Bringing women into technical education at times seems to be an insurmountable challenge. As a counter, a small drawing robot created by [MakersBox] might help. The robot was used in a ChickTech workshop for teen girls.
The goals for the robot were to have an easy to build, easy to program robot that did something interesting, and was also low-cost so the workshop participants could take it home and continue to learn. These requirements led [MakersBox] to the Adafruit Pro Trinket 3V, stepper motors for accuracy, and a 3d printed chassis to allow for customization.
Another version of the Arduino should work without any problems and even possibly a Raspberry Pi, suggests [MakersBox]. With the latter’s more diverse programming environment opening up a lot of possibilities
Drawing robots like this for education are not new. [Seymour Papert] created one of the first turtle robots, seen at the left, in the 1980s. He even created the Logo programming language and adapted it for use with the turtle. An interesting similarity between [MakersBox’s] and the original turtle is the drawing pen is in the center of both.
Loving to draw but deathly afraid of pen ink, [Marcel] came up with a little drawing machine made out of Lego that will do it for him. It’s not a very complicated build but it does have several different components arranged such to complete a task, and that in itself is cool. Oh yeah, just kidding about the “afraid of pen ink” thing.
RC Car Servos are used to drive the pen in the X and Y directions. These servos only have a 180 degree range of motion which is not enough to move the pen very far. To increase the pen’s travel distance, [Marcel] attached a large gear to the servo which rotates a much smaller gear that rides on a rack gear attached to the bed. A Lego hinge takes the place of a Z axis and is used to set the height of the pen that is strapped to the machine via rubber band.
In order to make the machine draw, the user moves an analog joystick. The changing resistance values of the joystick’s potentiometers are measured by an Arduino. The Arduino then moves each servo to the appropriate position using PWM. If you’d like to know how to do this, check out the Knob Tutorial.
Some of our more seniorexperienced readers may remember a toy called the Spirograph. In case you don’t, it’s a geometric shape drawing toy. The way it works is a plastic disc with gear teeth around the perimeter and various holes on its face is spun around a plastic ring with gear teeth on the inside. A pencil is inserted in one of the holes in the disc and, when spun around the inside of the ring, draws different complex shapes called hypotrochoids.
This was fun enough to keep a kid entertained for a few minutes. It took a while to make a complete shape and sometimes it was easy to mess up (especially if the hole chosen for the pencil was near the outside of the disc). [Darcy] thought it would be neat to combine the Spirograph’s drawing style with modern technology. The result is called the Art-O-Matic and it draws some pretty wild art, you guessed it, automatically.
Drawing is difficult for a lot of people… So, why not build a robot to do it for you? [Darcy] had an idea for a rather unique drawing robot — he calls it the Isoscel-Ease.
Instead of using a boring XY gantry, a deltabot, or using a scissor linkage (actually that one is pretty cool!), [Darcy] decided to try harnessing of the power of triangle geometry! As you can probably guess, the linkage forms an isosceles triangle, hence the name. A pair of stepper motors increases and decreases the odd side of the triangle, allowing for a full range of continuous inky movement (there’s no pen actuator) over the page.
It’s a very cool little drawing robot, and it was completely designed in SketchUp — He has lots of photos of the build process and example drawings on his site — But don’t forget to stick around after the break to see a video of it in action!