De Zelfmaker

Minerva

Minerva is a 3-D printer, and a lot more. The print head can easily be swapped out with other tools, to turn it into a 3-D microscope, or a sticker cutter, for example.

De Zelfmaker produces, sells, and gives workshops for building Minerva. Of course you can also ask us any questions about it.

The machine

Minerva has a so called delta geometry. That means that the head is controlled by three carriages that all move vertically. The head itself is connected to the carriages with rods. By placing the carriages at the proper positions, the machine can accurately position the head.

The benefit of this design is that all motors are connected to the frame, so they do not move with the head. Because of this, the head is very light can can accelerate quickly.

The extruder, which delivers the plastic to the head, must also not be mounted on the head, or else it would become too heavy. Because of this, it is mounted to the frame. The filament is pushed to the head through a so called bowden tube (kind of like a brake cable).

The machine not only contains a microcontroller (with an AVR, the same as the Arduino uses), but also a mini computer. This allows Minerva to provide a powerful interface to the user through a web browser and the computer (or phone) that was used to send the command to the machine does not need to remain connected while it is running.

The Software

Minerva comes with Franklin. Franklin is written by Bas Wijnen. Its goal is to optimally use all the features of the machine. A few highlights:

• While the machine is running, settings can be changed and they instantly update. This is very useful to calibrate the machine, but also to correct some problems that may occur during a job.
• There is an API that allows direct control of the machine from software. For example, when a microscope is mounted on the head, this allows the software to integrate the movement of that microscope into an experiment that also controls lights and records images from the microscope.
• Franklin uses a custom protocol internally, which gives better control over the machine than would be possible with G-Code. For example, it is possible to change the target of a movement while it is ongoing. Through the API, this feature can be used to control the machine with a game controller, for example.
• Of course Franklin is also capable of running G-Code files.