Ametek VAWT rewind

[fungus]

I've taken the old ametek out of service as its been replaced by the new gen, have been thinking of making a vawt out of an ametek for a while. I've got it dissassembled and taken a few photos (http://www.anotherpower.com/gallery/fungus?page=33) - theres 640*480 there and much larger photos (warning:4mb each) at high res.

Full specs of the motor from inspection:

DC motor

4. pole
   
21. armature segments
    
21. teeth
    
21. coils (I think)
    
    

wire is about 0.6mm dia - seems around 19AWG

Rated at 38v/900rpm(1100 OC)

The iron core is skewed, not sure how many problems I might have when rewinding?

16mm shaft, 17mm 6203 bearing

I'm thinking of rewinding it for a Lenz2 VAWT, probably a 3*2, not sure what rpm they give though? I know ed has geared an ametek to a lenz2 but I thought direct drive would be better.

A couple questions:

*Is there a standard wiring scheme for DC motors or will I have to figure it out myself?

*Any other suggestions?

I have seen FrankG's page on rewinding DC motors which was helpful but anyone got any other ideas?

Thanks,

Angus

[Flux]

*Is there a standard wiring scheme for DC motors or will I have to figure it out myself?

Yes. Dc machines use a closed winding and will be lap or wave wound. In your case with 21 comm segments the probability is that it is wave wound. There are whole books written on dc windings, I always found lap logical, I never really got my head round the wave winding but there are standard formulae for slot and commutator numbers for wave windings.

With 4 poles, if it has only 2 brushes then it must be a wave ( it could still have 4 brushes as a wave). If the ends of one coil go to adjacent segments then it is lap. If they go diametrically opposite it is a wave.

You must keep the coil span and commutator connections unchanged.

It looks to be machine wound and you will not achieve that winding density with hand winding especially on a first attempt. You will also struggle with those staked connections to the commutator.

Good fun project to learn on.

Flux

[andyman5002]

Hey Angus if you decide you dont want to attempt the project, I would be interested in buying the unit off of you if you are no longer using it?

Ive been thinking of setting up a small mill for a while now as my motor conversion is too big and have been looking for an ametek.

Cheers Andy

[electrondady1]

hi fungus ,

glad to see you try a vawt.

we  "believers" (lol) can use your help !!

it seems most drag type vawt's top out at around 120 rpm

ed's lenz2 design is capable of over 200 rpm.

still i think that's along ways from what your alternator would require

without an overdrive of perhaps 3 or 4 to one .

one thing you might want to design in right from the start is a breaking system.

if you build a mill capable of overcoming the start up torque requirements.

it will probably have no problem overpowering a shorted out alternator in high winds.

good luck with your project.

[fungus]

Well started unwinding it , there is 40 turns per coil.

I marked both the laminations and the commutator segments

I've taken out 4 coils so far, made a table of the start slot, end slot , start segment, end segment;

1:start slot 2:end slot S:start segment E:end segment

#1 : 1:17 2:1 S:3 E:13

#2 : 1:7  2:12 S:14 E:3

#3 : 1:16 2:21 S:2 E:12

#4 : 1:6 2:11 S:13 E:2

There is two brushes, and there is two 'sets' of coils that overlap each other by one slot and the connections by one commutator segment, looks like a lap winding?

[Flux]

No , its wave wound. It has to be to use 2 brushes on a 4 pole winding. A wave only has two circuits and can always run with 2 brushes. A lap need the same number of brushes as poles.

Your commutator connections also indicate wave, with a lap the coil ends go to two adjacent segments.

What you have done to keep tabs on the coils and connections is fine. Somehow you will have to label or identify the coil ends when you wind, everyone has different methods.

Good luck you are young and keen.

Flux

[fungus]

Also does anyone know the best TSR to run a Lenz2 at? not sure ..

[wiredup]

hey andy what type conversion motor do you have.you know size in h.p. and # of mags and what size mags.i have two ametek 30s i might trade for the right conversion motor.......johnny

[andyman5002]

Hi johnny, it was a 4 pole 3HP motor, I can't remember the mag sizes now, I think I used 15 mags per pole. Me and my dad put a lot of effort into it and would like to use it someday and I think he would be a bit peeved if I traded it, but thanks for the offer. If your willing to sell one I would be interested??

Andy