Building rotors

[bj]

Got first two rotors built, so decided to mount them on the spindle,

and do a little coil testing.  They turned out nice and true, so I was

happy with them--until--aren't they supposed to attract each other?

Can't believe I made such a stupid mistake.  Good thing I am building

two ten footers, as I will still be able to use both of them.  That is if

I can cure this little brain disconnect that seems to be the problem.

bj

[TomW]

bj;

Do they repel each other?

If so, maybe you can offset rotors by an odd # of magnet spaces?

I had one that was doing that and all it took was rotating one rotor by a half turn [I think]. Its been awhile so maybe it was a quarter turn? I had pulled it apart to grease it and my grease pencil marks got munged by handling so I knew it was right once so may not apply to your situation. I now grind a divot on both rotor edges to avoid this problem in the future.

Good luck with it and hopefully its not a total wash.

Tom

[tecker]

The only thing that may work is to red rill holes to compensate. Reuse for anothe unit is better.

[Flux]

Depends on the number of fixing holes in relation to the number of magnets. There are some cases where turning one rotor will correct things. In other cases it doesn't work.

In this case it would be far more sensible to build the other two to suit but for a single machine it would need re drilling and all the problems associated with drilling a complete rotor with magnets on. It can be done but needs thought and care and in this case it is not a wise move.

Flux

[kajs]

they not only should attract each other, but also neighboring magnets should be of opposite polarities facing up (upper sides of siblings must attract too)! it sounds that you have skipped that part.

[bj]

Tom--thanks for good luck wish, all is not a total loss.  Twelve magnets

per rotor, so I could just redrill the holes one magnet over and it would

work, and I may do that, or just make an opposite pair, and then I will

have two working sets.

I think I made the mistake when putting magnets on the second disk.  Placed  one right, and noticed I had not made my witness mark on the second rotor, so took off the magnet and grilled in my mark.  Somehow must

have flipped it when I put it back.   The N,S,N,S orientation is correct

on both rotors, just one magnet out.  Like I said before,  DUMB.

Up side is that second set will be easier.

bj

[bj]

Flux-- twelve magnets, four locating holes.  I can redrill the back rotor

one magnet over--40 degrees, or just make the second set as mirrors of the first two, but one magnet over.  Maybe I need a few less coffees in

the morning.  Couldn't believe the strength they had repelling each other.

When they are finally right, all the Dan's warnings will be well heeded.

thanks  bj

[bj]

Typo--should read 30 degrees

bj

[MattB]

um... if you have 12 magnets, and 4 bolt holes, you should have opposite groups of 3 magnets in relation to each bolt hole.. just rotate that rotor 90 degrees.

[bj]

MattB  think my head has been in a dark smelly place the last few days,

you are absolutely correct. All is fine now-on to test coils.

Many thanks

bj

[TomW]

Hehe.

Exactly as it was with mine when I reassembled it wrong.

Despite being funny looking Matt knows his stuff!

Glad you figured it out "the easy way".

Tom.