Dear Gravity Light contributors and supporters,
Just as the sun has finally come back to London, Martin and Jim have emerged from months in the workshop where they have been further refining and testing Gravity Light. They have now finalized the design that will be used for our global trial and, of course, be sent to those of you who requested one in your pledges.
Specifically, Gravity Light is now even more robust – ensuring it can cope with overloading and rough handling. We have also been through a process of virtual modelling, in parallel to the extensive physical testing, which has led us to refine the gear geometry and redefine the specific formulation of plastics, so we now have a low cost solution that we are confident meets our targets for strength. Given it will be put through it’s paces in a variety of different environments, this will help ensure it lasts as long as possible!
Several ways to improve the quality of the light have been explored. We now have the ability to provide a wider range of power and duration adjustment, and we have further increased efficiency. We felt that the range should be extended so that we can understand from the trial what is essential, what is most useful, and if other applications for the power can be found.
The insight from Martin’s personal holiday to Sri Lanka fed into our exploration of useful peripheral devices that could be attached to Gravity Light. We plan to get feedback during our trials on which are the most useful.
We now have the exciting – and long – route to producing our first batch! This entails completing the tooling, testing samples, ironing out any issues with the production process, getting final samples and then – when we’re happy the quality is right – it’s full speed production. Providing no glitches, this takes us to the end of the summer when we’ll start shipping the units around the world.
Thank you for your patience. As we mentioned, your overwhelming support enabled us to make an even better and more efficient model.
It’s incredibly exciting to see how many people think GravityLight would be a great solution in their countries and communities. We’ve also been honoured to receive recognition as a World top 10 most innovative companies in energy by FastCompany, to win the 2013 Invention Award from Popular Science and to be nominated for the Index: Design to Improve Life Award.
For previous updates: www.deciwatt.org/updates
Martin and Mary Riddiford visited Nawala School on 19th February 2013, where 20% of pupils’ homes have no electricity and kerosene lamps are used for lighting.
(Below are some excerpts of the full report which you can find over at www.deciwatt.org/updates)
Newton, Matthew and the Headmaster had arranged visits to 3 of these homes, and to meet the families.
Martin reported "I brought a GravityLight prototype to Sri Lanka to get first hand feedback and reaction to it as a replacement for kerosene lamps. In particular I wanted to get insights on how & where it might be fitted, the ease of finding suitable material to fill the weight bags, and whether its use pattern would be acceptable.
First we had a demonstration of a typical kerosene lamp, which usually consists of an old medicine bottle, and a metal lid pierced with a hole for the home-made wick made from a strip of cloth. Filling it involved lots of spillage.
Typical usage was reported to be 3 kerosene lights, one kept alight throughout the night. This level of usage costs about 500 Rupees (~US$4) per month. This is a significant amount of money for these families.
The intention is that the basic, lowest cost GravityLight will have a built in LED light, for general illumination. It has screw terminals which enable a wire to be connected with several additional LED lights along its length for additional ambient lighting, at the end of which is a more powerful light to be used as a task light, which can be hung over a table, or pointed like a torch. Although the light level is still low, it is far better than the kerosene lights it seeks to replace. This should enable the family to do more in the evening – including reading and learning! This set-up should be able to replace the 3 lamps which are currently used. We are researching whether GravityLight can provide a very low level night light too.
We are planning on completing the design and development by April, and hope to be manufacturing the first trial batch in the summer. We will be gifting units to organisations, including Extra Cover, around the developing world to get feedback from real life use and abuse before committing to full scale production.
More detailed updates will be posted regularly at www.deciwatt.org/updates.
Martin Riddiford in Sri Lanka
We’ve taken the opportunity to draw breath as our current manufacturing partner has taken leave for Chinese New Year.
As the campaign was running so successfully we accelerated our programme and worked hard over the Christmas and new year period to issue revised data for a new iteration of development plastic parts.
We now have these parts and are currently testing under extreme loads to help understand points of failure in the mechanism. We have included some pictures below to illustrate this process. To help keep the manufacturing cost as low as possible we are using plastic rather than metal gears so it’s vital that we rigorously test this aspect.
The additional funds raised through your fantastic support for the campaign has allowed us to further refine and test functionality ahead of trial. This means we are ironing out some of the issues we had thought we would have to address during the trial programme. So the good news is the trial units can be more representative of the product that we aim to finally bring to market.
It does mean that we are having to revise our schedule and it looks like we will slip the original expectation possibly by a couple of months. We want the lights to be as good as possible for this trial, and the additional R&D progress we are making will benefit the much larger production build we are now undertaking. We felt that all who await their own GravityLight would understand this and, hopefully agree.
We will post a more accurate schedule soon and of course will continue to provide updates on our general progress. One key aspect of which is identifying the candidates who will support the trial programme by distributing, controlling and feeding back the research on users’ experiences.
To see more development images and keep up to date, visit www.deciwatt.org/updates.html
All the best,
Static load test on moulded gears.
Wow. After 40 amazing days the campaign has now closed. We want to extend our heartfelt thanks to all of you who have helped us. Rather than using our time to individually respond to all your inspiring comments, we’ve been getting on with the main job in hand. No offence.
We are working flat out to complete the production specification and already have the second tranche of tooling underway with our supplier in China. We hope to minimise any delay caused by the imminent Chinese New Year holiday and will be sending separate updates on progress in a few weeks.
You can also visit http://deciwatt.org where we will be making regular updates.
We have been extremely busy responding to all the amazing comments, questions and requests-for-information from all four corners of the earth. The response has been wonderful, if you want to know more about the project and how we will use the funds visit http://deciwatt.org/
As we are soon to hit the holiday period we want to extend our warmest regards to all contributors and wish the very best for 2013.
Happy Holidays/Merry Christmas,