Building a big 3D printer has its own challenges. The strength of materials does not scale linearly, of course, and long axes have a tendency to wobble. That said, building a bigbot isn’t hard – stepper motors and aluminum extrusion are made for industry, and you can always get a larger beam or a more powerful motor. [James] is going in the opposite direction. He’s building tiny, half-scale printers. They’re small, they’re adorable, and they have design challenges all their own.
At this year’s New York Maker Faire, [James] is showing off his continuing project of building baby 3D printers. He has a half-scale wooden Printrbot, a half-ish scale Mendel Max, a tiny Makerbot Replicator, and a baby delta and baby Ultimaker in the works.
Click past the break for a gallery, and more info on [James’s] tiny creations.
The major design challenges for a tiny 3D printer isn’t the frame or the mechanics. You can always scale down laser cut parts, and belts are available in any size. The problem is the mechanics and electronics. A NEMA 17 stepper motor is just too big for these tiny machines, and you can only make an electronics board so small.
To solve these problems, [James] is scaling down to NEMA 8 motors. They’re available, they’re expensive, they don’t have much torque, but they do work. During one of the builds, [James] found there are exactly two NEMA 8 standards with different bolt hole patterns.
A RAMPS or RAMBO board only comes in one size, so to scale these printers down, [James] had to build his own, minified 3D printer controller board. He shrunk a RAMPS board down to a mere 50mm x 35mm. He has a few versions of electronics, one using discrete Pololu drivers and an OLED/click wheel display. There’s another board using integrated Allegro drivers that’s just barely larger than a postage stamp, yet still has all the capability of its bigger brothers.
A 3D printer is useless if it can’t print, and on this front these micro machines fare well. The sample prints coming out of these machines look great, even though the filament spool is bigger than the machine itself.
This is creativity in action and a task that is a lot harder than building a normal-sized 3D printer from scratch. This booth isn’t getting a lot of visitors at Maker Faire, but it is a unique build that exemplifies the DIY ethos of the 3D printer community.