Building an small Alternator

[WXYZCIENCE]

I built this alternator from an old tape drive motor. It measures 4" in diameter. The Arc magnets came from some very rare obsoleted hard drives. The wire is a double insulated type. Tested at 1200 rpms the output is 175 watts. I learned a lot about alternators in this project, completed February 2006.

The stator is first insulated with an epoxy paint.

The first set of windings is in place.

The arc magnets stored in a holder.

The completed armature.

The completed alternator

[zubbly]

hi WXYZCIENCE!

beautiful looking job. maybe you could share what type of epoxy you used to insulate the stator with and how you applied it so evenly over the surface of the stator teeth.

what gauge wire you used and how you arrived at the number of coil turns you decided to use.

maybe its just my eyes with age creeping up, but the mags look so different in size on the surface of the rotor compared with the ones you show in the magnet holder.  are they 2 different sizes?

thanks for sharing!  have fun

zubbly

[WXYZCIENCE]

The arc magnets are held in place on the mild steel core by epoxy and the overlapping aluminum holder was then machined down to cover .25 of an inch of the arc magnets. The armature was then tested to 8000 rpm.

[Bruce S]

Another very nice project you've put up here.

Now several questions come to mind, but have you thought of trying Hard drive magnets?

They have a very similar curve to the mags shown which By the way look like some out of an old 67Meg SCSI drive.

The newer smaller but way more powefull neos being used in the IDE drives of today could be stacked to get the smae height.

Thoughts?

Bruce S

[WXYZCIENCE]

Bruce, the magnets I used came from a hard drive and there were 4 arc in each plus one  park magnet. I ended up with 12 altogether. They were so strong that when they got pinched on my finger I went looking for a screwdriver to get them off. I now store all  my magnets in a careful way. I am looking for some more Arc type their hard to find!  

[nothing to lose]

"I am looking for some more Arc type their hard to find! "

Yes they are. Or maybe not. If you want new ones.

I had the #29 type arcs custom made. Look for the post on those.

 I am confused on the pictures there, one looks like a solid ring of arcs, the other looks like they are spread out with gaps between them on the rotor.

 They look longer and narrow on the rotor?

 What size are those?

 Looks like a great job. Real nice work.

[WXYZCIENCE]

N.T.L. Yes, the magnets are spaced to develop a counter EMF. This allows the alternator to start with less force. At very low speeds we don't need to develop power. I steal some of the magnets force because the magnets are so strong. (Them over unity guys hate to hear that.)  The physical diameter of the holder is machined to achieve this spacing.......I built an alternator for a windmill once that won't even start till the wind is almost gale force. Mind you once it starts, it works well.  
I looked at your #29 Posting. Two questions will follow.

Do you have any left and do you want to part with them?Joe

[nothing to lose]

Yes I still have some left, not alot. Maybe 50 to sell yet.

The info and a paypal address is in the post or e-mail me.

http://www.fieldlines.com/story/2006/2/24/102153/206

[WXYZCIENCE]

N.T.L. What I am looking for is small diameter 8 will have to be 2".

[nothing to lose]

 E-mail me info on what you need and I can check on them when I get ready to order other stuff. ID OD Width length, more specs you can give more chance I might be able to get them. And if you have an idea how many you want.

 I actually want to get alot of various sizes myself eventaully anyway. If it's something they stock off the shelf I can maybe get them easy in low volume. If I have to have them custom made like the #29 type I may not be able to get any for awhile.