Teaser : The angle samples will probably be shipped soon, and are expected to arrive around the beginning of February, so IRL making will start happening then.
Basically, it is a small robot, suspended by strings, that rolls the strings to move, and doing so, draw ( on a wall ).
It is still at the draft stage, but the main ideas are here.
Main eccentricities of this design :
- Uses belt and pulleys instead of strings. More expensive, but more reliable and precise.
- Has motors on-board, adds weight, makes it less giggly.
- Will use software calculation to maintain the robot aligned with the horizon.
To get an idea of how it works here is a picture of the back ( part that faces the wall ) :
Basically, the motors turn the pulleys, the pulleys push/pull the belt, and that makes the robot move. As simple as that. You actually need cosine things in the software to have Cartesian coordinates/movement, that's probably the most difficult part of the project.
At the top you can see the pen, attached to a servo. The servo is for not-drawing when not necessary, or even for controlling depth if you use a brush, or brush-pen.
Not featured here, the contact between the robot and the wall ( other than the pen ) will be handled by roller balls.
A picture of the top :
You can see the motors, arduino and servo. Missing are the arduino shield with pololu drivers on it.
Design challenges :
- Figure out if this can work
- Design a contrapteur part for the roller balls
- Find how to attach the servo to contrapteur … maybe via a lasercut part.
- Find how to attach the pen to the servo. Lasercut or 3D printed part. Or something dirty at first.
- The software is the real challenge. Must understand Gcode, like the mini-cnc, but moves nothing like it.
Apart from that it all seems fairly easy.
I'll continue to refine the design, and when the contrapteur sample parts arrive, assemble it and test it … it should be a quick build.
Note : This took 15 minutes to design, contraptor really rules !
Should be easy to do in ( inch ) contraptor too.