Ralphs Water Wheel

[mitcamp]

I used 2 15 in. disc with 16 mags on each disc 2 x 1 x 05 rectangles. The stator was wound with 27 turns of 3 in hand #15 gauge. This is the same as the 12 footer thats common here.

Water Wheel Specs

1.  wheel diameter 10 feet
   
   
2.  16 blades, 6 feet wide, 7 inches deep, blades are C shaped but with 5 sides. It looks like a 8 sided nut wit 3 pieces missing.
   
   
3.  on pontoons
   
   
4.  total weight 2200 pounds

   
   
   

We installed a 30 to 1 ratio gearbox. and observed the following.  

     8 R.P.M at wheel shaft, no load

     6 R.P.M at wheel shaft, loaded= 12 amps

We then installed a 45 to 1 ratio gearbox and observed the following.

    8 R.P.M at wheel shaft, no load

    4.25 R.P.M  at wheel shaft, loaded= 14 amps

     

Watching it in operation,I noticed the bottom paddle is causing a wave, with a splash to the blade coming up next, so I have 2 questions.

1  Would this system worked better with C type paddle, like a 15 inch diameter pipe cut in 2 pieces lengthwise.

2  Would this system worked better with 12 blades instead of 16 blades.

I sure could get a smile from the owner,if I could get 25 - 40 amps out of it.

Any and all suggestions appreciated.

                                  Mitcamp

[12AX7]

Hello Mitcamp!

WOW!!!

I don't have any answers to your questions, but instead plenty of my own!

It looks like Ralph put in lots of time and $$ into his water wheel, and it looks VERY SWEET!

Did he design it himself?

How many hours ?

More PICTURES??!!  Please!

In operation,  are the paddles completely submerged?

Any idea how much the river level changes?   (low to high)

The picture you have posted,  does it show "average" flow?

Any chance of a video posted to .. say..  Youtube? (close ups would be nice)

Your posted tests..   What is the voltage at the tested current values? and what type of load?  

(in other words..   what is the output in WATTS?  with the two gear boxes?

During your tests..  what is the Unloaded voltage vrs  Loaded?

Can you stall the wheel by loading down the alternator ?

I'm sure I'll have plenty of other questions!.

Like whether you have any concerns of "cogging"  or regulation ect ..ect.

But I'll delay them for a bit..  

It's been years..   since I've posted my list of questions/ideas.. about building a water wheel.

I had a Lot of response from others that you may find interesting.  

If you are bored and have the time check out my dairy entries,

New Camera

Low speed hydo

How slow can it go?

and  Watts that?  Hertz much?

I got a few very good comments  Zubbly, Otzles , Nando and others!

Concerning Ralph's wheel and your alternator my "gut" feeling is that a "much larger" diameter alternator would help.  

I'd suspect that some others will be asking..  What type of load is Ralph looking to use?   as well as lots of others!  

The standard issues in a wind gen are very different from a hydo set-up!

Bottom line is...  WOW!

I'm looking forward to watching this project/thread!!

Mark

ax7

[mitcamp]

Hi Mark, Ralphs friend designed it. He (allen) gathered infomation on the net for 3 or 4 months. Ralph then sent the design to the local machine shop

Yes, the paddles are completly submerged

The picture of the wheel in the water is normal level. After a day or 2 of rain the wheel will pick up 2 R.P.M and make a difference of 2 more amps or so.

The voltage was 12.4 and his load is his fairly Large battery bank with a C60 Trace controller.

When I said unloaded " I meant the wheel was spinning with the alternator disconnected.

Very little difference between either gearboxes, maybe 1 or 2 amps more with the 45-1

Your last question. " Normally the wheel turns 8 R.P.M with no load (alternator disconnected) When we connect the alternator to the system the R.P.M of the wheel drops to 6 . I never got a chance to short the 3 leads, to slow it down, but I,m sure it would not stop the wheel. And there is certainly no cogging from the alternator.

                          mitcamp

[thirteen]

Very nicely done water wheel.  I could be wrong but it looks like you used type - E bearings which are roller where ball bearing use less energy to turn. You may have needed them for the wieght it carries. Would a synthetic oil in the gearbox create less drag? Would lighter grease or oil in the bearings help? Would the front of the pontoons direct the water better if they were pionted to help the flow of the water to the paddles and help with the tapered piont instead of a blunt box? Are you able to see the water flowing under the paddles they might be causing restriction next to the pontoons?  I do not know paddle wheels, I work with fine dust and we use a bucket elevator to lift up the fine powder. We put small holes in the bottom of the buckets to help release the vacum created when the fine powdewr is being dumped out. Could this help with the water paddles I do not know? Could there be holes cut into the sides behind the paddles to help lighten up the wieght and also on the web plates? Would this take take away from the strength needed? If you do you could make a pattern of some sort out of the holes. It might make it lighter so less weight to turn. Will you need a branch catcher in front of the paddles? Just some ideas to play with or toss down the creek. Thirteen

[hiker]

just my thoughts...

so the curve of the blades are making a backwash wave..

thinking you dont have fast enough water speed to match the blades..with the load..

might try a flatter angle on the blades..

might lose out on tork..but gain rpms..but thats up to the load ...??

again just my own thoughts.............................2 cent..

[Flux]

Nice work

I think you are near the maximum output if your speed is being nearly halved when load is applied. Small improvements may gain you a bit but I don't think you are going to double the power out. Undershot wheels have to be really large to get much out.

You may be able to restrict the channel a bit and increase the velocity under the wheel.

It would be interesting to know your overall efficiency with gearbox and alternator. I doubt that there is a lot of room for improvement without a serious increase in cost but it may be that a lower ratio gearbox and a much larger and more costly slower alternator may have got you a bit more but there comes a time when the cost is prohibitive for the slight gain. You have probably got a good compromise.

Flux

[tecker]

Just like the wind the whee; won't move any faster than the water unless you compress the water and free up the blade on the rise angle .I like the design .I would assume the creek rises in bad weather .You have to work with a drop off in my opinion . Concentrate the water and work with a dropoff .

[electrondady1]

that's a really nice device!

perhaps the blades are not optimal but who knows about that sort of thing in this day and age.

40 amps is nothing to sneeze at.

what i like about it the most is it seems it has very little  impact on the stream

.

[electrondady1]

oops, 14 amps

still, what a nice machine.

[KilroyOdin]

It looks like it can generate a lot of torque. It might be able to power more than one PMA hooked up in parallel.

[scottsAI]

Mitcamp,

Interesting project. Your power is maxed as it. Yet there is more to do.

The water flowing around the assembly must be aerodynamic in shape.

I see a flat area to the water. Causing turbulence to the water flowing into the blade area, restricting your power.

Shape the assembly to FUNNEL the water into the blade area.

2x water speed up can be achieved in the blade area.

Please include a picture of the wave, like to see how the whole blade area interacts with the water under load.

Have fun,

Scott.

[mitcamp]

Thanks for your comments

Thirteen, I will add another photo of the front showing pointed pontoons. Early when we put in in the water, we decided to stop the wheel by putting a 3 inch green ash tree into the spokes. It cut the tree like putty.

hiker, flatter angle on the blades was also on my hitlist but would be more labour intensive, and would have to go back to the shop, but could be done.

Flux, I still have my old 18 footer  18 in. disc with 24 mags 2 x 1 x 1/2 on each disc and also have the orginal 12v stator 18 coils 4 in hand 14.5 ga. with 27 wraps. Its been on the shelf for 4 years and would be a simple change over. That stator cut-in at 72 R.P.M.

tecker, would you explain more on "free up the blade on the rise angle. Anything to do with the blades is going to be a labour intensive job. But if Ralph thought it would put out more power, he would send it back to the machine shop and have it upgraded.

Kilroy,you may have something here. I could add another alternator on the opposite side of the wheel. I could be busy this winter as the wheel will be taken out of the water for the winter.

Many thanks guys,will keep you posted.  Mitcamp

[ghurd]

I am Very impressed!

I thought the same thing about the turbulence and how it shows in the photo, maybe throw those rocks off to the far side next to the wheel?

I wondered about more power from a 12V version of the 17' PMA, which is probably not cost effective for the extra little bit of efficiency.

G-

[mitcamp]

I tried to post another picture showing the front of the pontoons, but it failed. The front is designed to catch the water and direct it toward the center. You can look in my photo uploads on this site. waterwheel front 1541.jpg

                             mitcamp

[DanG]

Now if you just harness the flow of comments on your post too!

If the wheel sheared a 3-inch branch closing the spoke openings with something (hardware cloth, roll fencing, cedar lath slats, plastic fence lattice, etc.) would guard against that liability a long ways in the eyes of the Courts... Ya, I know but someones dog might think its better than rolling in....

I'd be voting for a self-tensioning serpentine belt if that was a category...

Also - working against natural creek bottom versus having a sluice floor to keep water piling up against the tines, that buncher claw could sure sneak some creek changes in fast...

How many spots have you tried it in, the shoreline being close as pictured introduces turbulence...

[TomW]

[spinningmagnets]

Very impressive ! I haven't built a water wheel, but from reading, I believe you might realize a small improvement by changing the blades to a Poncelet-style. They would have a smooth inner curve, and a much bigger radius. I would make the buckets out of plastic pipe sections where the pipe diameter is about 1/2 to 2/3rds the diameter of the whole water-wheel.

If the bucket edges are submerged one foot deep, the flowing water it collects will slide up the curve (imparting energy) and then as it stops and slides back down, it imparts a little more. This will also cause less turbulence. By that I mean if the bucket edges were turning at 80% of creek flow speed, it might turn at 85% with less turbulence.

http://www.greenmuseum.org/c/ecovention/sect2/waterwheelsketch.jpg

[12AX7]

"In for a Penny, in for a Pound"

Hello Mitcamp

I've been trying to figure out an "elegant" way of asking the dollar investment in the water wheel,   the best I've come up with is   "What is the cost ratio between the water wheel and the alternator"    But that makes things difficult,  So.....  how much bling?

The Wheel appears to dwarf the alternator in both size and investment.

It surprises me that the "unloaded" RPM of the two different gear boxes are the same?

The 30:1 and the 45:1 have the same unloaded 8 RPM,    What is the wheels RPM without a gearbox attached?

With out a doubt, a great deal of time has been put into its planning and building.  During that, process was there ever a "calculated" power output?

A long time ago I had a chat (and I am not sure with who) about increasing wheel efficiency. It was suggested that if one were to put in vertical vanes in the water (leading into the paddles) that by reducing turbulence and causing the water to push against the paddles in a more "linear motion" more wheel speed would be achieved.  

It has already been posted whether spending the extra monies on larger alternator would be cost effective; however taking into consideration the investment already made it the water wheel.....  The way I see it   "In for a Penny, In for a Pound"

The current values you have listed,   is the total current, or per leg of three phases?

You mentioned 45 amps would be nice,    12v x 45a = 450 watts.

I would not be surprised if the 45:1 gearbox is not consuming close to that amount.  To say nothing of the year-to-year maintenance it will require.

I do not recall anyone here building an Ultra Low speed alternator, but that does not mean it cannot be done.   YES, it would cost a lot more than a standard "wind" alternator but this hydroelectric system is a very different animal.  

You may want to search low speed alternators.   I recall Vatman working on one,  but I've not seen recent postings from him.  

Looking forward to more pictures!

Mark

ax7

[frepdx]

" ... 450 watts.

I would not be surprised if the 45:1 gearbox is not consuming close to that amount.  To say nothing of the year-to-year maintenance it will require."

Is the gear box splash lubricated w/80weight? It might drain more power as it gets up to speed. I'd test the gear box power usage at speed, maybe remove it and use a scale for an improvised torque meter.

[ruddycrazy]

If I can add my 2.2 cents worth here,

                                     As stated above the torque required to drive the gearbox I feel is the big restraining point for more power. Another way to drive the alternator would be using pulleys and either Vee belts or timing belts. At some point in the stepup a variable pulley set could be installed to vary the ratio to find the sweet spot. The torque required for the pulley setup will be heaps lower any gearbox and the longterm cost of maintenance will be a heap lower.

Regards Bryan

[veewee77]

One potential problem I see with this setup is the fact that the stator in the alternator is mounted on those stainless (or whatever) all-thread rods. While this may be ok in short setups, those look a tad on the long side. As the alternator is loaded, those will tend to flex in the direction of rotation, and as they do, they will pull the stator against the rotating magnets and could cause a failure. A suggestion (and I may be wrong here) would be to put diagonal braces between the adjacent posts so they won't flex. The outside end of one all thread braced to the inside end of the next one all the way around. This will keep them from flexing and pulling the stator into the rotors.

JMHO - YMMV

Doug

[dnix71]

That's an amazing piece of work, but it looks lethal. The triangular slots on the sides shouldn't be there, and there shouldn't be any braces near enough to the blades to act as a pair of shears/scisssors.

There are dumb people out there that could get you in trouble. There are pix on the web (google: strkr98 pumpjack accident) of some kid who climbed the fence around an oil donkey and lost his arm. It happened in Feb. Those don't move fast either, so they don't look dangerous.

[scottsAI]

Ghurd,

Like minds think alike!

We agree the gears are not using enough power to make going to larger generator worth the cost. No load speed to full load is 2:1 right where it should be.

With that said, Possibility its over loaded. No load speed should be without the gears. Suspect couple RPM higher, if true, then 4.25 RPM is over loaded. Loading it MPPT (style) limiting to 5 RPM may peak power.

Need faster flowing water. Funneling is the only solution with the existing hardware.

Have fun,

Scott.

[joestue]

As far as getting 30-45 amps from it, Can you measure the torque generated by the wheel?

I'm thinking measure the flex on the bolts, then torque it with a 10 foot bar and some lead weight, the way you have it bolted makes other methods difficult.

The 45:1 gear ratio is good, it is able to load the wheel to about half the unloaded rpm.

But with only 180 RPM at the alternator, alternator efficiency is going to suck.

If you want to go through the trouble of taking the alternator off, I highly recommend plotting the rpm vs torque with a pony brake, and do the same again with any changes made to the wheel.

[Ungrounded Lightning Rod]

The water splashing up in the buckets is normal for an undershot wheel.

To get efficiencies approaching those of overshot wheels you make that happen deliberately, typically with the poncecelet design.  The blades are partially submerged and recede at half the speed of the incoming water.  The edge is tangential to the incoming water and so the water smoothly climbs the blade, pushing over more of its surface than it would if it were hitting a flat blade face on.  The water transfers most of its momentum to the blade as it runs up and back down, exiting with a backward velocity relative to the blade that makes it leave the mill with very little forward momentum remaining.

A poncelet can in principle get essentially 100% of the power in the water and in practical designs can get 70% or more, compared to typical pre-poncelet undershot designs that got maybe 35% if they were lucky and spent much of the rest creating heat and turbulence when the water hit the paddle blades face-on.  The poncelet's efficiency is thanks to that rise as the water interacts with the blade.

To make it work well you need to block the sides of the blades to keep the hump of water from running around the edges.

[12AX7]

This post sounded familiar..  

Going back a few years..   but seems to still ring true?

 Re: Low speed hydro (3.00 / 0) (#68)

by elvin1949 on Thu Mar 23, 2006 at 06:09:47 AM CST

12AX7

 It is the design that i like.

Low rpm water driven at flow of stream rate.

Your water wheel is very doable.

 Float the water wheel on pontoon's.

Drive the gennie off of the outside of the wheel.

When first assembled use a dummy shaft for the output,test with a prony brake to measure power,

then build a gennie to match that output.

 Power to the batteries.Simple

later

elvin

[12AX7]

Hello Mitcamp

Check out this thread by Vawtman

I think this is the direction Ralphs alternator should head.

5. All the mags are on  (Mechanical, All Topics)

posted by vawtman on 08/24/2008 07:41:53 PM CST

29 comments (0 new)

(not sure how to post the direct link)

Mark

ax7

[wooferhound]

> (not sure how to post the direct link)

Putting a link in is easy

visit the page that you want to link to

highlight the link in the address bar

then rightclick the link in the address bar and select -Copy-

go to the story you want to comment on and select -Reply- or -Post New Comment-

when you are ready to insert the link, rightclick the page and select -Paste-

There is your link in the Comment/Story

[gizmo]

Well dinx that should have come with a graphic content warning, I was eating my lunch!

I hope the silly kid is right handed, poor bugger.

Glenn

[12AX7]

Okay,  let me try this...

http://www.fieldlines.com/story/2008/8/24/184153/928

[12AX7]

And after posting this, I see that Vawtman hasn't posted for a few months.

I hope he is still around!

[12AX7]

Any Updates?

I hope this thread hasn't died!