Actual claw on tindie.com fundraiser
I have a project running on tindie.com for a real claw machine kit.
Here is a video of the machine in action.
Emma after some practice-
Pick up and drop -
I like to document my work as I go along, so this instructable contains multiple versions with varying components. I think that this is useful because it seems unlickkly that you would happen to have all the same scrap peices as I do. I have also tried to show how to build a moderatly complex system by bulding one peice at a time and then combining them. By keeping things modular you are able to swap out large peices without having to rebuild the whole thing.
Here is a rough outline:
- Get each motor working by itself, I used a joystick with potentiameters to control the motors, one POT per motor
- Get all the motors working at once - by wiring all the motor drivers to the Arduino at once and combing the control codes, we are able to run everything at once. This same setup will be used l to control the whole machine.
- Build a small test rig with just one axis - It is easier to work on something that you can put on a bench top then it is to work with something mounted the ceiling. So I will show you how to cobble together a test set-up that will let us work out some of the details without having to build a large rig.
- Build a large rig - once everything is working on the test rig, we can go ahead and make it bigger. This required some different materials, but the wiring, code, and motor setup don't nned to change.
- Test and improve - Once the system is working it is easy to see things that can be improved. I wound up replacing the original joysticks with a larger controller from a kids game. The whole thing is pretty flexible so there is alot of room for modification and impruovemnt.
Most of the project is built with salvaged computer parts. Here is a list of parts that you could salvage or buy.
Power supply - I used a power supply salvaged from a server. There are good instructions for hacking one of these here http://reprap.org/bin/view/Main/PCPowerSupply I also pulled a 12volt power supply out of a printer that would have worked well.
Motors - At least 3 motors are needed. I used 2 DC motors and a pretty big stepper. The DC motors are both pulled from an Epson Printer/Scanner. The stepper is a NEM23 from Keling Technology. A smaller one would be fine. You can get one here http://www.sparkfun.com/commerce/product_info.php?products_id=9238.
Drivers - You can build, buy, or salvage drivers for the motors. Buying is the easiest and they are not two expensive. I used a steppper driver and the DC motor driver from the RepRap Gen2 electornics. The DC motor driver is here - DC Motor Driver v1.1 Kit http://store.makerbot.com/electronics/electronics-kits.html. Sparkfun as a good stepper driver here - http://www.sparkfun.com/commerce/product_info.php?products_id=9402
This motor sheild from Adafruit would work well - http://www.adafruit.com/index.php?main_page=product_info&cPath=34&products_id=81
Microcontroller - The Arduino platform is fun and easy to use. http://www.arduino.cc/ I used the
Arduino Duemilonove with a hefty screw sheild http://store.makerbot.com/electronics/electronics-kits/arduino-breakout-shield-v1-4-kit.html
Controller - I started with thumb joystick controllers like on a PS2 - but I found that a controller from Leap Frog Baby worked out better. http://www.amazon.com/LeapFrog-10210-LITTLE-LEAPS-PLATFORM/dp/B000EIV1OM
Claw - The claw is made from mouse shells and strips of plastics cut from a printer housing.
Wiring - Most of the wiring is discarded cat-5 network cable
Track - For the test rig I used wooden tracks, for the larger set up I used metal J-trim 1/2" x 10' - this was in the drywall section of home depot - it is the only thing I bought specifically for this project.