Connecting Coils for the stator

[d3lilley]

I am building a stator that is supposed to charge a 12v battery. I just finished winding 6 coils, and I have several questions. Do the coils need to be equidistant away from each other? Also, I need help with connecting the coils. I've been looking at different websites and I got a bunch of different possible ways to do it.

The first option I saw was to solder on flexible wire to both ends of each coil, and have all the wires rap around the outside of the coils and go out of the mold. Then it said  to connect them to "connection blocks(not sure if I am using the right term." I am skeptical about this method because if I do this method then I will have 12 different wires leading out of the stator mold, and it seems like it could be a mess.

Second option I saw was soldering the ends of each coil together, except leaving one end of one coil attached to flexible wire that will lead out of the stator mold, and this wire will be directly attached to a controller.

Third option - (this ones a bit harder to explain)  Imagine the six coils in a circle. I would solder every other coil to each other. For example, coil # 1,3, and 5 and coil # 2,4, and 6 would be connected to each other, and I would leave one end of each coil open and solder it to flexible wire and have it lead out of the stator mold.

These were just the three best options I saw, their were plenty more but they did not make sense to me.

Which do you think is the best option? Or is their another method that would work even better that I just overlooked?

[wpowokal]

What plan are you following?

Google search this board for "3 phase basics"

Though with six coils I wonder what your plan is, most basic units have 9 coils.

allan

[Flux]

Unless you know what type of winding you are using ( which it seems you don't)then your best option is to bring all the coil ends out ( and you are right it can be a mess)

Normally many of the coil interconnections are done inside the mould and only 3 leads come out but this only applies to a 3 phase star connected winding.

If you don't have details of the type of winding are you sure you have the correct number of turns and size of wire. Far better to follow some plans that are known to work if you have no basic idea, there are just too many things to go wrong.

The coils should be equally spaced but you don't need and won't be able to achieve absolute perfection with hand wound coils.

Flux

[gotwind2]

You would be best to buy Hugh Piggotts 'A wind turbine recipe book' - Google it.

You can rely on that as being accurate.

Ben.

[d3lilley]

For the most part, I am following http://www.scoraigwind.com/pmgbooklet/itpmg.pdf It says to attach it to flexible wire. Could I do it another way that is a little more organized.

[Flux]

This is from memory but I think that is a 6 coil 8 magnet 3 phase star connection.

You can connect the 2 coils of each phase in series ( join start to finish)

That leaves 3 starts and 3 finishes. Join your 3 starts together as a star point and you are left with 3 leads to bring out.

You can make the connections on the outside of the coils but keep them within the mould. You could do the connections inside the coils but space will be severely limited ( I wouldn't try it that way on a small machine).

If you want to retain some versatility you could connect the phase coils in series in the mould but bring out the 6 ends and do the star point externally, that way you have the option of a delta connection if you want it.

Flux

[TheCasualTraveler]

     If this is your first stator I would bring all the wires out of the mold and make your connections after the stator is poured. Not the prettiest way but 1 wrong connection or 1 reversed coil inside the stator and you have a pretty worthless stator. It also allows you to try out different wiring configurations.

     Just the humble opinion of one who also was confused at that stage.

[d3lilley]

Thanks for the advice. I decided to attach all of them to flexible wire, and then I think I will put it into a star connection. Only problem I am having now is soldering the magnet wire to the copper wire. I've soldered before, but usally I can twist the wires together to make it easier to connect, but the magnet wire does not "twist" together with the flexible wire. Anyone have any links or advice on how I should go about this? It took me about 20 minutes to get one coil done...

[d3lilley]

When I wrote about soldering the magnet wire to the copper wire I meant soldering the magnet wire to the flexible wire. Sorry I hit post instead of preview by accident.

[TheCasualTraveler]

    when I did my first stator I did not solder any wires on till after the stator was poured. I just brought the magnet wire out of the mold. Look in my files for stator.jpg

     It sounds like you did not scrape  the varnish off the magnet wire. You need to use fine sandpaper and clean the clear insulation off the magnet wire. The wire will look reddish brown with the clear insulation/ varnish on it and when clean will look like bright copper. Clean a half an inch or so of the end of the wire, then you may want to "tin" the wire to make soldering easier. Take your soldering iron and solder  and coat the end of the magnet wire until it is smooth silver. Then joining them should go easy.You can then twist the flexible wire around the magnet wire to hold it in place. Make sure you are using the right solder, rosin core. Do not use acid core that is for plumbing pipes.

[d3lilley]

Can I just use a propane torch and heat the end of the magnet wire untill it gets red hot? Will that burn the insulation off?

[Flux]

Yes you can burn the insulation off but you will need to clean off the oxide to be able to solder it. If you burn it off and dip the still hot wire in methylated spirit it will come out much cleaner but you will still have some cuprous oxide to remove.

In the end for reasonably thick wire the quickest way is to scrape it with a sharp knife. Abrasive paper is better for the very fine wires but slow for normal sizes.

One of those things that comes with practice.

Flux

[TomW]

stator.jpg:

[Fused]

Heres a idea I found from reading here at FL.

I attached all 12 leads to their own brass bolt for connections to remain open for experimenting with different wiring schemes. I used deox on all connections to help prevent corrosion.

Hope it helps

Fused