. Flick the drive round as hard as you can (usually clockwise),

If it won't blow a spark across an 1/8" gap when cold then it's probably dead/dying.

Nice thing to have as a desk ornament/paperweight even if it doesn't work.

Beware of "asking" it to jump any larger gap or it may find it easier to spark internally and cause permanent damage. Best way to test is to connect the HT lead to a sparking plug and then hold that against the mag base. That way the gap is controlled to 20/25 thou.

 

[Nomad]

I love "organic" machinery like this - it's a work of art even it doesn't work

One common problem used to be the internal condensers failed. About 10 years ago I saw a place in usa selling modern condensers for about $30. I've just found out we can now buy them in the uk for about £10 ! Bargain
Lots of good info and stripdown guides on their website http://www.brightsparkmagnetos.com/easycap/index.htm

 

[zeppelin builder]

Today I bought this for $12, didn’t know what it was at the time of purchase but I thought if anything its a cool desk ornament.

Anyway, I gave it a rough clean up and I’m curious as to what it could be off (era wise - it’s obviously off an engine), how to test it, and ultimately whether I can make it spark.

Do people buy still use these?

Its an m1 bth the cam ring is missing but are easy enough to find the used them on petters stationary engines with fixed ie non movable cam ring .motorcycle ones had the movable type that advanced and retarded the timing they are way superior to joe lucas stuff
And had mica condensors
With the missing parts you should get a big fat spark
Turning over you will feel a bit resistance thaat will suddenly collapse this is where the points should open for optimum spark
It may need rewound theres around 10000turns of wire 3 thou thick wound round the rotating bit
I have all the gear to re condition them
Winding machine and a reaaly powerfull magnetiser
Re magnetising takes about 3 seconds

Very time consuming and fiddly to rewind
So very pricey
I might start doing them if i ever retire