One of the Holy Grails of desktop 3D printing is the ability to print in multiple materials, for prints that mix colours or textures. There are printers with multi-way hot ends, add-ons that change your filament, or printers with tool changers, that swap hot ends as needed. [Amy] has taken the final route with her Hypercube, and her Doot Changer allows her to print in two materials with ease. Best of all, she tells us it only cost her $20 to make.
For those not familiar with Hypercube-style printers, they have a roughly cubic frame made using aluminium extrusion. On the rear upper rail are a couple of receptacles with metal locating pins onto which a hot-end unit can be slotted. The printer carriage has a magnetic coupling that can pick up or disengage a hot end from its receptacle at will, as can be seen in action in a short video clip.
The build starts with a 3D printed inner and outer frame, sourced in this case from Shapeways in nylon. Both frames have holes which are designed as a friction fit for off-the-shelf tritium vials. These vials use the radioactive decay of tritium with a phosphor coating to create a dim glow which lasts approximately a decade. With the inner frame held inside the outer with the vials acting as structural supports, the inner and outer surfaces are then fitted with semi-transparent mirrored acrylic, creating a nice infinity effect.
It’s a fun trinket that would be perfect as a MacGuffin in any sci-fi film with a weak plot. [Sean] notes that while the tritium glow is disappointingly dim, the device does make a good nightlight. If you’ve built one and get bored with the hypercube, you can always repurpose your tritium vials into a nuclear battery. Video after the break.