Wind generator no longer up or running.

[duffy]

I think you also need a special winding machine to make this kind of thing out of carbon fiber. I wouldn't try winding one, but maybe you could buy them?

 

[blueroomelectronics]

Sorry to hear about your generator, it looked very promising.

They want to put wind generators on the lakeshore here in Toronto, the nay sayers say they make a low frequency vibration that drive folks crazy (even though they'll be at least 100m out in the lake)
Personally I think they're a necessary power source and welcome them, I'd really like a small one at the house. (I'm still getting up the nerve to mount an HDTV antenna on the roof)

 

[tcmtech]

I Will have it back up and running one way or another soon! I dont give up easily!
Once I get everyone else's priority work done its at the top of my list!

I might even put off a few low pay jobs and bump it up a few days!

 

[killivolt]

I Will have it back up and running one way or another soon! I dont give up easily!
Once I get everyone else's priority work done its at the top of my list!

I might even put off a few low pay jobs and bump it up a few days!

I recently seen someone use a piece of underground pipe cut it into three wedged sections grinding they tapered off the trailing edge and rounded the leading edge ?

For the size of this project the diameter and length of pipe may be prohibitive and may not be strong enough to handle the stresses and vibrations any more than the aluminum.

kv

 

[Boncuk]

They want to put wind generators on the lakeshore here in Toronto, the nay sayers say they make a low frequency vibration that drive folks crazy (even though they'll be at least 100m out in the lake)

Big wind generators indeed produce strong low frequency vibration and sound. The sound is similar to the main rotor noise of a Bell UH1 helicopter.

I don't know about the laws in Canada - in Germany wind generators are only allowed to be operated at a minimum distance of 1km away from settlements.

Still the noise is audible in a clear and slightly damp night - whopp whopp.

Reducing rotor speed would reduce noise, but also power output, hence efficiency. The blade tips have speeds ranging to Mach 0.97 which is already transsonic speed.

At Mach 1.0 they'll cause a sonic boom followed by self destruction.

Boncuk

 

[tcmtech]

I have seen pipe blades before but the design was a little bit different and far bigger than any thing I will attempt.

I saw the remains of a system some farmer built about 25 years ago. It used well casing pipe and steel sheet bent into an airfoil to make the blades It worked very well for a few months as I was told.

The problem was the rotor was 30 ft in diameter and ran on a 10 ton truck axle that did a 90 degree turn and ran the drive shaft down the center of a massive tower.
At the bottom was a second truck differential that did another 90 and then drove a 1200 RPM 50 KW military surplus generator.

Guess what happens when you take that much blade and generator power and have it going during a 40 to 60 mph storm!
No way in hell can a person find enough load to slow it down!

He turned on every thing he could find including two electric ranges and went in the root cellar and hid until it flew apart!
The electrical lines in his house made permanent scorch marks on the walls!

I believe the remains are still laying at the abandoned farmstead where it originally tipped itself over!
If I ever get back over that direction I will try and get a hold of the guy that showed it to me and get some pictures. It was some real farmer Fred engineering to behold!

 

[Boncuk]

Guess what happens when you take that much blade and generator power and have it going during a 40 to 60 mph storm!
No way in hell can a person find enough load to slow it down!

half a dozen of discs and 12 brake shoes will do it.

 

[tcmtech]

If he wold have kept the air brakes functional from the original truck the big axles came off I think all he would have needed was a portable air tank to reactivate them. The guy that took me out to see it and I speculated about that due to the axles not having the brake drums on them or the air brake actuators in place.
By removing the spring on the one side of an air brake pod they can be converted so that they work like normal automotive brakes and wont lock up when no air is applied.

 

[duffy]

Wouldn't it be better to just fold the tail? I notice you don't have that option on yours, might save you some headaches.

 

[tcmtech]

Its just more stuff to add and maintain.
Folding the tail is great for parking a wind generator but when its parked it does not produce anything! I dont see how folding the tail will save a defective blade.
I have never had a blade failure from over speed until now. And I still dont think this was a over spin issue. The day it happened was not windy enough and the electrical system was working so there was more than enough load on it.

And as I said in the beginning there was a big void in the fiberglass resin that I believe was the root cause of this.

I build my systems to purposely work with the very High winds.
I can produce far more energy in one single 30 - 40 mph day than I can in an entire week of 10 mph days.

To me, if I have to park it on a windy day that says its a weak design!
The whole concept of a wind generator is to get as much energy from the wind as possible.
Parking it on a windy day is like someone saying they have to put a cover over there solar panels on bright days because they will produce to much power!

Bigger and stronger on the next design! I have a 1.8 kw PM AC servo coming and I plan to reuse the frame from this system with a set of 6.5 foot blades I have from before.
The servo motor is rated for 1.8 kw, 200 volts at 1500 RPM with a intermittent overload capacity of 10kw!
No way my 6.5 foot blades can over speed on that with direct drive!
(well, tornado maybe)

 

[duffy]

The tail folding is automatic, works in high wind. Offset generator mount and a spring does the trick. It's specifically to stop these kinds of situations.

You never looked at those old farm windmills that drove waterpumps? They had this.

 

[tcmtech]

The only windmill pump heads I have seen were in the scrap yard. I put a few there myself.
I never really paid much attention. The few old timers I know that used them said they would turn out of the wind well enough but would lock in place and need to be reset manually.

I tried an off set self furling design many years ago when I was in high school It worked up to a certain point and then would start to oscillate horribly. I pretty much abandoned that design after that.

I also have an original 32 volt 1KW Paris Dunn from the 1930's. It tips itself up to slow the blades down. It worked well enough but the constant tip up and bang down did too much damage to the old windmill tower it was on. It would constantly shake the tower when it was going up or down and that constantly loosened up the tower bolts and would break the bracing cables.
I will likely restore it and put it up some time but its going to get a different control system.

But I am open to ideas though. If you have a tail control design thats known to be stable I would be interested in trying one.

Still personal preference is to just get better quality blades. My brother built a CNC machine and with a little work its capable of doing a good set of blades.
We are trying to find a good airfoil design so we can do a set set out of wood and then do a fiberglass overlay.

Doing something myself and watching it fail sits better with me. Far more so than paying someone to fail for me!

And as I stated before I never had over spin failure with my own home made blades so maybe I will just have to go back to doing it myself.

 

[duffy]

Maybe this is a biz opportunity. Microcontroller-controlled automatic tail furling device for high wind conditions. Automatic reset, no oscillations. Might be able to do the mechanism with just one solenoid.

 

[tcmtech]

HeHEhe, no.
If its not mechanical I dont want it on my wind generator.
No micro controller anything. I can handle springs and pivot bearings, if they work!

I prefer all mechanical. Mechanical takes far more environmental abuse than electronics ever do.

I have pondered on a simple design where the generator and gearbox assembly are mounted on sliding rails and have a spring holding them forward. As the spring moves back the very end of the tail vane would tip one way just like the rudder on an airplane.
Thats about as far as I have thought out tail controlled governing systems.

 

[Sceadwian]

Mechanical devices can't be smart though tcm =)

 

[tcmtech]

All that micro stuff is way beyond me and I dont care to make the investment for the equipment to program it or the time to learn how to do it. I learned PLC years ago and thats enough for me.
Smart machines might work for some but I would prefer to build a bulldozer instead of a robot.

All I need is to come up with is stronger and bigger. Thats will within my abilities.
I found Carbon fiber sheets and resin on eBay for not to extreme of price.
Perhaps I will have to buy several yards of fabric and a few gallons of resin and do an overlay of that on a pine or redwood core thats laminated with alternating carbon fiber and wood.

I think I will buy one more set of fiberglass blades and see what becomes of them first.
Another month or so and I will have all the money I spent last winter rebuilt so I will have something to work with for play money again. The bad winter drained me. So I am still limited on what nonessential or work related expenditures I can justify.

 

[Sceadwian]

tcm, I've spent about 100 dollars total on micro controllers and a programmer. Another 50-100 on components and tools combined in my entire life for electronics. I've often seen the same arguments used for not using micro controllers. They're not that bad, it's fear of learning that's the real learning boudary.

 

[tcmtech]

Both my parents are teachers by profession! I am terrified of learning new things through a genetic predisposition!

Its not the cost outlay or the code and programming learning, I could likely learn it in a few good days if I wanted. Microcontrolers are becoming more interesting to me day by day thanks to guys like you and a few others here.
I just dont see the need for it in many applications. I realize the set up is cheap and easy to do. The problem is all of the added circuitry to make a micro controller live in a harsh electrical environment and actually control something is what I dont care for.

I like PLC systems though. Its what I learned logic control stuff on and they already have all the added protection and input/output circuitry built right in.

I just prefer that when things have to be in an outdoor environment simple rugged and mechanical works! Its what I want on my design. I already know how to make electrical and hydraulic controls and what not but simple just works for me.
Static build up, rain, snow , ice, summer heat, don't bother springs. Lightning strikes dont bother them either!

I have more than enough mechanical design and fabrication skills to add tail furling and or variable pitch blade controls if I need to. I just have had nearly 20 years of home made wind generators designs without any of that stuff that never failed from over spin issues.
A bad blade is what I am writing this one off as and thats all.

If I build my own blades and get a repeat of this incident then yea I will put more over speed protection on the designs but until then my personal experience just says a random manufacturing flaw caused the failure.

If I did not build it I cannot guarantee the quality. We all have gone through that a few times in one form or another.

 

[duffy]

I agree with Sceadwian. You can buy a programmer for $100 to do pic chips (I recommend the Picstart). Development system is free, download MPLAB off the Microchip site.

For ATMega processors, you can rig up a programmer with just a few resistors and a couple of connectors -
Simplest 128 atmega programmer - Scientific, embedded, biomedical, electronics contents.
And once again, the development system is free. They WANT you to use their chips.

This is a big shift from how it was in the 1980's. I went through all kinds of contortions to get an 8048 to go, actually had to build two friggin' programmers - one to program an EPROM (2716 or something) and another to transfer that EPROM to the EPROM in the 8048. You kids got it easy these days. In my time I had to walk uphill, both ways...

The mechanical system just isn't going to stop every possible oscillation mode. It's not going to know if the batteries are topped off and to shut the windmill down and save wear and tear. It's not going to have a blinking light on the tail boom. WTF? You want your electricity-generating windmill to not have a blinking tail light?

 

[tcmtech]

Hmm...Blinking tail light.. Maybe!

I run directly to a my home made GTI unit so I dont need to worry about battery charging. I convert all usable power directly to AC and use it on my place! The GTI advantages is that I dont put current or voltage limiting on them and so they just load up the gen set as the speed increases. My GTI's go from linear to exponential load at a specific voltage. Going from 1x to 10x amps draw over a 10% voltage increase keeps any over spin from happening.
My load bank is set up to pull a very heavy load too. Should the GTI go off line the load bank will pull the gen set down so far that it will nearly stall and the blades! Blade efficiency gets very poor at low RPM's

Until I build a new wind generator I have no idea how much oscilaton I may or may not get.
SO how am I going to sense all this stuff a micro controller is going to be needing to look at and how am I going to produce an actual physical output big enough to make adjustments on a 600+ pound system?


I am doing some shop cleaning in my spare time this next week or two so should I put up a new thread relating to neat stuff I will have for sale?
I have at least 10 Trace and misc inverters of assorted sizes (multi hundred watt to multi KW capacity) that dont work plus my old 60 volt 200 AH battery bank and a bunch of other neat stuff that will likely go cheap too!

I will probibly invest in a Micro controller programing set up this fall so I have something to play with next winter if I get another 6.8 feet of snow agin and cant do anything.