More Ignition Experiments

Boyo,

This thread brings back a ton of memories working with post ww11 mopeds and motorcycles when I was a kid lol.

Wonderful and quite do-able stuff here, I am having a blast reading over all of this.

Good show, Thx
Regards, John.

Just in before anyone says anything...

I know I said it was 'my' idea, but I think everyone knows that's rubbish - if nobody else had done this before I would be massively surprised. It was just 'my' idea this time

It doesn't matter whos idea it was, all I'd like to say is thanks Paul and Nuts for showing us less electrically minded how it works and how to do it.

Stu.

OK, next question, how would this work for a spinning coil magneto like the Lucas N1 on my Stuart Turner?

Ianhw77k wrote:OK, next question, how would this work for a spinning coil magneto like the Lucas N1 on my Stuart Turner?

In theory it will work just the same, but the coil would be harder to achieve.

Hang on, I need to think about this one, as they work on brushes. I think it would be easy enough on a single cylinder mag, not so sure about a multi cylinder engine though, as the slip ring has breaks in it. Also the points rotate on this type of mag, which could present problems.

There may be ways round all this though, but it would require some thought. What I really need is a rotating coil mag to look at & tinker with.

Hi Matt, Read your post and found it fairly easy to understand most of it (bear in mind i know zero about ignition electrics). I currently have 1xMK20 & 2xMK25s on the bench and i cannot find a spark on any of these VILLIERS, I know you and others have had success with this method, i would like to try it myself and have questions.
I would like to use 22swg or smaller, 22 swg would i estimate give 350 to 400 turns is this overkill or is more better.
You also mention a stop switch is this still your thinking and if so is this a ordinary on off switch.
I would like to use a 6 volt coil and shall visit a autojumble to see what is available.
I have built a coil winding machine to make the job easier, so its down to maplins for the wire and find a autojumble.
Any thoughts and comments are most welcome.
Best Regards Keith.

Hi Keith,
As per my previous reply to Matt excellent 'how-to'.

Woodsman wrote:Hi Matt,
Stripped the magneto and wound new primary using 22 gauge enameled copper wire (£8 from Maplin) Connected one end internally to body and took other end out through old bakelite HT connector. Wired to 12 volt ignition coil from autojumble (£3) and fitted new HT lead and plug. Turned it over and got an excellent spark. Drop of petrol in the carb' and she fired up first time.
I now have a running Villiers MK10 for less than £15 spent on ignition

Brilliant 'how to' Thanks again.

Like Matt I lost count of the number of turns but I guess I put on about ten layers. The first few you can wind quite neatly but they can get a bit ratty as you progress. BTW I didn't bother with insulation between layers and it works fine but I suppose it would be sensible to do so.

Good luck.

Another excellent reply right there too. If Woodsman (Paul) has done the same thing on the same (or a similar) engine then I would say follow that.

In theory the insulation between layers shouldn't be necessary, but it can help to keep things tidy. However, remember it will take up space.

As for wire gauge & number of turns, it's very much trial & error, more turns will give you more voltage, but thinner wire will give you less current. Ideally you need a good balance of the two.

I would say 400 turns would be a good amount & should give you what you're looking for, depending on the state of the magnets of course.

As for a stop switch, the usual method of earthing the points should work best, I think. It's been a long time since I did anything with this method, I'm still in the process of setting up for proper magneto repairs & coil rewinding. I've got a nice coil winding machine, but as yet no copper to wind on it & I'm still waiting for an order of the correct insulating paper & resin to show up. Then I can get cracking & have a go at a few.

I'll be interested to know how you get on though. This is still a very viable alternative to expensive new Villiers coils & the more success stories we get, the more engines will have been saved from the scrap man.

Hi Paul,Thanks for your reply,i guess i will go with 22 swg its down to Maplins tomorrow then autojumble on Sunday to see whats available, when i wind the coil do i leave both ends out and how do i wire the circuit up and did you use a on off switch,i have stripped one old coil and 22swg i think i will achieve 50turns with the coil winding machine i have made,if i can get these engines running i will be well pleased. Best Regards Keith.

Hi Matt, It was Paul who alerted me to your post I love the idea of giving these engines a new life without having to spend serious money to do it which i do not have to spare,I think i will go with 22 Swg wire and i have stripped a us villiers coil and with the machine i have made i reckon we will get approx 50 turns per layer, you say that the points earth should be sufficient and i take it a on off switch is not necessary ,do i leave both ends out of coil and how do i wire the circuit, best of luck with Magneto repairs and coil winding venture, I will keep you posted of how i get on Best Regards Keith.

Yes, best to leave both ends loose on the coil, even better to solder proper flexible cable ends onto them as the winding wire can quickly work harden & snap off if wiggled about a lot (it can also do this with just the engine vibration).

I would think a simple switch to earth out the points will be sufficient to stop the machine, any old on/off switch should do, even a strip of metal like many of the original magnetos had on them (although that can be tricky to insulate, but isn't impossible). You may even be able to utilise whatever is left of the original stop switch, if there was one. The alternative is to put an earthing strip next to the spark plug terminal & earth out the plug to stop. But it's always best to use an insulated tool with those.

Good thread Gents,

Just to assist - I work in an industry where generators are in the low Mega watts - but the same principles apply - and that's keeping dirt and moisture out of your windings on your ignition or gen set systems - no matter how cheap our fixes are to keep our lovely old engines going its a really good idea to use a v cheap pot of electric motor insulation varnish - readily available from fleabay at a reasonable cost of around &7.50 and cheaper if you search google... giving the seasonal and ingress of dust/ dirt protection it needs!

Just a thought....

Best

Hamish

Hi Keith,

I had a vintage battery isolator for our first Villiers. Brass and bakelite so looked the business.

One of these might look 'cool' ( so I'm told) if a little contemporary:

http://www.maplin.co.uk/p/red-push-to-make-switch-n01ar

http://www.maplin.co.uk/p/spst-metal-body-cj98g

Otherwise a simple single throw toggle switch should do the trick. Most seem to be double pole but you can just ignore the extra one.

BTW. I'd be interested to see a picture of your winding machine - my son and I shared the work but our thumbs were numb by the end of it

HI Matt, OK i will leave both ends out & i will solder flexible ends on as you suggest,when i have done this do i wire end off the top layer to the 6 or12 volt motor vehicle coil + and the inner end to points, if this is ok where does wire from coil negative go to, I will go with the metal push strip from cooling cowl to sparkplug to stop the engine this original, I will keep you posted of the outcome. Best Regards Keith.

HI Hamish, I did intend to wrap this coil with insulatin tape, it is inside the flywheel not out in the elements what do you think Best Regards Keith.

You may need to experiment with which coil connections go where. Obviously there are only 2 wires, so it's not much of an experiment, but you may find it works better one way round.

If I'm totally honest I can't remember where all the connections go. I'll have to re-read the thread & get back later on. But I think the negative ignition coil terminal goes to the points (which complete the circuit to ground) & the positive terminal is connected to one side of the coil you just wound (the other side of that one going to ground). Don't quote me though, I just popped in to check my emails & google where to find the fuel filter on a Peugeot 206 (turns out it doesn't have one! They have a "lifetime" filter on the end of the pump, inside the tank! Who'da thought it?) I'll have more time later.

BTW Hamish is right about protecting the coil. Tape will probably do as this is a low voltage, low current coil. But you could encapsulate it in something like araldite, or even something like Wickes own brand builders adhesive (like No-Nails or Gripfill), opting for the solvent free version. Whatever you have to hand really.
I'm sure it'll be fine, but remember every time that magnet passes the coil, back EMF in the coil will cause the wires to move (very very slightly) so over time they may wear. But that would take a very long time & it would probably continue to work for ages afterwards as a few shorted coils won't make much difference.

Woodsman wrote:Hi Keith,

I had a vintage battery isolator for our first Villiers. Brass and bakelite so looked the business.

One of these might look 'cool' ( so I'm told) if a little contemporary:

http://www.maplin.co.uk/p/red-push-to-make-switch-n01ar

http://www.maplin.co.uk/p/spst-metal-body-cj98g

Otherwise a simple single throw toggle switch should do the trick. Most seem to be double pole but you can just ignore the extra one.

BTW. I'd be interested to see a picture of your winding machine - my son and I shared the work but our thumbs were numb by the end of it

Hi Paul i do not have any photos and if i had i do not know how to send them ,I can give you a brief description of the machine i made,I started with a ECLIPSE hand wind drill brace opposite side to hand winder is a static handle i removed this this left a spiggot 3/8th"dia x 1/2" long i then made a stand from 1" dia bar x 2" long in one end itapped a 1/4" UNF thread this to enable it to be bolted upright on a flat plate in the other end i bored a 3/8th" hole 1/2" deep , 1/4" from top i drilled and tapped hole to hold drill brace fast, the drill brace is now fastened paralell to the plate,I then made a second pillar out of 1" dia bar to fasten to the plate same as 1st plate except this is longer as it needs a hole drilling at centre height of drill chuck i drilled this through at 3/8" dia, this then needs a tophat this has a stem 3/8ths dia xapprox 2 1/2" long this is again 1" dia bar and this bit is left 1" long in the end a 7/16th" hole is drilled this holds the end of the iron core we are winding,we need to make a similar one for the drill chuck as this is a small chuck i made my spiggot x 1" long just shy 1/4" dia ,this again 1" bar i made mine 3/4" long this needs a 3/8th" dia hole x1/2" deep this needs a hole through the to hold the iron core captive so that when we turn the handle the core will spin,we also need a simple frame to hold 22SWG wire we are using to make the coil, on my set up 1 turn of the handle gives 3.666 turns on the coil so its just a case of counting the handle turns eg 10 Turns =approx 37turns on the coil, i made mine out of metal as i have a lathe, but i don:t see why it could not be made from wood, i bought the hand brace at jumble sale for £2. hope this makes sense if you need more info i will be happy to help.Best regards Keith.

HI Paul, the holes in both tophat spiggots need to be 7/16ths" dia i have said in my 1st reply 7/16ths" on 1 spiggot and 3/8ths" in the other this is wrong they both need to be the same ,oops another senior moment . All the best Keith.

Hello Keith,

You're spot on squire - any sort of protection will keep your investment in time, effort and money a little more protected... dirt and moisture can cause big damage leading to loss of performance - even on little systems we like to use - and please ensure its well ventilated as too much heat can also cause overload/under load problems...also leading to loss of performance...

It seems as if nothing is simple these days!! - but don't spend to much time on this - your suggestion sounds fine - and if you think its not working you can easily change later!

Best

Hamish

StewartH wrote:Hello Keith,

You're spot on squire - any sort of protection will keep your investment in time, effort and money a little more protected... dirt and moisture can cause big damage leading to loss of performance - even on little systems we like to use - and please ensure its well ventilated as too much heat can also cause overload/under load problems...also leading to loss of performance...

It seems as if nothing is simple these days!! - but don't spend to much time on this - your suggestion sounds fine - and if you think its not working you can easily change later!

Best

Hamish

Hi Hamish, I will go with the tape to cover the coil,I am still unsure of how to wire the circuit and being complete duffer with ignition systems i shall wait till Matt gives me the way to do it. Best Regards Keith.

Hi Keith,
I'll have a go - I'm sure Matt can correct me if I get it wrong.
Having wound your new coil and fitted back between the cheeks, run one wire though the hole in the left of the contact breaker box under the Tufnol insulation and solder to the brass terminal in the middle, the one that also connects to the condenser - in other words exactly as per original. We found it easier to free the contact breaker box from the backplate first. Run the other wire out through the HT terminal hole and seal as best you can. Connect this wire to one of the LT terminals on your newly acquired ignition coil. Connect the other LT terminal to somewhere on the engine. We mounted the coil by using the existing strap and fastening it under one of the fuel tank bolts so we used that point as our earth.

So it should look something like this:

The best way to think of it is like this:-
The coil you are winding is a power source. This power source is replacing the 6v (or 12v) battery in a normal car or motorbike coil ignition system. Therefore, one side of your newly wound coil (thinking of it as a battery) needs to go to earth (the same earth as the points eventually ground out to, so the magneto back-plate). The other end of your newly wound coil needs to go to the auto-type ignition coil, where the power source would have previously gone (so the positive side, or whatever it says on the coil).

From there on it's a normal car-type ignition system, where the negative side of the auto coil (the only remaining, as yet unconnected low tension terminal) goes to the insulated side of the points (along with the condenser, so could even be connected to the condenser wire).

So keep your newly wound coil ends reasonably long, so you can switch them over & try it both ways. Basically I've no way of knowing which end will be better as the polarity of your new coil depends on the direction of the windings in respect to the direction of the magnetic field passing over it. So to reverse the polarity of any simple coil you simply change the end connections over. In theory one way will work better than the other, but in reality the difference will be so slight I doubt you'll notice a difference.

Unfortunately Paul's diagram above (thanks Paul) just needs the points moving so they are between Lt2 & "handy earth point", which is already built in. Then substitute the points (as they are in the diagram) for a straight through, uninterrupted wire.

A stop switch on that diagram would go from Lt2 to earth (effectively holding the points closed). It would need to be open for running & closed for stop.

I can't do diagrams like Paul, well I probably could, but I would need to teach myself & that could take time, but I could draw it out on paper & take a photo if necessary.

Also worth mentioning, condensers can cause many ignition problems. Make sure your condenser is OK. A sufficient test for this circuit (in the absence of an insulation resistance tester) would be to use a normal multimeter, set to the largest Ohms (resistance) value possible (usually 2Mohm) testing the condenser from it's metal body to the wire/terminal. But try not to have your hands touching both contacts, as you will get a slight resistance reading through your skin.
You are basically looking for an open circuit, which will mean the capacitor (just another term for condenser) is still functioning correctly.
For a proper magneto or coil system this test would be done with a high voltage insulation resistance meter, using around 250v (or even 500v) (you definitely don't want your fingers touching that!). But the 3v-9v from a normal multimeter should suffice for this system.

Oops. I suppose I should have dismantled the engine to check but didn't want to have to reset timing, my apologies.
Thanks Matt.

Woodsman wrote:Hi Keith,
I'll have a go - I'm sure Matt can correct me if I get it wrong.
Having wound your new coil and fitted back between the cheeks, run one wire though the hole in the left of the contact breaker box under the Tufnol insulation and solder to the brass terminal in the middle, the one that also connects to the condenser - in other words exactly as per original. We found it easier to free the contact breaker box from the backplate first. Run the other wire out through the HT terminal hole and seal as best you can. Connect this wire to one of the LT terminals on your newly acquired ignition coil. Connect the other LT terminal to somewhere on the engine. We mounted the coil by using the existing strap and fastening it under one of the fuel tank bolts so we used that point as our earth.

So it should look something like this:

HI Paul Thanks for that ,there is a Autojumble in Huddersfield on Sunday so we will see if we can find a couple of coils,I have wound the coil on my DIY machine i reckon we have approx 700 turns to fill the coil it took approx 20 minutes,I am pleased with the result.Best Regards Keith.