Team 3D/Materials/Overview

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This is a breif (I swear) overview of how 3d printers operate.

Fabrication

3d printers work by forming materials in to form some kind of structure, typically using layers.

All the 3d printers at the space form plastic, by melting it down, and then moving a head to extrude it out into a layer. This is known as Fused Filament Fabrication (FFF).

This is done by taking filament melting it down, then pushing it through a nozzle then cooling it down. The part that does this is known as a Hotend, as Reprappers were great at naming things (Todo: add picture of hotend). These include a heater, and a thermistor, for measuring and regulating the current temprature.

Supports

Because 3d printing is done layer by layer, and it is typically impossible to build thing over nothing, one must use supports to support the print (hence the name)

FFF 3D printers typically print vertically and use block supports (todo: add pictures); while these allow for reasonably complex prints; these supports need to be removable, and removing them can require some force.

Motion

3D printers move with either belts or leadscrews (todo Pics), these can be setup in various ways.

These are typically driven by stepper motors, which allow for precise open loop control (i.e. the printer has no feedback on it's position). Note that the open loop nature means that you CAN crash the head into various things if you aren't careful. Typically if a printer is angrily clicking at you, it is unhappy. (todo: sound)

Note that these can impart a reasonable amount of force, not enough to break any bones, but still enough to hurt.

Control

FFF printers are CNC machines with a very specific tool head. As such they inherit a large amound of similar features from CNC. Other printers may not.

Commands and Slicing

FFF printers run "standard" gcode, with lots of extensions (also reasonably standardised). The main addition from traditional CNC is the addition of a new axis "E" which moves the extruder (Todo: add gcode snippit)

To translate between 3d models and gcode a slicer is used; this splits them model down into layers, and then calculates the toolpaths from there.

As 3d printers all run the same gcode (mostly), you can run any 3d printer with any slicer, if you have the right config. Note: we don't have config for all slicers and all printers YET.

Electronics and Firmware

FFF 3d printers typically run on arduino style electronics, normally ATMEGA2560s (i.e. cheap 5v 8bit microcontrollers).

These do all the precice real time processing, by taking in Gcode, buffering it, and then generating pulses.

To power the heaters and motors the boards will typically have a 12-24v supply.

Most of the spaces FFF printers run marlin, and have LCDs to display Info

External material