Where I live, short power cuts are fairly frequent and can be very irritating. I have also wanted to experiment with CCTV for some time. After experimenting with test UPS systems using cheap inverters and old car batteries I decided to scale it up.
When homes have an alarm system installed it usually contains a backup battery in case of power failure. These batteries need to be replaced every few years to ensure the system performs correctly.
The waste batteries are usually sold to scrap dealers for their lead content, but alarm installers are usually happy to give/sell them to you for an incredibly low price. We have picked up 7AH batteries for less than 50p each.
The project was designed, tested and built by myself and Dom.

Check out the video:

A full how-to is availible at

I am proud to announce that he write up has been featured by the authors of Instructables on their homepage and has also made appearances on Hack A Day and Life Hacker. Gaining the project well over 10 thousand hits (not including hackaday)!

If you like the project please vote for us to win the Green Tech contest on (Vote button in header of page). Thanks!

Prusa Mendel RepRap 3D Printer

After having a interest in CNC machines for a while now, and playing around constructing things like my modified Cannon Pixma IP3000. I have decided to build a RepRap Mendel. This should be more successful than my previous CNC attempts as it uses widely available parts, and any special/custom parts i can download from and print on the RapMan 3.1 printer at college

I will post updates in the form of images of the build on my Flickr account

Great success! 3D printer is complete and working well: Flickr

Homing axis:

Time lapse of printing a “Footed Vertex”:

I was having troubles with my steppers jumping, i have now moved on to Sanguinololu electronics.
Trimming the current pots seem to help with jumping motor problems.

I have adapted several hot end designs in order to make parts as simple as possible to produce.


USB Robot *Instructables Robotics Week Winner*

We won! The prize is a “Robotics starter pack”. Will post the contents when i get it!
Update: The pack contained an Instructables badge and some stickers, 3 packs of “sugru” silicone putty and a copy of Autodesk SketchBook Pro! Thanks Instructables!
This instructible will describe the processes required to build a system for interfacing with a robot (and the basics of building a robot) around the velleman K8055 USB interface board (availible online or at maplins) The robot is built mostly from scraps i had at home and parts from a car breakers yard the whole project cost around £50 but will be much less if you have parts at home