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Forum Index : Windmills : Furling on a F and P , Have I got it righ
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fillm Guru  Joined: 10/02/2007 Location: AustraliaPosts: 730 |
Hi Tas, Well I think it is outstanding work , and if you keep going you will end up with a nice set of blades , but if you vary from the origional cordinates of the GOE profile then it is not a GOE222 profile, but I do think there is a small amount of licence in a few areas . Here's a pic of the Alu profile and from what I can see you are dam close , if you want an off-cut to assist , then I am more than happy to send you one to use as a template etc, drop me an email through the Blade order section if you want . 
Keep up the good work..  PhillM ...Oz Wind Engineering..Wind Turbine Kits 500W - 5000W ~ F&P Dual Kits ~ GOE222Blades- Voltage Control Parts ------- Tower kits |
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| Taswind Newbie  Joined: 13/12/2012 Location: AustraliaPosts: 31 |
Hi all , thanks for the replies and advice , have not had a chance to do any more to the blades yet , but am picking up a couple of sanders off a mate on the weekend , so will get back into them next week . Will start to get them into a better shape and do a weigh of the blades and see how close they are , or not  .
Have made them a bit longer than needs be so will have to decide the finished length of them as well . downwind , would love to see how you went about making your blades , so you better get on to your write up 
Phill , thanks for your generous offer of the profile shape , and i might take you up on that , should be able to get close from the pic you put up though . Thanks all for the advice so far , and I will put another pic up after a bit more sanding . |
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Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
If you do a bit googling you will find the profiles in autocad format. There are plenty of free or trial programs that will open and print them. What I did was print the profile and then taped it to a piece of tin and used a sharp punch to and lightly tapped around the edge. Then cut it out to use as a template for planing/sanding. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
@Taswind, PM me a email address and i will send you a early draft of what i done, and how with the gig. Its changed 20 times since i begun the project, but the hardware remains the same. I need to go back and start the article from stage one, hence its a coming thread, it takes time to set up and photograph each stage, as well as the text to explain the stages. A half ass approach, dont make a good thread and helps no one with a fragmented thread, and i think a instructable is a far better then a "Hey Look at what i Made" approach So hence no public 1/2 ass thread as yet. Edit....... i just read my post, and thought it may have implied i thought your postings were fragmented, not at all, my comments were to my pending posts of my own project not yours. Pete. Sometimes it just works |
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
G,day Madness , I did find a couple of printable profiles , and then scaled them to the size of the blades Iam making . Great minds think alike , I have made a template out of tin , so I have a profile of both sides of the blade , so I can run it along the blade and see if I need to remove more material .
G,day Pete , my posts probably are fragmented , bit all over the place with this , steep learning curve
PM sent No it's not , think your inbox is full ??? |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Ok emptied my inbox, nothing worst than a full box. Pete. Sometimes it just works |
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| Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498 |
That's what she said. There are only 10 types of people in the world: those who understand binary, and those who don't. |
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
Geez , Iam old , sitting down to breakfast and my son comes over and hands me his Ipad . There you go dad , what's that I say , it's your windmill blade . He has it drawn up in a wind tunnel program , shows you the drag and lift a profile will achieve . Don't know how accurate it is , but had a bit of fun playing with it this morning ,lol Pete pm sent |
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
And she is dead ,lol, pulled it down and put the aluminium tail boom and a bigger tail vane on it a week or so back , well today the wind finally turned back to the regular westerly flow , the best direction for the mill, after weeks of easterly stuff . With forecast winds of up to 50 odd klm an hour , thought this will give her a workout. Had a few gusts come through just after lunch about 25 klm , and for the first time she was furling , maybe a little early if anything , but she was looking good . Went down to the shed to check the new little Turnigy meter i had installed to see what sort of output it was getting , it showed a peak of 276 watts , so furling must have been pretty close ? After a while a few more bigger gusts came through and I had a glance up from what I was doing to see what sort of power was coming in , it said zero ,huh, so went out to have a look and she is slowly limping around with three bent blades  .Looks a bit like a whisk now .
Not sure what happened , looks like they have hit the tower , but never heard it , could they have got out of shape when it was furling ,side on to the wind, as this is the first time that it has furled, and put pressure on the blades bending them into the tower ?? Oh well , work in progress , onwards and upwards
Have to get back on to the new blades . |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Is it possible that the tail is allowed to come around too far in full furl and hit the blades. (No tail stop)
What was the distance between the blades and tower, before the egg beater became a whisk. 
Pete. Sometimes it just works |
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Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Taswind's misfortune prompts me to ask a furling question I always wondered about. Assuming one has a theoretical Horizontal axis windmill that has the blades rotating with the turbine shaft pointing directly into the wind for full power. Now, with a theoretical steady wind direction, how far round from directly into the wind should the shaft point for an effective full furl? 90 degrees seems too far for me as it gets the whirling blade ends too close to things they could hit. Is 60 degrees enough? Or perhaps 75? The reduced power of the wind hitting the blades side on at these angles is surely sufficient to prevent over speed etc., has anybody got some recommendations derived from trial & error? Oh, I should add that I ask this question for a mill that does _not_ have the pivoting tail furling thing - its actually a downwind mill furling over the top that I am considering. A pivoting tail is too much trouble at my location. Klaus |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Klaus, That would largly depend on the design of the mill, but in most cases i see no problem with 90 degrees. On average the blades are set forward of the yaw bearing with enough distance so the blades clear the tower, and the tail piviot is often a little distance behind the yaw bearing, so at 90 degrees their should always remain a clearance gap/distance between the blades and tail. But the tail needs some form of a stop to prevent it going past 90 degrees, also some mills use a few degrees of tilt back on the mill axle so it kicks the blades out away from the tower to give greater blade clearance to the tower, although tilting the axle back decreases the distance to the tail when at 90 drgrees, so some caution needs to be taken to prevent a tail strike, this might mean the full furl position needs to be reduced a few degrees from 90 to maintain clearance. Pete. Just read your edit...... i didnt think downwind mills actually had furling to start with, or do you mean an up wind mill that furls like the Whisper mills do, with the tail fixed and the alternator and blades furl back and over. Sometimes it just works |
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| Tinker Guru Joined: 07/11/2007 Location: AustraliaPosts: 1904 |
Yes, exactly, and as I believe you run a downwind mill you're the obvious person to ask. What I want is an easy way to stop the blades from over speeding and tilting it up -helicopter fashion - looks an easy way to furl it. This gets the blades away from any mast guy wires as well. The tail (I thing a 'canard' wing is more correct here) would be fixed straight ahead, always pointing directly upwind. But I would mount the wing so it maintains a constant angle of attack throughout the furl. If you look at the up/ down movement of a desk lamp you get the idea. A related question is regarding the precession effect, do downwind mills require an offset between the wind seeking pivot and the rotor axis? Klaus |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
Dont be fooled by the name i selected, it was a bad choice i made long ago. No i dont run a downwind mill and think they are a design waiting for a failure to happen. I run a up wind mill using a modified narcel from a Whisper mill that hit the deck and trashed the alternator. (the narcel survived) Here is some photos i took a while back of the furling angles of a Whisper. 
The method works vey well as there is no tail offset and the mill always faces directly into the wind, the only real part i dont like is how the mill comes out of furl, as its a little violent with the forces in play, although i do run a much bigger blade set than the original whisper mill. It was a free narcel with good sliprings so thought it was worth a try. Now i have reduced the blade weight by over 5kg from the PVC GOE222 blades to wood blades the return from furl is much softer. Pete. Sometimes it just works |
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
G,day Pete , sorry for late response Have a tail stop and the tail is fine , you would see marks in the tail if it hit as it is only .6 mm alum , but it is clean , no hits . It must of hit the tower , maybe the blades flexed back ? From memory there is around 120 -150 or sp mm clearance to the tower , maybe needed a bit more . On a different note ,picked up a cheap 200 watt Chinese mill at a garage sale today , anybody know what the difference is between the 12 and 24 volt models ? Are they wired different or does one just have a higher cut in , not sure what this one is. Might give this one a fly and pull the F and P mill down and get the new blades finished off and attached . |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
What is the Chinese mill, perhaps a photo might help. Is it DC output or 3 phase. It might be internal voltage regulated, so set for a nominal voltage. If you are able to spin it up with a drill or motor of some form with no load and a multimeter on the leads you would see what voltage it will get up to. Another test would be to spin it by hand at around 60 rpm (easy to count 1 rev per second) and see what voltage it produces, as this might give an idea to output voltage expected. For example we would like a mill to reach cutin at around 80 to 120 rpm, so to keep it simple lets say you get @7VDC at 60 rpm then it would be better suited to a 12v mill with a 120rpm cutin. If you get @15VDC at 60rpm then it would better suit a 24v mill at 120rpm cutin. As for the Whisk mill, it might suggest a poor blade strength or a design failure, we often under estimate the force of the wind and what higher rpm and poor blade balance will do, in some ways you may have been lucky to have it fail the way it did, as it appears to have caused little damage other than a blade failure, a loss of a blade may have torn the whole mill and tower down due to out of balance vibrations. Is it possible the mill become unloaded due to bad wiring or a fully charged battery and spun up to a point of blade self destruction. What dump load do you have and what method of control do you have to protect the mill should the battery be fully charged and need to divert the power somewhere. Pete. Sometimes it just works |
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
Sorry no photos , have misplaced my camera , have been looking for it for a few days but it has not turned up yet 
Have been having a look around the forum and it looks like the jaycar style of turbine . Swapped them over this arvo and currently the wind is blowing 4 to 5 Mps hate to say it but it is kicking the poor f and p mills butt , but to be fair the wind really has not been blowing the right direction since I put it up until it swapped direction the other day and the f and p mill failed ,and the wind has been steady from that direction ever since . The Chinese mill is currently putting out between 1 to 5 amps and has gone up to 9.9 on a couple of gusts But if the f and p mill was spinning as fast as this thing is it would be putting out more amps 
This thing is noisy though where the f and p is silent When I swapped mills you can see marks on the tower where the blades have hit it , looks like the blades have just bent back with the wind force and just curled the blades out from the tips . I don't think the mill became unloaded , wiring is still attached and working as should be . Currently don't have a dump load as just have not produced enough power from the mill to worry about it , until tonight' , have currently just had to turn the inverter back on and I have swapped the fridge back over to the off grid supply as the batteries are now full , so will have to sort something now , but will just turn things on to use power for the moment , and just run a few more things off the small off grid system that I am using while the wind is blowing
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
Shut it down for the night , noisy damn thing , don't want to upset the neighbours and get them off side .
Will try the wiper snipper cord trick tomorrow , that I found earlier in my searches , thanks to the forum |
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| Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333 |
If its a early Jaycar mill, they have blades like bulldozer blades, and about as noisy as a bulldozer. There is a thread or maybe a front page article on the forum to modifying these chinese blades to work much better, worth a look. Mate! you are kidding yourself if you think you dont need to have a dump load and some form of a basic controller with a mill. Either of 2 things will happen, you will boil the battery dry, or self destruct the mill, or if not both. For 99% of the year you wont have a problem, but when the winds hit with high force what will you do and will you be there to do it? The fridge is a poor base load to use as it might be on or might be off, on average it should even out, but perhaps not"? Much better to use stable resistive loads like AC lighting that you can adjust to balance the input to output loading. Fine but what happens when you go to bed and the wind increases, or away at work? How good are you batteries? Perhaps they are rather secondhand and can not absorb the current from the mill, and do you understand how a battery charges, with how current adsorbing decreases as the state of charge increases, meaning if the mill makes 10 amps and the battery is only drawing a 5 amp charge what happens to the extra 5 amps. Basically if the excess current dont go somewhere, the mill unloads and RPM increases, making higher voltage, and boiling the battery, on the way to a runaway mill to self destruction. Pete Sometimes it just works |
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| Taswind Newbie Joined: 13/12/2012 Location: AustraliaPosts: 31 |
Morning Pete First job this morning is to drop the mill and try some of those changes . I never said that I don't need a dump load , just have not worried about it . My solar controller can also set limits for a dump load , which I have wired and set up to a solenoid ready to switch on a dump of some form , but have not bothered with making a dump as yet . The power I have made from the mill probably would not have run a light bulb so far
The power last night coming from the mill would of been negated just by turning the inverter on , it draws nearly 3 amps to run itself , and when the fridge is running also that is 9 amps draw together. I work from home , so most of the time I am about here , I have been playing with off grid solar for a while so understand batteries and charging etc , but mills are a new experience . The dump will happen it just hasn't been needed yet Thanks for your time and input though , I do appreciate it . Right , off to change these blades , am getting quick at getting it up and down now , 5 min can have it down and back up again |
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