I want to build an arduino robot using the cheapest possible components.

December 1, 2014 12:06 PM

The robot will consist of a mobile platform with various sensors attached, and a robotic arm. It will need to be capable of moving around a room and picking up small objects. I've been looking at kits like this on various Chinese websites but it is difficult to know if they are capable of supporting a robotic arm. Have you ever done anything like this? Can you reccomend a platform and an arm that will work well together?
posted by night_train to Sports, Hobbies, & Recreation (4 answers total)

Best answer: You might have more fun with the Lego Mindstorms platform.

http://www.lego.com/en-us/mindstorms/build-a-robot/gripp3r

Rest assured, Mindstorms is not just a kids toy. There are hacks such as NQC that let you program Lego Mindstorms in C:

http://bricxcc.sourceforge.net/nqc/

If that doesn't convince you, I'd look into servo motors. Arduino has servo.h to make it all easier for you. And you'll find Instructables on how to make your own servo grip:

http://www.instructables.com/id/Single-Servo-Robotic-Gripper/
posted by hz37 at 12:30 PM on December 1, 2014

How heavy are the objects you want to pick up? You basically want to make sure the whole thing won't fall over. The nature of lever arms means that you need torque at every joint, and the more torque you need the more costly it gets. This means that even cheap arms are rather expensive, considering their limited capabilities.
posted by Standard Orange at 11:57 PM on December 1, 2014

Best answer: +1 on Lego Mindstorms (EV3 or NXT) unless you have a very good reason to want to avoid it. It will give you the technology and parts you need to build almost any type of gripper arm and robot base. Plus you have dozens of books on Lego robot building and tens of thousands of websites with fan-designed robots (my own included :) to use as a base to work from.

Small correction hz37: NQC is very old now and is targeted at the Lego RCX from over a decade ago. If you buy a Lego Mindstorms NXT you'll want NXC (which also works with the new EV3). Or if you are on a Windows platform you can use RobotC. For platform independence you can run Java (leJOS) or indeed go all-in and boot off a pure Linux distro to run Python, Lua, Go (ev3dev).

If you are locked into the Arduino platform you can still use Lego parts. Dexter Industries sell shields that can adapt an Arduino board to the standard Lego footprint and come with H-bridges for motor control etc. Take a look here. Mindsensors has similar shields available here.

Standard Orange makes a good point; engineering a mobile robot platform that can navigate an internal space, locate an object, orient a gripper arm to the object, pick it up and move it to another point is a Non Trivial task. For highly constrained environments you can solve this using waypoints, markers or beacons. You also need to build an arm that won't topple over the entire robot.

Good luck!
posted by Not on your nellie at 6:30 AM on December 2, 2014

Response by poster: Thanky you all for your answers. The Lego looks amazing but is a bit expensieve for me at the moment. I may go with a cheap arduino set up and then move the the Lego if my ideas prove to be up to scratch.
posted by night_train at 11:15 AM on December 2, 2014