That's pretty much how I had planned on it, the relieving with multiple saw cuts; though I like the idea of heat and compression to reshape it a whole lot better.
Using the full 26" width, you'd need quartz radiant heat, or a gas infrared heater to heat the full panel to at least 286* F, then slap it on the form and throw a sandbag, several sandbags, on it.
I think. I need to get a piece of this stuff and start experimenting.
As far as a form you'd only need one section equal to one portion of one sail. They aren't that hard to build, if you think in terms of lofting a plywood boat hull. One sheet of 3/4" ply for the ribs and luan underlayment for the curved surface.
I just had a radical idea using this same corrugated Polycarb panels that I used. I might even try it with mine in warmer weather, now that I suspect the Vertical corrugations are causing extra drag and costing power. (and part of the shaking)
The idea is to turn the corrugations with the wind directions as Turtle says for much less drag, but since they don't bend that way without bad random buckling, simply do a bunch of cross-cuts every few inches ACROSS one side of the corrugations with my table saw so that they will bend in segments. (or; a circular saw carefully)
The arc or curve would not be perfect though, but would be more of a segmented curve. It is sorta of controlling the bend with the saw curfs on the inside of the Poly blades. The saw curfs actually have to cut all of the corrugations on the INSIDE of the blades, and then the curfs would close in as the Poly is bent. Sorta just controlling the Buckeling into small sections to bend the segmented curve. Then just over-lap a few Horizontal pieces and rivot them together to get the blade height you need.
Of course doing the curfs would make it much weaker, but this may not be that important because the steel support arms support most anyway. May have to rivot the Poly blades on with many Rivots to hold the shape right.
Doing the Straight bucket would be easy I think. But getting the blades to bend right into any Helix shape might be Very difficult. I'm no Geometry Genius if you may have noticed. Might have to cut the curfs at slightly different angles across the Poly to bend right to the steel support arms?? Not sure though.
Bet it would be much less drag that way. I will do a test on a small scrap piece I had left over to see how it looks. It might just work.
Yes, the corrugated has some limitations, but it is quite cheap I think compared to clear, non-corrugated (smooth) Poly panels. I had looked for the smooth on Ebay and it was too expensive for these big sheets. (hundreds) And hardware stores had smaller pieces for even more money.
So, cost was the main thing for me. I got mine at Lowes and its called TUFTEX. http://www.tuftexpanel.com
Of course Homedepot store has the same (same profile) stuff called SUNTUF. You can order different profiles (shapes) , lengths and widths like 37" and 40" I believe. I just noticed that some of the profiles are much smaller than mine. That could mean less drag and more power -- possibly??
Could probably make a BIG 8' tall by 5' diameter with a couple those between 3 4x4's. Would be neat.
Electrondady1: Yeah, I am left to wonder about what could of been If I had just made the straight bucket with these corrugated Poly panels. I don't know if the corrugations would have screwed up the stability or not , but look at my last years video of my Small straight bucket Vawt freespining so nicely and evenly in a big wind, and it has no support at top OR any pole in the middle:
So I had thought this Helix Vawt wouldve been even easier to stabilize than the straight bucket, but I was wrong. It takes a LOT to hold it down steady.
Today, I took a few minutes to go out and tape a few little light plastic 'flags' on the inside of the Helix blades to watch how the flags bend back and forth in the low winds, and one thing is for sure, the wind IS definitely flowing back and forth nicely thru the center (6" wide including pole) air gap between the blades as the rotor turns into and away from the wind direction. So thats a good quick evidence I found out today.
I will need to tape about 20 more little plastic flags on the rotor to get a better picture of the air flow around and over the blades.
Turtle: Yes, I think those 1" by 1/4" thick pieces of steel would work with the extra cross supports welded on. That is what I also intended to use at first, but found out the cost of them was way to high for me.
But as I was making this Vawt , I found a much better, cheaper place to buy steel from instead of Lowes or TSC or any store. It is a local Co. that does Structural Steel. My dad found it accidently driving around town. Glad he did, I would have never found it in the Yellowpages, because its only under reference of 'Structural Steel', and they don't even say they sell small pieces of steel there.
So I am happy about that. I will keep trying myself and wish you guys the best with your projects. Hope you find some secrets we can all use.
I really like the tranparency of your vawt. Here at work we use Lexan ( polycarbonate ) sheets for our signage. It's almost unbreakable. We Vacuum form most every thing . I have seen the same type of material at our local lumber dealer. I think that it would bend or form a helix shape as well. It then would not have the ribs that make bending as difficult . Just make sure it's not acrylic as it does not bend . KEEP UP THE GOOD WORK .
i'm going to look around for some of that same material. but i don't think i'll try a helix. looking at brews latest video with the tied down top , it looks like the remaining movement is a result of a torque pulse.
i wonder what a squirrel cage would look like if it was fashioned from a clear material
Y'know, the more I ponder the "see thru" aspect of this, your ribbed wonder, the more I wanna try it.
Running the ribs with the wind, I might add. I picked up a big bundle of mis-cut 1" x 1/4" flat strips 4' long, at the metal shop a while back- trussed up, they ought to be stout enough for to support the wings on a 4' diameter model of this thing, no?
Yeah, it is just too fascinating to not keep trying. Since its more of a Hobby for me, and I had gone full circle with all the other RE- things last year (Solar electric, Solar air and water heating, hawts, pedgen, etc) , it was time again to attempt another Vawt!
Of course, for me, tools are way too expensive for me to throw around or I probably would have with my 20 hours of stupid welding mistakes! Ha My knuckles even looked bloody from welding??
It is a 20 pole dual rotor. (40 total magnets) Magnets are N42 1" diam. by 1/4" thick.
15 total coils / 5 coils in series per phase. (Star hook up) Coils are 20 gauge / 80 turns per coil
Can't recall the accurate diameter of the steel rotors. I think it was 11.25" diam.
The total thickness of the stator was almost or about 5/16". The mag to mag air gap is quite large though at 1/2". I could get it alittle closer if I got some different washers. The steel rotors are not exactly true and there is a slight slop to the trailer hub bearings since it is very easy to turn.
I dont' like getting too close to the stator. They are a pain to make.
I have tested the alternator to making 200 watts into 100watt (120vac) light bulbs with a drill. But when hooked to a 12 v Battery, it takes mega TORQUE to get much power because the rpm is reduced down so slow for a Vawt.
Here is a little update. You guys were right. This thing was WAY too flimsy and HAD to have Guy wires added the way it is, even though I don't care for the look. Originally, I wanted a Vawt that would look really good with no wires, but with the 4x4 wood pole it is simply impossible. Maybe I will save up for a very strong steel 4" diam. pole to mount it to in the springtime.
Because of all these crazy winter snow storms, I didn't have time to get steel guy wires, so I tried some nylon rope I had on hand because bigger winds were coming, but as you can see in the video below it only helped some because the rope still flexes more than I thought it would. So my next step will be as many have mentioned to secure the whole thing with steel guy wires.
I also made the simple Voltage doubler and it does help quite a bit. I emailed Windstuff ED and he told me I could just use those smaller DC capacitors at Radio Shack for the small amount of watts (1-5w) that my Vawt does from 35-60rpm in low, typical 5-10mph wind days.
He was right. Thanks ED! I had wasted a lot of time trying to get these big AC run capacitors to work but they never did. These small Dc Electrolytic Caps work fine for what I intended.
My Radio Shack only had the 35Vdc Caps so I got those. They are blue colored about the size of my small finger and I chose to get 4 of the 1000mf and hook pairs of them in parallel (for more MF) and then in series like ED showed in his simple circuit. It was a little cheaper to do it this way at a dollar and a half each. Of course they had the bigger 2000mf for $5.50 each if one wants to do it that way.
So with the 35A bridge rectifier, it only costs me several bucks to make this neat little Voltage doubler for my 3-phase alternater. I like it. It keeps putting away the little watts consistenly day and night. Adds up to an extra 10-60 Watt hours daily for my little 12v system -- and I'll gladly take it! ha
I think I will get 4 more of these caps later and hook them in parallel with these and see If I can get a little more amps. I watched the ammeter when I added the other two pairs and could clearly see the amps being accepted into the batts went up some. I'm not very smart with electronics, so It may help or may not??
So it looks like the biggest problem as many have said, is simply the pole was way too flimsy and not secured correctly. I was just trying for the great looks I guess. The vertical corrugations most likely are part of the problem too and may cost some power, but I love the look so I accept it.
Even though the Vawt is in a bad location, it still does 10-50 watts in the up and down turbulance. I never seen it do anymore watts even briefly. This terrible location does not do this Vawt justice. Because of this, I would still call this a 100 watt Vawt. It would do some decent consistent charging in a clean flowing location like in a big open field or something.
I have a 4' diameter Hawt very close by this Vawt (about 20ft away) to compare it too and watch the two ammeters side by side. This Vawt (now around 18SF) does a little better Watt hours in any wind than the 4' hawt in what I believe is a somewhat better wind location 25ft in the air. (7' above my house roof peak)
The watts from both are close to each other when there is decent wind. But what makes the Vawt better is mainly Ed's Voltage doubler. The Vawt can keep putting away 1-5 watts in lulls and low winds as the small Hawt keep spinning but goes under the cut-in often and thus makes no power quite often.
Unfortunetly I can't make a doubler for the treadmill motor Hawt since it is just Dc and not 3-phase. But if it were, and could make the Voltage doubler for it also, I think the small Hawt and this Helix Vawt would make about the same watt hours.
So even though I didn't get everything I wanted, I still like this Helix Vawt. It is a decent charger I think -- and is virtually unnoticable from the distant roads.
It has been a very interesting experience and I'm very glad it works!!! Everyone who visits finds it very fascinating.
Well, after observing it all day in around 5-15mph wind gusts, it looks like the changes only helped some. It still shakes in bigger wind gusts right between 1-2 amps. I even screwed a short piece of 'Treated Decking board' on the top to make it more stable. It did help some though but was no magic bullet.
I think everything is quite even with the blades. I took careful measurements this time. Of course, its not 'Laser and Machine Dynamic balanced' or anything, but still pretty decent.
So It is looking more and more likely that there ARE some limitations to making the Blades from these type Corrugated Poly panels. Maybe the Corrugations are causing most of the instability and swaying?? Here is first Video of it after all the many changes I made recently:
Nevertheless, I still really like this neat looking Vawt. It is still charging my Batts OK even now. But I realize I really need to make one of Windstuff Ed's simple Capacitor Voltage doubler, because I am missing a decent amount of power when the rpm is under the 12v battery cut-in. (when under 75rpm)
Also I am just using those Radio shack Rectifiers with the higher Voltage drop. I should probably get the lower Voltage drop ones to lower my cut-in more.
This Vawt has some impressive Torque but goes quite slow most of the time, especially in this bad location. In a better location it would do better.
So I will do that soon and keep trying to improve it even more.
Well, I spent ALL day Saturday and half of Today Re-doing and Re-welding about half of the entire Helix Rotor. The way it was it was missing most power and would have fatiqued the welds on the steel Rotor center pole at top and bottom.
I took off the 4 support arms in the middle of the Rotor and Re-welded them on at a proper EQUAL twist angle for the upward twist of the Polycarb blades.
Somewhere below I mentioned 25.5 degrees, which is wrong. The middle support arms need to turn 30 degrees each 'section' (for 3 sections) which equals the 90 degree twist from bottom to top. Also, I was a little off on the weight of the Helix Rotor, I weighed it and it is 41 lbs including the Polycarb blades.
The first photo below is the super-simple jig I made to help me to just 'eye' where to weld the next arm above to 30 degree turn. This time the twist angle is even all the way up the blade. Before, it had something like 60 degree twist at the bottom (half) and 30 degree twist at the top. I suspect this was what was causing most of the terrible instability and shaking. (Hoping it was!) Now, after much pain in the neck work, it is fixed to be even twist all the way up.
The second photo shows that putting the polycarb blades back on (with new mounting holes) was even more difficult this time.
I don't know if you can see it or not, but I was forced to follow what twist the corrugated Polycarb wanted to follow for the most part, in order to get it close to all the support arms for mounting. I did manage to do it though (by myself again), but had to pull the polycarb outward diagonally at the bottom, which was a bit weird. BTW,Because of this, I highly doubt one could do the full 180 twist with an 8 foot long piece. The corrugations won't allow it without buckeling. (Maybe a 12 foot long piece??)
So the diameter at the top it about 36 inches at the top of the rotor, but at the bottom of the rotor the diameter is about 38 inches. That couldn't be avoided. I hope it don't screw something up.
So I had to trim off a few inches of the polycarb off the bottom outside edges of both blades. In the photo I hadn't trimmed them yet.
The third photo is the new way it is now. From what 5-10mph little wind there is, it sure appears to be turning faster and looks much more stable, but I won't know for sure until Tuesday when bigger 20mph winds get here. I will make new video then showing it.
Heres a cool website that makes/sells Commercial Vawts for Expensive Street light Poles. Looks like most of theirs are just 90 degree Helix (twist) Vawts -- and only one full 180 degree which they call a Double Helix.
I thought it was really neat that there bigger GUS-5 is about the size of mine and they claim it does 300 watts. I would be over-joyed now with just 60 watts in a big wind gust. They want 22 grand for theirs. I think I am quite happy with my $200 Homemade brand!
They have neat videos of their GUS versions on Youtube if you search. One shows how fast their small Double Helix goes. Really fancy Renewable Light Poles. They must work since they sell to cities and big Corporations. One of the Videos has them on the roof of a Toyota car factory.
Anyway, I hope these improvements work better in a couple days.
Yes, I am still thinking about 'Beefing up' the Main 4x4 post somehow. It is amazing just how easy it is for a Vawt this big to actually Twist the 4x4 like that.
It surprized me. The main post at the Top is still not that rigid and strong, so maybe adding another 2x4 on top will help a little more. I will still try to beef it up better, because without guy wires, sure it needs it. I can't use guy wires anyway, because the Vawt is right on the property line.
I really wanted something that looks good without guy wires, but I am beginning to suspect that there are limitations to how good of a Vawt a person can make out of this Vertically corrugated Polycarbonate panel!!
I think we all suspect to some degree that these vertical corrugations are causing some turbulance and blocking the flow of wind thru the center to some degree. Especially with the way the blades don't overlap the way it is now. But I think I can change it for the better and still get something good out of it if I keep at it. BTW, I forgot to say how big the air passage is in the middle. The air width space is almost 6 inches including the 1.5 " (approx. OD) pipe in the middle. So around 2 inches on each side of the center pipe. I am thinking of increasing this air space to 7".
The rotor sure has a lot of Torque to it. I can barely hold it back in a decent wind.
Well, I've now observed the Vawt from the wind coming from all directions, and it shakes just the same no matter what direction the wind comes from. So I don't think the Main 4x4 Post is having any affect on it.
I was just looking at your video on You tube and I think you could solve the problem by buiding a square support frame. If you watch with the direction you have it turning ( clockwise) The cup is catching the wind at the farthest point from your main pole . That is moving the arm back at that point then as it turns the top arm comes back a little and repeats etc. So if you add another pole at the open side, bridge accross and anchor with guy wire it should have enough support. There is alway's going to be some vibration at certain speeds.
The commercial helix that you linked looks quite a bit smaller. How about just beefing up the support structure? Could you guy wire the top of that pole in the directions that it's weakest?
Doesn't what Caleb said about balance also kind of apply to drag and cross section in the wind? At one rotational position the bottom has max cross sectional area (and force), and the top has minimal area. Then 90 degrees later, the top has max area (and force) and the bottom has minimal area. It seems that in itself would try to shake the turbine.
Does the force vector have anything to do with it? As in, wind hits blade, is deflected downward, progressively through rotation, and weight of unit absorbs vibration.
Constant up-thrust moment through entire rotation
Maybe, I don't know
Turtle, slow
-- Edited by keithturtle on Thursday 11th of February 2010 12:29:45 AM
Yeah, it would be nice if the supports could somehow be adjustable like that just in case, but I don't think I can do that precise. The way it is is actually very strong and rigid especially with the 3/8" solid rod cross supports added. Well, I guess I am in unchartered waters for sure. I had thought this Helix would be easier to stabilize than the straight bucket, but I was wrong about that. The Vawt has been shaking often all night and all day. Good name for this video is "Houston, we have a shake problem"
I didn't take the big washers off today, (0 F windchill!) but I did take a 3oz. finger clamp and put it at different locations on the Vawt rotor, but it made no noticable difference.
Like I said, it looks like there are many Helix Vawts on Youtube that sure look like 90 degree twists to me. Here is one Commercial Vawt I have seen that spins fast and stable on Youtube. I've seen it and others.
http://oregonwind.com/ Some appear to not even have top bearings yet spin stable in big winds. So I have done something quite incorrect with mine.
Most probable now to fix is the twist angle of each blade not being equal from top to bottom. The bottom half of the rotor has probably about 60 degree twist, and the top half 40 degree twist. (each blade) This must be the problem.
Of course, the blades are still equal side by side, but thats evidently not enough. So I will try to fix this and hope it's the main problem.
Also, another thing I am going to do is move the blades an inch more (or; two inches) inward toward the center pole so that the blades can over-lap a bit. Right now, the way it is, there is NO over-lap of the two blades at all. Instead each blade stops EVEN with the center pole. I may try this first before the total tear down.
From my testing with my previous small Vawt, this change would add a little more speed (rpm) and makes it more stable. I need all the help I can get. So then the swept area will be reduced closer to 19 Sq. feet.
I can't change to 180 degree, OR the 4 blade Vawt because that would be a TOTAL redo. Plus, the two blade 90 degree is heavy enough I suspect at about 35 lbs and 4 blade would be 70 lbs which is just too heavy for me.
Well its been a bit discouraging but I will re-do it and really pay close attention to angles by making a wood template to check angles this time before welding.
Thanks everyone for ideas, I will keep at it until I get something more stable.
i was hesitant to suggest this early this morning because of all the work it would involve, but it sounds as though you have made a commitment to tear your sweetie down any way .
i was looking closely at the way you have your circular arms attached and i see you have the round stock welded to that angle iron. and the angle is welded to the vertical axel
i didn't realize you had done it like that
i was thinking that the curved round stock was welded to a tubular center section that slipped over your vertical axis
how about a piece of thick walled tubing that would slide over your vertical axis with your round curved stock welded to it you could drill and tap each one a for a set screw. and you could balance them just by spinning them on the shaft and grinding on the heavy side. ( O )
Thanks guys. Even though I don't really know much about 'Static balance', I still doubt that is the problem. I see many 90 degree Helix Vawts on Youtube (even Commercial ones) and many of them are spinning steady and fast even without a Top bearing!
It looks to me, the 90 degree Helix still has equal weight on all 4 (90 degree) corners of the rotor, top and bottom. Today I was thinking and I think I found the main problem this time. Recall I said that I wasnt paying close attention to the twist angles when I welded, and that there is much more twist angle at the bottom of the rotor than at the top.
This has to be the problem as Caleb said, but it is not the Weight causing it, but rather the difference in Twist angle from top to bottom! THAT has to be what is causing the rotor to go out of balance. (hoping like crazy)
So it will take me a whole warm day (whenever that comes) as soon as I can , in order to grind the 4 inner support arms loose and pay VERY close attention this time to the 22.5 degree twist angles (the two pairs of inner arms), and re-weld them back on and try to re-balance the thing and put it back up.
The reason I was so impatient, was I had 7 hours of Very dumb welding mistakes to fix as I was making it. So now, I guess more like 14 hours. Ha
Doesn't what Caleb said about balance also kind of apply to drag and cross section in the wind? At one rotational position the bottom has max cross sectional area (and force), and the top has minimal area. Then 90 degrees later, the top has max area (and force) and the bottom has minimal area. It seems that in itself would try to shake the turbine.
"I think those high mass steel support arms should be balanced individually."
Well, the arms weighed exactly the same and the same length, but the bending of their 'arc/curve' varied a little bit, but I figured the most important thing is the final LENGTH of the curve of all 8 support arms would be as close to each other as possible. And they were within an 1/8" of each other in length. It was somewhat difficult bending.
Well, what was said about 'Static or Dynamic balance' sounds like it is the case with this Vawt. I thought I got it in 'Weight balance' by adding the 6 big washers but it is NOT working better. It is nighttime right now and I went outside to watch it in 15mph gusts (from a good wind direction) and it may even be shaking worse than before!
As I had said before, attempting to weight balance it was sorta weird. I had to put the 6 washers in one upper corner. Maybe it is causing it to do like Caleb said??
Now that the wind direction is much better than before, the charging IS WAY more consistent now into the batteries, but it now starts shaking like the dickens between 1 and 2 amps.
Tonight and tomorrow will have even bigger winds upto 20mph, so I hope it can hold together until tomorrow and I will take the washers back off and see how it does. Can't shut it down 'electrically' because it shakes even worse!
I can sure see the nice charging potential of this if only I could figure this out I am certain now it would go up and over 100 watts easy even in this terrible location. But when it starts shaking bad the amps can't go up much due to the wobble. (at least not for many seconds)
I have a bad cold right now, but tomorrow I will at least go out and take the 6 big washers back off. Yet another snow storm and wind chill in single digits.
I highly doubt this horrible turbulance (whatever) it is caused by the 4x4 pole itself, because it is a HELIX shape which means that no matter what there is always plently of space for air to flow thru and/or around in the rotor.
I wouldn't call myself an expert, but I believe you can do a "static balance" on things that are short: their length is much less than their diameter. I've seen grinding wheels balanced with that method. But long skinny things like a wind turbine may be "statically balanced" but will cause vibration at speed. If one weight is blaced near the bottom of the turbine and another weight is placed near the top, but 180 degrees to the first, it will be balanced. But when the turbine starts spinning, the bottom weight will pull one way and the top weight will pull the other making the turbine want to rock.
Ah okay, I can see how that could happen. Thanks for the explanation.
Thanks guys for input. That is good to know that I'm not imagining things.
I always suspected this was a complex issue and I'm no expert at anything either. However, I did take it down yesterday and do those two things I had mentioned. I straighted the mounting of the generator with the Blade rotor so that it can be properly aligned and the lug nuts tightened good.
I took the whole thing back into my living room (ha--only warm place), flipped it horizontally and tried my best to 'Weight balance' the whole blade rotor.
It was off but not THAT much off I think. It is tricky and took some time. It took about 6 half inch washers on the lighter side to seemingly balance it good. (By 1/2" washers I mean the big washers that go with 1/2" bolts)
So the weight of these 6 big washers is only about 3 ounces which for this big of an object, I don't really know just how 'bad' that really was off??
So the Vawt is EVIDENTLY in decent 'weigh balance' and so I put it back up. But 'Static balance' is another story. It seems to be much more complex.
My understanding is even though it can be in perfect 'Weight balance', if I actually welding one of the support arms slightly different angle from the one across from it (the opposite arm), then the angle or 'slant' of the Polycarb would be somewhat different at that area and could cause the whole thing to go out of balance and shake like that. (sorry, difficult to explain)
But I doubt any of the arms are THAT far off. Also, as was said, the Vertical corrugations (or, ribs) going Vertical instead of going horizontal, could be causing some of the swaying. I still do not know for sure. But they HAVE to go that direction. These corrugated panels will not bend at all the other direction. They buckle. So I had to just accept them this way.
There is no wind today, but there will be 12mph tomorrow, and the very nice 25mph the next day coming from a better wind direction. So I will find out then if the changes I made make it better or not. (And I can make another video with it charging if better)
Well, I am certain 'Static Balance' CAN possibly be achieved because of watching the Commercial Vawt called the 'Mariah'. (which is probably my favorite// esp. the new one)
The 'Old' sytle Mariah use to be just a straight Savonius 30 ft high rotor!! How they were able to do that without guy wires is amazing. But I would think, If they can make a stable 30ft high straight blade rotor, I could make a decent 6 ft high Helical blade rotor-- Surely! ha
I wouldn't call myself an expert, but I believe you can do a "static balance" on things that are short: their length is much less than their diameter. I've seen grinding wheels balanced with that method. But long skinny things like a wind turbine may be "statically balanced" but will cause vibration at speed. If one weight is blaced near the bottom of the turbine and another weight is placed near the top, but 180 degrees to the first, it will be balanced. But when the turbine starts spinning, the bottom weight will pull one way and the top weight will pull the other making the turbine want to rock.
I doubt you'll ever get it to balance. It's a dynamic balancing situation, and with any given wind velocity the amount of weight or counter-force needed to make it spin "in balance" is different.
I don't understand this statement. It seems to me unless mass is actually shifting positions on the turbine (things bending, etc.) that balanced at one speed should be balanced at all speeds. Is my thinking wrong?
I doubt you'll ever get it to balance. It's a dynamic balancing situation, and with any given wind velocity the amount of weight or counter-force needed to make it spin "in balance" is different.
There may be an element to the degree of rake, or sweep, but that can only be varied by extending the vanes; pretty complicated to change on the fly.
Possibly the vertical rib issue may be bigger than you realize. The quickest fix would be to rebuild the blades so the ribs run with the wind.
Then again, best approach might be three blades, I would tend to think.
I still gotta get the green pipe monster spinning, so I cain't criticize. You are making progress, and I'm not
I've balanced mine that way. You can just add washers to the bolts on one side one at a time until you get thet balance you want. If your going to bolt another 4X4 along side you should make it a pivot point so you can tip it up and down for working on it. You'll probably have to take it inside to balance though so wind doesn't throw it off.
Ok, I put the temporary brace on the mid-section like I said, and it is helping to hold back the swaying quite a bit. It was too risky to try and take the Vawt down today. The 4x4 will go straight down from that mid-point later when I can cement it in. Sometimes, a really big turbulant wind gust hits it and it still shakes for a few seconds, but much less than it was doing before. Also the power seems to be more consistent.
Here's the latest Video with Temporary cross brace:
Sometime this coming week I will take it down and do those other two things I had mentioned in order to make it even more stable and consistent. But it is charging Batts Ok even now I think.
Sometime after the snow melts, I will try to make a video of it with a battery and ammeter in the yard showing the power it is making.
Hello, Well as some here highlighted that the pole looked too shanky, I can certainly agree now. When Video recording this I stopped the Vawt rotor and waited for a lull in the wind gusts.
I then realized how EASY it really is to sway the thing back and forth due to the easy leverage of the supports sticking out. I had never done the simple test before. So that is certainly a part of the problem. So when the weather permits some days ahead, I will cement another 8' 4x4 post in the ground and have it come up and bolt to the lower support that sticks out that mounts the Generator (trailer hub) to.
This should take away about half the sway right there. I actually held it back at that point with my hands and the Vawt rotor clearly does spin better with less 'braking effect' from the swaying.
For a temporary help, I will just screw another wooden brace at that point down to the ground. It will be good for now.
Here's a better looking Video with the sun shinning. You can see the potential there. I now doubt the Vertical ribs of the Polycarbonate is causing much of the balance problem.
There are two things I realize now that I must address that are most likely affecting the balance adversely that should be fairly easy to fix.
The first is the Alternator itself is not in perfect alignment with the whole Blade rotor. I will have to take the whole Vawt back down to file the 1.25" diam. hole that goes thru the support that the alternator mounts to. The 5 lug bolts are just loosely on because I knew it was somewhat crooked, but didn't have the time to fix yesterday.
This could be what is causing it to be out of balance so bad. Or at least it is another part of it.
The second thing is Weight Balance. I did not realize that it was possible to 'weight balance' a Vawt. But today I realized for the first time that it seems like it would be reasonable to tilt the whole Vawt HORIZONTALLY and see how in or out of 'Weight balance' the rotor is. If the two blades and their angles are indeed EQUAL, the rotor should rotate in a balanced way. And if it does not (which is probably the case), I can add appropriate weights until it is in weight balance.
I'm still not absolutely sure this would work. Has anyone every balanced a Vawt this way?
I saw 80 Watts for a few seconds today. So I am still hopeful!
I will keep working on it before my weld fatique and break from all the vigoruous shaking going on.
Thanks-- Well, I can sure see the nice potential of this Vawt IF I can correct the balance problem. It sways badly mostly under one amp. In bigger turbulant gusts I have seen the ammeter briefly go over 5 amps but the pole is still swaying some which is clearly preventing it from spinning up to fast rpm and Max power. It is still charging the batts pretty good even with it all messed up. But it may be straining the welds??
I've only watched the Ammeter a few minutes, but I bet it will go up around 100watts briefly even with the swaying later, if I keep watching it.
Now, I suspect the Vawt may be able to even hit 200watts if the Problem were fixed. The potential is there. I am excited about that at least.
The house causes massive 'blocking' turbulance and certainly is playing a part in the swaying, but I'm afraid the bigger cause is I must of welded one of the cross support arms a little bit off the correct degree. It will take time to fix.
I should've paid closer attention before welding. I really didn't want to use Guy wires for this. (Even though it does Have temporary Braces on it now) My last small straight bucket Vawt didn't even have a top bearing and it would stabilize itself and spin like a Top in giant wind gusts. It must be the whole balance of the two blades is out of whack.
Thanks guys, I will go ahead and do that soon. I have some 1/8" thick (redish color) rubber sheet that would work perfect for that.
Well, I am somewhat discouraged. Here is the Newest video, and it is obviously OUT OF BALANCE or something??. I HOPE it is not caused by the vertical 'ribs' because that would be a BIG problem.
We are just beginning to get this East Coast Winter storm as you can see. Just started a few minutes ago.
In the video the wind gusts are not even that strong at all! It's just that the pole is shaking bad in probably a 15mph turbulant gust. I sure didn't expect this to happen!
You can't see it but I am actually standing up against my house video recording this and the turbulant wind gusts are coming from around BOTH sides of the house and sorta slamming into the Vawt at the same time.
I do not know for sure if this could be part of the cause of the terrible balance situation. I tend to doubt it at this time.
Right now I suspect the problem is either the blades really are out of Balance in that they are not EQUAL. I really didn't pay super close attention and was in a hurry when I mounted them.
Or, the Worst case senario would be that the Vertical Ribs of the Polycarbonate blades is causing it to sway and go out of balance. I HOPE it's not that!!
The much bigger turbulant wind gusts are coming this evening and all night. (Possibly up to 30mph!) So I will keep observing it in even bigger gusts and then probably shut it down electrically for the night.
I would appreciate ideas and comments if anyone has had this happen or suspects what is or could be happening??
where you bought the polycarb they should sell a rubber gasket material that goes between the corragations and whatever your fastening to. You could probably use that to cushion between the bolts. Just cut it into small chunks so it won't block wind. It would probably be better if you make another one to mount the Polycarb on the inside of the arms for better support in strong winds. I like it, can't wait to see video in decent wind.
Yeah, thats the way I wanted it, to be much Less noticable from a distance. I use to have a small tiny 6 sq. ft Sheet metal blade (straight bucket Vawt) up-- and even though it was only 2x3 Ft, it was still quite noticable from the distant road when it was turning.
So this one is over 3 TIMES bigger (hoping 3 times power) and yet it is WAY less noticable and the Helix shape itself is less noticable if you look at the shape from any one location. I Love it so far -- looks like art to me. ha
This Helix Vawt makes a lot more sense to me now than just the Straight bucket Vawt. I would think it could have maybe even 40 less drag than the straight bucket, so I am very enthused about it.
I would have LOVED to make the full 12 ft high Vawt with two of those Clear Polycarb panels, but I couldn't afford the steel pole at this time. Another cool thing is they have different colors of those Polycarb panels, like black, blue, red. Would also look neat to match one's house color. (IF it works that is)
Today, of course, didn't even have a breath of breeze. It was 0 to 1 mph. (The wind curse thing)
But tomorrow is some good wind arriving but from the worse direction, but the Vawt should still get plenty of turbulant puffs of gusts to see how it does.
Yeah, that is something I will watch, but I was thinking more of using rubber washers in front of the steel washers (That go with each mounting bolt of course) in case I need to take the blades back apart to move them.
I think it is good for now, but I will watch closely to see if any of the steel washers will start to 'grind' and vibrate into the Polycarb panels in the weeks ahead. If I see any evidence, I will certainly put the rubber washers in place.
I had made this 3-phase alternator a couple years ago. It was my first one. Right now, I have the cut-in at about 75rpm (for 12v batts). I think it will be fine.
The rotor is almost always slowly turning, even in a 2mph. Of course, all it could do at that speed is light up a LED! ha Like many commercial Vawts say that, but they fail to say how much electric it is making. (only mili-watts!)
This alternator (20 pole/20ga. coils/5 coils per phase) I made still has a little too much resistance. I was just learning back then, but now I would've made it with bigger magnets so I could've used bigger gauge coils and probably 50 percent more power out of this Vawt Rotor. But oh well, I am still happy with it.
We'll see what it can do in a few days. I just hope this Vawt is decently balanced so as not to shake the whole pole to death when the really BIG wind gusts get here.
It's exciting -- if it does, I'll rebuild it better.
Good work. Following up on the comment I made about gluing that sheet- you can probably get by with clear silicone if it's specified for use on plastic. I think your arm support will do well with the ribs running with the wind, instead of vertical.
CmeBREW1 Congratulations on a great looking Helical VAWT! These seem to have low start up speeds. I will be interested to see what your cut in speed is. What is your alternator rating?
Of course, this is a 90 degree Helix (twist) Vawt as you can see my best attempt in the first photo below.
It is very important that the Whole rotor be perfectly straight up and down with the generator (the Hub). So the next Photo shows how I done it. I temporarily mounted the 3/4" pillow block bearing at the top and made sure it spun straight and easy before doing the FINAL big welding to the main plate attached to the Hub alternator. And I welded a few more angle supports to it with small pieces of 3/8" solid rod.
Of course, weld spatter gets on the magnets, which is a pain to clean back off with masking tape. But this method it the only way I could think of to do this correctly.
Next, I had to screw on the Polycarb blades with 1/4" bolts. (1.5"long) I used some finger clamps to help me do this also by myself. This was more difficult than I thought it would be.
It was made difficult because of my just guessing the 22.5 degree twist angles to weld the cross supports on to the Main pole. Because their is more Twist angle at the bottom section than the top, it made fitting the Polycarbonate somewhat more difficult to do.
As you can see in the last close up photo, I had to just leave a 2" gap at the bottom cross supports so the polycarb would not buckle badly at the top. It is no big deal though , I will put longer bolts in there for that.
But both sides are still equal. Both sides look the same exact way.
This is not a PERFECT Helix Vawt as you can see. But I am happy with it, since It's my first attempt at a Helix.
As you can see in the close up, I locked in all bolts with lock washers and nuts so they can't vibrate loose.
It has been a very fun project and I can't wait to see what it will do when some real wind gets here soon.
I will make a better video and see what power I get out of it in this turbulant location. (You can't see it in the video, but there is my house close to the right side and a bunch of trees close to the left side. Not to mention the hilly turain.
