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Finally starting plans on a new genny!
By Jeff, Section Mechanical Posted on Sat Aug 2nd, 2008 at 05:34:14 PM MST
New - 1st genny, radial with CAD drawings

OK, I'm finally typing & saving this in WORD. I've tried to post this new topic so many times and it hasn't worked, I learned the hard way to type and save it first!
    I'm finally starting on my first genny. I know it's not the ideal as it's a radial, but between limited budget and materials on hand, this will be it.
    For starters, it's 24inches in diameter. An old backing plate from a clothes dryer. It has a 1 1/2inch lip on it, and several holes in the center on about a 4inch-bolt circle. The center hole is 2inches in diameter. If the pictures are hard to see more detail, I'll re-do them "not to scale" and with fewer mags. I plan on 30 N42's on the inside of the 1 1/2inch lip. I have 24 coils ready-made from a ceiling fan, but they may have to be re-made or modified due to the small gauge wire.
    I have a friend that owns a cabinet shop that will be making the stator for me. It will be 1 1/2inch wide banding material (wood) that he can knock one out on his banding machine in a couple minutes.
    I do have plans on adding an inner row of mags to make it a duel rotor, but again, my budget is going to make this a later addition.
    My first question is: I'm looking at mags and picked out these two:
        1inch dia. N42 by 1/2inch thick
    http://www.magnet4less.com/product_info.php?products_id=147
or:
        1 3/8inch dia. N42 by 1/2inch thick
    http://www.magnet4less.com/product_info.php?products_id=356
Remember, these will be attached on the inside of the rotor "pan" on a 1 1/2inch wide lip. Being close to the edge, or bottom of the "pan", do you think the larger magnets would produce bad effects in the flux field?
    OR, being the size it is with 30 mags, just go with the smaller mags to eliminate any problems as I'll be adding another row on the I.D. at a later date?
    I'm going to wait on any more details until I get any comments, and I'll try to clear up any drawing then also.

Finally starting plans on a new genny! | 16 comments (16 topical, 0 editorial)

Re: Finally starting plans on a new genny! (3.00 / 0) (#1)
by Jeff (ruralmcguyver at yahoo dot com) on Sat Aug 2nd, 2008 at 11:40:20 AM MST
(User Info)

Here's the CAD drawings I have so far. I know I sized them right for the board, but due to the size/diameter of the rotor, details may be hard to see. Let me know!

I used 1 1/4inch dia. mags for the initial drawing to check spacing. After looking at the selection of mags, I picked the two I mentioned above.

Detail View:

Rural McG

Re: Finally starting plans on a new genny! (3.00 / 0) (#2)
by electrondady1 on Sat Aug 2nd, 2008 at 04:00:44 PM MST
(User Info)

but jeff,
radial alts. are ideal!
for vertical axis mills.(keeps the rain out)

first , what is the thickness of the steel you are mounting the mags to.
will it be enough to contain the magnetic flux?
if not, add some sort of steel banding material until no flux is detected on the outside .

from the drawing it looks as though the coils are too narrow to reach from one mag to the next.
the legs of the coils must be over two poles.

one thing that you might want to think about is the clearance between the ends of the coils and the top plate if the mags are 1" and the lip is only 1.5" .

with a radial layout you might want to consider the possibility of using overlapping coils with this configuration.

i find the idea of a 24" dia. radial alternator to be a very exciting.
(I'm weird that way)
and the idea of using a found object as a basis is sweet.

winding coils is fun !don't fret if your existing coils don't work.

have you considered using rectangular mags ?
you could place about 75 1"x.5" on that circumference.

gotta go.

Re: Finally starting plans on a new genny! (3.00 / 0) (#3)
by Jeff (ruralmcguyver at yahoo dot com) on Sun Aug 3rd, 2008 at 10:24:28 AM MST
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electrondady1,

Thanks! I just checked the material thickness. It's 0.023inches, that's about 24 or 25 gage. So, it looks like I'll have to plan on some extra backing for the mags. I was hoping to keep the outside diameter nice and clean/clear. If there ends up needing a RPM change, the belt is still good for this dryer, and I could make another pulley to run it any RPM needed. I even wanted to keep my option open to run it with a solar water heated/ammonia engine.
The drawing was just an 1st sketch. I'll remember that about having the coils sized/spaced to be able to overlap 2 mags at once. Thanks again. If you notice, even the mags I drew were not the size of the two I mentioned.
If I end up having to put too much backing on the mags, it's going to eliminate what I had planned for a future inner row of mags. I have another "pan" just like the 24" one except 17 3/4" I.D. If spacing requires it though, I could always use the smaller one. OR...possibly a 1 x 2 x 1/2" mag mounted length-wise on the dia.???
You mentioned a possible clearance problem between the stator & rotor. If needed, I had 6 bearings 1/2" dia. x 1/4" wide I could mount on the stator so they stuck up just enough to provide protection to the stator if the thing got wild & the rotor wobbled around.
Overlapping coils I thought of, and is possible, but I think might be more hassle. Simply because I'm having a friend make the stator, and it would have to be twice as thick. There's always the possibility we're going to have to make more than one anyway. It also runs into more problems when considering a future inner row of mags.
I was hoping the coils could be used as-is, or probably removing some windings. Did I mention the initial sketch/plan was using the coils from a cieling fan? I knew from what research I've done here already, that I'd end up with higher voltage & less amps. Since what I have to run from the genny to indoors is 14-3 wire, I wasn't concerned with higher voltage, and converting it once inside. I just measured the wire size on the coils though. Bummer! It's 0.014" or about 27ga. !!! wayyy to small, I think!
I'm not worried about making coils, so it looks like I might consider an oblong shape, possibly 3/4inch tall, by 1 1/2 long. Easier to overlap the mags that way.

Well, I appreciate your input & support! I'm going back to look at mags, and start some updated drawings!

Thanks!
Rural McG
[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#4)
by Jeff (ruralmcguyver at yahoo dot com) on Sun Aug 3rd, 2008 at 10:39:03 AM MST
(User Info)

added:
I forgot to ask, but any recommendations on wire size for coils? I figured with the size, 3-phase will be a definite probability. If the VAWT runs into too many problems running it, this genny will be set up & run by the engine I mentioned. I'll just make another for the VAWT.
Rural McG

Re: Finally starting plans on a new genny! (3.00 / 0) (#5)
by vawtman (vawtman(at)charter(dot)net) on Sun Aug 3rd, 2008 at 10:46:22 AM MST
(User Info)

Hi Jeff
I would hold off on the dryer drum idea.Take your time and have fun.

Mark

Re: Finally starting plans on a new genny! (3.00 / 0) (#6)
by Jeff (ruralmcguyver at yahoo dot com) on Sun Aug 3rd, 2008 at 03:16:51 PM MST
(User Info)

Vawtman: Please elaborate, hold off due to the thin gage? I have been thinking along that line. Then I recalled something when you said "drum". The actual drumm of the dryer is about 11-12 gage, and has a ceramic coating. I originally thought of making a rotor out of this as the configuration would be about the same except: the gage is heavier, obviously. Also since I would have to cut it, I could leave myself a 2-3inch lip.
It may not sound like it at first, but I am taking my time. Don't have much choice actually. But, this is also the only thing I have to take up a lot of "idle time", other than reading. So...I'm looking at this as a worth-while project, but NOT to be absolutely limited to powering it by a VAWT.
I have the benefit of a great CAD & computer setup (no printing capabilities at present). Obviously little experience at making a genny, but all the resources for that are now "at my fingertips". You guys here are a great influence (some of my friends and family may say otherwise), and there's the incentive of having some "free" power eventually!

Rural McG
[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#7)
by Jeff (ruralmcguyver at yahoo dot com) on Sun Aug 3rd, 2008 at 03:38:13 PM MST
(User Info)

8-3-08
I've updated just about everything. It's nice to have AutoCad and draw things to scale so you can get a real idea of how things will fit.

To start with, when I changed magnets and drew the thing up, I realized I needed to use the smaller "pan" for the rotor. There's several reasons, but the main two are cost for magnets, and the spacing of them. The smaller pan is also slightly heavier gage... 13 gage, about 0.09" thick.
I didn't go with the 2" by 1" by ½" coated magnets per Hugh Piggot's choice due to clearance problems on the 1 ½" lip of the rotor. Instead, I'm thinking of these 1 ½" long by ¾" wide by ¼' thick ones.

http://www.magnet4less.com/product_info.php?products_id=48

    I wish they had them in ½" thickness, oh well. These will be mounted length-wise on the diameter, and will give me better spacing when I eventually add an inner rotor. They're only 29lb. pull through the ¼" thickness. Think they'll be enough having 24 of them on each rotor?
    I'm going to have to bite the bullet & make some real coils, so I added a detail for them also. Keeping in mind the size of the rotor, and number of mags/coils, it's time to seriously consider the gage wire. I do need to keep the voltage in the 110-140 range due to the length of run from the genny, and I'd like to be able to use the 14-3 UHMW wire on hand for that. Hopefully it will be in the 50-75ft. range, but I have 100ft. of it.
    I don't suppose I'd be lucky enough to be able to use this same wire to make coils with? Or is this another silly, newbie question?

Here's some updated drawings:

Rural McG

Re: Finally starting plans on a new genny! (3.00 / 0) (#8)
by electrondady1 on Tue Aug 5th, 2008 at 03:21:46 PM MST
(User Info)

jeff,
the mags you are talking about using are way too powerful to put on your rotor.
if you google search the board i think you will find that 1/4"plate is about the minimum you can use for 1/2" thick neo mags.
as well, if you use very wide magnets they will not sit properly on the curved surface of your rotor.
thats why i suggested using a lot of smaller mags.
you can make up for the reduced flux density with a greater pole count .

[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#9)
by Jeff (ruralmcguyver at yahoo dot com) on Tue Aug 5th, 2008 at 05:30:39 PM MST
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Thanks. I figured I would have to add a plate behind the mag anyway after your first comment. That info is in the 20-some pages I've copied & saved for this project. I just don't remember all of it right off the bat. The little space behind the mag-backing plate with the 1 3/8" mags is 0.024". 1 1/2" wide mags would leave a 0.03" gap. At the thickness of the "pan", I wouldn't be surprised if it pulled the surface flat, LOL! Really though, I already thought of that, it's a nice place for JB Weld to hold the mag in place.

Good news! I have two motors, both are 220v and one is from the same clothes dryer. They both have 14ga. magnet wire in the coils! If it works out OK, I'll have to scrounge up a couple more to make all those coils! Obviously, I'll only be making 1 to start out with, but at least that's a lot closer to the ideal gage.
Rural McG
[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#10)
by Jeff (ruralmcguyver at yahoo dot com) on Thu Aug 7th, 2008 at 01:06:18 PM MST
(User Info)

Another update, LOL, oh well. My cabinet maker friend came by last night. Wondering if I wanted him to make the "hoop" for the stator. I had to laugh, nowheres near ready! I did, however, get him to take the pans I plan on using for rotors. He can "band" them with the metal strapping I was going to use to make the lip thicker for the mags. Once that is done, they should be at least 3/16inch thick, if not 1/4inch.
Then it'll be time to buy the mags!!! Yippeee! It looks like I'll have to wait until about the 20th of the month before I'll have the $$. I have to wonder though, since I can fit 48 mags on the diameter, would 1/4inch thick mags be enough? Remember if I can get a steady 5amps charging power out of this, it will be all I'll need. That would be 48 mags on the inside, AND 48 on the outside.
Rural McG

Re: Finally starting plans on a new genny! (3.00 / 0) (#11)
by vawtman (vawtman(at)charter(dot)net) on Sat Aug 9th, 2008 at 08:42:31 AM MST
(User Info)

I would just go with 24 1x2x1/2 mags(per your last drawing) and have a rotating band of steel with no mags.
I've had thoughts for a small vawt of just using a pulley and attaching a steel band of the apropriate thickness and width to it.Then another band from that(no mags) rotating has one.
Heck for only 5a you may get away with one coil(Eds idea).

P.s Is your mail working?

Mark

[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#12)
by Jeff (ruralmcguyver at yahoo dot com) on Sat Aug 9th, 2008 at 10:18:11 AM MST
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Did I mention the 48 1 x 1 x 1/4 ones I can get in N48? For all 96 (inner & outer)the set is only $120!!! But after drawing the thing up, I realized where you may be coming from. With the 2x1x1/2 ones mounted long-ways on the ID, it takes 24 of them. I can get them in N45 here for about $100.

http://www.magnet4less.com/product_info.php?products_id=62

Then, if it doesn't produce enough with just the "single rotor", I could always add the inner rotor later. Just as a single rotor though, I'd have twice as many mags as most radials do. THEN, If the thing works half-way decent at all, I should put out some serious power! For the size & construction though, it would always be limited to not much more than 300rpm.

Mark: You'll have to explain a little more about the band w/no mags. Yes, my email is working. ruralmcguyver at yahoo dot com

I am able to manage all my electric needs (and then some) with a steady 3amps input into my battery bank. I have 6 12v 115amp/hr batteries now!!! This isn't counting what I'm getting from my 45watt H.F. solar panels. So...I figure the 5amp figure I was shooting for with this gennie was a good-safe goal.

I appreciate all your help on this. Even though I enjoy doing this kind of thing, it is kind of a 1-shot deal, at least for a year or so. So it's not like if the mags I buy don't work, I can set them aside to use on another project & buy some more.

For now, it looks like the 1x2x1/2 ones are pretty sure. If I do have to add the inner rotor though, it'll take me another year to save up for them.

Thanks again everyone!
Rural McG
[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#13)
by vawtman (vawtman(at)charter(dot)net) on Sat Aug 9th, 2008 at 12:14:49 PM MST
(User Info)

Oops your mags were wider so the 1x2s would be 36pl for that diameter in my opinion.

[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#14)
by Jeff (ruralmcguyver at yahoo dot com) on Sat Aug 9th, 2008 at 04:02:14 PM MST
(User Info)

36 Places???
i WENT BACK TO THE DRAWING BOARD. Crap! sorry about the caps! Anyway, it looks like 24 mags on the I.D. of the larger 19 3/8 pan. I still think this may be the best setup for me. As long as I cross my fingers and get 3-5 amps out with just the "single rotor" config., the future addition of an inner rotor would be gravy. Here's a pic:
http://www.otherpower.com/images/scimages/9063/Generator_v1C_24_Mags_Main_View.jpg

I left the 0.3inch gap between the mags because of the smallest gap on the future possibility of an inner rotor. Obviously the dimensions of a coil will have to be made to match up with an exact coil/mag config with every 3rd coil.

Thanks again!
Rural McG
[ Parent ]

Re: Finally starting plans on a new genny! (3.00 / 0) (#15)
by Jeff (ruralmcguyver at yahoo dot com) on Sat Sep 6th, 2008 at 03:47:51 PM MST
(User Info)

Here's a drawing of the cieling fan motor I wanted to convert. The rotor is only 1/2inch thick laminated steel, but I do have the material to wrap around the outside to build up for the flux on the backside of the mags. There are 8 more coils inside of the ones shown, I just didn't draw them in as I didn't know if I would include them in the finished product.

Rural McG

Re: Finally starting plans on a new genny! (3.00 / 0) (#16)
by Jeff (ruralmcguyver at yahoo dot com) on Mon Sep 8th, 2008 at 12:10:52 PM MST
(User Info)

Tried getting some pictures yesterday, and got stalled by computer problems. Here goes again today...

The cieling fan motor

One of my solar water heaters, 34 x 36inches. Holds/heats just over 2.5 gallons.

A wheel & bearing assembly my friend gave me. Wheel is 20" dia. shaft is 1.5" but steps down to 1.25" at the wheel. The darn thing is NON-magnetic!!!! Oh, that's a 1lb. spool of 5-cord Kevlar thread sitting next to it. They go for about $75ea. and I picked up 2 cases of 24ea. for free when the Aerospace company I worked for went Enron. The owner of the building & warehouse said stuff had to be out by Oct. 31, 2002, so a friend & I filled up two large pickup trucks!
Rural McG

Finally starting plans on a new genny! | 16 comments (16 topical, 0 editorial)

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