Renewable Energy Innovation has built a number of pedal generators for both adults and children. Pedal power helps to demonstrate the concepts of power and energy in an interesting way, along with helping to promote cycling and all things pedal related.
There are a number of pedal powered generator designs available:
- An amazing book for human powered devices, which includes a pedal generator plan, is 'The Human Powered Home' by Tamara Dean and published by NSP.
- The Campaign for Real Events have been involved with pedal power for a number of years now and their website has lots of details of various pedal powered generators:
- The Magnificent Revolution have done some great projects and have plans for bike generators on their website
- Bicycology also have plans for a pedal generator and their great energy trailer
This DIY guide explains one pedal generator design, based upon the Magnificent Revolution design and using a permanent magnet generator. The main concept was to find a relatively cheap design which does not require any welding and can be built with commonly available parts and tools. It is mainly built from relatively thick angle-section aluminium which is bolted together. This guide has been broken into two sections: the bike stand and the generator and electricals. The bike stand can be used for other designs such as a pedal powered smoothie maker….
The stand might not fit all bicycle frames, but it has worked on all the typical mountain and racer style bikes that I have used so far.
DISCLAIMER: These instructions are given as a guide for the competent pedal power enthusiast. The authors do not take any responsibility for damaged tools or any injury which may occur. Please stay safe when using power tools and do not experiment with electricity unless you are sure you know what you are doing. Consult a qualified person if you are unsure at any stage.
Step 1: Parts required
- 30mm x 30mm x 3mm (thick) L section angle aluminium (1¼” x 1¼” x 1/8”) – Use a thick grade (3mm or better). Steel could also be used (and is generally easier to find for free), but we had aluminium available and it is lightweight for carrying to events. (Try www.aluminiumwarehouse.co.uk).
- 25mm x 25mm (1” X 1”) box section steel – This is commonly used as old school table frames. Only a small length (50mm) is required.
- 6, 8 and 10mm nuts and bolts and spring washers – The main structure is held together with these. Stainless steel nuts and bolts along with locknuts, which should ensure they stay corrosion free and the bolts stay tight even with long-term vibration.
- 34 x 6mm 20mm long bolts with locknuts
- 4 x 8mm 25mm long bolts with spring washers and nuts
- 1 x 10mm 80mm long bolt with 3 x nuts and spring washer
- 1 x 6mm 100mm long bolt with butterfly nut
- Bike brake cables – These must be the thick ‘brake’ type cable (or use a number of gear cables to share the load) as it will be under quite a lot of strain. These do not need to be full length, so old broken ones can be used, as long as they have around 1m of useable cable.
- Plywood – Approx 150mm x 150mm and around 10mm thick.
- Hinge – An old door hinge will work well
- Roller – This can be made from aluminium –or from different things e.g. a roller-skate wheel.
- Thick elastic – Bungee cords or elastic for tent hoops will work
- A permanent magnet generator – Type MY1016 available from eBay. This is a 24V motor designed for use in an electric scooter. We will be rotating it so it will work as a generator. These are available from eBay at a cost of around £30-40 delivered.
- Diode – This must be rated for more than 20A and at 50V DC or higher.
- Electrical cable – Quite high currents can flow so use decent, thick (2.5mm2 as a minimum) multi-stranded (flexible) copper cable as the main power cables.
- Spade connectors or Heat-shrink and solder – to connect to the diode
- Heat-sink compound – to connect diode to the metal frame
- A bike – Any type will do. Best if it has slick tyres as the knobbles add to noise and heat. I use a low cross bar (woman’s) mountain bike with a road slick back tyre. This allows people to easily get on and off the generator.
Lots of the parts required can be found or are general bits that will be in most garages and sheds. My guesstimate costs for the parts if they were bought new are:
- Angle aluminium 3.5m £15
- Nuts, bolts and washers Around 50pcs £5
- Brake cables 2 £4
- Wood Small piece £0.50
- Elastic 2 elastic tent hoops £1.00
- Generator 1 £35
- Hinge 1 £1.00
- Diode 1 £4.00
- Wire 5m £5.00
- TOTAL COST: £70.50