Water wheel design help?

[Armagh]

I intend to make a water wheel to put in a small stream near my house. By my own measurement the stream carries about 1.6 litres per second as of yesterday, but it hasn't rained with me in nearly two weeks. I intend to make the wheel from air dried Irish elm, and had planned on a 'backshot' design. I've googled a bit and can't find anything in any way useful about design specifics of a waterwheel. I can knock an attempt together of course, but I'd like it to be as efficient as possible. Can anyone here point me in the right direction? Thanks in advance.

 

[Mike Jordan]

If you care to search for "water wheel" or "water mill" you should be able to see a marathon post from 2018 detailing a small ornamental wheel and house that I made and a relatively huge wheel that Coley made. There are lots of photos of both wheels and a brilliant WIP of Coleys wheel and how to make one. Both of our wheels were overshot and just made for enjoyment but you should find all the info you need for a breast shot wheel.
Best of luck. Mike.

 

[RobinBHM]

I seem to recall that elm has to be kept wet to avoid rot when used in waterwheels.

 

[bourbon]

Overshot is more efficient if you can figure away to put it in place

 

[AndyT]

Just in case anyone couldn't find Coley's and Mike's threads:

garden-waterwheel-t100644.html

 

[Armagh]

Thank you all very much. I'd clearly used the wrong search terms.

 

[Mike Jordan]

Looking again at your original post it occurs to me that you are talking of a small stream with no substantial change in water levels, just a small flow. I would expect that you are interested in an undershot wheel, the construction will be different to the two wheels shown since the water isn't held on the she of the wheel but is forced to push paddles on the edge of the wheel while passing through a restricted channel.

 

[TheTiddles]

If I was going to make something that was going to be permanently wet, I wouldn’t be making it of wood, not these days.

1.6l/second, that’s a very tiny amount, if you think of the head you’ve got there the total power is piddly, so what are you intending to get from the waterwheel?

Aidan

 

[Hornbeam]

For any size of hydropower installation you must talk to the environment as technically you are altering the flow characteristics of the stream.
Ian

 

[MusicMan]

It could probably charge a mobile phone. Plenty of designs on youtube.

 

[Armagh]

I've a decent head of around 12 metres. I've spoken to someone more knowledgeable than myself on the matter and the potential output does seem to be disappointingly low. It's certainly not worth investing in something like a pelton wheel. I might still build the wheel myself even just as a project. I was, and still am, specifically interested in the design of the wheel itself. How many blades, at which angle etc. I've found the thread by Mike and Coley to be quite instructive. I intend to buy Mike's book as the excerpt Coley posted looks like exactly what I'm after. Thanks men.

 

[ColeyS1]

I think it was a random google search showing the different variations.

Sent from my SM-G960F using Tapatalk

 

[Armagh]

OH! Good to know. Thanks.

 

[Mike Jordan]

I'm happy to confirm that I haven't written anything on water wheels other than in the 2018 post.
Mike.

 

[TheTiddles]

I've a decent head of around 12 metres. I've spoken to someone more knowledgeable than myself on the matter and the potential output does seem to be disappointingly low. It's certainly not worth investing in something like a pelton wheel. I might still build the wheel myself even just as a project. I was, and still am, specifically interested in the design of the wheel itself. How many blades, at which angle etc. I've found the thread by Mike and Coley to be quite instructive. I intend to buy Mike's book as the excerpt Coley posted looks like exactly what I'm after. Thanks men.

12x1.6X9.81=188W assuming you use all the height and have 100% efficiency, using a more realistic 2.5% efficiency... just about 2W, that’d be why we don’t use waterwheels to generate electricity.

I suppose you could make a bird scarer with it though

Aidan

 

[Wrongfoot]

I don't want to rain on your parade, but if you're building anything you should check out https://www.gov.uk/guidance/new-hydropo ... -build-one .

You may think you can do anything you like on a stream going through your own land or that your project is too small to matter, but the State may not agree and can insist you remove your work and if you won't fine you or charge you for destroying it. Could turn a fun project one of the more frustrating and stressful things you've ever tried, it's no fun being the wrong side of an environmental regulator. Rules depend greatly on where you are Scotland, England ,Wales, NI or Eire and the type of watercourse and whether you'll block fish movement. All it'll take is a nosy neighbour to cause a lot of hassle and anyway I'm sure you want to do the right thing. I expect you'll have to engage with some bureaucracy even if just to confirm you are exempt from regulation and licensing...