Another Stator/Rotor Question

But even if a new ‘74mm’ stator was a push fit on the rotor, a 75mm would have .020” clearence all round!

That can’t be right can it?

If it is right, is it safe to bore 1mm out of a new stator?

My rotor are 74,2 mm and stator are 75 mm (orginal?). Before I mounted the stator, I put it on the lathe and freshened the hole because there was some pieces of plastic stuck out of the stator so the hole was smaller.
Then it have a gap on 0,4 mm. I also drill out the three hole a little bit and set it up with more clearece between 1 to 5 o’clock.

Again too we are back to determining how much generating power is lost when you exceed 10 thou.
If 20 is not a noticeable loss then 20 seems like a great idea.
But facts first!

time better spent learning rather than just wondering
The single or three phase stator coils are wrapped alternately and sequentially around the stator.
if one magnet is farther from the coil by a few thou then on the opposite side the rotor will be CLOSER by a few thou.
it averages out..no change even if it is perfectly centered..
only by reducing the rotor diameter or increasing the bore of the stator will there be a change in power.
Elimination of friction is the first goal, having full strength in the rotor is second.
25% low gauss is not satisfactory despite passing screwdriver hang test which IMO is juvenile...
That's from "measuring" the rotors with a gauss meter...then spin testing them on a piece of test equipment.
I have demonstrated all of this at local norton club tech sessions.

FWIW
When I fitted a Lucas 3 phased on my bike I noticed it was a about .006” in a couple of places. Upon examination I saw it was actually the potting/insulation that was the problem. Simply cleaned it up with a round file and it has been good for over 15k miles. Never had to touch the metal in the stator or on the rotor.
May not be the case for everyone, but just something to think about.
Pete

My new Lucas 240W 3 Phase required shaving metal and potting material in the 1 to 3 O'clock area.

Onder said:

Contact WILL cause smoke and then fire. Anybody remember the date run on the rotors that were prone to
cracking and losing their magnets? We talked about it at one time.

Click to expand...

A friend's Nort. stopped putting out power then smoke out of primary during a group ride. We pulled the primary cover and an atom bomb of white smoke came out. Many chunks on the bottom to clean out. He drove home with primary outer cover strapped to seat and all lighting off. Battery power. Expensive day.

<only by reducing the rotor diameter or increasing the bore of the stator will there be a change in power>

so if we turn the rotor down or turn the centre of the stator out where does 20 thou v 10 leave us?
Less power, but how much less?