Alexander Weber has a nice build log on his drawbot called Mechpen, that is available on GitHub:
This is Mechpen, my newest drawbot.
The idea was to have a robot arm that could sketch on a rather large surface.
It is a SCARA (Selective Compliance Assembly Robot Arm) robot arm, meaning the robot has a shoulder and an elbow joint and a hand. Mechpen has a reach of 140 cm which means it could sketch up to A0 format.
We believe in helping people understand how the world works. With so much development going on in robotics at the moment, now is the perfect time to get to know what it takes to build your own robot. The MeArm Pi is an award winning robotic arm kit that’s simple enough for a child to assemble. It integrates directly with the Raspberry Pi you know and love and you can either control it directly using the on-board joysticks or by programming it from the Pi in your favourite programming language.
We’re used to projects that take everyday household objects and modify or enhance them into new and exciting forms that their original designers never intended. A particular theme in this endeavour comes from the IKEA hacking community, who take the products of the Swedish furniture store and use them for the basis of their work.
A quick search reveals IKEA hacks to be a regular feature here, we’ve brought you more than a few. Just a selection are an IKEA desk laser cutter from Craigslist finds, an IKEA table that has been used as the frame for a 3D printer, and a rather pretty IKEA lamp hack. The IKEA hacking community are a resourceful bunch, and we look forward to more of their creations.
Building a simple robot arm is a lot more straightforward than it used to be. If you have a laser cutter, or a bit of cash and don’t mind waiting for postage, there are inexpensive kits like the MeArm. If you have a 3D printer, there are any number of 3D-printed designs for you to tackle. What if you need to satisfy your urge to build a robot arm really quickly, and you don’t have a laser cutter or 3D printer? You’ve got a pile of servos from that remote-control project, how can you make the rest?
If you are [roboteurs], you raid the stationery cupboard, and create an arm using rubber bands, paper clips, and binder clips. The binder clips grip the servo arms and hold the whole thing together, the rubber bands provide extra attachment , and the paper clips are bent to form the jaws. It’s not the prettiest or perhaps the most capable of arms, but it undeniably is an arm, and we’d doubt it could be done any more cheaply.
In this particular case, the arm serves as a demonstration piece for [roboteurs]’ Printabots Maker Kit for people without a 3D printer. It uses their controller board, but there is no reason why it could not be used with any other board capable of driving servos.