..or alternator/magneto/generator whatever you want to call it, though stator is the correct term 
Note that these instructions apply to the FZ6, but it could be used for other bikes provided you follow the table below. It's assumed you have correctly diagnosed a broken stator (make sure you measure it's output in AC!)
Tools/equipment needed:
- Allen key set (or the big one from your bike tool kit)
- Pliers
- (glass) needle nose pliers (with a smooth grip, i got some from maplins for £5)
- 500g of 18 gauge (1mm) insulated copper wire, I used two 250g coils
- epoxy resin (i used car fiber glass repair kit stuff, it says it resists oil/chemicals/water etc). Araldite didn't seem to be temperature resistant enough
- T30 torx screw driver
- a mechanic friend on standby
- soldering iron
- silver solder (the best for this apparently, i used lead-free tin stuff)
Step 1: Remove the stator assembly
- Unbolt the stator cover on the left of the bike
- Trace the wire up under the tank and unplug it
- You might need a tap with a rubber mallet, but you should be able to pull the whole thing out now
- bear in mind that it's being held in place by some strong magnets too
- there's a magnetic gasket that you can reuse
- watch out for cogs falling out, but they are easy to put back in
- use a jug or something to catch the dribble of oil that will come out
Step 2: Unscrew the stator
- This might be tricky, the 4 torx (T30) screws inside are all threadlocked in, be sure to use good quality tools, and make sure you have a good hold on them
- I ended up slicing my hand open and going to A&E during this step, so be careful of sharp edges.
- I also had to get the wire cover drilled out by a mechanic as it was well and truely stuck. I could probably have gotten away with leaving it in, cutting the wire and soldering it back on later
3) Uncoil the stator
- Cut the 3 wires connecting to the cable, try and cut them on the wire
- Then try and find the last strand to be wound on and start unravelling it all using a pair of pliers
- keep hold of the plastic insulating bits around the wires, we'll use them later
- IMPORTANT: try and remember how many turns are on each coil, also try and remember how they are connected, I didn't do this properly and hence had a lot of problems. Though now I know how it works, so the most important thing to know is the number of turns, as this equates to the output voltage
- This will take an hour or so, try and leave the insulation on the iron core
4) Repair the core
In my case one of the wires had shorted out and burned a hole through the insulation. I mixed up some epoxy and covered all the exposed bits of metal i could find next to where the wire would be coiled.
5) A discourse on inductors and stators
Before we start winding we need to understand the interaction between the magnets and inductors (coils).
Our bikes create 3 phase voltage. Each of the 3 wires coming out of the stator is generating an AC voltage, each of which is out of phase with the others. There are 3 different wires that wrap around the iron core. All the wires are connected together at one end, this act like an internal ground, this is called a WYE configuration. It is probably possible to use a delta termination too, which is supposed to give a smoother output and be more fault tolerant. I just copied off what yamaha did originally. To wire in a delta fashion each end of the wire is connected to the start of the next (1-2, 2-3, 3-1), and at these points we tap the wires for power (i.e. connect up the external wire too)
The next big issue which I have is that most internet guides (usually for fireblades), suggest using an ABCABC pattern, which won't work on our bikes. This is because we have a different number of magnets (you can see them inside the flywheel if you look closely)
I also need to explain the naming convention. ABCABC means we have 3 different wires, (A, B and C), and that we connect 6 of the poles on the stator in that order (direction doesn't matter). So pole 1 is A, pole 2 is B, pole 3 is C, pole 4 is A, etc. The capital letter means each is the same direction. Lower case would mean the opposite direction
For the FZ6 we use the following pattern: AaABbBCcCAaABbBCcC
That is we have an 18 pole iron core, with groups of 3 poles all using the same wire, and alternating direction
i.e.
Pole 1: Wire A, Clockwise
Pole 2: Wire A, Counter-Clockwise
Pole 3: Wire A, Clockwise
Pole 4: Wire B, Clockwise
Pole 5: Wire B, Counter-Clockwise
Pole 6: Wire B, Clockwise
etc.
Each wire is wrapped 24-25 times around each pole
eg:
As I understand it groups of alternating coils on the same strand act like a single coil (but we don't need to know that)
For other bikes you could count the magnets and number of poles on the stator and work out the configuration using this table:
http://forumrc.alexba.eu/nutpol_e.htm
Presumable other bikes only use 12 magnets, and not the 16 of the FZ6.
Judging from the R6 stator I have this is also the case too.
6) The wiring
Pick a place to start and choose a direction, as long as you do it all the same way it doesn't matter.
- Start with a pole, and leave about 6"(15cm) of spare wire and begin wrapping from the center
- It's important to keep these as tight and neat as possible, I used the roll the wire came on to keep them tight, and using my fingers and some non-metal tools to push the wire around.
- You should be able to get 10-11 complete revolutions around each pole on the first layer.
- After the first layer work your way back to the centre, and make sure none of the wires overlap, as this wastes space.
- Wrap the wire a total of 24.5 complete revolutions around the core.
- I counted each half revolution as a "turn" (how many times i turned the core over), and did a total of 49 turns per core
- Try and finish your 3rd layer in the center
- 1 or 2 turns difference shouldn't make too much of a different, but try and keep it the same as the spec.
- For each group of three you should be changing direction, going CW, CCW, CW
- After the group of 3 is done, make a wire go around the inside to the next set of pole and begin again
- I used the pliers to carefully compress some of the windings, which gave me plenty of space for the others
- Leave another 6" of free wire when you finish
- Repeat this for the other 3 cores
7) Joining it
- Lay the wire in place for where you want it to be, the end of the wire will all be connected together on the side of the stator with the wire holder. The other ends will be soldered onto the main wire, try to have these ones finish close to the wire clip so that the wire will reach.
- Once you have the right length, clip the wires to the right length, and sand the enamel off the ends of the wire
- Join the 3 ends together (on my diagram A12 B15 C18), use pliers to wrap them together and solder the ends
- Cover any exposed wire with some of the cloth from the start, and try and bend them down a slot so that it won't come loose
- Solder each of the remaining ends to the main wire, I found this a bit tricky as they didn't want to stick. It's best to put the cloth insulator on before you solder, you can then move it over the join, and tuck it under the clip and keep it secure
8) Test it
measure the resistance between each of the 3 wires, and also the core, they should be the same (<1ohm), and there should be no continuity to the metal core. You should also check this as you assemble it too
9) Sealing it
- mix up some more epoxy and coat the wires and any potential dodgy areas with epoxy, being sure to leave the inside bit of the core clean
10) install it
- screw it back in, make sure the epoxy is dry and the wire is out of the way
- i used blue threadlock to stop the bolts coming loose
11) test it
- fire the bike up, measure the output voltage in AC between each connector, it should be 30-60V, plug it in and check your battery is charging
Below are some of my pictures as I was wiring it. You can see how I did the first strand, and how I kept the wire tight
Spot the mistake in the 1st picture though, I wound 2 adjacent coils in the same direction, and had to unwind it and do it again, luckily i spotted it straight away.
keep the wire pulled tight with each turn, or you will run out of space
Note that these instructions apply to the FZ6, but it could be used for other bikes provided you follow the table below. It's assumed you have correctly diagnosed a broken stator (make sure you measure it's output in AC!)
Tools/equipment needed:
- Allen key set (or the big one from your bike tool kit)
- Pliers
- (glass) needle nose pliers (with a smooth grip, i got some from maplins for £5)
- 500g of 18 gauge (1mm) insulated copper wire, I used two 250g coils
- epoxy resin (i used car fiber glass repair kit stuff, it says it resists oil/chemicals/water etc). Araldite didn't seem to be temperature resistant enough
- T30 torx screw driver
- a mechanic friend on standby
- soldering iron
- silver solder (the best for this apparently, i used lead-free tin stuff)
Step 1: Remove the stator assembly
- Unbolt the stator cover on the left of the bike
- Trace the wire up under the tank and unplug it
- You might need a tap with a rubber mallet, but you should be able to pull the whole thing out now
- bear in mind that it's being held in place by some strong magnets too
- there's a magnetic gasket that you can reuse
- watch out for cogs falling out, but they are easy to put back in
- use a jug or something to catch the dribble of oil that will come out
Step 2: Unscrew the stator
- This might be tricky, the 4 torx (T30) screws inside are all threadlocked in, be sure to use good quality tools, and make sure you have a good hold on them
- I ended up slicing my hand open and going to A&E during this step, so be careful of sharp edges.
- I also had to get the wire cover drilled out by a mechanic as it was well and truely stuck. I could probably have gotten away with leaving it in, cutting the wire and soldering it back on later
3) Uncoil the stator
- Cut the 3 wires connecting to the cable, try and cut them on the wire
- Then try and find the last strand to be wound on and start unravelling it all using a pair of pliers
- keep hold of the plastic insulating bits around the wires, we'll use them later
- IMPORTANT: try and remember how many turns are on each coil, also try and remember how they are connected, I didn't do this properly and hence had a lot of problems. Though now I know how it works, so the most important thing to know is the number of turns, as this equates to the output voltage
- This will take an hour or so, try and leave the insulation on the iron core
4) Repair the core
In my case one of the wires had shorted out and burned a hole through the insulation. I mixed up some epoxy and covered all the exposed bits of metal i could find next to where the wire would be coiled.
5) A discourse on inductors and stators
Before we start winding we need to understand the interaction between the magnets and inductors (coils).
Our bikes create 3 phase voltage. Each of the 3 wires coming out of the stator is generating an AC voltage, each of which is out of phase with the others. There are 3 different wires that wrap around the iron core. All the wires are connected together at one end, this act like an internal ground, this is called a WYE configuration. It is probably possible to use a delta termination too, which is supposed to give a smoother output and be more fault tolerant. I just copied off what yamaha did originally. To wire in a delta fashion each end of the wire is connected to the start of the next (1-2, 2-3, 3-1), and at these points we tap the wires for power (i.e. connect up the external wire too)
The next big issue which I have is that most internet guides (usually for fireblades), suggest using an ABCABC pattern, which won't work on our bikes. This is because we have a different number of magnets (you can see them inside the flywheel if you look closely)
I also need to explain the naming convention. ABCABC means we have 3 different wires, (A, B and C), and that we connect 6 of the poles on the stator in that order (direction doesn't matter). So pole 1 is A, pole 2 is B, pole 3 is C, pole 4 is A, etc. The capital letter means each is the same direction. Lower case would mean the opposite direction
For the FZ6 we use the following pattern: AaABbBCcCAaABbBCcC
That is we have an 18 pole iron core, with groups of 3 poles all using the same wire, and alternating direction
i.e.
Pole 1: Wire A, Clockwise
Pole 2: Wire A, Counter-Clockwise
Pole 3: Wire A, Clockwise
Pole 4: Wire B, Clockwise
Pole 5: Wire B, Counter-Clockwise
Pole 6: Wire B, Clockwise
etc.
Each wire is wrapped 24-25 times around each pole
eg:
As I understand it groups of alternating coils on the same strand act like a single coil (but we don't need to know that)
For other bikes you could count the magnets and number of poles on the stator and work out the configuration using this table:
http://forumrc.alexba.eu/nutpol_e.htm
Presumable other bikes only use 12 magnets, and not the 16 of the FZ6.
Judging from the R6 stator I have this is also the case too.
6) The wiring
Pick a place to start and choose a direction, as long as you do it all the same way it doesn't matter.
- Start with a pole, and leave about 6"(15cm) of spare wire and begin wrapping from the center
- It's important to keep these as tight and neat as possible, I used the roll the wire came on to keep them tight, and using my fingers and some non-metal tools to push the wire around.
- You should be able to get 10-11 complete revolutions around each pole on the first layer.
- After the first layer work your way back to the centre, and make sure none of the wires overlap, as this wastes space.
- Wrap the wire a total of 24.5 complete revolutions around the core.
- I counted each half revolution as a "turn" (how many times i turned the core over), and did a total of 49 turns per core
- Try and finish your 3rd layer in the center
- 1 or 2 turns difference shouldn't make too much of a different, but try and keep it the same as the spec.
- For each group of three you should be changing direction, going CW, CCW, CW
- After the group of 3 is done, make a wire go around the inside to the next set of pole and begin again
- I used the pliers to carefully compress some of the windings, which gave me plenty of space for the others
- Leave another 6" of free wire when you finish
- Repeat this for the other 3 cores
7) Joining it
- Lay the wire in place for where you want it to be, the end of the wire will all be connected together on the side of the stator with the wire holder. The other ends will be soldered onto the main wire, try to have these ones finish close to the wire clip so that the wire will reach.
- Once you have the right length, clip the wires to the right length, and sand the enamel off the ends of the wire
- Join the 3 ends together (on my diagram A12 B15 C18), use pliers to wrap them together and solder the ends
- Cover any exposed wire with some of the cloth from the start, and try and bend them down a slot so that it won't come loose
- Solder each of the remaining ends to the main wire, I found this a bit tricky as they didn't want to stick. It's best to put the cloth insulator on before you solder, you can then move it over the join, and tuck it under the clip and keep it secure
8) Test it
measure the resistance between each of the 3 wires, and also the core, they should be the same (<1ohm), and there should be no continuity to the metal core. You should also check this as you assemble it too
9) Sealing it
- mix up some more epoxy and coat the wires and any potential dodgy areas with epoxy, being sure to leave the inside bit of the core clean
10) install it
- screw it back in, make sure the epoxy is dry and the wire is out of the way
- i used blue threadlock to stop the bolts coming loose
11) test it
- fire the bike up, measure the output voltage in AC between each connector, it should be 30-60V, plug it in and check your battery is charging
Below are some of my pictures as I was wiring it. You can see how I did the first strand, and how I kept the wire tight
Spot the mistake in the 1st picture though, I wound 2 adjacent coils in the same direction, and had to unwind it and do it again, luckily i spotted it straight away.
keep the wire pulled tight with each turn, or you will run out of space
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