This week’s selection is the unusual Mechanical Laser project by Thingiverse contributor Evan S.
Los Angeles-based Evan S, aka AdditiveTech, designed a rather simple – yet quite complex – design for displaying a laser pattern.
You’ve probably seen this type of technology at a big event involving a laser show. The idea is that a brilliant laser blasts a target, and that overloads your retina slightly. By moving the laser around, the persistence of vision creates a trail in your retina that can be any desired shape.
But how, exactly do you get a machine to “draw” a recognizable pattern with a laser?
Evan’s approach is to lay the laser loose between two rotating cam wheels. These wheels are of varying shapes, thus when you rotate them, the laser resting on them will tilt slightly in different directions.
Aha, this is easy, right?
Well, not so much, because the wheel shapes must be exactly correct – and matched to each other – in order to tilt the laser in the appropriate directions.
How do you determine what those two shapes might be? Evan uses mathematics to design the pattern, as you can see here:
Yes, it’s a bit complex, but if you watch the accompanying video you’ll see that this is entirely possible:
Basically the desired shape is boiled down into a series of consecutive points, which are then mapped into the equations, and a wheel shape is generated.
By 3D printing these unique shapes you can then mount them on the laser projector and crank them around to show the pattern on the wall – and it shows best in the dark, obviously.
Evan has smartly included a 3D representation of each wheel’s pattern embossed directly on each wheel. This makes much sense.
The project is entirely downloadable from Thingiverse at no charge, where you’ll find the few parts required to make this work. Evan has included wheel designs for two patterns: Star, Batman, Club and Heart.
But the real fun will be to design your own pattern and generate the correct cam wheel shapes.
Via Thingiverse
