which motor/generator to buy on ebay?

[msawusch]

Ebay has several listings for the following PM motors for wind projects. The descriptions don't include all the specs but here is the info provided. Any opinions as to which would be the best choice?:

1. Ametek 38 VDC 12 amps max RPM 1150 around $55
   
2. Johnson 220 VDC, creates 6VDC at 208 RPM, 12VDC at 483 PRM around $20
   
3. McMillan Electric 3/4 HP, 130 VDC to 8 amps around $38
   
4. Argord 2.5 HP 130 VDC rated to 18.5 amps around $32
   
4. Ametek 40 VDC no other specs $50
   

[Basil]

Try this for a few watts. Cheaper than Ebay. I have a mill made with one and it's great for bringing a battery up slow. When watching it I have seen 45 watts at times. I'm sure it's did more.

http://www.surpluscenter.com/sort.asp?numrec=20&lastrec=20&sort=1&keyword=MCDD&catna
me=electric&UID=2008051803451742

[Chagrin]

Ametek motor info:

http://www.tlgwindpower.com/ametek.htm

Motor #3:

http://www.fieldlines.com/story/2008/3/24/20427/4905

Motor #2 looks pretty dang small and motor #4 is cheaper at Surplus Center. Don't see any specs on those.

[ghurd]

Take #2 off the list.

The Johnson 220VDC is two and a half inches long, less than one inch dia.

Breaks my heart to see people pay $20 and $30 for it because they don't convert mm to inches.

G-

[TomW]

G-;

However, nothing teaches not to touch the hot stove better than touching it.

EbaY should be renamed FleeceBaY. Its not even on my list of options anymore.

Tom

[ghurd]

I am going SO OT,

But the dude selling them (if it is the dude commonly selling them) has very few Neutral or Negative feedbacks about them.

It is just what he said it is.

One guy left a neutral stating something like "measurements should be in inches".

[TheCasualTraveler]

I'm gonna take a stab at this.

My guess is - None of the above.

Am I right?

If I'm not mistaken you want high DC voltage with low RPM's. Oh and permanent magnets, definitly permanent magnets.

[ghurd]

No one is ever right!

Except for the PM thing.

"High" DC voltage?

If it powers a red LED, a train, or if you stick your tounge on it?

"Low" RPMs?

VAWT, HAWT, motor in the 4-cyl car driven 60 miles to work at 85MPH?

[spinningmagnets]

I'm still learning, but this post was about a motor that seems to be the best ive read about so far. He got real lucky and it only cost $35, but it sounds like it would be a good deal at a couple hundred. I hope he posts soon with more info on how it turned out.

http://www.fieldlines.com/story/2008/4/4/23164/05034

Good pic of a PMM, 3-phase AC servo, 77lb, 12V @ 150 RPM's/48 @ 600

[DanG]

My concern for conversions is moisture intrusion - just enough water vapor to condense out every time it cools off will find the weak spots in coatings and connections. If not outright leakage just the sun heat-cool cycles forcing atmosphere exchange from partial pressure-vacuum cycles through a pinhole leak will draw in moisture over time...

The term "Wash Down" motor means designed for being pressure wash cleaned on a regular basis, like in a food processing facility - that is a good add-on when searching. Some might say the friction of the seals would make for a hard starting wind turbine but since it's a known loss a bit of extra blade root width or length would cover it.