We’ve never seen someone build a plotter out of buzzwords, but [roxen] did a really good job of it. The idea is simple, place the plotter over a sheet of paper, open a website, draw, and watch the plotter go. Check out the video below the break.
The user draws in an HTML5 Canvas object which is read by a Java Web Server. From there it gets converted to serial commands for an Arduino which controls the steppers with two EasyDrivers.
The build itself is really nice. It perfectly meets the mechanical requirements of a pen plotter without a lot of fluff. The overall frame is T-shaped, for the x- and y-axis. The movements are produced by two steppers and acetal rack and pinion sets. The pen is lifted up and down by a hobby servo.
We like the use of rubber end caps to hold the frame fixed with friction against the table and a single ball bearing to to contact the table in the direction of its movement. This has the added benefit of being a 3-point contact that automatically squares the assembly to the same plane the paper is in. Any twisting of the frame will have little effect on its drawing ability since it’s end-effector is a ballpoint pen.
We really enjoyed this project, and think it would be fun to play around with. You could hack it to take text input, and output the handwriting you would have if you were replaced by a unconvincing robot copy of yourself.
Thanks for the tip [Daniel R.]!
Not a hack, there isn’t any 3D printing involved
I’ve never used gear rod before. What’s the common way to affix it to whatever you’re building?
Most commonly, there are holes through the side of the rack that let you attach it without disturbing the tooth profile. Sometimes there is a counter bored or counter-sunk hole in the middle of it for a fastener.
I thing better performance can be achieved using accelstepper library.
The opposite would be fun also. Drawing with the pen on the paper, and getting the image also on screen.
this is called a camera
Or a digitizer pad :)
Why is the drawing choppy? Poor stepper resolution?