Skip to main content

How to build junkbots: Drinks can, unbalanced motor

The junkbots project has now being running for 18 months in Northamptonshire, UK. But how have the junkbots being built? A video produced by one of the particpants can be found here, showing some of the examples.

Several ways have been investigated by the participants in the next few blogs some of these will be talked about.

Let's start with the main approach, simplest way and probably the quickest:- A drink can and an unbalanced motor - shaking its way around.

Take a 330ml drinks can and put it on its side. Fix an electric motor over one end of the can, packing tape is good for this (but not very environmentally friendly). Attach something to the motor's spindle that unbalances the motor, the goal is to get it vibrating. Broken propellers, cogs with Blu-tak, cogs with modelling clay have all being tried.

The problem with this, is turn the motor on and the junkbots rolls over onto it side and goes around in circles. A couple of fixes students have tried, adding outriggers at the bottom of the robots (marker pens are pretty good for this). The other main way been tried is 'legs'; straws, ice-lolly sticks taped to the side.

The vibration makes the junkbot move but it is not controllable. A modification tried by one group of students has the tank-track principle. Add two unbalanced motors and by using one or both motors at any time there is a lot more controllability added.

A feature of a lot of the junkbots  that slowed them down is too much weight (unlike the one shown above - minus the can), in many cases lots of extra decoration was added to the junkbots that lead to slower junkbots (or in some cases stationary junkbots).

Comments

Popular posts from this blog

junkbots 3 - bring it all together

Junkbots session 3: Move the robot but now there are rocks in the way.  This is the last of three posts - Introduction and sequence - Loops and just having fun - This one: Making decisions and bringing it all together. What is the Junkbots project The Junkbots project has been running for a number of years as an initiative to bring sustainability, computing and engineering together by building bots out of junk; details of the project can be found at.  https://junkbots.blogspot.com/  . Junkbots is an extension of the Research into the teaching problem-solving going on at the University of Northampton please feel to visit  https://computingnorthampton.blogspot.com/2019/01/problem-solving-research-outputs-and.html  for more details.   What are we going to do? ·         Play with a Scratch robot on the screen! ·         Build on the routines from the previous session. ·    ...

Junkbot Raspberry Pi: 2 Raspberry Pi Junkbot in action

First video of a junkbot being controlled by a Raspberry Pi. The bot was developed by Hayden Tetley and Scott Turner. Hayden's time was paid  for through the Nuffield Research Placements  Scheme ( http://www.nuffieldfoundation.org/nuffield-research-placements ). Next post will provide further details on how this was done. If you would like to know more about the Junkbots project contact scott.turner@northampton.ac.uk

Junkbot Raspberry Pi: 1 ScratchGPIO

A development I have being wanting to develop for a while is the combine the Raspberry Pi with a Junkbot to add some control.  This the first of postings about these experiments. All the development will be around ScratchGPIO ( http://cymplecy.wordpress.com/scratchgpio/ ) so this posting will look into its use . Why ScratchGPIO? Short answer - simplicity. It is designed to look and work like Scratch ( http://scratch.mit.edu/ ) but allowing access to board that can drive motors. Installing ScratchGPIO? As a suggest use as lastest as possible version of the operating system as you can on your SD card. Initially we had trouble with missing Python files that was resolved when using an updated version of the operating system. In the LXTerminal Type in: sudo wget http://goo.gl/Pthh62 -O isgh5.sh then type in sudo bash isgh5.sh You should get to new icons for ScratchGPIO5 and ScratchGPIO5Plus Now use these instead of the Scratch that came with the operating...