New project

[Derb]

Hey Keitho. howzit going Boss? Where did you find your F & P ? I have a .8mm on an old Anderson engine. These motors are just the Biz and can really poke out some ergs at very low revs. I got a couple for free (broken down trade-in washing machines - heaps in NZ) and the most expensive part of the job was the tiny pot of eurethane to insulate the joints and windings after the soldering. Even the bridge rectifiers (3 x 35 amp) were only about $4-00 each. Once fellow members get into these units and realise how cheap and easy they are to deal with, they will be real popular. Just set up your revs (constant) to poke out voltage required and no further regulation required. Looking foward to seeing more pix. Cheers, Derb.

[KeithO]

Hi guys , Its still slowly progressing.
Due to difficulties in manhandling it , I couldn't site it down the creek far enough for a high water entry point
so it is now a breastshot.
I will have to put up with lower output as the buckets were not built for this configuration .
Thats the price I'll have to pay for changing horses mid stream  

Anyway its sitting in position , unfinished and grubby , as is the flume although the supports are very temporary and it will be a bit of a race to get it all framed up before the rain arrives.

Here is a video of its present state at late autumn (driest time of the year) that my daughter made for me.
So its just turning , making 20 watts or so

[Derb]

Nice one Keitho. Out there doin it.    Good to see it with a bit of flow come the rains. Cheers.

[KeithO]

Cheers Derb,
We are north of Westport NZ , so when it starts raining you know we are going to get a fair bit of it .
Average is about 6 ft a year

[KeithO]

Rain has arrived Yay....

Flume is holding up OK
So only higher sides on the forebay , proper generator enclosure and clean and paint for the wheel to do.

Its producing a constant 145 watts 16.5 RPM even with the forebay spillage and a bit of backwatering
So I'm relatively happy that it has potential to produce more.
Thats enough even now to run our house.

[Derb]

Hey Keitho. What voltage you running at? Are you using the existing F and P bearing assy or using pillow block set up? I cleaned off all the plastic from the alloy brg housing and set it inside a piece of box section by pouring epoxy resin into the cavity around the housing. (after welding my mounting bkts to the box 1st) Now looking for a cheap 24v inverter. The magneto on my old Anderson was toast so I have fitted  a cam and contacts to the mag sprocket shaft and can run the car coil straight off the DC side of the PM generator. (at present am running the setup at 12v via gearing/revs) I have since found an earlier Gentle Annie motor which is more akin to an old 1/4 hp motor in size which I am fitting to a morrison exercycle for the missus. These units have a much friendlier mounting configuration and are easier to draw off your tappings.(no soldering required) Cheers Boss.

[KeithO]

Hi Derb
Its running at 48v nominal v

The bearing mount is the standard f&P alloy  mount , I just threw it in a fire and burned the plastic off.
Then made some U bolts out of 6mm stainless allthread to mount it.

Gentle Annies

You have got two sets of three phase windings
these can be wired in parallel  by jumpering on the standard plug for a better output
But what I found was  if you  can separate the Wye connections and bring them out on separate leads,  then series wire  the two windings and rectify each phase with a bridge rectifier separately then you will get more output at low power inputs.
ie  little water wheels

I think its called jerry rigging on http://www.fieldlines.com

This probably needs a drawing ...

let me know if you want to have a go

[LowGear]

Wow!

After watching the first video I wondered how much could 4" PVC cost and then the second video showed me you'd need something a lot bigger than 4".  I then wondered how much you were losing because of the 90 degree turn just before the wheel?  Would it make a difference if the water fell from above the wheel flowing in the same direction as the wheel?  I was curious that you used a chain drive rather than both pulley systems being belt?

Don't get me wrong.  I've been screwing around with a centrifuge drying system for over a year so another Wow for your hard work and accomplishment. 

Casey

[KeithO]

Hi Casey

The wheel is sitting in a natural notch in the creek bank on inside of a 90 deg bend in the creek away from flow during summer flash floods.
It was originally going to be facing the other way with the water being fed over the top further down the creek but the reality of moving it by hand down the creek bed changed my mind  
So I have to put up with the lower entry point it has now,  the water has to decelerate to drop at the correct angle into the buckets , or you'd lose power from the water slapping into the underside of the descending buckets so i don't think I'm losing too much in the corner.

There is a study on Breastshot performance here https://docs.google.com/viewer?a=v&q=cache:XV1ouI6CJpwJ:steffenreichel.homepage.t-online.de/Muehlen/Infos/ModernWaterwheels.pdf+&hl=en&gl=nz&pid=bl&srcid=ADGEEShGzgYHPO-0LxHgVmQTtAqjd0uRUo3LOO8Fog7zSeplH3TCzGWoOMOHdBIXtOcpa-m2SYWOLHjtmNBB-3LXqbHN5nYuMOdkgL6B4L0OLZekCJEA1XQPb6d7ZAKB7ZG1zDMlhymj&sig=AHIEtbSwSQDbB58vdGQ3WyyPKZufts4ggg
Mine resembles what they did in figure  8

I had thought of going tooth belt for primary drive but chain and sprockets are easier to get out here in the sticks.

Cheers
Keith

[rcavictim]

Outstanding there Keith.  Outstanding!

[BruceM]

That's a very impressive job, Keith.  I could get along quite nicely on your output.  Enjoyed your videos and following along with your progress, thanks!

[Tom Reed]

I could sit there and watch that wheel spin all day. 

[wrightkiller]

Thank's  for posting Keith 

[sailawayrb]

Quite the project and I am very happy to see it is working nicely!!!

Your current breastshot configuration is only producing about 50% of the power that we estimated the planned overshot configuration would produce...which makes perfect sense since we are only filling about 50% of the buckets we had planned on filling (and we are only using 50% of the head we had planned on using).  We should try to improve this!  

Your penstock water flow velocity (i.e., feet per second) currently feeding your wheel appears to be way more than adequate! What did the volume of your buckets turn out to be and how many do you have on your wheel?  What percentage of the bucket volume is currently getting filled by the flow rate (i.e., cubic feet per second) that you are now feeding the wheel at your operational RPM?  

I guess where I am going with these questions is to determine the feasibility of trying to raise the water entry point and also increase the penstock channel cross-sectional area (i.e., increase the penstock wall height) so as to generate adequate flow rate to completly fill the bucket volume and also fill more of the higher buckets.  Just increasing the entry height alone will reduce the flow velocity and also reduce the flow rate if you don't ALSO increase the penstock channel cross-sectional area (i.e., Q=VA).  So you need to "optimize" your penstock cross-sectional area AND your entry height given your wheel location and given the optimal flow rate your wheel requires based on it's operational RPM.  However, please also keep in mind that increasing the penstock channel cross-sectional area will also increase the weight of water that the penstock will have to be able to structurally handle and this would have to be properly dealt with too.  So the goal here is to generate just enough flow rate to completely fill as many high buckets as possible without having too big a penstock that is not feasible to build.

If you know the optimal flow rate your wheel requires (see my previous posts about this), you could use this "Ditch calculator" link to optimize your penstock cross-sectional area AND your entry height so as to get this optimal flow rate:

http://www.wrd.state.or.us/OWRD/WR/cwre_info.shtml

I would suggest using 0.012 (i.e., wood channel) for the "n-factor" Manning's roughness coefficient.

Bob B.

[KeithO]

Thanks for the supportive comments guys , I love these forums

Hi Bob B

I agree , the output is at present Okay at best.

The first changes are to double the height of the forebay flume walls
Then sort out the tailrace , the buckets were dragging through about two inches of water in the second video , not good

The bucket filling vs rpm question is an interesting one.
I thought 16.5 rpm was a bit fast , but with the buckets only having a capacity of roughly 15.5 litres and only using a quarter of the 24 , we have

6 buckets x15.5 ltrs x 16.5rpm = 1534.5 ltrs or 405 US gal  per minute dropping 3.5 ft @.55 eff should give us 147 watts

Obviously  I need to speed up the wheel a little , easily adjusted with the F&P generator , and the removal of backwater will help.

As for lifting the entry height , I think that might be getting into the area of diminishing returns , my designs for vanes to match the water angle to the wheel  for a backshot always seem workable on the kitchen table , but not so easy when I'm standing in the creek

Cheers
Keith