Axial Flux turbine at 10,000' with Clipper and Classic - setup questions

[wbuffetjr1]

The air pump is 120VAC. It is powered thru the inverter and turned on by a relay. Using the Float Hi program in the classic. At this point the diversion seems irrelevant to me?? The turbine has yet to make a single watt because of the wind curve.

[ChrisOlson]

Chad emailed me and asked about his wind turbine, so thought I'd chime in on this one.

A wind turbine at 10,000ft pressure altitude is a difficult situation. Normally aspirated aviation piston engines lose 3%/1000 ft density altitude. So a Lycoming O-360 that produces 180 bph at sea level will only produce 126 bhp @ 10,000 ft. Propeller efficiency, however, drops at a rate of 4%/1000ft. Without going into into the technical reasons, a propeller that can absorb 180 bhp at sea level and produce, say, 750 lbs of gross thrust at 2,500 rpm will have to run at 2,750 rpm at 10,000 ft density altitude to absorb the 126 available brake horsepower.

Wind turbines are no different.

So while Chad's turbine should produce something in moderately high wind speeds (say around 15-20 mph) is it going to have very poor performance in the normal range of windspeeds most of us put up wind turbines for. A site with 12 mph average wind speed annually is a very good site in most areas. There is not enough energy in the moving air mass at 10,000 ft to make that worthwhile. IMO, the money would be better spent on a turbocharged diesel generator set with automatic start/stop to fill in for the cloudy days. With, of course, a suitable building or enclosure to protect it from the elements and ensure that it starts when needed.

The solar panels should work very well at that altitude. But it would take a really, really big wind turbine (or many of them) to match what a suitable genset can do for standby/backup power.
--
Chris

[Adriaan Kragten]

Hello!!

Also, the tail that came on the turbine is WAY to small. It currently takes a 15mph+ wind to turn the turbine into the wind. I am building a much bigger tail for it. Are there any negatives, besides early furling, to having an oversized tail??

Youtube video is up - just search for axial flux at 10,000'

The fact that you need a very high wind speed for the turbine to turn into the wind is not because the tail vane is too small but because the friction moment of the head bearings is too large. Any safety system which turns the head out of the wind at high wind speeds works only properly if the friction moment of the head bearings and the friction moment of the bearings of the vane arm is low. Only in this case, the system will take a new position of head and vane arm for a low increase or decrease of the wind speed. For large friction moments, there will be a lot of hysteresis in the delta-V curve (delta is the yaw angle). I don't know the construction of the head bearings of your windmill but I know that for some designs, non machined welded pipes with some grease in between are used and such a construction has too much friction.

Increase of the area of the vane blade will probably result in increase of the weight of the vane blade and this makes that the vane has a stronger tendency to go to its lowest position (if the inclined hinge main vane safety system is used, which is described in my public report KD 431). So you need a higher wind speed to turn the rotor enough out of the wind. The effect of an heavier vane blade can be compensated by decreasing the angle of the hinge axis with respect to the vertical.

[kitestrings]

Chad emailed me and asked about his wind turbine, so thought I'd chime in on this one.

Nice to know your still kickin' Chris, and informative as we've come to expect.  Regards,

[wbuffetjr1]

Thanks a million for the reply Chris!!

I have to clarify that this turbine is fun for me. I am enjoying learning about them and working with it. We don't NEED the extra power up there I just WANT it. I also want to learn because I will be using another turbine someday at another location lower in elevation.

Adriaan as you mentioned I do think part of the problem with my turbine is the yaw tube was built from 2" schedule 40 pipe instead of mechanical tubing. An unfortunate mistake by the builder. The schedule 40 has the "seam" in it and may be part of my friction problem. I used mechanical tubing for the yaw shaft.  I.D. of the schedule 40 was 2.067" if memory serves me and O.D. of mechanical tubing was 2.00". There are no internal bearings in the yaw tube. It spins on the "roller blade wheel" bracket I mentioned above. There is ~1.5" gap between the yaw shaft and the top of the yaw tube so no metal on metal there.

The current tail vane is built from 10 gauge steel. I built the new tail out of aircraft aluminum so it could be twice as big, but hopefully not much heavier.

[ChrisOlson]

Nice to know your still kickin' Chris, and informative as we've come to expect.  Regards,

Hi,
The generator in Chad's turbine is evidently a copy of my compact 20-pole design. That generator was designed to run from 30 to 140 VDC output, and it produces 2,500 watts continuous @ 140VDC with good cooling in the winter time.

So I am a bit confused about the power curve being used with it, assuming it was built to my specs.

I used to have the entire design of that generator and turbine on a website. But we lost our internet provider that made that possible, and got a new internet provider. Our uplink speed is no longer good enough to run a server on it. We do have Google Drive now and perhaps I could export the web pages as PDF and put it on Google Drive. I don't know. Never tried that before.

There is one fellow from California, I think it is, that tried to copy it. But he didn't get it quite right. The stacking in the coils has to be perfect to get it to fit in the dimensions required, and provide for harmonic-free AC output for the Classic controller.

Hugh is retired from teaching wind turbines now, but perhaps I can contact Hugh and send him the web pages and maybe he can host it on his site or blog too.

It has been several years since my website that had the build details has been up.

[ChrisOlson]

This is the power chart for that generator for 48V power system, with a 3.2m rotor @ 1,100ft density altitude.

Note there is a difference between Voc and measured operating voltage of the generator. This is important because the Classic will unload your turbine and the Voc must be kept within the range of its over-volt protection (I use Classic 150).

Note that I clamp the TSR of the rotor as wind picks up to keep it under control until it gets to 20A output from the generator. Furling does NOT work with these machines to control power output. That's why you need a clipper. I have a furling tail on mine but it is heavily weighted to keep the turbine pointed into the wind. The power curve and clipper controls the speed and power, not the furling tail. The furling tail is only for storm protection at 35+ mph wind speed with high gusts to prevent the rotor from exceeding 450 rpm. Otherwise this turbine stays firmly planted into the wind, even at 30 mph where it is already running in the over-voltage range.

Note that what you get from the generator vs what goes to the batteries is two different things. The Classic has losses, and it gets REALLY hot in high wind. But it is tough. I have yet to burn one out.

Be careful of continuous power output above 2.5kW. The windings in the generator can take 20 amps continuous for one hour if the temp is above 30F. It is best to unload the turbine above 20 generator amps, let the voltage go into the Classic's over-volt range and use the clipper to tame it. If you try to clamp it harder by pulling the TSR of the rotor down further, it will over-heat the generator.

A picture of what the stator (should've) looked like if was built properly, along with another photo that shows the fit of the generator rotors over the stator windings. The common 12-pole/9coil generators have very "dirty" DC output. This generator was designed specifically for the Classic. The windings and spacing/timing have to be PERFECT to get clean DC power into the Classic, with no ripple like a solar panel. Otherwise your Classic will overheat and shut down and then you got a runway turbine.

You should be able to use the chart to determine what the voltage input to the Classic has to be. But your smaller rotor will run considerably faster than my 3.2m rotor does, although it won't make as much power, especially at 10K ft.

Not a conventional design, according to the homebrew books. But this thing has been running flawless for 7 years without a failure and has produced 9,344 kWh in that time. We don't run it in the summer - the brake is on from about May 1 to end of Sept unless we get several cloudy days in a row.

[wbuffetjr1]

Chris,

I read your post about 15 times, let it soak in and I have a couple questions.

I THINK the turbine was built fairly well and at least close to what you did. I am assuming you saw the build specs on the youtube link, but here they are again. It has 72 turns of 15 gauge wire. The builder claimed this was a "high voltage" stator. He said it is capable of 300V - no idea if that is correct. I am using a Classic 250.

Do I absolutely have to know the RPM-Volt number for my turbine to tune the curve effectively? That would require lowering the tower, taking the blades off and purchasing something to measure RPMs.

I think I have a better grasp of the TSR than I did. Is it correct to say that you and I both want our turbines to spin at a 6 TSR? and you said that my turbine will have to spin faster than yours to get to TSR 6 due to smaller blades. So, does that explain why my starting voltage is so much higher than yours? In my first round of experimenting I had Step 0 on my curve set to 60V,  70V, 80V, 90V and 100V. At each one of those settings I saw the voltage go up to that number and sit there and go no higher. Today on the MyMidnite site I saw the voltage go up to 130.2V, but no higher. Of course I have no idea what wind speed that was at. When I go out in September I am installing a component to be able to remote monitor my weather station as well.

Is it correct to say that I could set the amps on my curve to match your amps and all I would need to figure out is the voltage?

One thing you said in your post has me a little worried. If the Classic heats up and shuts down I could have a run a way turbine. The wires from the turbine come into the Midnite Clipper and then go out to the Classic. The Clipper has it's own manual setting for volts to clip at. With it set up like that wouldn't the turbine be kept under control even if the Classic goes kaput?? I built this whole thing assuming it would.

Thanks again!

[ChrisOlson]

Chad, you are using a smaller rotor, so the turbine will run at higher rpm and voltage. But not likely cutting in at 130V, which is near the upper limit of the design operating voltage of the generator.

My turbine actually has 65 turns per coil, not 72.

You don't need to know the rpm/volt, you can set your power curve by trial and error. Just be aware that with the Classic when the battery reaches absorb voltage it doesn't furl, even in high wind where this is likely to happen. It will unload the turbine and let it free-wheel. That's why you need a clipper or you will have a runaway.

Furling is a black art. The turbine's rotor has to be producing thrust to overcome the arm of the offset of the head vs the leverage of the tail. The tail is normally going to be offset about 45 degrees opposite so the rotor is dead into the wind. When it unloads the furling doesn't work because there is not sufficient thrust from the rotor to make it work.

There has to be storm-velocity winds before my machine will start to furl, and by that time it's operating well over the Classic's voltage limit where it can charge battery, and the clipper is loading it but the turbine is producing about 4kW at very high voltage. I do not use a MidNite clipper - my clipper is three-phase AC water heater elements. The furling is only to keep the rotor speed below 450 rpm in storm winds. Otherwise it does nothing to control the output of the machine.

Even in moderate wind with solar charging the battery, if the battery reaches absorb the Classic unloads it and it goes to high-voltage three-phase AC water heating with my home-made clipper. The turbine is very noisy and fast when it's running unloaded from battery charging on three-phase AC load. I use SSR's, switched very fast with pwm to control the clipper load.

It is not even close to the "conventional" homebrew book designs.

With your Classic 250, not sure how to set this up the way I have mine. The Classic 150 has over-volt protection that allows this, but it stops battery charging when it goes over 150.

In all cases, the Classic does not like "dirty" DC input. It requires an accurately wound and built generator to keep the Classic's operating temperature within limits. Most axial generators will have more of a square sine output due to the way the rectifiers load the phases, and they run at too low of an AC frequency to have clean DC output when rectified. They depend on the battery to smooth it. The Classic uses capacitors to smooth it on the input side, so the quality and frequency of the AC output of the generator is paramount to the Classic's smoothing capacitors being able to do their job without overheating the FET's. This is a problem you don't have with solar panels.

[wbuffetjr1]

Ok. So I need to figure my cut in issue. First off, the builder said he was doing an "exact copy" of your design so I am not sure why he did 72 turns instead of 65. What difference does the 7 extra turns mean for my turbine?

Any ideas why this turbine does not seem to want to go past what ever voltage I set for Step Zero??

Could the airgap between the magnets and the stator be too tight?? It appears to be very close. IIRC the builder wanted to set it at 1/8".

[ChrisOlson]

7 turns will make more voltage at the expense of higher internal resistance in the generator. That sounds like something this guy in California did, that tried to copy that design. Which won't be a problem with your smaller rotor.

I'm guessing that the reason it won't make any power is because you don't have enough wind, or the blades aren't producing enough power to get it past cut-in. Are the blades installed right? I saw one guy put his blades on backwards once, like an airplane propeller. That didn't work all that well. It will definitely turn with the blades on backwards, but it won't make any power.

No, the airgap has nothing to do with it.

I've also had people ask me, "where do you get a three-phase water heater element - can't find one". You don't. You buy three standard off-the-shelf water heater elements and wire them either wye or delta for a three-phase load. In delta they will draw more current and clamp the voltage lower. In wye they draw less current and clamp the voltage higher. I use delta/wye switching on my clipper to "shift gears" on the load when the AC voltage gets too high in wye configuration. All you need is a three-pole DT mechanical contactor to switch it from wye to delta, and vice-versa. Coil off is wired wye. Coil on is wired delta.

The clipper is a very important part of the system when the turbine is combined with solar. The MidNite clipper just wastes the power into big resistors. I designed mine to use it so the turbine can do something useful in the winter when the solar gets the battery to absorb. And actually, three-phase AC water heating is highly efficient. Way more efficient than battery charging. We have three 55 gallon water heaters. It's not unusual to get at least 50 gallons heated to 140F  in the two pre-heaters on a nice windy day in the winter when the sun is out. I've seen some people try to heat water with 48VDC and it takes wires the size of your little finger to do it, and you never get any hot water.

[wbuffetjr1]

Chris
I definitely know the guy in California.... He took a $1,000 deposit from me and after two years hadn't even STARTED my turbine. Turns out he took my money and used it to build a CNC machine. STILL trying to get my money back from that guy.

The water heater solution sounds very nice! I have the Classic 250 set to run a diversion load off of Float Hi. I have a SSR running a 1/2HP pump to help aerate a lake with trout in it.

Maybe I screwed the blades up! The builder balanced the blade set and set me the hub with one blade attached. I just installed the other two blades to match the first one. I assumed he knew.....

At the risk of looking silly, but trying to avoid confusion. These are the 9.2' blades from CMS I already have. Which side of these things face the tail??  EDIT: Currently have Side B facing the tail.

Side A

or Side B

[ChrisOlson]

The blades look like they are installed the right way. Side A is the wind-facing side.

I'm a little concerned about what appears to be your yaw shaft in the image you sent me via private email. See the attached images. If the turbine is running in storm winds the side load on the top of the tower approaches 1,000 lb-f laterally. If the machine was built to my original specs it weighs just south of 300 lbs. Notice the size of my yaw shaft and it has a machined flange on it so it has a turntable that works like the fifth-wheel on a semi. I use either the excavator or a skid-steer loader to install the turbine on the yaw shaft, slung with a chain. Two guys can't lift it unless those two guys are big enough to pick up a small-block Chevy V-8 and carry it around. But this is what it takes to get it to survive storms. It ain't no light-duty Rube Goldberg trailer spindle outfit with a bunch of crap stacked on threaded rod.

I made a zip of the old build website. This should work in a desktop browser on your computer if you go to the projects folder and click on the index.html file.
https://drive.google.com/open?id=1PPhSmPrUsGLcc1UrAzPZzjPZW5z5jaHU

I'm afraid you're going to have to take that turbine down, take the blades off it, and spin it with a stout 1/2" or 3/4" electric drill to see what it's got. Who knows if the phases were wired correctly? The phases should be wired wye configuration and it should produce one DC volt (rectified) for every 2.44 rpm. Every third coil in the stator should be wired series, end lead of the preceding coil connected to the start lead of the next one. You will end up with six wires, which are the start and end leads of the three phases. Connect all the ends or starts together for the wye connection, the other three are the phase outputs to the bridge rectifier. I use a 200A bridge rectifier out of a Leece-Neville alternator that already has the six diodes mounted in a heatsink, and it has three studs on it to connect the three phases of the generator. But I think your MidNite clipper already has the bridge rectifier built into it.

Most of those industrial 1/2 - 3/4" drills with handles on both sides will spin at ~200-250 rpm. Chuck up a socket and turn the turbine with the bolt on the end of the mainshaft to see what it's got. So at 200 rpm you should be getting around 82 VDC, open-circuit. At 450 rpm it should be 185 VDC.

If it checks out on voltage output, you can hook it up to the Classic and try to see if you can get it to cut in at a reasonable speed like 150 rpm where it should produce around 60 VDC and start charging your battery. But I doubt you will be able to hang on to the drill if it starts producing power thru the Classic unless you have like 2 foot long handles on the drill to hold the torque.

[ChrisOlson]

I definitely know the guy in California.... He took a $1,000 deposit from me and after two years hadn't even STARTED my turbine. Turns out he took my money and used it to build a CNC machine. STILL trying to get my money back from that guy.

Ok, so that fellow that is building my design cheapened it up. For one, it takes a big yaw shaft with a turntable on it, or it won't yaw correctly. The tail has to be right or it won't face the wind. The tolerances in the generator are very precise, and that fellow does not have the equipment or the machining skills to build the generator to the required tolerances to get 0.62 tesla in the core with <2% THD.

It's been a few years now but I remember I talked with one of the guys at Missouri Wind about it, as they gotten one from this guy. They wanted to get one of mine to compare but I had decided to get out of the wind turbine business and was not interested in the Wind Turbine Wars.

Jeff at MW&S made a video of it, you can read the top comment on the video that summarizes all the problems they eventually found with the copy. Including the cheapened generator mounting. Mine is designed to keep wind-blown snow out of the generator. In the winter the generator is warm, if snow gets into it it melts, then freezes and will lock the turbine up, or you have ice rubbing on the stator.

https://youtu.be/MsUQhru1Nzs

The big waterjet cut plate on mine is a stressed member that prevents flexing in the torque tube in high winds, and is necessary to prevent rotor to stator contact with the tight tolerances in the generator. There is no double-nutted stuff on mine - the stator mounting bolts are torqued to 45 lb-ft with steel bushings in the stator. That's why this fellow put in 72 turns instead of 65. So he runs a wider air gap to keep it from hitting, makes the rotors too small and wastes flux in the core, and throws more copper at it. 7 extra turns is like 10-11% more internal resistance in the generator. It will still work, but is not going to have the duty cycle required to survive long term.

I never intended for these turbines to be built by somebody that only has a set of wrenches, a torch and a Lincoln stick welder. The design was to prove that a highly skilled machinist and craftsman can turn the typical ~900-1,200 watt 10-11 ft diameter axial into a reliable 2.5-3.0 kW machine with the aid of Maximum Power Point Tracking. While I ended up with the credit because I built it, Les Vincent (Flux) and Hugh were part of the original discussions on the generator design to achieve it. I don't remember how many hundreds of emails we sent back and forth, and Les is no longer with us. But the end result was a huge success in proving that the axial's superior low-wind capability can be combined with high wind performance and reliability, the lack thereof that had previously burned up many axial turbines.

[ChrisOlson]

Would like to point out a couple things related to the clipper if you decide to use the clip power for something useful. The turbine will produce 20% more power on AC clip than it will charging batteries.

That homemade clipper shown in the zip worked for a little while. It had 7.2 ohm water heater elements wired delta. The elements were clamped between 1/4" steel bars and mounted in the box on ceramic standoffs. I knew aluminum would not stand up for heat sink bars and didn't have any copper ones. But it didn't make any difference. That clipper would absorb 6,000 watts. But when I observed smoke emanating from the box I knew there was a problem. It got so hot it melted the ceramic standoffs out of the box. Should've made the box from steel, but steel rusts, and as it turns out it got so hot it would've burnt the paint off a steel box anyway.

So I eventually went to water-cooled clipper with the water heaters. I ran a 10-3 from the AC side of the rectifiers to the utility room in the basement. We have three water heaters. Our primary heater has two 2,500 watt 240V elements in it. The pre-heaters have the same 7.2 ohm 120V 2000 watt elements that was in the clipper.

The well water goes in the first pre-heater, then to the second, then to the primary water heater. The top and bottom elements in the first preheater, and the bottom element in the second one, are clipper loads. The top element in the second pre-heater comes on when our battery gets to 51.4 volts, powered by the inverter's AC output.  All four thermostats on the pre-heaters are set to 165F, which is as high as they will go.

The thermostats on the primary water heater are set to 140F. We try to have enough water pre-heated with clip and excess power that the big elements in the primary heater never come on.

The turbine does 35% of the work in getting our water to 140F, as it comes out of the tap, in the winter time. The last three elements in the water heating system only have to boost it a few degrees. Electric water heating is darn near 100% efficient. Gas water heating is very inefficient, usually less than 50%. Electric is 95-96% efficient to point of use.

I've seen gas companies claim:
Electric water heaters are often considered to be close to 100 percent efficient. This is true at the point of use. However, if you consider the overall energy efficiency (from production of the electricity to the point of use), the result is much less. The overall system efficiency of an electric heating system-including the energy consumed to produce the electricity in the first place - is about 28.5 percent whereas the overall efficiency of a propane system is close to 93 percent. Therefore, a propane model with 50 percent combustion efficiency is actually more efficient than an electric model rated at 100 percent efficiency,

Which is fine, and this is a bunch of double-speak hoopla. We produce electricity with our power system, not fart gas coming out of a pipe drove in the ground. So I figured out how to do it with power we make ourselves instead of using propane. And besides, my wife won't allow a propane tank on the place, much less having a line coming into the house. Your wind turbine is one of the most efficient water heating power generators there is if you figure out how to get enough voltage from it so it can actually do something. Charging batteries with it doesn't let it perform to its full capability because of the losses in charging batteries. It's cheaper to charge batteries with a combustion engine generator when the solar doesn't keep up, than what it costs for a suitable size wind turbine and tower.

So learning how to apply the efficiency of the AC clip power is quite important with a MPPT turbine if you don't want to waste it.

[Mary B]

I remember your build as it progressed on here and some of that discussion! Awesome machine!

[MagnetJuice]

I have to clarify that this turbine is fun for me. I am enjoying learning about them and working with it. We don't NEED the extra power up there I just WANT it. I also want to learn because I will be using another turbine someday at another location lower in elevation.

I think that Chad is willing and able to learn. Can we can help him make some good lemonade out of the lemon that he has?

He has two good magnet rotors and a stator, which is the heart of an alternator. The stator has a few more turns than the original design by Chris, but that could be OK because this turbine has to operate at 10,000 Ft elevation.

Maybe we can find out what areas need improvement and make recommendations. If the bearings are OK and the construction is solid, the air gap could be fine-tuned. It appears that the yawing mechanism also needs improvement.

After the improvements are made, it can be determined if the tail has to be modified and which set of blades would be a better match for it.

I think that Chad wants to get this turbine working as good as possible so he can learn from it.

Ed

[bigrockcandymountain]

Thanks for all the info now and in past posts Chris.  I have a very different turbine from yours, but your posts about how to make the classic work with everything have been a great resource. 

Maybe the OP will post some pictures here of the yaw shaft.  Maybe collectively we can come up with an easy beef up plan for it. 

[ChrisOlson]

If it were me, based on what Chad has told me, I would take the turbine down and bench-run it with a big slow speed drill to see what it's got. From what I understand the voltage climbs, but then it never goes any further to make even the first watt of power.

Running the machine with a drill, open-circuit, will tell what the thing can produce for open circuit voltage. I doubt there will be much success trying to get it to produce power with the Classic by running it with the drill. I've tried that before and the torque overcomes what a person can hold by hand because the Classic "kicks in" when the input voltage gets sufficient to cause it to start charging, and when it does it jerks the drill right out of your hands.

But the open circuit voltage will tell. There is a difference between open circuit and clamped when it goes to work. What happens with that difference depends on the internal resistance of the stator. But if it makes the right voltage at the correct rpm's it will make power.

If it passes the open voltage spin test at the right rpm's, then the problem lies with the rotor not producing enough power, or the tail not steering it into the wind so it's running at 45 deg furled. The tail does not stick straight out the back. It's about 45 degrees offset, opposite the head offset. If the tail is not right, then the turbine is not facing the wind and the angle of attack of the airfoils will cause it to not have any power.

Edit:
During the spin test I would also check the phase-to-phase voltage to make sure all the phases are balanced and there wasn't a mistake made in wiring up the stator.

[bigrockcandymountain]

Another way to test open voltage without an optical tachometer is to hand crank it.  Stare at a clock with a second hand and do one rotation per second.  Note the voltage.  Do two rotations per second.  Note the voltage.  That is all the testing i did on mine and it worked out very close i think.  You might even be able to do that test standing on the tower.  Of course that is a bad idea and don't try it for your safety etc.

[ChrisOlson]

Well, if you have a AC frequency meter you can use that on the tower too. But not many people have one. The formula is
AC freq = RPM * poles / 120

So re-arranging the formula is (for a 20 pole):
RPM = AC freq * 6

At 360 rpm the turbine should be producing 60Hz power @ 105VAC, checked between any two phases. The DC rectified voltage should be 146 at that speed. The reason the AC voltage is lower than DC is because the AC voltage is RMS (Root Mean Square) and your AC voltmeter does not measure the peak voltage of the AC sine wave.

When you're doing this, if it's running on the tower and free-wheeling do not touch any two of the phases with your fingers. If it's built right it will put out 20-30 amps at that speed and lay you right out on the ground quiverin like a bowl of jelly during an earthquake.

[MagnetJuice]

When you're doing this, if it's running on the tower and free-wheeling do not touch any two of the phases with your fingers. If it's built right it will put out 20-30 amps at that speed and lay you right out on the ground quiverin like a bowl of jelly during an earthquake.

I can imagine that after reading that, Chad would be looking out the window at that monster on top of the tower, biting his fingers, sweat pouring down his face and his knees knocking together in fear saying “I will never again go near that thing”

Or maybe not. I think it will take a lot more than that to scare him. I have seen him kill an elk with his bare hands. 

[ChrisOlson]

Doesn't matter if you think you are tougher than the Terminator. 200 milliamps at sufficient voltage to overcome the electrical resistance in your body will reduce your toughness instantly. Care must be exercised working around either high voltage AC or DC power systems.

https://www.asc.ohio-state.edu/physics/p616/safety/fatal_current.html

[MagnetJuice]

Care must be exercised working around either high voltage AC or DC power systems.

I totally agree with that statement.

Chad said that he wants to get his turbine working as good as possible so he can learn from it. He seems to be capable of doing the required work. He said he lacks the electrical know-how and just needs a little guidance. I think we can help him.

He said that he doesn't need the power, so it is better to bring the turbine down and bench test it. With a large drill to spin it and a cheap multimeter that measures 20 amps AC and DC he can get a lot of usable data.

[wbuffetjr1]

Wow! Thanks again everyone for all the input!! I am not sure why, but I am no longer getting emails when a post has been made to this thread. I checked and I am still subscribed. I haven't been ignoring y'all, just didn't know there had been any activity.

It sure is nice when things just work. HOWEVER, I guess I wouldn't be learning near as much. (How's that for positive spin)

Here is one problem. Once I get up to the cabin communication ain't happening unless I drive back down the mountain. As you can imagine, experimenting with the turbine, driving down to make a post, driving back up to experiment more, driving back down to check for posts, driving back up to implement suggestions, driving back down to post results, waiting for replies, blah, blah becomes a VERY time consuming process. Plus I have to use the forum from my phone which I hate!! Sooo, I need to make sure I understand what to check and what to do with what I find BEFORE I get up there. I am reading and re reading all these posts.

I will be taking the 9.2' blades with me just in case...

I am 100% going to take the tower down and spin the turbine with a drill like Chris suggests. I can run the turbine "open circuit" by turning the Classic to Mode OFF, correct?? I am a big softy, but trying to hold the drill with the Classic making power sounds like a fun challenge! Should at least make for a good story! 

I'll pass on touching any wires though....

I have a really good multimeter, but I do not have anything to measure RPMs of the turbine. Any suggestions for a cost effective way to get that measurement? In a video the builder posted, he halfheartedly spun the blades by hand and got it up to 20 volts. He also posted videos of him testing the resistance of the stator and each phase was 1.8 ohms. 

Before I left the cabin I did individually test each of the three lines coming in from the turbine one time when it was spinning. Just to make sure I had power coming in on each line. The voltage on each line was moving around some, but they all seemed real close. Is testing two lines together at one time a better way to check it?

Here's a stupid question... Does the order I connect the three lines from the stator to the Clipper matter at all? I just hooked up the three wires to the three lugs on the stator and then just randomly connected the other ends of the three wires up to the clipper. Could that be the issue?

I am sure hoping the tail is positioned correctly.  Here are a couple pics that show it from different views. I know some better pics would be better, but all I have is screen shots for now.



Here is a pic of the flange at the bottom of the yaw tube. (I hesitate to even say this next part after what Chris said earlier)...That  flange rides on top of two roller blade wheels held in place with a heavy duty, bolt together bracket. 


Here is the yaw bracket:


Entire turbine with tail and all (no blades) probably weighs ~160lbs or a little more.

[wbuffetjr1]

I have seen him kill an elk with his bare hands. 

 I see what you did there!!! Lol

[MagnetJuice]

I think the yawing mechanism is your main problem. Those polyurethane wheels are rated at 200 Lbs. You would think that two wheels could handle 400 Lbs. Not so, because the load is shifting and not evenly distributed, so most of the weight of the turbine can be on one wheel at some time. And when the turbine is turning, any little bump puts more pressure on the wheel than the actual weight of the turbine. It is a matter of time before those wheels will crack.

There are other problems. Even a hard polyurethane wheel will flatten a little with that load. With a flat spot, it is not going to roll easy. A turbine that cannot turn fast enough to face the wind is not going to produce a lot of power.

Then there is the little bearings in the wheels, how long will it be before they rust and freeze?

Most builders use a pipe inside a pipe with two bronze washers and plenty of grease. A setup like that works trouble-free for many years.

Ed

[wbuffetjr1]

Ed
I should be able to fix that fairly easy when I get there this month. I want to do it RIGHT. Is the two bronze washers method the way to go or would an actual thrust bearing be even better?

[wbuffetjr1]

Hey hey hey!! Made my first watts! Looks like it made 85 watts today. Those are first watts ever made.

Was pegged at 130V from 15:04 to 15:26.

4 thumbs down on my video. I must have made some folks mad.

[MagnetJuice]

I think that most builders stay away from bearings. Maybe because of the complexity or the maintenance required. I think that they prefer to have a little bit of drag there to keep the turbine from dancing around trying to chase every little change in wind direction, that wastes power. Other more experienced users here might want to comment on that.

Ed

[bigrockcandymountain]

I have a bearing.  It is an offshore thrust bearing 51115 so about 4" od i think.  I put a zerk on to pack it with grease.  It gets greased a couple times a year.  Probably once in 2 years would be enough.  I also grease the tube with a needle through a couple drilled holes.  It is almost 3 feet long so takes a bit of grease. 

To me, it looks like your setup would be easy to add a bearing up inside the tube. It would be small though Or you could put a larger one down where the wheels are.  You would need to weld a flange on though. 

Bronze washers are fine too.  In my case, the bearing was probably cheaper.  It was 15 or 20 bucks i think. 

[bigrockcandymountain]

51107 bearing is a perfect fit inside your 2" sch 40.  Might have to file where the seam is.  Grind the od of the lower race so it is free and you should be good to go.  I would drill and tap a zerk on the side of the pipe so it shoots straight into where the balls are in the bearing.

[SparWeb]

BRCM beat me to it, so I'll just add that I use a bearing too.  In my case it's a tapered cone bearing which supports radial and vertical load.
If it runs short of grease, there are a lot of places for sliding to happen, limiting any chance of damage or locking up.
The skateboard wheels in your photo are not a robust solution.