rewind progress

[fungus]

Got the wire I needed , theres 140 turns of #28 in each slot there , wire is just big enough to be 'handle-able'








It's going to be a tight fit in there..

[electrondady1]

fungus are you actually keeping track of the turn count as you go?

 or are you using a specific lengh of wire per coil ?

[Flux]

That is the thing that distinguishes a winder from the average person, it takes a lot of self control to count turns. Small errors don't matter much but more than a few turns error will be problematic.

With hand winding wire length is no use, each coil gets progressively longer. It would work for pre wound coils but you can count them with a counter on the winding machine.

Making a mark every 10 turns is not a bad idea, then when the phone rings or you get disturbed you don't loose count.

Looking good so far, you will sweat blood on the last few coils.

Flux

[fungus]

The way I'm doing it:

Dividing it into sections of 20 , I am laying the wire in by hand, then writing down the number of turns on the chart so I know where I'm at , seems to work quite well, so I can go away for a while if I need to.

[fungus]

But I've run out of wire with 6 to go .. ordered some more so ..

A couple questions:

Would it really need lacquer and how could that be done?

Is it possible to solder the connections to the commutator? I've tightly twisted the wire around and then 'crimped' the stakes so far but I would have thought solder would make it more reliable ..

And what would be the best thing to put over the tops of the slots? I know motor slot lining would be best but not got any here..

[ZooT]

Epoxy would probably work ok over the wires in the slots, particularly if you worked it in a bit to "pot" the wires.

At the motor shop I used to work at we used "sticks" over the wires, they were strips of thin plastic or something that looked like wood and then we'd tie or/and tape the open loops on the ends and dip the entire thing in varnish and bake it to pot everything solid.

I don't know how much of a difference it'd make on a fairly low speed wind turbine generator...but on a 3500rpm electric motor....if it's not rock solid the insulation will wear off the wires from friction over time if it doesn't self destruct first from the open loops on the ends of the rotor stack expanding outward till they hit the stator coils.....

[ghurd]

I'm glad I didn't flat out say it was impossible!

I soldered the wires in the crimped things.

If you have Sherwin-Williams, they bought Krylon. Part numbers may have changed, again.

I use Krylon V1 (1405), V2 (1385), and V3 (1386).  Spray can stuff.  About US$7.50 a can. Holds the coils in place pretty (very?) well.  I can't remember which was better when I used it, either V2 or V3.  It's runny and really wicks into the windings.  

Makes it makes it quite solid and a pain to remove (not that mine didn't work perfect the first time).  :-O

Mine just didn't work.

G-

[Flux]

Yes you will need to solder the wire to the commutator tags, you will never crimp them satisfactorily. You did clean the insulation off before you twisted it round didn't you?

You will not need slot wedges for a VAWT, but if you want to be sure bits of wooden dowel will do. Ideally you need to varnish it, it will never be worth using proper oven bake varnish, just use an air drying varnish from RS or even polyurethane wood varnish ( Ronseal) will be good enough. I wouldn't use epoxy, if you need to alter it you will wish you hadn't.

If it was running at servomotor speeds you would need to be much more careful.

Flux

[fungus]

Yes I did strip the ends first ..

Just thinking I did take apart another (smaller/less useful) DC motor a while back and have the slot liners (it wasnt varnished ..) which might just be the right size ...

I had thought about wood varnish too , seems like it could work well .. I assume that would be painted on thickly or would dipping be much better? The krylon stuff sounds good too , will have a look ..

[Norm]

I use a $1 pedometer taped onto my foot

and tap my foot for each turn...then

when finished with one segment write it down,

and reset the pedometer....

[blueyonder]

 hay fungus your doing a good job there.

 and thanks for the very good pics . now i can see what is involved .

  a while ago i thought doing a rewind wasent for me.

  well now im dead sure it isent.

  i think my hands -fingers and brain are to stiff for that kind of thing.

   but i did save the pics you posted.

  who knows .maybe one day.

  and thanks gurd for being honest about your rewind.

 dont worry about it being a tight fit. your just a lucky boy.