White wire, headlight, elctrical stuff

[xPosTech]

Hi Jason

That's a great idea of adding more coils but it has a couple of snags. One is the manufacturing tolerances of the housing itself. The coil has to be positioned very close to the rotor. Thousandths of an inch make a big difference in the voltage output. There would have to be a method of aligning the pickups after the cover is installed.

Another is that the legs of the stock coil is the pickup. The two poles induce magnetic flux in the legs. When one pole is at 12 o'clock the opposite pole is at 6 o'clock. The two legs are 180° apart; so are the poles of the magnet(s).

One magnet has north facing out; the other has south facing out. They cross the gaps of the pickup at noon and 6 o'clock. The pickup doesn't know/care that there is two magnets.

I don't either. If this were one of the diametrically magnetized rotors then it would be only one magnet. Until someone does the iron filings trick I don't know/care either.

Wow. When verifying two poles 180° out I noticed that the rotor isn't even round! At least on the engine I have here. And the coil isn't aligned with the rotor in the middle. I.E. the gaps are different. The top gap is at least twice as wide as the bottom!

I'm sure I would have seen this on the scope but I'm glad I noticed it now.

On every small engine I've worked on, there are only two screw/bolts holding the coil. That's to allow alignment of the coil (with a business card). They didn't have a two-legged pickup, though. With four screws holding the coil (unless the holes through the laminations are a good bit bigger than the screws) there is no coil alignment.

I'll let you know after I remove the screws at 1 o'clock and 5 o'clock if it makes a difference. Also looks like I might be able to "nudge" the pickups a little closed together to decrease the gaps.

I just loosened and aligned the coil; the holes are big enough to slide it around a bit. You will need two business cards if you do that. I still think I can close the gap a few thousandths by squeezing the legs together in a vise.

Ted

 

[jasonh]

I had thought about the legs and the magnetic flux, but I just don't see how much of a difference it would make. If you look at the stator assembly from a scooter or MC, there are no legs. I do agree that the coils need to be very close, so maybe attaching to the cover is less than ideal.

 

[xPosTech]

It's the half moon cutout that's the key. That's where the gap (really close) is located. Different ignitions use different shaped pickups.

The leg design doubles the available voltage and current. One leg "pushes" while the other leg "pulls". Legless (just one half moon gap) only sees one pole at a time.

Ted

 

[Hot Dog Piggy Tails]

Ha Ha the reaason you cant get the old(primary) firing if because the lines of flux and Gauz is split because the only thing you did was put another tap. theres only so much inductance of gauz acailable . Correct me if Im wrong but the middle of your stater(Magneto pickup) is wound the actual picups are on the sides(half moons) this is where the gauz and lines of flux draw across not by the coil the coil just inducts it. the fact of electricity follws path of least resistance. there is more resistance through the one you put on extra right? the spark plug is gapped this white wire then has an output. you probably had a bulb on the new on or it may have been shortes put the phases will be in sinc if you close the C

Im sorry I didnt read all of the other postes!

 

[Creative Engineering]

Ted, obviously you know something about electronics too. And you're right, if we all keep banging away at it methodically we should be able to make a substantial improvement.

When I originally called the white wire a tap to the coil: that was incorrect. I had yet to unwind a coil.

The white wire is actually connected to a completely separate inner coil of 300 turns. They wrapped 300 turns of 26GA. around the frame, soldered one lead to the frame, and the white wire to the other. They wrapped this coil with that white clothlike tape and resin.

Then they overlayed this with 3,600 turns of 35GA. wire, soldered one end to the frame and the other to the blue wire. Once again wrapped with tape and resin.

They share a common ground only. Unless it is possible: that this set-up is acting like a transformer through inductance I can't see that taking coil 1 out of the loop will affect coil 2. I think I'll wait for you to get your scope so you can look into it further.

I already did an exacto-destructo on one coil. I'm not a big hurry to fry something.

There's a ton more info here to answer...you guys got way ahead of me last night.

One other thing I was wondering. I'm fairly certan that coil frames are made up as a lamination due to cost? It is really cheap & practical to high speed stamp thin sheet metal and then rivet it together as opposed to machining a solid. Is there any difference in terms of electrical function? Would a solid steel frame work just as well?

Jim

 

[sojudave]

I've been thinking about the white wire comments that I've read.

I haven't dismantled the coil in my sacrificial engine yet, but I assume that it's a coil within a coil. One for the ignition, and one as a tap for 6V power. I think this explains why, (depending on what is connected to the white wire), the ignition spark becomes weak.

How about a second coil directly across from the first? Coils are cheap, and easy, to make! This new coil could easily be wound to produce 12V and an adequate amount of current.

This would eliminate the inductance problems associated with a shared coil.

Maybe this week I will completely remake the entire coil assembly with the new one having a second coil. This might be a really nice upgrade that could be offered as a direct bolt-on.

I don't have a running bike right now...So I will need a local member who would be willing to bring thier bike in for a test. Anyone in the Tampa Bay area game? Don't worry I have plenty of spare electrical parts if I accidently let the smoke out of your ignition module.

Jim

This white wire, good lighting thing.... it seems as if we're making a mountain out of a mole hill. Why doesn't someone just get two small 6v deer feeder batteries, or one 12v, and run some descent lights off of that. They are rechargeable and small enough to hide on a bike. Batt---fuse----swtich----lights----done.

 

[jasonh]

This whole core with the legs thing is bugging me. I just don't think it is absolutely needed. Though you're right, Ted, I didn't realize that's where it's closest. Anyway I've been reading a lot about alternators the last couple weeks (mostly axial flux design as used in DIY wind turbines) and it's becoming clear to me that you don't NEED the core. Granted, if you've got a piece of steel or iron to wrap the wire around, might as well. I just don't think we need the legs.

I think if we're worried about the inductance, we just need to go with bigger magnets. I would machine a round out of steel and remove material at each end for magnets, 1 N 1 S. These would preferably be N50 or N52 grade to get the best bang for the buck. Anyway, the magnets would then be epoxied or screwed into place (or both). This would give a much better rotor to work with.

I would say just use a diametrically magnetized cylinder magnet, but I haven't found anything with a hole in the middle that is a suitable size (I believe the stock rotor has a diameter of 1 3/8" or so), and I don't know about drilling magnets...

Just for reference, a stator for a 50cc Scooter. This is one of the fancy multi-coil ones. I've seen em with just 2 coils as well.
Chinese Motorcycle and Scooter parts - Jinlun 50cc Scooter Stator / Generator

A 2-coil version: http://www.scooterparts4less.com/web_gas/4Stroke_Stator_2coil18mm_logo.jpg

Sojudave,

Some people don't want to mess with batteries and recharging them, or they don't have anywhere to hide batteries. Some of us just like to tinker If everybody was fine with a bandaid like batteries, no good advances would be made in anything.

 

[sojudave]

This whole core with the legs thing is bugging me. I just don't think it is absolutely needed. Though you're right, Ted, I didn't realize that's where it's closest. Anyway I've been reading a lot about alternators the last couple weeks (mostly axial flux design as used in DIY wind turbines) and it's becoming clear to me that you don't NEED the core. Granted, if you've got a piece of steel or iron to wrap the wire around, might as well. I just don't think we need the legs.

I think if we're worried about the inductance, we just need to go with bigger magnets. I would machine a round out of steel and remove material at each end for magnets, 1 N 1 S. These would preferably be N50 or N52 grade to get the best bang for the buck. Anyway, the magnets would then be epoxied or screwed into place (or both). This would give a much better rotor to work with.

I would say just use a diametrically magnetized cylinder magnet, but I haven't found anything with a hole in the middle that is a suitable size (I believe the stock rotor has a diameter of 1 3/8" or so), and I don't know about drilling magnets...

Just for reference, a stator for a 50cc Scooter. This is one of the fancy multi-coil ones. I've seen em with just 2 coils as well.
Chinese Motorcycle and Scooter parts - Jinlun 50cc Scooter Stator / Generator

A 2-coil version: http://www.scooterparts4less.com/web_gas/4Stroke_Stator_2coil18mm_logo.jpg

Sojudave,

Some people don't want to mess with batteries and recharging them, or they don't have anywhere to hide batteries. Some of us just like to tinker If everybody was fine with a bandaid like batteries, no good advances would be made in anything.

Hey sorry about my post. I didn't mean to bring down the creative process. I'm not usually like that and didn't realize it until after I posted and started thinking about it.

 

[jasonh]

Hey sorry about my post. I didn't mean to bring down the creative process. I'm not usually like that and didn't realize it until after I posted and started thinking about it.

Oh no it's understandable. it certainly would be WAY easier to throw on some batteries and call it a day. But a lot of people have been wishing for something like this. I think if this can be done cost effectively and is very simple for someone to bolt on, lots of people would be happy. Then I'm going to take it one step further and do up a good ignition for the performance guys.

 

[Walter F.]

Did somebody say performance guys? You guys have my head spinning, but I have a question, does anybody have a schematic of the CDI box and what does it contain besides smoke? Walter F.

 

[Retmachinist]

Ted, obviously you know something about electronics too. And you're right, if we all keep banging away at it methodically we should be able to make a substantial improvement.

When I originally called the white wire a tap to the coil: that was incorrect. I had yet to unwind a coil.

The white wire is actually connected to a completely separate inner coil of 300 turns. They wrapped 300 turns of 26GA. around the frame, soldered one lead to the frame, and the white wire to the other. They wrapped this coil with that white clothlike tape and resin.

Then they overlayed this with 3,600 turns of 35GA. wire, soldered one end to the frame and the other to the blue wire. Once again wrapped with tape and resin.

They share a common ground only. Unless it is possible: that this set-up is acting like a transformer through inductance I can't see that taking coil 1 out of the loop will affect coil 2. I think I'll wait for you to get your scope so you can look into it further.

I already did an exacto-destructo on one coil. I'm not a big hurry to fry something.

There's a ton more info here to answer...you guys got way ahead of me last night.

One other thing I was wondering. I'm fairly certan that coil frames are made up as a lamination due to cost? It is really cheap & practical to high speed stamp thin sheet metal and then rivet it together as opposed to machining a solid. Is there any difference in terms of electrical function? Would a solid steel frame work just as well?

Jim

Jim, I hope you guys get this figured out. I have an instument panel all wired up on my winter build with headlight and tail light wired through the white wire and switches. According to continuity everything is good but I haven't fired it up yet. I am using l.e.d.'s so I thought I would be o.k. but a better, or 12 volt system would be the ticket.
Thanks John

 

[jasonh]

Did somebody say performance guys? You guys have my head spinning, but I have a question, does anybody have a schematic of the CDI box and what does it contain besides smoke? Walter F.

I know Norman tried tearing into it once, but it's all epoxied up in there so hard to see what's going on.

My guess is just a couple basic things like capacitors and such, and maybe a small coil. it's really light so there can't be much copper in there, which is why the spark sucks so hardcore.

I'd like to know what voltage spark these little black boxes put out. My guess would be less than 10k. When I'm done, we'll have a nice fat 30kv spark, and probably better high-rpm spark performance.

 

[jasonh]

Jim, I hope you guys get this figured out. I have an instument panel all wired up on my winter build with headlight and tail light wired through the white wire and switches. According to continuity everything is good but I haven't fired it up yet. I am using l.e.d.'s so I thought I would be o.k. but a better, or 12 volt system would be the ticket.
Thanks John

If you put more than a couple watts worth of draw on the white wire, you'll probably have issues with the motor not wanting to run right.

 

[jasonh]

Hey I'm curious, can someone with a running motor (no running motor right now) and a voltmeter check the voltage of the blue wire while the motor is running? (AC volts please) I would just check the voltage between the blue and black wires, to get the best ground.

 

[Walter F.]

I wonder if one of the dealers who deal directly with the Chinese could get us a schematic? There is a copy of "The Two-Stroke Tuners Handbook" here somewhere (posted back in spring I think) and on the last page is a hand drawn CDI box schematic but is very hard to see. I think better performance lies in the CDI box as well as increased voltage from the magneto. Walter F.

 

[jasonh]

I'm going to ditch the CDI box all together. I will be going with a setup that is more like a car. The only thing the magneto will be used for is to trigger the spark, it doesn't need to be high voltage. But it does require a good 12v source. I think that will be the way to go. I think a transistor-assisted ignition will be easier and cheaper than a new CDI, not to mention better high-rpm performance.

I have found schematics for a multi-spark high performance CDI, but it would cost quite a bit to make.

 

[sojudave]

I know Norman tried tearing into it once, but it's all epoxied up in there so hard to see what's going on.

My guess is just a couple basic things like capacitors and such, and maybe a small coil. it's really light so there can't be much copper in there, which is why the spark sucks so hardcore.

I'd like to know what voltage spark these little black boxes put out. My guess would be less than 10k. When I'm done, we'll have a nice fat 30kv spark, and probably better high-rpm spark performance.

All I know is that a cracked CDI is not good for the ingnition process. BTW, Has anyone thought of adding the extra coil to a place outside of the cover? Make a small box and mount it to the cover or whatever?

 

[jasonh]

I've thought about it, even adding an entirely new rotor/stator assembly. The only problem is it would then require a wide crank, since there's not much clearance there.

 

[Finfan]

Jim: The laminated sheets of metal sound like the core for a transformer. On a transformer they are made that way to avoid something call "Hysteresis Loss" It is a way to break up induced currents in the metal which reduces power loss. I imagine that something similar is going on with a magneto. Good luck figuring that out!

 

[xPosTech]

Ted, obviously you know something about electronics too. And you're right, if we all keep banging away at it methodically we should be able to make a substantial improvement.

When I originally called the white wire a tap to the coil: that was incorrect. I had yet to unwind a coil.

The white wire is actually connected to a completely separate inner coil of 300 turns. They wrapped 300 turns of 26GA. around the frame, soldered one lead to the frame, and the white wire to the other. They wrapped this coil with that white clothlike tape and resin.

Then they overlayed this with 3,600 turns of 35GA. wire, soldered one end to the frame and the other to the blue wire. Once again wrapped with tape and resin.

They share a common ground only. Unless it is possible: that this set-up is acting like a transformer through inductance I can't see that taking coil 1 out of the loop will affect coil 2. I think I'll wait for you to get your scope so you can look into it further.

I already did an exacto-destructo on one coil. I'm not a big hurry to fry something.

There's a ton more info here to answer...you guys got way ahead of me last night.

One other thing I was wondering. I'm fairly certan that coil frames are made up as a lamination due to cost? It is really cheap & practical to high speed stamp thin sheet metal and then rivet it together as opposed to machining a solid. Is there any difference in terms of electrical function? Would a solid steel frame work just as well?

Jim

Even though they are two separate windings they act as one via the common series connection and the common core, and will interact.

A transformer is two windings (or coils) on the same core. A simple way to get multiple windings on one core is to tap one of the turns as you're winding. Cheap AC welders tap every few turns on the secondary, then add a high current switch for the different output currents.

You can also wind them individually and then connect them in series. This is done when higher current capacity is needed in one winding or the other.

The Chingineers (or Russians) used a transformer instead of two simple coils to get two outputs. We (US auto, MC, small engine) have usually used two completely different circuits.

Yes, the core is made up of stamped out sheet metal then riveted together at the mounting holes. Laminations are used to make multiple winding transformers to enable easily wound turns, then connected together. Imagine two sets of cores, one shaped like an upper case E, the other a mirror image. Once they are wound the ends are physically connected to make a core.

Ted