Tell HN: Giving away my homebrew windmill | Hacker News Reader

Tell HN: Giving away my homebrew windmill

173 pointsjacquesm39 comments

Hello HN.

After lugging it with me for a bit over a decade without ever having a good place to re-install it I'm giving away my windmill. It's a 2.5 KW rated variable pitch machine that took over two years and a small fortune to build.

The project is documented here:

https://jacquesmattheij.com/how-to-build-a-windmill/

The machine definitely needs work, (1) the slipring assembly and tower shaft and mount will need to be re-made, (2) the whole thing could do with a new coat of paint.

It's built with imperial hardware so you'll need to buy some bolts to mount the blades. It is also heavy, you'll need two people to lift it into the back of a vehicle. The blades are 2.5 meters long (three of them), the total machine is 5 meters in diameter when assembled. Some metalworking skills or access to someone who has those is a must. If you have a lathe that would make things much easier.

It goes without saying that this is a prototype machine and that installing and operating it is at your own risk, if you live in a city you are likely not going to be able to use it but if you have a remote cabin or something like that with steady wind this will give you power to spare.

Let me know if you are interested and able to pick it up near Hilversum, the Netherlands.

I'm going to be wonderfully pedantic here, in full HN tradition: What you have here sir, is a Wind Turbine. A 'Windmill' mills grain as part of the rotation. :D

Milling is not necessarily confined to grain.

While gristmills are one of the oldest types of mills, many windmills in the Netherlands were poldermills to drain low-lying land, and the industrial revolution brought us a variety of carpet mills and powdermills and everything mills, although they were mostly based on water mills, and steel mills, which don't even involve turbines.

I saw "homebrew windmill" and thought he was milling malt for home brewed beer. Then I thought he was powering his homebrew kettle with wind. Then I realized I'm a bit slow this morning and "homebrew" is "DIY".

I thought it was a homebrew package named windmill.

In nl we call all of them windmills. We even have 'watermills', windmills that pump water, the same term is also used to indicate a water driven mill. But from a tech perspective you are right, Wind Turbine is the correct name.

To be entirely correct you still have to call them "wind turbines" in dutch when talking about the energy generating kind.

You have to, but everybody calls them 'windmolens'.

https://nl.wikipedia.org/wiki/Windmolen

I think that’s common in English, too. Checking various online sources, I couldn’t find one that’s strict on the narrower meaning. For example, https://en.wikipedia.org/wiki/Windmill says “the term is also extended to windpumps, wind turbines and other applications.”

On the other hand, I think windmills that pump water are called windmills, not watermills. Watermills always extract power from moving water (saw mills don’t extract power from saws, nor do gristmills extract it from grist, though)

The Kinderdijk mills (https://en.wikipedia.org/wiki/Kinderdijk) aren’t called water mills, for example.

True, you shouldn't. But I've heard farmers refer to their pumpers as 'watermills', which technically they aren't. In the end it doesn't really matter, people seem to find a way to understand each other even if their use of language is imprecise. A bit like the internet protocol guidelines. So it's important to at least try to use things properly and leave the fixup to the recipient in case the sender wasn't doing it perfect after all.

I think "mill" is an accepted term for a generic powered machine installation. Examples include sawmill, fulling mill, textile mill, steel mill, paper mill, etc... The first two at least date back to the medieval period.

In this particular case "windmill" also implies a certain aesthetic that fits the project quite well.

Technically, is he not milling electrons?

I don't think he is crushing electrons into their constituent parts.

May I suggest donating it to Engineers Without Borders? They can and will surely put it to good use generating electricity in an impoverished nation. A good friend of mine spent some months in Malawi building clean water infrastructure. EWB is a good charity.

That is an excellent suggestion. Can you put me in contact with someone there?

I'm Canadian so I only have EWB contacts here.

I'll reach out to you on Twitter

Thank you!

If curious see also

2012 https://news.ycombinator.com/item?id=4579932

2012 https://news.ycombinator.com/item?id=4584772

2015 https://news.ycombinator.com/item?id=10791461

I think the titles are important here

* "How to build a windmill"

* "How to Build a Windmill, Part 2: Parts, Nuts, Bolts and Blades"

* "How to build a windmill part 2: Parts, nuts, bolts and blades (2012)"

Upgrade experiment: https://www.scientificamerican.com/article/rooftop-wind-powe...

That would make a good topic by itself, especially if anyone could toss in expected results (e.g. like the calculations in https://en.wikipedia.org/wiki/Evaporative_cooler )

Would this work with water flows?

Well there's hydropower (gravity) or tidal power (celestial bodies). Otherwise I don't think water can be focused the way wind can.

So an inversed Dyson bladeless fan.

I am extremely interested (I live on a boat which I built myself [also here in NL!] and I'm trying to make it zero emissions) but sadly I think the rotor diameter of 5 meters is a bit big for me to handle. The weight of 85kg is no problem at all, but the large rotors would be tough to fit on the boat. Would it work with significantly smaller blades (say 1.5m diameter?) and some gearing? The blades are a work of art, so if someone can use the whole thing they'd of course be a better candidate than me.

Alternately, I noticed you built a half scale alternator - if you're looking for something to do with it, I'd love to build a wind turbine around that :)

I'd love to hear more about your boat!

Hi Owen, the alternator is closely matched to the blades, shortening the blades would mean it would no longer work except in hurricanes :)

The half scale one was already donated to someone while I was still in Canada.

This is the same person whose story, "Restoring and MIDI-fying a Baby Grand Piano" made the front page of HN a couple weeks back:

https://news.ycombinator.com/item?id=23562784

What an inspiring piece of work -- I wish I had somewhere I could use it!

Brings back memories of so many hours poring over https://www.goodreads.com/book/show/431651.Mother_Earth_News... as a young teen...

This was a wonderful project and I enjoyed reading your treatment both when you first published it and again now. A huge accomplishment.

Life is always changing and it is tricky letting go of precious things from the past so well done.

It's very kind to be passing this on to another hacker here and I hope it finds an appreciative new home.

I don't live in the Netherlands but I just wanted to say that it's a very inspiring project and also that it is a great thing of you to do that you are giving it away to someone else.

Upvoted and hoping it finds a good home :)

Great project! The wooden blades were really cool to see. How noisy does it get?

Not so bad until it runs at 500 RPM+ or furls, then it will make noise loud enough to hear clearly, because it will run coarse. Normal conditions you won't hear it at all. Those blades are pretty good.

Thank you! I hope the person who takes you up on your offer documents the new installation. I really appreciated reading about your process.

Aaaand now I want to build a wooden wind turbine.

Check out 'otherpower', the fieldlines community is very helpful:

https://www.fieldlines.com/

Why not a 3D printed one?

It's just fun to build things by hand. Woodworking requires a lot more skills, so there's always something new to learn. It also seems slightly more realistic to me to build a 35-foot tall structure using wood rather than a 3D printer (but I don't know 3D printers that well!)

What kinds of grains have you milled with it? Is the mill included?

I'm sure if you hook up a three phase motor to a bunch of stones that it will be happy to mill you some grain. Or crush your ochre or gemstones, saw your wood, pump your water, pulp paper or any of the uses that the windmills of old in this country were put to.

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