Crumble Junk-Eggbot
In a previous post, I discussed being lucky enough to have a session accepted at Mozilla Festival #Mozfest https://medium.com/@scottturneruon/the-junk-robots-are-coming-1801db867b7
Here are the materials from the session.
Inspiration
It was discussed briefly in the previous post but there were three inspirations for this session:
· Femi Owolade supported by Nic Hughes ran a session at Mozilla Festival 2016 using the Crumble’s to make a wheeled robot.
· The junkbot project https://junkbots.blogspot.co.uk/
The Kit
· Kinder Egg (without the Chocolate and toy)
· Crumble
· 4x Crocodile clips and leads
· Battery pack and 3xAA
· Tape (lots of)
. Sticky-tack of some form.
· Pens
· Paper
· Scissors
· Glue and Glue gun (optional)
Stage 1: Fix the vibrating motor into the Egg.
Put the vibrating motor into the Egg with the motor electrical connections sticking out the bottom larger half of the egg. Make sure the unbalanced load is free to move — this is a bit that causes the vibrations needed to move the egg. The motor can be held in place by sticky-tack or strong tape, or glue (when using glue this is done under adult supervision only). Sticky-tack (avoiding tradenames) works well if you use it pack around the motor — avoiding though, jamming the motor.
Stage 2: Sticking the pens on.
This is the trickiest bit. The easiest way to do is to cut a strip of tape. Place two pens onto the tape ensuring the pens are the same length from the tape to the nib and the distance between the pens on the tape are far enough apart to place the egg between them. A fantastic idea, that came up during the session from one of the participants (thank you Alan O’Donohoe for that) was to use some bits of the sticky-tack to position the pens before tapping them in place.
If you are using three pens, the third pen should be placed so that all three form a triangle with equal sides, that means the egg can stand-up on a piece of paper on the pen nibs, without anything supporting it.
If you are using four pens, the other two pens should be placed so that all four form a square with equal sides, that means the egg can stand-up on a piece of paper on the pen nibs, without anything supporting it.
Stage 3: Add the battery pack and go.
Using two wires connecting the battery, to the motors. Remove the nibs and set the bot off. It is hopefully vibrating and shaking and scribbling lines on the paper.
To see one in action go to:
Stage 4: Crumble
The junk-based eggbot is built, but it moves a little chaotically. So to give a bit of control a Crumble Controller from Redfern Electronics is add. This is a relatively cheap device that allows easy programming of up to two small motors and some sensors. This project only uses one motor but adapting it for two is an interesting idea.
Disconnect the battery connection (the connections on the motor can stay as they are). Connect the USB cable to the Crumble. To the right of the USB connection, there are two connections marked + and -. Connect Red wire to the + connection and the other end to the red wire of the battery pack. Connect a black wire to the — connection and the other end to the black wire of the battery pack.
Stage 5: Connect the Egg!
On the Crumble, on the right-side, there are two motor connections connect the Motor to these connections. Don’t worry about which of the motors wires is need you to swap them around later.
Stage 6: Programming it — Making the bot moves.
The software can be found at https://redfernelectronics.co.uk/crumble-software/ it includes how to set it up on your machine.
Start the Crumble software. Drag from the left the Program start, motor, and wait for blocks. Now join the up start block at the top and the motor block next and the wait block last.
Your code should look like this.
Click on the stop within the motor block. It should change to forward. Now you are ready to make it move. Press the green arrow and with the battery pack on, it should (hopefully) keep moving.
If you put a second motor block after the wait block with the stop in the block. It such then stop after 1 second of moving.
Stage 7: Making it do more.
- Drag a do-until block in (found in the control menu).
- Go to variable menu and add a new variable, I have used t, select the block marked let=, and drag it into the blank space.
- Drag an increasing block onto the screen and drag it into the blank space.
Go to the operator menu and drag onto the screen a = block, go back to variables menu and drag at into the first space on the = block and click on the second space on the block and type in 5.
Now for the challenge put all these together to copy what is shown below. Now, put the egg-bot on the paper, with the pen lids off, press the green triangle and the motors should be spun in different directions.
This is a junkbot so it may just cause the bot to move in a slightly different direction but hopefully, it should just draw some squiggly lines.
Crumble Junk Eggbot in action
