Author Topic: My waterwheel project (Read 44902 times)

southline · « **on:** February 25, 2012, 06:18:59 PM »

Hello all,
I just wanted to share my winter project. Its been great fun to build so far and I can't wait to get it in the creek.

http://s1241.photobucket.com/albums/gg510/southline/ I hope this link works.

It a 4' poncelet waterwheel made from 3/4" plywood and 45 gallon HDPE barrels. Generator is an old ECM1 motor from a waterfurnace geothermal heat pump. It was designed for 20 to 30cm head at 100 l/s. I'll update later. Any advise is most welcome too!

Adam

RP · « **Reply #1 on:** February 25, 2012, 10:45:52 PM »

That's neat. I like the method of fabrication with the router too.

keithturtle · « **Reply #2 on:** February 26, 2012, 02:01:36 AM »

It looks as if you have an excellent water resource there. Do your best to not waste any head, might need to add some more rocks to that dam. Nice wheel

Turtle

southline · « **Reply #3 on:** February 26, 2012, 12:45:54 PM »

Thanks RP, Turtle,
I agree some work is needed on the dam.. I have been having too much fun building the wheel.
I plan to survey the river to see what kind of head I actually have over the 300 feet approx. My first guess is maybe 6'. I'll do that when the snow is gone and the trees are still bare.
I'm trying not to rush..
Has anyone had experience with an ECM motor used as a generator? I'm surprised at the voltage. Very ball park estimate 250 rpm gave me over 50v.. I even tried a 16w CFL bulb and got it to work.

Adam

Basil · « **Reply #4 on:** February 26, 2012, 07:17:44 PM »

The next thing you know ECM motors be $300.00 on EBay.
I have have had some luck with it also. Just not done yet.
http://www.fieldlines.com/index.php?PHPSESSID=87836b9959198f81b8e9b2ee2e50606f&topic=143584.18
Great project.
Hope you can do yours faster than I am.

Ungrounded Lightning Rod · « **Reply #5 on:** February 27, 2012, 12:43:42 PM »

It looks like it was assembled without any waterproofing finish on the plywood. What are you using to keep the water from rotting the wood?

southline · « **Reply #6 on:** February 27, 2012, 04:16:10 PM »

Quote from: Ungrounded Lightning Rod on February 27, 2012, 12:43:42 PM

It looks like it was assembled without any waterproofing finish on the plywood. What are you using to keep the water from rotting the wood?

The plywood was treated with 2 coats of polyester resin cut with acetone to allow it to penetrate the wood before assembly(WARNING: killer fumes, flammable). It stays sticky for a long time even with a lot of hardener. Another coat of finishing resin after assembly. The finishing resin was applied while the wheel was on its side and allowed to fill any extra space in the router groove. The resin idea came from wood boat finishes..

Adam

southline · « **Reply #7 on:** March 02, 2012, 09:10:15 PM »

Update: I couldn't wait to get the wheel in.. 3 15w lights wired in delta. I'll get the multimeter and amprobe out tomorrow if the weather holds out. I'm looking foreward to tweaking..
http://s1241.photobucket.com/albums/gg510/southline/
Adam

dave ames · « **Reply #8 on:** March 03, 2012, 12:06:10 AM »

Thanks for the look Adam,

An absolutely beautiful job casting that race! A nice stable platform that will let you tune your design in..nice 2nd life for those blue plastic barrels too!

Looking forward to further reports

? do you see a jackshaft in the future? those ECM bearings seem to be tougher than they look..but if we can take the pressure off them,.. might be one less thing to worry about.

Cheers, dave

southline · « **Reply #9 on:** March 03, 2012, 10:13:53 PM »

Thanks, Dave. My thoughts for the race was that it may be used again for a new and improved wheel when the plywood eventually rots. As for the jackshaft- good point, I can also play with the RPM and again reusable..
No updates due to 10" of snow and crazy wind.. I haven't even measured voltage yet

southline · « **Reply #10 on:** March 05, 2012, 09:30:14 AM »

Just an update, -20C last night. Yep frozen up, got some cool pics. Some measurements from yesterday: 1.2A / leg and 70v. This with lots of ice on the blades. I love winter but now I can't wait until spring

richhagen · « **Reply #11 on:** March 05, 2012, 03:26:01 PM »

I like it. The creeks I am familiar with get periodic deluges with high water after storms that would take that wheel apart though. Does that creek ever flood out after storms?

southline · « **Reply #12 on:** March 05, 2012, 05:00:41 PM »

Thanks, Rich
The river has never flooded in the 4 years I have been here and it has always been pretty steady. Even in the big storms its not over my boots. The day before these pics were taken I sealed and raised the dam 3", so with the ice today it looks crazy.

southline · « **Reply #13 on:** April 20, 2012, 09:03:22 AM »

Update,
Its been running 24/7 for over a month. I added an idler pulley to increase belt contact with the generator. The belt would slip when it rained so the lights at the end of the driveway (and all others) that are powered off the wheel would flash. I wonder what people driving by would have thought?

Has anyone thought about building a wheel out of "Trex" or other composite wood? I'm thinking this may be a more permanent solution.

birdhouse · « **Reply #14 on:** April 20, 2012, 11:30:21 AM »

southline-
looking good! so your using the power directly for outdoor lighting? no battery charging?

when you first posted, i was going to mention that plywood is not very good with being wet all the time, even when coated with varnish ect. but i didn't want to dampen your spirits. you did make a great proof of concept!

if it were me, and i wanted a wheel that would last forever, i'd go straight to steel or composite (fiberglass). both are harder to work with than wood and plastic, but would last a really long time.

you could even have the sides cut out of steel, and weld on little tabs to re-use your plastic ribs.

adam

southline · « **Reply #15 on:** April 20, 2012, 01:39:26 PM »

Birdhouse,
For now I just have about 40W of load on the wheel made up of outside lighting around the property (70VAC). I even have the low voltage "Moonrays" running. Since the wheel will freeze up in the winter I figure there is no sense in trying to go off the grid with batteries etc. I could try a turbine in the future since the river never freezes completely.
I'm just aiming for cheap and simple since its in the ~~plywood~~ prototype stage.

I'm in the process of designing a bigger wheel out of PVC fake wood. Just to make it look "old timey" and produce a little power also.

keithturtle · « **Reply #16 on:** April 21, 2012, 02:34:51 AM »

It's good to see it working, making power. With only a foot or so of fall, you have done quite well for yourself.

Keep at it. It's be a few more months till I'm that far along

Turtle

electrondady1 · « **Reply #17 on:** April 21, 2012, 09:10:06 AM »

congratulations on your water wheel
any sign of fish in that stream?

GoVertical · « **Reply #18 on:** April 23, 2012, 08:41:26 AM »

Super !!!! very nice

southline · « **Reply #19 on:** November 11, 2012, 02:26:41 PM »

Just an update. Been running strong since March. Cleaned a stick out and the leaves built up and stopped the wheel once. I'm looking foreward to this winter when work slows down so I can build the new one out of longer lasting materials. Someone once said "Waterwheels are addictive" I believe it.
Adam

ghurd · « **Reply #20 on:** November 18, 2012, 09:57:08 PM »

Just throwing an idea out there.

Couple more inches of head (rocks on the dam) would make a lot more power.

Heat ain't free.
Might consider using the power for heat?
G-

southline · « **Reply #21 on:** November 19, 2012, 11:52:23 AM »

Hi G,
I'm at the limit of raising the dam without raising the banks, its doable but i'd need a good loader (and back). I would be better off with a turbine and gain head by piping from up stream and it wouldn't freeze up. IMHO it wouldn't look as good as a waterwheel though. Maybe both in the future... Maybe off grid..

Is there a 100w water heater element? I like that I can use the power right off the wheel (70w of light at 70vac easly produced so I think 100w is doable with the next wheel). It follows the kiss principal. Your right with the heat. Energy storage in water of just offsetting heating bill.

I have solar hot water in the summer and the woodstove heats the water in the winter as well as 80% of the house heatload. Geothermal pick up the rest. FYI, Geothermal and refrigeration is my trade. I'm resisting getting too complex for now.

Adam

The new wheel (Thanks to Spencer's designs at the waterwheelplace)

ghurd · « **Reply #22 on:** November 19, 2012, 09:19:56 PM »

Quote from: southline on November 19, 2012, 11:52:23 AM

Is there a 100w water heater element?

I like that I can use the power right off the wheel (70w of light at 70vac easly produced so I think 100w is doable with the next wheel). It follows the kiss principal. Your right with the heat. Energy storage in water of just offsetting heating bill.

100W element? Sure. Just have to use up the battery in 3 calculators to figure out which one you need.
With more details, about how the volts and watts change with the load, it would be fairly straight forward.
Light bulbs have some strange properties, and for the test load they are not great.

40W 70VAC, and 70W 70VAC? Interesting.
The watts you stated (40 and 70W) are measued, as VA or volts times amps?
The pics in the link don't really show what I am wondering about.
I have a feeling the wheel is trying to make more power, but the waterwheel RPM limit is why the volts stay the same with an increased load... OR the watts being made has an issue with how it is being calculated.
Might throw on a few more small lights one at a time until the voltage decreased, and then get an amp reading. I have a feeling that would give some kind of idea what it is capable of doing.

"The belt would slip when it rained so the lights at the end of the driveway (and all others) that are powered off the wheel would flash"

Maybe a piece of gutter or half-section of 4" PVC over it would keep the rain off?

Maybe one of those antique cast-iron 3-belt 8"-dia pulleys just hung on the ECM shaft would smooth out the bumps?
I have a feeling those 'bumps' are bad on the bearings too. I don't know for sure.

The ECM is from the blower right? And NOT the pump?

Anyway. I love it.
G-

southline · « **Reply #23 on:** November 19, 2012, 10:44:45 PM »

Thanks G,
Ok.. I just realised my mistake. Shame on me and my apoligies for the misinformation.

I was just adding up the wattage of the light bulbs. Not true at 70 volts.

The voltage does decrease with the load due to the wheel rpm decreasing. I have managed to keep it around 70v by raising the head until the water is a couple inches form overflowing the banks. So as I increased load I added head.

Couple more inches of head (rocks on the dam) would make a lot more power. YEP! Almost double from when I started. At max now.
Might throw on a few more small lights one at a time until the voltage decreased, and then get an amp reading. I have a feeling that would give some kind of idea what it is capable of doing.
Maybe plotting a graph with volts, amps, (MEASURED OF COURSE) and RPM starting at low load to high load. I'm looking ahead to the gearing on the new wheel. It would be good to know the relationship of wheel RPM to generator RPM to power produced. I'll spend a little money on gearing this time.

100W element? Sure. Just have to use up the battery in 3 calculators to figure out which one you need.
I'll send you my solar powered calculator.

I don't know how to use it..

It is the blower ECM.
Again, Thanks G,
Adam

hydrosun · « **Reply #24 on:** November 20, 2012, 09:48:11 PM »

If you run the turbine without a load you can measure that voltage. The maximum power should be at about half that voltage. So if the open voltage is 140 volts then your 70 volts is the max with your setup.
A 100 watt heating element is dependant on the voltage. At 100 volts a100ohm resistor is 100 watts.
Chris

Ungrounded Lightning Rod · « **Reply #25 on:** November 22, 2012, 06:28:26 PM »

Yep. With a water wheel the fluid is incompressible and the wheel resistance doesn't appreciably change the flow of water to it - just the exit speed. When it's freewheeling the water leaves at about the speed it entered and the part of the wheel that interacts with it is moving at the entry speed. When it's at maximum power the water leaves the wheel with very little velocity. If the wheel design is efficient there's little loss to turbulence, fluid friction, etc. so the wheel is just deflecting the water, and thus "recoils" at the midpoint between the entry and exit speed. Thus max power RPM is about half the free-wheeling RPM.

With a permanent-magnet alternator (or other electrical machine with wild RPM and fixed excitation) the voltage is proportional to RPM. So max power for a wheel with such a generator system occurs at about half the free-wheeling voltage.

Ungrounded Lightning Rod · « **Reply #26 on:** November 22, 2012, 09:03:11 PM »

Quote from: southline on November 19, 2012, 10:44:45 PM

100W element? Sure. Just have to use up the battery in 3 calculators to figure out which one you need.
I'll send you my solar powered calculator. I don't know how to use it..

Who needs a calculator? P = E^2 / R. Assuming you're using a water heating element (or a good fan on a space heater) so R doesn't vary too much with temperature:

(70^2) / R = 100; (120^2)/R = rating. (E^2)/R = P
(70^2)/100 = R = (120^2)/rating multiply both sides by R, divide both
by W. Brings out R, so equate.
rating*(70^2) = 100*(120^2) Drop extra "R". Multiply both sides
by rating and desired power to bring
them above the division bar.
rating = 100 * (120^2) / (70^2) Divide both sides by (70^2) to get
"rating" to stand alone.
rating = 100 * (120 * 120) / (70 * 70) Expand squares.
rating = 100 * (12*12) / (7*7) Divide top and bottom of ratios
by 10 to get rid of extra zeros.
rating = 100 * 144/49 Do the multiplies for the squares.
rating = 100 * 288/98 Double top and bottom of ratio to
get the denominator close to a
round number.
rating ~ 100 * 294/100 Adjust top and bottom up by
about 2% to get to a round
number. (A calculator would have
gotten 293.8775510. To three
significant figures (i.e. more than
we really have) that's dead on.)

Cancel the 100s and you get 294, which is within 2% of 300.

300W isn't a typical value for heating stuff (though you could parallel three 100W devices). But 250 is, and it's only low by about 16%. If you're using something that heats up a lot (like a lamp or a hot-wire space heater element) it will be running cool and have a substantially lowered resistance, so a 250W nominal device might actually pull closer to your desired 100 watts than the 83 you'd expect from assuming the resistance is the same under a factor-of-three power drop.

ghurd · « **Reply #27 on:** November 22, 2012, 11:58:22 PM »

That is IF it is 70V and 300W at peak power?

70V 300W is 16.333 ohms.

Can get 120V and 240V elements in a wide selection of wattages.
16.333 ohms? 240V 3500W and 120V 900W are common values.

I think I misread what you were saying, so lets try-
70V 100W is 49 ohms.
240V 1200W is 48 ohms.

That may lead to the "Is it 220 or 240V?" thing again.
G-

kenneth keen · « **Reply #28 on:** January 21, 2013, 04:16:31 PM »

Quote from: southline on April 20, 2012, 09:03:22 AM

Update,

Has anyone thought about building a wheel out of "Trex" or other composite wood? I'm thinking this may be a more permanent solution.

I built the very same type of wheel several years ago and it has been over the river for three years now without corrosion. It was using a cable drum made of plastic, or better a recycled plastic cable drum as a "frame" for the same blue plastic fins as you have used. I attached the plastic fins to the drum with heavy 3mm wire in like I was "sewing" the fins to the drum. I only made holes in the fins and drum and then passed the cable through and that holds. It is not water tight, and lets water through at the sides but the attraction with the plastic drum is that it will never wear out. It is very much smaller than yours being only 50cms in diameter. Two feet for those with Victorian tape measures!

DaS Energy · « **Reply #29 on:** May 05, 2013, 06:23:08 PM »

Hello southline,

I see by picture you have included curved blade to your wheel.

18th Centuary german woolen mill had similiar wheel undershot. Discovered greater output by partial sumbmersion. Set so water inrush came to gravity halt before reaching top of blade. This left water freefall to second react as it left the blade.

Peter

DaS Energy · « **Reply #30 on:** May 06, 2013, 03:25:12 AM »

Hello southline,

A question. Why not use marine ply.

southline · « **Reply #31 on:** May 06, 2013, 09:30:30 AM »

Marine ply is a little too expensive for an experiment. When I was building the wheel I thought I would be lucky to get 2 years out of it. I'll post some pics of the new wheel later..
Thanks, Adam

southline · « **Reply #32 on:** May 09, 2013, 10:21:54 AM »

A few pics of the new waterwheel.
6" diameter, Width to be determined by blade material. I'm thinking of cutting steel barrels for blades because the plastic barrels are irregular in thickness and they get narrow at the top and bottom reducing the width of the wheel. I think the steel would corrode in a few years though. I'll try to make them easy to replace. Still thinking about the electrical.. Thanks to all for helping out with the math. Any idea how to use all three phases to heat my water tank? I could have 3 elements in the solar preheat tank. I'm still assuming 100W with the new wheel and a little tweaking with the gearing could get 100V.
Just FYI its running around 90hz as measured with my meter.

Thanks to all who have posted ideas, info and questions. This site sure keeps a person inspired!

Adam

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Author Topic: My waterwheel project (Read 44902 times)