My eyes weren't cooperating with the illustration from the Theory section, animated it here (author is free to use of course) - <a href="https://imgur.com/a/hVYWBB2" rel="nofollow">https://imgur.com/a/hVYWBB2</a><p>(note that i reverse a few frames in the loop to be less jarring visually, the current is probably not correct when the puck is moving left)
This is <i>incredibly</i> cool. The research video showing the little "robots" placing drops of glue to assemble carbon fibers is AWESOME! I haven't been this excited by an internet video in months.<p>My immediate thought: how could this be used to make a really cheap desktop pick-and-place system?
Pedantic: this isn't a stepping motor, it's just a plain linear motor.<p>Stepper motors have multiple teeth per pole: <a href="https://en.wikipedia.org/wiki/Stepper_motor#/media/File:Stepper_motor.jpg" rel="nofollow">https://en.wikipedia.org/wiki/Stepper_motor#/media/File:Step...</a><p>The rotor has slightly fewer teeth than the stator, such that one "electrical rotation" (each coil being switched on in sequence) causes the rotor to advance by the number of missing teeth. That is what makes a stepper so precise; it gets 4+ divisions per tooth.
This strongly reminds me of the ongoing efforts at the Miniatur Wunderland in Hamburg [0] (a very large model railway) to implement a model Formula 1 race track on which tiny race cars can move completely freely [1].<p>[0] <a href="https://en.wikipedia.org/wiki/Miniatur_Wunderland" rel="nofollow">https://en.wikipedia.org/wiki/Miniatur_Wunderland</a><p>[1] <a href="https://www.youtube.com/watch?v=xPUEOhMBpUw" rel="nofollow">https://www.youtube.com/watch?v=xPUEOhMBpUw</a>
Very cool. Might make for a fun chess board or model train/model city layout.<p>Edit: Glad he mentioned Carl Bugeja's youtube channel, this instantly brought Carl's work to mind.
I have wanted to do exactly this concept controlled via RPi with voice recognition to make a real ouija board. I only mention it because I will realistically never get around to it myself.
Different principle, but it reminds me of OpenDrop:<p><a href="https://www.youtube.com/watch?v=pSls9L_h3Q0" rel="nofollow">https://www.youtube.com/watch?v=pSls9L_h3Q0</a>
It also reminds me of:<p><a href="https://www.youtube.com/watch?v=9k7zywli4Vg" rel="nofollow">https://www.youtube.com/watch?v=9k7zywli4Vg</a>
> Next steps: Levitation / sliding enhancements<p>I wonder if vibration would help reducing friction. I.e. superimposing a low-power high-frequency component in the field to avoid static friction.
the Sri demo shows 2d motion. pcbs make it pretty straightforward to have an X and a Y array, but for some reason it doesn't seem to me like you can just easily drive both axes independently. could you really tune a 'step' to be on an arbitrary slope?