Not Spectacular but Definitely Specular

I watched Steve Mould’s video of Specular Holograms a while back, and it wasn’t until a cool student wanted to borrow my tabletop plotter to try it that I realized it was within reach. The plotter approach didn’t work, it really wasn’t designed to take the friction of a carbide tip etching surfaces. But its software stack is easily portable to anything with 2 stepper motors and a “tip” based action. So I thought it’d be a cool Christmas project to turn an old Creality 3D printer into something capable of etching specular designs.

And well, the results are mitigated so far, but I’m getting somewhere with a moving glint effect.

I need to tune the machine to barely touch the plexiglass, and figure out model creation. Moving a tip is easy these days, unsurprisingly though there are a lot more intricacies to uncover to get good results.

That’s a Wrap

Robotics 2025 concluded with 2 kids having built the small Etch-a-Sketch plotter after 5 sessions, and an extra one to just consolidate and draw. There isn’t much to say other than it went like a charm. I’ve added onto the Inherently Programmable Pi so they could have a basic HTML interface to their machine, I have yet to publish the update. This solution I feel is a bit of a game changer for engaging with robotics. At best it lowers the bar significantly for uninitiated learners; at worst it’s just darn convenient to get to work on your Pi project anywhere. A few years ago I’d promote it on a few online communities, these days I just don’t have the will to do much of anything online, but I really should.