Nifty cam-following plotter can draw many shapes
December thirtieth, 2022—
Earlier than CNC (laptop numerical management) got here alongside, automated machines utilized mechanisms like cams and tapers to behave as guides. These are bodily elements with exact contours meant to information the software, like an artist tracing traces with a pantograph. Such mechanisms are unusual at present, as CNC is way extra versatile and far simpler to implement. However Mr Revolutionary turned to these conventional methods to construct this cam-following plotter that may draw many shapes.
A “cam” is a rotating or pivoting part in a mechanism, which has an irregular profile to manage the actuation of one thing. Inside combustion engines, for instance, typically include rotating cams that to open and shut the valves on the correct occasions. On this case, the plotter’s cam controls the motion of the pen within the X axis. Wider parts of the cam push the pen additional proper, whereas narrower parts of the cam permit the pen to maneuver left. A rubber band pulls the pen arm cam follower tight in opposition to a cam. The paper strikes at a continuing fee within the Y axis, and its velocity mixed with the form of the cam decide the ensuing plot form.
This machine will look acquainted to these of you who’ve seen a Mr Revolutionary mission prior to now. It makes use of an Arduino Nano board paired with Mr Revolutionary’s personal driver board design to manage the 2 motors. One stepper motor controls the rotation of the cam and a second stepper motor controls the paper feed. The person can set the variety of cam rotations utilizing a Nextion touchscreen LCD panel. Mr Revolutionary 3D-printed the mechanical elements and mounted them to a small sheet of wooden, with a typical linear rail and bearing proscribing the motion of the pen arm to the X axis. It could’t draw any form, however this machine is kind of versatile and might produce fairly a number of attention-grabbing plots.