As a result of microcontrollers are so low-cost, plentiful, and versatile, electrical engineers have a tendency to make use of them even when easier ICs and even discrete elements might do the identical job. Mechanical engineers typically fall into an analogous entice and use motors once they might accomplish their purpose utilizing intelligent linkages. If we glance to the previous, engineers didn’t have the luxurious of taking these shortcuts and that pressured them to give you ingenious electromechanical options. Redditor DaveMakesStuffBC took some classes from historical past and utilized them to this 3D-printed mechanical 2D pen plotter.
This system doesn’t comprise any digital elements. It’s purely mechanical, however is able to drawing shapes like stars and determine eights. The consumer cranks a small wheel and the mechanism follows a preset path, transferring a pen alongside the best way. To vary the form, the consumer can swap out the wheel. Theoretically, customers might fabricate as many wheels as they like. With sufficient of them, they might write out the complete alphabet, each quantity, each punctuation mark, and even fairly a couple of of the extra fundamental emojis. The scale of the wheel limits the entire size of all of a form’s line segments, in addition to its width and top, however alphanumeric characters are, by design, easy sufficient for this mechanism to deal with.
The mechanism on the coronary heart of this 3D-printed system follows the identical precept as machining cams, which enabled automation earlier than numerical management (NC) after which pc numerical management (CNC) got here alongside. The wheel has two profiles projected round its circumference, with the primary controlling the X axis and the second controlling the Y axis. It’s a bit just like the groove in a document participant, however oriented in order that it might information each axes. An arm rides within the profile groove and holds the pen. It slides by a gap in a slider, which offers assist within the Z axis whereas permitting totally free motion within the X and Y axes.
The most important problem was translating a 2D form into the revolved profile of the cam wheel. DaveMakesStuffBC did the CAD (Laptop-Aided Design) work in Onshape, however didn’t present element on his methodology for producing the cam wheel geometry. One might accomplish that by trial and error, however there are additionally quite a lot of extra direct approaches. In the event you simply wish to print the elements DaveMakesStuffBC already designed, they’re accessible right here.
