Author Topic: VAWT new proto-type (Read 250660 times)

GoVertical · « **Reply #99 on:** March 26, 2011, 08:18:00 AM »

Greetings, when I tested the PMA last fall the PMA was on its side and performed with no problems. The lathe was a small 1/3 HP and the PMA created a stall condition at about 300 RPM. I never had a class in thermal dynamics but I have always heard you can not get more out than you put in. The stators are hard wired together and are a real pain to work with. Putting the PMA back together is going to be a real challenge. On all newer stators that I have made I have installed threaded brass buttons at all the connection points and they are very easy to work with. The PMA has been designed to be mounted vertically, if you could design away to mount it horizontally it may work. The bearing shaft is only 5/8, I do not know if it could handle the weight and rotational forces of the horizontal blades. Please keep in mind that this is just a prototype and I am using it to prove or disprove the stacked stator and rotor concept and to develop new fabrication techniques. I am hoping to reassemble the PMA today. Best regards

GoVertical · « **Reply #100 on:** March 27, 2011, 09:57:50 AM »

Greetings, the metal ring backed rotors are now installed. After I finished the assembly I realized that I should of taken the time to paint the metal rings to prevent rust. I plan on running a bench test today using the same test rig that was used last fall. I should be able to post some numbers later today. Cheers

GoVertical · « **Reply #101 on:** March 27, 2011, 10:00:14 AM »

electrondady1 · « **Reply #102 on:** March 27, 2011, 10:02:57 AM »

oden,
i have become curious about the physical properties of the material your using .
it loots like it machines nicely,
is it affected very much by moisture or temperature?
does it move around a lot or warp?

GoVertical · « **Reply #103 on:** March 27, 2011, 02:12:43 PM »

Greetings, the rotors and top and bottom bearing plates are cut from a plastic decking material that I purchased at Lowes. It is made from recycled plastic and saw dust. It is very stable, does not warp or crack, and is not affected by water or ice. It works well for this PMA application. I tried to use it for other projects that needed smaller parts that could handle a lot of stress and I found out that is does brake like fiber board, but it works well for larger parts. It does have limits.

I am off to the shop to perform the bench test again. I noticed that I posted conflicting information about the stator coils. The stators are the same stators used in the earlier test made last year, the only difference is the metal ring added to the rotors. I will post new test data soon. Cheers.

GoVertical · « **Reply #104 on:** March 27, 2011, 04:45:31 PM »

Greetings, results from today's testing.
Stator resistance 3 ohms.
Open Voltage AC: RPM's
13.5 200
26.0 400
52 800

I was unable to test current. I was using small diodes for the full bridge rectifier and I am not sure if they fried last year or today. I am off to Radio Shack to purchase larger one. Cheers.

GoVertical · « **Reply #105 on:** March 31, 2011, 12:52:40 PM »

Greetings, results from today's PMA bench test. New metal rotors installed. I was using the new bridge rectifier box. Battery voltage 12.3 Volts DC. Lathe speed 200 RPM. PMA output 0.15 Amps and I unable to increase output. Test data from last year without metal rotors showed 0.7 Amps @ 200 RPM with a max of 3.0 Amps @ 300 RPM.

I have to take the PMA apart to make sure the stator coils are lined up, if there is a offset it will affect results. The drivebelt may have been slipping. I may have ran the test with the dump load for the charge controller turned on, this may have also affected the results, but I am not sure. I plan on running the test again after lunch. Hoping for better results.
cheers

GoVertical · « **Reply #106 on:** March 31, 2011, 02:16:21 PM »

Greetings, I found the mistake, I had the multimeter on the wrong setting. New test result, 1.1 DC amps @ 200 RPM's, and 3.25 amps DC @ 300 RPM. Battery voltage @ 12.3 VDC. Because of the small lathe motor a stall condition happened again 300 RPM. The only difference between new test data and test data from last year is different the diodes in the bridge rectifier. Today's test results indicates that I was wrong with my earlier experiments that involved metal vs. nonmetal rotors, although the belt slipping on the lathe may account for some of differences with the data. But for me this is a mute point because of the definite fabrication advantages gained from mounting the magnets without the need for glue and the metal ring also contains the magnet fields from the top and bottom rotors decreasing any drag that may occur from magnetic attraction with any near by metal parts. I need to improve my bench test rig. Best regards.

GoVertical · « **Reply #107 on:** March 31, 2011, 04:26:43 PM »

Greetings, I took a current measurement of two legs with no load, just connected to the amp meter and had 4.8 amps AC @ 200 RPM. I am not sure what this tells me but I am guessing it is the theoretical max at that RPM. If anyone can fill me in please let me know.

GoVertical · « **Reply #108 on:** April 09, 2011, 02:09:31 PM »

Greetings, the board did not allow me to respond to a personal message from â€œElecticFreakâ€. I not sure why?

I completed cutting the blade hinge sets to attach the blades to the spoke and hub assembly. I should have the new test blade completed soon. Cheers.

GoVertical · « **Reply #109 on:** April 12, 2011, 03:40:06 PM »

Greetings, I completed inner rotors for 6 inch diameter PMA. The rotors require no glue for assembly. 5/8 hole was drilled first for the inner smaller magnets which are 2 5/8 x 1/8 disks. Then a Â¾ inch was drilled to hold the larger Â¾ x 1 inch outer magnets. The pull force of the magnet hold themselves in place without the need for glue. Assembly was very fast and easy.

REdiculous · « **Reply #110 on:** April 14, 2011, 01:21:08 PM »

Seems like a waste of magnets to me. Why use 3 magnets when you could use 1?

GoVertical · « **Reply #111 on:** April 14, 2011, 07:15:17 PM »

Greetings, I am trying something new, it is something I always wanted to try. One big magnet would have to be glued in place. This way I do not have to use any glue. The cost of three magnets is the approximate cost of one large magnet.

REdiculous · « **Reply #112 on:** April 15, 2011, 12:35:52 PM »

Instead of having those magnets on the disc face you could embed them in the disc and have the same basic thing only the alt would be somewhat smaller and use fewer magnets. Just drill 3/4" holes all the way through, add a little glue to the holes and slide the magnets in place. You'd have to bring the coils closer to maintain the proper gap but I'm sure you knew that already.

The way you have it I'd be worried about those magnets coming off at high rpm.

GoVertical · « **Reply #113 on:** April 15, 2011, 12:57:10 PM »

Greetings, I am assembling the PMA at this moment. I am trying to make it a low RPM device with high output. Max RPM will be about 300 RPM. The magnets are recessed in the rotors. I am unable to remove them by hand. I should be testing over the weekend and I will know then if I need to add glue. Thank you for the input. I will post results are testing.
Cheers

Bruce S · « **Reply #114 on:** April 15, 2011, 02:03:35 PM »

GoVertical;
How many blood blisters did you get while getting the magnets aligned and into the holes.
The fibre rotor, and cutting it. Are you cutting for a slight interference fit? the magnets should have enough force to hold tight for the RPMs you're going for.
Will be interesting to see the results.

REdiculous · « **Reply #115 on:** April 15, 2011, 02:38:06 PM »

You can make it cheaper, lighter and more compact by using 8 of those cylinder magnets instead of 16, and the performance should be exactly the same.

There should be an attachment showing what I mean...hopefully you can see that functionally there's no difference between the discs, yet the one on the left uses twice the magnets and takes up way more space.

GoVertical · « **Reply #116 on:** April 16, 2011, 02:58:14 AM »

Greetings, all my fingers are fine and in good shape. Knock on wood. Thank you for the info on the double verses single magnets. I was trying to information on that subject. Cutting the internal stator spacers is proving to be more difficult than I had predicted. I fabricated a V block jig to hole the 6 inch PVC pipe on the table saw, but I am still having trouble cutting a square spacer. I am searching for a lager diameter PVC pipe cutter. I have two more spacers to cut. Then I can cut the grooves in the spacers and make the electrical connects. Thanks again the for input.

GoVertical · « **Reply #117 on:** April 20, 2011, 07:53:40 AM »

Quote from: REdiculous on April 15, 2011, 02:38:06 PM

You can make it cheaper, lighter and more compact by using 8 of those cylinder magnets instead of 16, and the performance should be exactly the same.

There should be an attachment showing what I mean...hopefully you can see that functionally there's no difference between the discs, yet the one on the left uses twice the magnets and takes up way more space.
(Attachment Link)

Greetings, I found this reference about stacking magnets. Can you provide a reference that supports your statement.

http://www.kjmagnetics.com/FAQ.asp

REdiculous · « **Reply #118 on:** April 20, 2011, 03:35:17 PM »

For some reason I was thinking there was a dead space between the cylinder magnets but it just dawned on me that you're using the little disc magnets to combine them....you're right. Carry on!

MaxtorD · « **Reply #119 on:** April 20, 2011, 10:42:01 PM »

looking good. Thanks for all the updates.

dave ames · « **Reply #120 on:** April 21, 2011, 11:59:47 PM »

Cheers GoVertical,

checking in to say that we are still following along with great interest and looking forward to the new round of testing.

really some fine fabricating skills you have there with common materials. had to stop and have a look at some of the plastic decking boards in the home store the other day..i see some other plastic wood products now as well, some nice 6"x1/2" stock available as well as 2"x2" fencing rails, cool stuff!

thanks for the look into a fascinating project.

kind regards, dave

GoVertical · « **Reply #121 on:** April 22, 2011, 12:24:41 AM »

Greetings, thanks. I took a few days to fabricate a large diameter PVC tube cutter. I was getting poor results using the table saw. The internal spacers that I use to place the stators has to be square for best PMA output. I just completed assembly of the cutter. It still needs some fine tuning. I should know more in a couple of days.

TrackerJack · « **Reply #122 on:** April 22, 2011, 01:46:25 AM »

What the...

GoVertical · « **Reply #123 on:** April 22, 2011, 08:42:27 AM »

Greetings, the cost of a large diameter PVC pipe cutter is very expensive, over 1 K. My cost less than 100 bucks.

REdiculous · « **Reply #124 on:** April 22, 2011, 12:38:09 PM »

That pipe cutter looks vicious! Awesome.

Madscientist267 · « **Reply #125 on:** April 22, 2011, 04:47:47 PM »

Vicious, indeed.

Is that blade a spinner, or stationary?

Steve

GoVertical · « **Reply #126 on:** April 22, 2011, 11:02:11 PM »

Greetings, The blade is stationary. I tested the tube cutter today and found after one revolution the tooth in front of the cutting tooth prevented the blade to advance deeper for the next cut cycle. Tomorrow I am going to grind off every other tooth and pin the blade in one location and see if it will perform better. If not I may add a small power cutter to see if that will work.

GoVertical · « **Reply #127 on:** April 24, 2011, 01:10:44 AM »

Greetings, I spent the day improving the PVC tube cutter. I replaced the saw blade with a cordless grinder. The carbide blade will cut PCV and as a added benefit will cut the metal rings needed for the PMA's outter rotors. The cutter can be adjusted from 6 inch to greater than 8 inch.

ruddycrazy · « **Reply #128 on:** April 24, 2011, 02:16:40 AM »

One thing to remember using angle grinders, there are two sides to a cut off disk.... the cut off side and the suicide.....

The way that angle grinder is setup is too close to comfort from the way I see it. I would be inclined to rotate the guard around and move the grinder forward so it cuts on the cut off side. Also I would put a brake on so one would have to feed the pipe rather than let the thing try and run away by it's self.

I am not knocking the design and I do think it's a great design but I have seen too many people lose limbs by using angle grinders on the suicide.

Cheers Bryan

GoVertical · « **Reply #129 on:** April 28, 2011, 07:04:57 PM »

Greetings, resolved fabrication issue. I completed fabrication of the large diameter PVC cutter. I add cutting guides to provide a clean even square cut. I am now able to cut stator spacers to required lengths with a high degree of procession. Cheers

TrackerJack · « **Reply #130 on:** April 29, 2011, 06:33:22 PM »

Very inventive and well constructed.

GoVertical · « **Reply #131 on:** April 29, 2011, 06:54:44 PM »

Greetings, I agree with your first post before the edit. It does look like a device to extract information. On the plus side I can now cut the metal rings and PVC spacers I need for the PMA fabrication. Thanks for the kind words, all in good fun. Cheers.

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Author Topic: VAWT new proto-type (Read 250660 times)