Author Topic: Combining know-how  (Read 7850 times)

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Offline bvan1941

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Combining know-how
« on: February 11, 2012, 05:59:48 pm »
It's too bad we can't combine all of what we've learned from all the electronic/ mechanically talented and skilled people in these Forums. By that I mean, if one reads over the (3) Forums, some people have significantly improved or mastered parts of the puzzle very well . Let me give some examples from the perspective of a newcomer:

Combine a good solid generator capable of say 1500watts-3000 watts, with an efficient transmission, together with a variable pitch / rotor. All found and made here on these Forums by individuals that we all are familiar with.  It would necessitate gathering all these components and putting together a "prototype" for evaluation.  ( I can name several very skilled candidates to assemble this kind of project). It would take some degree of overall cooperation and maybe some donations (for material expense) from us, but if spread around, probably not much for what could be a real answer to all the variables with WT'S.
Just an idea for maybe moving forward? This would be a great project everyone would be interested in!
Bill

Offline WooferHound

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Re: Combining know-how
« Reply #1 on: February 11, 2012, 11:06:36 pm »
The
 AnotherPower
   Wind Turbine Plans
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Offline Volvo farmer

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Re: Combining know-how
« Reply #2 on: February 11, 2012, 11:27:39 pm »
Ya, people have done some pretty nifty stuff over the years. Problem is, when you get into transmissions and variable pitch devices, the machines quickly get out of the range of the average DIY fellow. Chris has admitted that it takes a very special type of person to duplicate his project, and he appears to have no desire to mass produce the thing.

It's one thing to be able to bolt three rectifiers to a piece of aluminum and wire them up right, it's quite another to be able to fabricate a chain drive gear case  with hardened steel shafts  and get the whole thing aligned right.  It's nice to see evolution and pushing of boundaries, but when it gets so far away from DIY, that less than one in ten thousand people could replicate the thing, it loses some of its appeal for me.

Offline rossw

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Re: Combining know-how
« Reply #3 on: February 12, 2012, 12:14:46 am »
It's one thing to be able to bolt three rectifiers to a piece of aluminum and wire them up right, it's quite another to be able to fabricate a chain drive gear case  with hardened steel shafts  and get the whole thing aligned right.  It's nice to see evolution and pushing of boundaries, but when it gets so far away from DIY, that less than one in ten thousand people could replicate the thing, it loses some of its appeal for me.

I wonder if there are not some sort of existing gear-cases readily available from some other purpose that could be re-tasked. I mean, obviously there are commercial/industrial things but way out of reach price-wise.

People already use trailer wheel-hubs and differentials and various other car/truck parts for trackers and turbines...

And while I accept something re-tasked my not be ideal, if we lose 3-5% in inefficiencies, but can use parts that are 50% or more cheaper (eg, using Ferrite mags and higher RPM), it may still be in the reach of at least some DIY people?

Offline Wolvenar

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Re: Combining know-how
« Reply #4 on: February 12, 2012, 01:49:04 am »
I think the idea in some fashion may have merit.
Determining what may be doable by whom, and agreeing on what is *the best* way to do it might be the tricky part.

I do think it is worth exploring in some fashion.
 
I would certainly think that having something available pre made to purchase, say a set of coils wound, or a stator made etc.. may be a valuable thing for someone who just wants to get a start. I know a large part of what held me back from getting serious with building any style wind alternators is the uncertainty of where to get quality wire with no local suppliers. It took zubbly pointing me in the right direction and giving me a crash course in wire before I had any place to start.
Sure miss the guy, I bet we would have a very good guide up here in no time if her were around yet.

Maybe a few guides depicting complete home brewed systems of varying sizes, entry level "toy" stuff like JeffD has recently posted, to heavy duty fully off the grid systems liek Chris, Ross and a number of others here have.  I love having journals all in one place for each person as it makes the work so much easier to follow. I think I learned more that way than any other.

Or maybe more simple things like users that have successful systems posting along the lines of:
 How would I design and build a new RE system for myself, knowing what I know now.
Where would I locate parts, etc all in one easy to follow spot.
..
Then the critiquing would come natural to a forum like this.

If anyone would like to build parts, generators, etc to sell,
I'd love to see that sort of thing in the Classifieds.
( not to invite any full blown commercial advertising or anything)

ok enough of my half awake rambling..
Trying to make power from alternative energy any which way I can.
Just to abuse what I make. (and run this site)

Offline Janne

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Re: Combining know-how
« Reply #5 on: February 12, 2012, 05:39:42 am »
I haven't looked at Chris's latest design, but if one would use self aligning bearings all along(mayby Chris already does), it should be quite easily doable for a DIY'er with some welding skills. That way the slight misalignments an average garage mechanic will get will not matter.

Variable pitch will be somewhat harder I think. Finding easily obtainable bearing blocks for the blade shafts will not be easy - in fact all the successful variable pitch machines built here use custom machined bearing blocks for the blades. Blade synchronization mechanism is also hard without at least an access to a lathe. Some designs have used pillow block bearings for blade shafts but they're not really ideal, as their axial load carrying capacity is quite poor.

If the design would stick to the tail furling instead of vari-pitch, then I think it could be possible to further popularize the design. Vari-pitch really is not that necessary either at these sizes of machines, mayby upwards of 7-8m it starts to be more useful, as tail furling becomes a big pain due to the gyroscopic forces.

For the bigger machines anyways the structure tends to be built around what parts one can get from the boneyard.. Geared motor units, used industrial transmissions, converted induction motors, or induction motors with capacitor excitation all come into play,  as custom solutions build from scratch will became too expensive to be feasible. But an average windmill builder is not tackling these bigger machines anyways, so I think it would best to focus any possible efforts to a turbine sized mayby from 3 to 5m in diameter.
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Offline bj

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Re: Combining know-how
« Reply #6 on: February 12, 2012, 05:56:06 am »
   Half awake as well Wolv, but--
   If it started with basic classification headers for wind speed, then under each of those a skill level, it
might be do-able.
   It would be a big project, but the end result might be worth it.
   Almost like writing a book?
"Even a blind squirrel will find an acorn once in a while"
bj

Offline Dale S

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Re: Combining know-how
« Reply #7 on: February 12, 2012, 11:30:18 am »
You can start by throwing away variable pitch, sure it's cool, that system midwould has on fieldlines is sexy as hell but Chris has shown that with properly tuned MPPT it's totally unnecessary.
And BTW he does sell complete turbines as well as all the separate parts.
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Offline WooferHound

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Re: Combining know-how
« Reply #8 on: February 12, 2012, 11:39:33 am »
Any beginner will need to make a small turbine first to get the basic skills down and understood, so they should start with a smallish machine first.
Once a person has constructed a machine, they don't need much help, and larger machines vary wildly in their design because people want to use materials they already have onhand.
So, It would be nice to make some kind of guide for the beginner to make a 5 footer and not worry too much about the more experienced builders.

So many folks want to make machines with stuff they already have. Maybe an in-depth discussion about how to make magnet rotors, then construct test coils and how to calculate turns, amps and volts from the test results.
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Offline ksouers

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Re: Combining know-how
« Reply #9 on: February 12, 2012, 01:32:57 pm »
Any beginner will need to make a small turbine first to get the basic skills down and understood, so they should start with a smallish machine first.
Once a person has constructed a machine, they don't need much help, and larger machines vary wildly in their design because people want to use materials they already have onhand.
So, It would be nice to make some kind of guide for the beginner to make a 5 footer and not worry too much about the more experienced builders.

So many folks want to make machines with stuff they already have. Maybe an in-depth discussion about how to make magnet rotors, then construct test coils and how to calculate turns, amps and volts from the test results.

Yes, yes, yes!
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Offline ChrisOlson

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Re: Combining know-how
« Reply #10 on: February 12, 2012, 06:43:12 pm »
I haven't looked at Chris's latest design, but if one would use self aligning bearings all along(mayby Chris already does), it should be quite easily doable for a DIY'er with some welding skills. That way the slight misalignments an average garage mechanic will get will not matter.

There's a little bit of a misconception there.  Using self-aligning bearings does indeed prevent having to machine bearing bores to the precise tolerances required for something like tapered roller bearings.  But the reason I have stuck with dual row angular contact ball (which are NOT self-aligning) on the mainshaft and self-aligning ball on the PTO is because of their ability to handle high loads with minimal power loss and no pressurized lubrication system required for the top bearings.

Oil bath taper rollers have to be run preloaded and require a constant flow of oil over them (or to be submerged in sump oil) to keep them cool.  Pre-lubed and sealed ball bearings require none of the above.

The other thing is that you cannot get away with much misalignment of the shafts.  The roller chain in a chaincase has to track true on the sprockets or you'll wear the side plates and sprockets (especially the small one) in short order.  You're dealing with a very close shaft spacing and can't get away with the sort of misalignment you could with, say, a motorcycle chain.

The nice thing about using self-aligning bearings on one shaft is that there's enough "play" in the bearing bore and mounting holes to "tweak" it until the chain runs perfectly true on the sprockets.

I never intended for that design to be easily doable by somebody who only owns a hacksaw, hammer and welder.  Most of what's in the homebrew books now is adequate for most people.  But those book machines have weak-kneed generators that cannot handle continuous high power levels without burnout because they dissipate too much power in the stator.  Their saving grace is that they typically run into stall at 12 mph wind speed, and get worse as the wind picks up.  That's why I abandon those designs and went off on my own.

There is no way I would even consider suggesting that a first-time turbine builder try to build one of my machines.  And that is why I have refused to publish any "plans" for them.  I simply do not have the time to babysit somebody who doesn't know what they're doing when they get a set of "plans" and can't figure it out.

That's the flaw I see in all this idea.  The homebrew designs have been designed to be able to be built by the average person.  And even then, folks have a lot of trouble figuring it out.  The homebrew designs use hand carved blades.  I don't because homebrew blades simply aren't efficient enough, or accurate enough, to get real power from the swept area.  Those turbines typically run at under 20% efficiency - but the thing is, that's fine for 99% of people who are going to try to build one, because as long as it goes around and can make a few amps it's a "success".
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Offline ChrisOlson

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Re: Combining know-how
« Reply #11 on: February 12, 2012, 07:57:28 pm »
You can start by throwing away variable pitch, sure it's cool, that system midwould has on fieldlines is sexy as hell but Chris has shown that with properly tuned MPPT it's totally unnecessary.

I had to do a complete reversal on that one.  For a long time I was against the MPPT control because I figured it wasn't reliable.  Well, frankly, the guys that build that controller didn't whap me over the head with a pipe to tell me different.  And with me, that's usually what it takes.

Until I got one in my hands, tested it, built a turbine for it, and flew it, I found out a whole bunch of stuff that I assumed about that controller that were dead wrong.

First thing is, you can't get it to explode and leave a smoldering crater in your utility room by running it over-voltage.  The controller is smarter than that.

The second thing is, you can't run it over it's amp limit and get it to melt down into a glowing pile of goo.  The controller is smarter than that.

After getting off my stump and preaching against it, I decided I'd better try it.  What I found, is that thing can wake up even the poorest designed turbine and get better efficiency from it.  If you build a book-design turbine, go to all the work to build a tower for it, get it wired up and get it running - assuming you live on even a halfway decent wind site, that controller is the cheapest $800 you will spend to actually get some decent power from your turbine project.

And what's more, instead of turning a homebrew turbine into a "MPPT buzz bomb" it actually enhances the safety of the turbine because it increases the chances of the turbine furling correctly, it reduces the chances of a generator burnout (and subsequent runaway) by keeping the power dissipation down in the stator, and it logs the power output of your turbine every single day so you don't have to guess at what it's actually making for power.

I spent the better part of two years designing turbines that were more efficient than the standard book designs.  Well, when you're wrong, you're wrong.  And I was wrong.  You can't even come close to the full wind-speed-range efficiency with a direct battery charging turbine that you can get with that controller.  The same principles that apply to solar panels wired series with MPPT apply to wind turbines.

And the nice thing is, it is designed and built by guys that have been in the RE business since Moby Dick was a minnow and have contributed a lot to the business from names like Trace Engineering and Outback Power Systems.  It ain't no Asian-imported unit that only does half of what it says in the advertising material.

So that's my .02 cents on it.
--
Chris

Offline bvan1941

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Re: Combining know-how
« Reply #12 on: February 12, 2012, 10:03:54 pm »
To all,
Very interesting and a wide range of great ideas that could /should be incorporated in this Forum!
I most certainly didn't /don't want to offend anyone here with what might be construed as me being critical for the level everyone has achieved with their projects!

The concept was definitely aimed toward those having already reached the level of making, watching and recording a wide range of performance of their WT's more than once or twice.
My thoughts were to discuss existing WT performance and thru incorporating possible improvements, move toward the next level of WT performance for Forum members. 

Outside of "tweaking" already accepted styles of the: 6', 8', 10', 12', 14', and 16' systems, the only thing new, is listening to a few members demonstrate and explain their new successful projects.

There are Forums I check for interesting new projects and there's hardly any progressive discussion, (outside of inquiry's from a "newbie"). I believe many don't want to rehash what has been discussed and known to all but the new group of members and cease discussion on things over time.

 I can't speak for everyone (just me) and at the risk of being presumptuous, "Where do we go from here in the discussion forums?" To me without a progressive debate and challenge, discussions get down to getting in the weeds and griping amongst the members. Not fun for anyone and humiliating !
Please read this knowing I've seen other great Forums dwindle for lack of progression.
This is an excellent Forum and has been great to me !
Bill


 



 

Offline rossw

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Re: Combining know-how
« Reply #13 on: February 12, 2012, 11:12:17 pm »
Thanks, Bill.

I split your post off into this its own thread - a couple of people thought you were "hijacking" the other thread... which is probably hard to do if you started it :)

Anyhow, it looked like a comment worthy of its own thread, and comments here seem to have born that out.

I agree, this forum - while very "new" and probably still "wet behind the ears" - has a lot of established talent from members, and it's been a perfect opportunity to wipe the slate clean and start again. Leave all the old baggage behind, pick up the best ideas and move forward.

I too hope we can (between us all) find enough "new twists" to keep things fresh, innovative and progressive.

Offline Janne

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Re: Combining know-how
« Reply #14 on: February 13, 2012, 03:46:56 am »
Just a note of pitch control, it's not really meant to optimize power output, the only purpose of it is to provide protection against overspeed. As such, implementing dodgy electrical controls for that really is a bad idea. Midwould's machine sure is interesting, but I think he already suffered some failure in the controlling electrics. What if it had been a storm condition?

It can work, big turbines use it succesfully too, but the difference is that they're properly engineered to be safe. The cost will be much too high for a DIY builder with all the required safequards against failures. For example, in the event of power loss there would be no way of controlling the turbine anymore, unless some form of backup is implemented. Big turbines have a capacitor bank inside the hub for this purpose, in the event of power loss the power from them is used to automatically feather the blades.. + Dozen other backup systems.

There have been a couple of DIY attempts here as well with active pitch control, and they've all failed miserably. My father's 12m diameter turbine to start with, along a couple of other half baked ideas. There was one exception into that, it was properly engineered, with mechanical backups in place etc, but was located in a bad wind site. In the end, all the controls, heaters etc ended up consuming more than what the 6m diameter machine ever produced. + Total cost spent on the pitch control system alone would have probably been enough to build a standard 5m axial turbine, at least before the raise on magnet price.

Only way I see a pitch control is feasible on self built machines is to use a mechanical overspeed governor, and even on those there are many places to get it wrong. But they can be properly built by reasonable effort, last a long time and work reliably.

Anyways, that's how I see it all.
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