Airhead Charging System Secrets

[RecycledRS]

Originally Posted by hardwaregrrl

I'm just saying, they ain't bulletproof!

Too true.

[norton73]

All my rotor failures (3) were after running down the interstate for 6-7 hours. Running 4K or so on the R90S, 5.5K on the GS. So far (fingers crossed) the Motorradd ElecticK on the GS has held up well. But I carry a spare on any overnight trip.

[Stagehand]

I've had three rotors go bad including one of Ricks 400w units.

Had a hairline crack in a stator wire that would only stop charging when it got warm.

Had it be the battery itself more than twice.

Once or twice it was wires (including the main negative) that had just vibrated/corroded into oblivion forming a high impedance air gap.

Have blown the charge light.

dont think a diode board has given me trouble.. maybe once, maybe way back on the R60... Now I am Very grounded.

Voltage regulator... just once I think.

[Stagehand]

[QUOTE=RecycledRS]

[I]

Your point regarding mechanical stress is a good one however since the stator and rotor are magnetically linked, any additional load on the stator will will be transmitted to the rotor resulting additional mechanical stress (your point), heat and induced AC frequencies from the stator. The fact that the rotor is DC supplied does not mean that the stators AC influence via Counter Electromotive Force (EMF) are not felt in the rotor. If we were to look at the rotor current using an oscilloscope I suspect there would be substantial AC influence. The power in the stator comes from the rotor.

I assumed that by mechanical stress on the rotor you meant the fact it was press fit onto the nose of the crankshaft, and not buffered at all from its mechanical shocks and pulses. This is what I was led to believe was behind the presumably premature demise of rotors, generally.

[RecycledRS]

The mechanical stress I was referring to is due to the stator and rotor being linked magnetically.

When the stator is loaded to 280 watts that equates to approximately 1/3 of a horsepower. That power has to come from some where and it is the rotor (via the magnetic link). This is in turn supplied by the cam shaft rotation. Since that magnetic link is ultimately produced by the coil winding, it too is stressed.

In addition, the coil is also subject to AC harmonics induced from the stator (once electron flow occurs in the stator winds it also forms magnetic fields which induce counter electromotive force, EMF, into the rotor). Harmonics can set up substantial high frequency vibration within the coil and thus cause additional mechanical stress on the winding insulation.

Of course these factors are in addition the centrifugal forces on the coil winding and vibration inherent from being mounted on the end of the cam shaft.

[Joerg]

Originally Posted by Stagehand

Now I am Very grounded.

PS: I hope you're not into airline business

[Beemerboff]

When the rotor goes it is often the last solder joint between the winding and the commutator.

ESPECIALY IF YOU FIT A ALTERNATOR MOUNTED IGNITION AND FOLLOW THE INSTRUCTIONS TO CLEAN OFF ANY PROTRUDEING SOLDER ON THE END OF THE ALTERNATOR !

You can check by lightly cutting the shellac on the wires as they exit from the coils with a box cutter blade and checking for continuity from there.

I have heard of tales folks who have pressed off the commutator , unwound a coil of wire, refitted the commutator and resoldered the wires, but I havent seen it done outside of a rewinding shop.

[Wirespokes]

Originally Posted by RecycledRS

This is in turn supplied by the cam shaft rotation.

The cam only drives the points or hall sensor, not the alternator, which is mounted directly to the crankshaft. This is the case on the /5 and newer airheads - earlier, I don't know how they worked.

Stagehand - I doubt there's any stress from being pressed onto the crank. But you're right about it being subjected to vibrations and rotational forces, besides the magnetic loads we all know about.

[RecycledRS]

Originally Posted by Wirespokes

The cam only drives the points or hall sensor, not the alternator, which is mounted directly to the crankshaft.

Crankshaft of course. Thanks for the correction.