Introduction: Windmill / Electric Generator
Disclaimer: This windmill generator will not facilitate off grid living. Tests show that it's about as powerful as 1 x AA battery (since completion there hasn't been a breath of wind to test it properly).
Double Disclaimer: I work in the financial services industry so have no formal knowledge/learning with regard to anything in this tutorial, everything I know I learned from YouTube.
This was a 'father son' / 'COVID-19 lockdown' / 'home schooling' project covering building stuff, windmills (it's my son's school logo) and sustainable energy.
Supplies
Scraps and things I had laying around (the only purchase was the lazy Susan bearing which cost ~£4):
- Wood off-cuts of various sizes
- 1 x 12mm threaded bar
- 2 x M12 nuts
- 2 x Locking washers
- Dowel
- Old cordless drill
- Corrugated plastic sheeting
- 2 x Pillow block bearings
- 1 x T Nuts
- Wooden cable drum
- Lazy Susan bearing
- 2 x Overlap cladding panels
- Cable ties
- Roof felt
- Screws of various sizes
- OSB board
Step 1: Constructing the Blades
- Squared off a bit of 2" by 3"
- Drilled 15mm holes through the center for the axle and 2 more holes on each side, off set so that the sales would be at an angle in order to catch the wind
- Threaded the axle and secured with a T nut and locking nuts
- Dismantled an old baby gate in order to salvage the dowel
- Glued a dowel into each hole
- It was way to big so we had to shorten each blade by half and fix a bit of wood at each end to secure in place
Step 2: Adding the Sales
- I had a sheet of corrugated plastic that some roofing sheets came packaged in which we marked out some oblongs that would wrap around each blade
- We cut out the 4 oblongs
- We drilled some holes that will be used to tie the sales to the blades
- Bent each one around and secured with small cable ties
Step 3: Creating the Body
- I had an old wooden cable drum sitting around which I squared off for the base
- We drilled a 20mm hole in an off-cut of 2" by 4" and affixed a pillow block bearing each side to allow the axle to spin freely
- This was the fixed securely to some OSB board
- I'd ordered a bearing for a lazy Susan (my only purchase for this project) and used it to join the base to the axle holder, this would allow the top section with the sales to rotate in order to catch the wind as it changes direction
- We threaded the axle and then using an angle grinder smoothed the end of it off so that it would fit to the "generator"
- Using some old over lap cladding we clad the base (for aesthetics and weather proofing)
Step 4: Adding the Roof
- With various off-cuts we fashioned a roof that would keep rain off the "generator"
- Then we covered with a bit of old roofing felt for additional resistance to the elements
Step 5: The Generator
- A generator (in it's simplest form) can be created by energy being passed through a DC motor in the opposite direction.
- We took and old cordless drill apart and salvaged the motor
- By switching the wires from the positive and negative terminals around it put the motor in reverse it would allow a clockwise rotation to generate a positive current
- A very rudimentary supporting block was fashioned to hold the motor in place, fixed to the base and the chuck tightened onto the axle.
- The motor was then cable tied to supporting block (using a bit of bubble wrap for cushioning)
- With the drill motor set to the least resistance (to allow the sails to rotate more freely) a test of us spinning the blades gave us an output of 1.52 volts... SUCCESS!
Step 6: Ready for Testing
I creosoted the structure as this will be living outside in the garden.
Once we have windy day we will test this in anger. By switching the drill motor to a setting with greater resistance we will be able to generate more voltage however there is a chance that the resistance will be to great and the sails may not turn.
Watch this space for a video of the first test...

Participated in the
Scraps Speed Challenge
21 Comments
1 year ago
I have 6 sons / 2 daughters... and we have "experimented" on many projects over the years. You mentioned having this in your garden... why not make it a power station for a little outdoor light?
Since (as experienced) you have had "little" wind (always the way that happens!) - maybe grab some of those Dollar Store solar lights - (which have a rechargeable battery inside) and connect both the mini solar panel and the wind turbine power - to charge the battery. Those lights also have light sensors so it only turns on when dark. Voila - light up the garden - naturally!
3 years ago
That is NOT a "windmill" because you are not milling wind! The official definition is a wind powered turbine, and with a generator it is called a wind powered turbine generator.
Reply 3 years ago
Althogh completely 100% right on the nomenclature....could you be a bigger stick in the mudd? WHAT WHAT, mudd only has one 'd'? ;-)
Reply 3 years ago
You are technically correct, but his usage of "windmill" is also correct. "Windmill" is a generic term used to describe structures which use wind power to perform work. The term "wind-powered turbine generator" is a more precise technical designation used to communicate specific information about the components, method, and purpose of the device. I've included a screenshot of Mirriam Webster's definition of "windmill" for reference. Even in the middle ages, the technical designation for structures that used the wind to mill grain was "gristmill," yet they were generically called "windmills."
Reply 3 years ago
@Raymond It is: https://www.dictionary.com/browse/windmill?s=t
Question 3 years ago on Step 6
do you how many volts it makes?
Answer 3 years ago
On a very windy day I managed to get just over 1 volt out of it, however i think this was due to the torque on the old drill bit mechanism that was slowing it down
Reply 3 years ago
Ok
Reply 3 years ago
Ok thanks👍😀
3 years ago
love the idea
3 years ago on Step 6
That is innovative. And nice to see a Dad and Son working together. It will be a memory that he will treasure. Well done.
3 years ago
Great project for teaching the principle. One problem is that the drill you are using is a universal motor with no internal magnets. A a result, it will NOT generate electricity at any speed.
You need a real DC motor with internal field magnets to make electricity. If you insist on a universal motor you wlll need to apply a current to the field winding to make it produce electricity. The universal motor is usually series wound and does not lend itself well to convert to a generator.
Perhaps you can use this exercise as a "Back to the Drawing board" moment.
The ancient DC generators that were in cars used a regulated voltage to energize the field winding. There is a lot of things going on here. With a fixed field current or fixed magnets, the output voltage is is a function of speed. However, if one can vary the field current, they can control the voltage output for a given speed. Get this into you child's head, and you will wind up with an engineer.
Good luck
Bill
Reply 3 years ago
I'm sorry, but this is DC motor with magnets that can be used as a generator. hc683lg motor
Reply 3 years ago
I am sorry but you are wrong. This gentleman is using a DC motor from a cordless drill and this motor does have permanent magnets for a field. I work with these units and have played with them as generators.
3 years ago
Insert one nail in each potato. Insert one short piece of the copper wire into each potato as far away from the nail as possible. Use one alligator clip to connect the copper wire in potato number one to the positive (+) terminal in the clock's battery compartment.
Potato Battery | Clock | Science Fair Project | Energy ...
3 years ago
Let me join with those who commend your efforts regardless the results.
Not having a 'dad' can really screw with a lad's life and having one who will actively participate with his child - well thanks for sharing. Hopefully, you can reassemble the drill and replace it with an appropriate DC Motor
https://www.hbarsci.com/products/ph1229?cmp_id=863318396&adg_id=40375198221&kwd=&device=c&gclid=CjwKCAjwqJ_1BRBZEiwAv73uwPArJ-v0YK8yK662wceq1-z7_hoIwov8BndMPMyqSW3QEDyKzlL6VRoCvAYQAvD_BwE
https://www.youtube.com/watch?v=vGw-SYNoMPc
https://www.youtube.com/watch?v=e3opKUYfL0Y
https://itstillworks.com/good-motors-wind-turbine-7581085.html
Hope these links help!
You can emphasis the importance of RESEARCH as part of the lessons!
Did you know that, if you shake the Orange Juice carton crazy fast and long enough, you can pour a frothy top? If you make him breakfast, you can make him 'Shook Juice.' It also works with milk. Kids get a kicj out of watching a parent violently shake the carton. Enjoy this time with them as it is fleeting as well as wonderous.
3 years ago
You're a great dad! Your son is going to remember working with you on this project for the rest of his life. I still cherish my memories of doing projects with my dad when I was a child. Great post!
3 years ago
Great project. Way to show your son how to be fearless in making. I especially like the blade construction technique. I'm sure you will have time to make another project or two before this is over. Thanks for posting.
3 years ago
A great project, probably something your son will remember doing when he looks back in many years to come. Well done.
3 years ago
What kind of power do you get from it? I have played with diy wind generators and so far the power has been low. Looks like a fun project though :)