Armature flats and strobe lights, to do with making a motor synchronous

["Kelly & Phillipa Williams" <kellyw-at-xxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

Hi ,

I have continued playing with our old washing machine motor with the object
of making it synchronous.
It is currently in it's unmodified condition. When we make a dot with twink
on the rotor, and turn it on, we see a yucky blur under fluorescent light.
It seems my fluorescent light is not working too well as a strobe light at
50 Hz - it's a *really* old crappy light salvaged from an office that was
throwing it away.
I thought the motor, even though it is unmodified (still 'slipping') would
still be running close enough to 50 Hz
(unloaded) for you to see the twink dot, even if it moves relative to the
case.
Q> is the motor not close enough to 50Hz to see the dot, or is our
flourescent light not working properly?

In a search for new ideas, I thought we might use the 555 ignition coil
driver circuit for getting continuous arcs / sparks, but modify the 555
frequency to get 50 Hz, run it through the ignition coil, and attach a xenon
flashtube (used for spark timing in cars).  This should give us the 50 Hz
necessary (mains frequency in NZ).  The only thing I'm not sure of is the
duty cycle.  Does it really matter?  Can I just use a 50% duty cycle, or
just match it to whatever works with the xenon tube?

I have an angle grinder and all the accessories, I thought that once I know
how to get a strobe light I will start grinding flats (2) on the armature, a
tiny bit at a time, and then recheck it against the strobe light, till the
twink dot stays at the same place relative to the case of the motor.

The motor is a 12 pole / 2 pole multispeed motor, I would use the 2 pole
speed, would that give an RPM
of 3000? (50Hz)

Is this all on the right track, or am I wildly off course here?


Thank you,

Alan Williams