Another Motor to convert

[fungus]

Got another motor to try to do a conversion on. I found this at a scrappy and quickly nabbed it at 7 pounds 50 :-)

It was still in full working condition apart from one blade that was bent; making it vibrate. I've straightened out the blade and I may use the set as blades; the blades are around 2' diameter. I was thinking 4 pole for it, reading this post: http://www.fieldlines.com/story/2006/12/24/154525/44

This would use up the remainder of my magnets (1/4" by 1/2" cylinders) nicely with 4 magnets per pole. The motor does only have bushings so I may replace them with bearings; the bushings are easily removeable. The motor itself has no power rating although the controller for it was rated for 250w. This should maybe give me 60w max I'm guessing.

I can get the rotor turned down on the lathe at school so I will be able to do so tomorrow or the next day. I was planning to just turn it down, epoxy the magnets on and put heatshrink over the whole lot.

Do I seem to be going along the right line here? Any suggestions or improvements would be brilliant.

Heres some pictures:

[fungus]

Some information I forgot to add.

It has 6 wires coming out of it; 3 sets of coils. It doesnt seem to be like other box fan motors; a proper 24 slot motor; deeper than the ones shown in the link. I've ordered some proper bearings off ebay; £3 inc. shipping so pretty cheap. These will probably sit in the bushing holders fine. The rotor is deep enough to have 2 magnets on top of each other so it could be skewed. There seems to be 4 sets of coils in series for each 'phase'; so I may be able to go for 4 coils without reconnection? Ghurd or Zubbly if you could help please... :-)

Thanks,

[ghurd]

Cool little motor Angus.

"I was planning to just turn it down, epoxy the magnets on"

That's what I do.

The intention is to keep the factory coils?

About what size is the coil wire?

How many ohms per phase or set of coils?

My guess, do not turn it down for 2 magnets deep.  Looks like it will fall apart.

That's a 220V motor?  The coil resistance is probably pretty high.

And the coil wire pretty small.

Might be OK because it has 6 wires.  Wish I could find one like that.

Keep the magnets close together.  The flux can be shorted out, back to the rotor, with a piece of malleable steel for each magnet.  It lets the next neo be placed a little closer to the last one.  I could post a sketch if you don't follow that.

Careful not to epoxy the steel to the top of a neo.  :-(

It's easier for me to epoxy 1 magnet per pole, per day.  Use slow cure epoxy, not `5 minute' epoxy.

Looks like it will be a high voltage, low amp PMA.

That kind of blades sure don't go very fast.  I think they sort of self-stall.  Hub can be good for wood blades.

Be gentle handling it when the coils are exposed.

Big fun!

G-

[fungus]

Hi Ghurd;

The motor is a 220v motor. The wire diameter is around 0.2mm so pretty small. The separate windings read; 220 ohm; 38 ohm and 200 ohm. The outer 'ring' of laminations is around 11mm thick; while the magnets are only 6; I think it should be alright?

Thanks,

[ghurd]

Looks OK for 1 magnet deep. It won't need 2 deep.

That 220 ohms, ouch.  Higher than I figured.

Going to be hard to get half amp total out of it.

If the right wire can be found (not easy- maybe not possible), seperating the coils will help.

The voltage from that will be crazy high. Be careful.

Might try 3 step-down transformers near the battery?  One per phase.

I'd finish it anyway, just to see what happens.

[fungus]

Hmm you're making me think of rewiring it...

I can spot the connections on the outer coils to separate; the only concern I'd have is that they would be too short. If I wanted to rewire it should I 'untie' it to get a proper look?

[fungus]

Well I took off the cable ties that encase the connections and snipped the wires. It appears that there was 8 wires overall; with several terminating in the connections. I've resoldered the wires and put the leads out. Tomorrow I will be turning down the rotor on the lathe.

 

 

[ghurd]

Now it has coil groups of 2, 2, 4 and 4?

What ohms each now?

Sometimes the last turn on one coil (going to the first turn on the next coil) can be loosened a bit giving more wire on both ends to work with.

What is the ID of the stator? Just curious.

[fungus]

The ohm readings are 120, 40, 110... wierd-thought there was 8 wires but theres only 7.. the last one connects to nothing else.... and there isnt any other wire ends....

I got the rotor turned down today though:





The magnets are completely flush with the surface.

[fungus]

I'll have to check it again tomorrow as I'm somewhere else now

[ghurd]

How's it going?

G-

[fungus]

Well...

I found the 8th wire before and it all assembled ok... BUT it was very hard to turn but pretty smooth, lit up an led with the blade holder to spin it. The airgap looked very small. I got the ball bearings to put on it but I must've messed up on alignment slightly when assembling so its stuck and I cant get the bearings off the shaft