Propose a final project that integrates the range of units covered in the FabAcademy.
My final project aims to fabricate Vertical Axis Wind Turbine that can produce enough power to charge some super capacitors, run my tachometer, and display my RPM count on an LCD.
The main inspiration is how to harness low-tech and digital fabrication technology to create sustainable energy solutions for off-grid systems and stand-alone devices.
Advancements in the field of microelectronics have not only miniaturised wireless devices but have also decreased their power requirement by an order of magnitude. This project aims at looking to ways we can power these devices sustainably by harnessing one of natures most ubiquitous and powerful forces: wind.
The heart of this project is the 3D printed generator. The main aim is that the the turbine generates enough power to run my fabduino, hall sensor tachometer and LCD.
The turbine will spin in the wind, turning mechanical energy into 3 phase AC current. This will then be rectified to DC using a diode bridge rectifier, and stored in a 8 parallel-arranged super capacitors. The tachometer will record the RPM and output that to the LCD, which which will be powered directly from the generator’s power output.
The end goal is to be able to test the efficiency of this turbine by testing various loads under various wind speeds.
Most of the FabAcademy projects I researched beforehand have covered one aspect or another of turbine designs, but none have experimented with the possibilities of 3D printed generators. Here below I mention a few that have inspired me.
Denis Chavarry Hernandez and his wind generator.
Jari attempted a Darrieus design using composites. This was perhaps the inspiration on why NOT to make composite wings, as getting the design, balance and precision right is very tricky.
But here are some of my other inspirations along the way:
I will design the wind turbine, the 3d printed generator, and all of the electronics components except the PFM DC-DC step up module. This will involve various fabrication processes, mainly CNC machining, laser-cutting, 3D printing, electronics design and composites.
The 3D printed generator will be printed in PLA material. The rotor houses 10x10x30mm neodymium magnets, and sits within a stator that is wound with 3x100 turn phases 0.2mm (30 AWG) insulated copper wire. We had this readily available in the lab. It turns on a 12mm diameter precision steel axis which was recycled from an old 3D printer.
To house this I CNC milled a base using 15 mm plywood. For my wing vanes I used 5mm acrylic (not ideal) sandwiched together with a 3D printed “twister” and shaft collar to hold it all together.
For the actual wings/blades I prototyped using a cheap and easy to lasercut polyurethane sheet, but then decided on aluminium flashing as a more durable solution. I also had to cut this by hand as it was to hard for the lasercutter.
To integrate it all I made a composite out of brulap and milling a foam mold to create 4 composites which will provide the housing.
I intend to find and use as many of the materials available in the FabLab and Fabricate as many of the parts as possible using the weeks and methods we have covered in the FabAcademy.
As you can see from my Final Project page, many of the essential components we scavenged or up-cycled from within the lab. One of my primary inspirations in making this project is to show that we can use natural, readily-available, and recycled materials to generate sustainable power.
The only exception are the wing blades and possibly the step up converter, and the Lipo batteries.
All of these materials bar the step-up module, the aluminium flashing and my bearings were scavenged and up-cycled in the lab.
This project has been made 100% in the FabLab. The only components for lack of time I was unable to fabricate were the step-up converter for my charge control system. With more time however, this is a relatively straight forward electronic component to make. Here is a list of what was fabricated:
I am a journalist by training and so have zero background in wind energy, engineering, or power electronics. Trial and error has been my approach from the start. Learning by doing. Far from attempting to make any highly efficient, kilowatt generating turbine, this has been an investigation (and crash course) in how to generate small-scale renewable power in a FabLab.
I have attempted to incorporate various aspects of 2D/3D design and digital fabrication in this project. As much as feasibly possible have been sourced and made in the lab.
My idea for success for this project is being able to generate enough power to run the tachometer PCB circuit and LCD output. It more of a proof of concept that can then be scaled or improved. My other ambition for this project is that it remain free and open source for others to pick up, improve and grow.
I have been busy prototyping this project using as many of the FabAcademy weeks as possible as I go along. Right now for the last two weeks these are the final tasks I have left to complete: