Finally Ready To Start My First Build

[HaroldCR]

 I recently received some items from Florida. Among them was a Johnson 2.25 HP 90V DC Permanent Magnet Treadmill motor. It is rated 20A at 3150 RPM.

  I took it to my shop and hooked up the VOM on 200V DC scale. Turn the shaft by hand and get a reading on 2+- volts. Threads are left handed, so I reversed the VOM leads, and wrapped a baler twine around the belt section on the heavy flywheel. Moderate pull gets over 16 volts. Rpm is not real fast, maybe 100  Shaft tach is still in Florida. This is no load reading.

  I have an idea on how to mount the motor for the stub shaft that will go through the yaw bearing and down into the top of the tower.

  I have wood sorted out for the carving of the blades, but, there is where my problem lies. Hopefully I have provided enough info to get some input from the members here, to keep me out of trouble, maybe?  I will be charging a small battery bank in the beginning. Maybe a couple 6V Golf car batteries, in Series at 12V.

 I believe startup might be a little stiff, with absolute voltage as the shaft starts to turn. I also believe, 8' blade would start the machine.

  Up where we live, the wind is always 12-18 Mph or so. Trees are always swaying in the breeze, IF we have any wind to speak of. This is NEARLY every day, or, at night, when fronts sweep through off the Caribbean. we are HIGH up.

  I am afraid I need to put a drastic face pitch on the blades to obtain the start up, but, also to help govern the RPM's, by "batting" the air some, with the steep pitch

  This is where I need some input.

  The first machine I built, I governed the blades at right around 220 RPM's. Used a gearbox to speed up the AC Alternator, and it worked like a charm. This is totally different.

  Any ideas This is a VERY inexpensive build, so, The home built Axial-Flux Alternator does not interest me at this time. I just would appreciate input to get this one working without searching the farm for pieces one day.

  Thanks for any and all comments, ideas, info.  

[ghurd]

Define "drastic face pitch on the blades to obtain the start up, but, also to help govern the RPM's".

Meaning a low TSR?

I don't follow "I believe startup might be a little stiff, with absolute voltage as the shaft starts to turn. I also believe, 8' blade would start the machine."

If you also believe, 8' blade would start the machine, then that motor is worse than most treadmill motors, which are usually pretty bad.

I have a feeling you underestimate the starting torque.

With the standard math, Cut in for that motor is almost 500RPM.

That puts it into something suited for a relatively lowish TSR and maybe 40" dia?

G-

[HaroldCR]

 Back in the day, very few wind generators were fixed pitch. I am used to an adjustable pitch or a twisted-"Feathering" type blade set up. If a blade has less face to the wind, it has more starting torque. That comes from adjusting the angle of the face of the blade. It also results in the blade having to move the air aside when running up to speed, so, it "governs" the RPM's some, as well as spill some of the power of the wind.

  Forgive me for not remembering the correct terms for all this. My mind is not as sharp as it once was. It's embarrassing, to say the least.

  The Math is a real part of my problem. I can't remember stuff well, anymore. Figuring things out, I get distracted and lose my thoughts. It's bad.

  The motor has the heavy flywheel on the shaft. If I run my hand over it, to spin it, it might make 5 RPM's, before stopping. It DOES register 2 volts in that 5 RPM's. When I pulled the cord to spin it, I saw 16 volts for an instant, and it probably spun 20 RPM's

  To turn the shaft without the flywheel on it, As soon as you do the "Flip" with the thumb and finger, it turns maybe 1 complete revolution.

  The 4 KW unit I used before, I could get 10 turns or so, by finger flipping the shaft. There was NO output at all, until it got up to "Cut in" speed. This motor shows Voltage as soon as the shaft moves. That is what I mean by "Stiff".

  I did a lot of prop blade stuff years ago, but, the memory is cloudy. I know there is decent torque in a larger blade when it starts to turn and turn the shaft. I'm used to 10' + blade dia.

  Being I will have a small battery to start with, I don't want to overcharge it, and, the wind up here is not what people usually think. Right at this moment, it's up to 20+ MPH + gusts. This is fairly normal. I want to restrict the charging to not burn up the battery. I will also need assistance on how to regulate the charge. On my other build, The governor took care of that, along with furling.

  Yes, I need a lot of advice.

[ghurd]

"Forgive me for not remembering" whatever it was I forgot.  Yea, me too.

It's not a problem because things have changed due to far superior magnets and better cheaper electronics.

The terms are correct, or correct enough to understand.  A couple of the meanings behind the terms are possibly a bit outdated.

There is no battery charging load at 2V.

Every permanent magnet DC motor should show voltage if the shaft is moving.  2V is pretty low

Could run the motor with a 12V battery and record the RPM.

The blades need to move faster than that to charge a 12V battery.

And with that motor, the blades need to be spinning really fast.

The charging is now restricted based on the battery voltage.  If the battery is over voltage, then the dump load comes on to keep the battery at a manageable level.

The furling, hopefully, takes care of over-speeding blades.

That 20+ MPH is big wind.

I figure most machines furl at about 25MPH.

G-

[taylorp035]

8ft diameter is way too big.  About 4ft or less would be ideal.  If you have a real windy place, I think that a normal set of hand carved blades should be fine for start up (mine starts in 10-12mph for my treadmill motor with a 50" diameter).  As for hitting 12v, about 420 rpm according to your motor specs, which is the middle as treadmill motors go.  If you need more torque, you could almost go with 6 blades, which will help start up.  I would build a 3 blade and then watch it for a while and then make some adjustments if needed.

How high up is your tower?  Do you get a constant wind or is it turbulent?  If you are on a beach, then you should have some nice winds to play with.

 

[HaroldCR]

 Thanks Ghurd. I believe you are the one that sells a dump load device  Would you have something that would work on this motor  I know it's not what is recommended on the forum, but, it's what I can afford, to play with, for now.

  Thanks for trying to answer my fuzzy questions. You should see the looks I get down here from the locals, when I try to talk Spanish and have to constantly stop to try to remember what the hell I am trying to say. !!!

  Taylor, your thread is what got me thinking about trying this. The motor was only $30.00 and you said you have one working. I believe yours is higher RPM rated, no

  I am nearly on top of one of the highest hills for a few miles. I have a very smooth airflow, especially if I get up above all our trees we planted. I figure a 60' tower is plenty for now. That will put me nearly 30' above the tops of the trees. Might need to build a winch powered elevator to get my old butt hauled up to work on the thing, if needed.

  I will lay out a set of 3 blades. Make them 3'long and 6" wide. Try for a TSR of 6, maybe More info when I get them drawn out, before I cut anything.  Thanks for joining in to help me.  

[Rover]

This sounds very similar to the ones Taylor and I have. My bench tests can be found in my diary at http://www.fieldlines.com/story/2009/12/16/153710/66

Mine is a 2.0 hp Baldor 2400/RPM 90VDC 21 AMP (Ghurd makes fun of treadmill motors, and most are poor quality but I like that Baldor).

My cut in , going into 12 volt battery is roughly 400 rpm (produces 100 mA).

I have seen it produce in excess of 26 A in very high winds (30+) , takes a good 12-15 before it will cut in though . I'm running ~ 52" diameter blade set  (22 inch hornet/eagle  blades (6 of them), on 3 each blade extensions (as an experiment))

There was no flywheel on mine , and depending on the weight would probably would have removed it. I am running a heavier rotor to get past the brushes though.

My mount is a 2" scheudle 40  pipe over a 1 1/2 inch schedule 40. I have a thrust bearing inside the 2" that the 1 1/2" butts against. The 2" pipe is connected to a flange that is mounted to a piece of trex decking (plastic wood) 10 inches long that supports the motor and the tail.

Motor weight is about 30 lbs.

pic here http://www.fieldlines.com/story/2010/1/24/957/57415

[Rover]

An image of the Baldor

[ghurd]

That's me.

Actually, I think most people would recommend it as a decent starting point for something like what you have, especially on a budget.

If the system grows, and gets a fancier controller like an Outback or TS-60 later, then the ghurd controller can be used for LVD or low voltage alarm or something, with just a couple parts changes.

I doubt it will make 20A.  Never can tell what one will do.

Probably be good with the basic kit, one extra fet, and 12 of the power resistors.  Economical and functional.

I do not have a problem with treadmill motors that can be made to work,

except for the dishonest claims on ebay!

G-

[ghurd]

Here is a great eBay listing:

(More than 10 available)

"Wind Generator Rotor Bosch 9129064071 Permanent Magnet"

First sentence of the description:

"These rotors are not permanent magnet."

Useless for wind, no generator or magnets included, and 100% positive feedback.

G-

[taylorp035]

My motor is a beast b/c it is larger than most treadmill motors.  The numbers are in this post:

http://www.fieldlines.com/story/2009/12/9/161052/039

3960rpm @ 150 volts = 26.4 rpm/volt, which is very good for treadmill motors.  The bad ones are 40-50 rpm/volt.

The motor says 16.9 amps continuous.

The pics are old at this point, as I have different blades on it and the hub is bolted on instead of using wire....

My current diameter is 4ft 2".  My cut in is approximately 12mph.  I would guess the cut in speed to be at the 8-10 volt wind speed (I don't have a wind speed gauge, so I use volts).  Therefore, I am not loosing any power at very low wind speeds.

So, I would STRONGLY suggest that you make a smaller diameter (close to 4ft)  b/c you will have a very hard time hitting 12v with a 6ft diameter (400 rpm).

Here are a couple of my videos that you can look at:

http://www.youtube.com/watch?v=oz8jva9YB78

http://www.youtube.com/watch?v=J5TuLH7BnGk

http://www.youtube.com/watch?v=asEV_k43aZg

Here are my videos with the 67" blades which had a very low pitch, but were still too slow.

http://www.youtube.com/watch?v=tiOqI-3TVuQ

http://www.youtube.com/watch?v=VDbeqO6hJdc

http://www.youtube.com/watch?v=dIpe7d5iN9I

As toy can see, it take a lot of wind to hit 12v with a 67" diameter.

[HaroldCR]

 Thanks for posting all the info you have available. I WISH I could view videos. I have dial-up, and, it's slow. They ran Fibre optic cables through our area, but, I am outside the limit of where a good signal will start to drop. I asked them to put in an amplifier, but, things like that require thinking, and, there's not much of that done down here.

  NOW, they are offering one of those plug in the computer thumb drive type thingys  All I have to do, is pay them $85.00 for that little device, and then, I only pay $15.00 a month, and up, according to how fast I want the connection to be.

  I'm not Computer literate, and, all this stuff, they throw at me, in fast speak Spanish, so, I'm slowly trying to figure this out.

  I'm on a fixed income, and pay all the bills, UNTIL my wife starts to draw her pension. MAYBE after May 8, the new President will start taking applications for Pension payouts. Until then, I build furniture and the like, to have money for these projects.

  There are many people here that are having trouble keeping up with rising prices. I hope to get this stuff figured out, so I can start a small business, helping people to put in RE systems. Water runs nearly everywhere here, so I also have a water project started. THAT will be the Rube Goldberg system, when I start the Diary about IT.

  I did spin up the motor, and had to reverse the red and black leads on the battery, to keep from spinning off the flywheel. Near as I could figure, right around 400 RPM's at 12V is what I have.  I figure if I can get 10 amps input to the battery, it will do what I need, except for the fridge. I have 1000 WATT 1400 KVA UPS that I will used as in inverter. Probably won't start the fridge. Wish I knew electronics. Maybe a capacitor could be rigged, to give that initial GRUNT, to start the compressor

[ghurd]

Did you spin the flywheel and measure the voltage,

or connect it to a 12V battery and measure the RPM?

The actual voltage and RPM you should be looking for is about 14V for a 12V system.  Some people would say try for 14.5V.

G-

[HaroldCR]

   Ghurd,

 Counted the RPM's with a 12V battery hooked up. Got right at 400. According to the formula above, it comes out at 420, so, I'm pretty close. Spinning the flywheel, I have too many things to keep track of, so, I did see 16 V for an instant, using the pull cord  Not very scientific, I know.   I promise to do better, but, I was impatient to see just what this motor would do. I've never messed with this style motor.

  Last night I drew up a blade shape at 36" long. Now, I will reduce it down to 24". I can always cut it down, if need be. That will give me a 48" dia. Seems awful small to me  I have confidence in you guys that have used a treadmill motor.

[taylorp035]

Sorry, I sometimes forget that many people still have dial up.  As for the usb wireless internet, I know someone who has one and it is very slow.  I would say it is about as fast as dial up, but we don't get very good cell phone reception in my neck of the woods.

I think your idea of starting at 36" blade length would be a good route to go with.  This way you don't have to make a new blade set every time you change your mind.  I personally have fun carving new sets of blades, so I have a 30", a 50", and a 66" set.  My 8ft set blew up...

I just went outside today and I was hitting 22v in a steady 18-20mph wind.  And I will confirm that my start up speed is somewhere between 10-12v worth of wind.  Once the mill gets moving, it only takes a light wind to keep it going.

[HaroldCR]

 I cut the blade blanks out a couple days ago. I used 1¾" thick wood. The blades are 24"long, each. I have been looking at different profiles, and, have decided to use what I can actually get out of the thick blanks. The blanks measure 4¾" wide at the root, and 2¼" wide at the tip. There is no curve along the trailing edge, just a straight edge from end to end.

  I will try to get some photos posted later.

[taylorp035]

That sounds really good!  My blades were made from 1x4" wood, so your extra thickness will increase your possible attack angle near the root.  As for the straight line, I think that curving it has a very minimal effect, but I can say that my CNC blades that I made had a curved trailing edge and they had ZERO whooshing sound, even at 30+ mph (30" dia @ 3,000rpm   ).

[HaroldCR]

 Taylor

 Could you give me some ballpark measurements of the widths of your blades, say, Tip, center and root area. I'm just trying to make a set that just might work the first time around.

  AS for the thickness, I will stay with the 1¾ at the root, for maybe 10", then take some off both sides to narrow the thickness, and carry it on out to the tip, at about ½" or so, thick, and have the pitch angle go from the thick root, to getting more flat or less pitch angle at the tip, so it doesn't have to push the air away, with the back side of the blade.  Sound about right

[HaroldCR]

Update:

 I have been very busy sawing logs for clients. Today, I finished the last of the 3 blades, and used a Dial caliper to check each blade. Got them all within a frogs hair thickness of each other. Sanded with 200 grit, and applied a thinned coat of sanding sealer. Couple hours later, used a flat sanding board and did the final cosmetic sanding, and applied another coat of thinned sanding sealer.

  Drilled the blade mounting holes in the flywheel, and tapped them all, 3 holes per blade. Made the front disc to bolt over the hubs for securing the blades to the flywheel hub.

 Tomorrow, if my left side is not hurting so bad, I will start the motor mount bracket, using a section of 3" channel, inverted, so the motor cradles between the returns of the channel. 2 Bolts will hold it + a large Hose Clamp, just to be sure. Then, look around for a bearing solution. Should have more supplies by the end of next week, IF the hardware stores are open. It's "Semana Santa" don'tcha know  Things shut down for 4-5 days, so, might not get the shopping done.

  Plan on 1" square tube for the tail boom and brackets welded on for the furling swivel. Wanted to do slip rings for the down leads, but, not at this time. Let's see how it performs first.  Need to get the Ghurd controller ordered and find a 100V 50 Amp minimum diode to put between the machine and the battery. Figure to buy volt meters and amp meter for a vehicle. They are 12V rated.

[taylorp035]

Sounds good!  Please post some pics when you are finished  ( I like youtube videos too! )

[HaroldCR]

Blades are bolted to the flywheel. Flywheel is on the motor. Motor is bolted to the 3" channel base. Got the furling swivel brackets made, and the tail boom tube cut from a longer piece from another project.

  Worn out from the sawing, out in the sun, so, just goofing off and working slowly. Don't have anything for a tower yet, so, when I get paid for the sawing, I have a shopping list made out.

  Keep forgetting to take the camera out to the shop. I WILL remember it, eventually.

[HaroldCR]

 Little update:

 Wind got up a little tonight, so, I went to the shop, took the unit out and found a spot that had good enough wind to get the blade to turn about 25 RPM's. We planted our place in trees, and they are causing the wind to be very turbulent. Need to get the unit up over the trees, but, I'm pleased the thing will start up.

  No need to get stupid and have it run up, holding the motor and bracket in my hands.

[taylorp035]

25 or 250 rpm?  And yes, the wind has a lot of power and holding it in your hands is a very bad idea ( I made that mistake once... ).

[HaroldCR]

25 or so, RPM's. I'm not THAT crazy.  Wind was blocked by shop, houses, trees, tall cattle feed grass. Tops of trees were waving pretty good, though. Today, it is probably 20 gusting to 30 or more. Plenty of wind for a machine up here.

  Also got most of the wooden dam built in the creek that crosses our place, so I can get the pipe to run the diversion water to the bucket type water wheel with the pumps on it, for the hydro project.  That will be another Diary, at a later date.

[DamonHD]

Ah, wind and water envy!

The only usable moving water (and wind in some ways) of any significance round here is the nest of sewer pipes under our house and I am not fixing a turbine that gums up in there... %-P

Rgds

Damon

[HaroldCR]

 Lets see if the photos get on here.

  Nope, no luck

 

[ghurd]

Which photo(s) do you want to show?

G-

[HaroldCR]

 I have 5 photos in my files section ??  I looked real good, and could not find that ADD button

[ghurd]

You didn't see the ADD button?

(sometimes its not there, hence the new eminent change to the new board software)

I thought these were the best and showed everything.

If I didn't know better,

I'd say you lived in the jungle!

G-

[HaroldCR]

 Thanks Ghurd. Those photos are fine. Since I took them, I found a spray can of White and ran it all over that bare iron. Looks a LOT better, now. LOL  It's amazing what can be done with stuff, IF one just lets the mind wander while looking at "Junk", as my late first wife used to call it. LOL

  So far, I have less than $50.00 in the build. Time allotted does not count, right ??

  In the outside photo, it is just sitting on top of that lumber stack. Winds were up probably 15-18 MPH, with gusts to over 25. All this by guess, but, neighbors flag was really flying stiff, during the whole time.

  Occasionally, the blades would turn, maybe up to 40 RPM's, so, I wasn't far from the machine. It really hunts the wind very well. No load, and, it sat quite still while turning, so, balance and tracking are very close to perfect.

  Now for the controller and Batteries. MO should be in the mail, tomorrow.

  On another note, I have a PWM motor controller, for another project. I used it on our home built Sawmill, on a 12V DC ¾ HP motor. It's rated 12-36V DC at 120 Amps. At first, it kept blowing the fets and a trace on the back of the PC Board. Finally found someone that figured out the problem. It was BEMF Voltage Spikes. He sent me a few pieces to put on each motor lug, to ground. They look like light brown "Chiclets", just a hair larger, with 2 wire legs. Would you have ANY idea what they might be, and put a couple in with the controller

  I have another project to use the PWM on and hate to watch it burn up the fets, again.  Thanks for putting the photos up,  Harold