Was experimenting with materials to burn with the laser... and came across one that takes it *real* well. So, I'm assembling an appropriate system to handle this material...
For now, I'mma keep it secret. Most of the hardware's in-place, just need a couple bolts to hold it together, and maybe a rubberband or something a tad more sophisticated, but I kinda want to see it working, so might stick with a rubberband and get on the software sooner rather'n later.
A major nicety. (@frankstripod would dig this one) It works with the original laser-focusing head, in the original sled/rail-system. No additional optics. The "material" seems to be *exactly* at the right position when the focusing head is fully-extended. Just figure out which coil(s) extend the head by applying 5V through a resistor around 150ohms.
This won't be a cartesian system, it'll use polar-coordinates. I kinda dig it.
What else am I willing to share at this point...? I've got *a lot* of this material, and it comes (came) in two common sizes (though I'll need to assemble another mechanism for the larger size).
Oh, the polar-coordinates... well, I'd like for the system to handle vector images, but the mechanics don't really allow for reversing the rotation, so it might have to be pseudo-raster-style (spiral?), at least for now. Rotation-reversing seems doable with neodymium magnets, but the ones I've tested cause some drag. Also, what with the steppers and not having microstepping implemented yet, this will probably be pixellated, anyhow.
Which reminds me, I need to figure out how to drive the rotational motion... The original system, I think, is too fast for the laser to do its job. Besides, the circuit-board/motor, that came with the hardware I ended up using, is a bit difficult to interface. But now that I realized extending of the focusing-lens... well, I might be able to get away with some other hardware where the circuitry is easier/easy to interface... if it will burn at that speed.
I've a few ideas for this... one is graphics, even motion-graphics(!?). Another is e.g. audio-storage, possibly data. It's utterly ridiculous to use it for those purposes, but I still dig it.
Planning on a backlight, for sure, for viewing the images... Possibly strobed for motion-images (a zoetrope?). For audio/data read-back maybe a solar-cell (which is handy since it's so large compared to a photodiode, no need to move the read-back sensor! Thanks to this guy using a solar-cell position-sensor used in a ball-balancing system for the brilliant idea! #Balance Wheel).
So, to recap: Two 'systems' in great supply (free). Material in great supply (free). Potentially all the motor-driver circuitry is easy to interface and free with one of the 'systems'. Might even be controlled via a parallel-port. Possible motion-graphics... And utter ridiculosity and irony in one! Wee!
Oh, and the possibility for strobed "columns" wherein the images are spread and interwoven over the entire "wheel," only visible with strobing (or possibly another wheel spinning?)
Possibly even something like this: