3D Printing & Modeling + Ed3DP

2. 3D Printing

2.1. Slicing- CURA

This chapter covers the process of converting your 3D model file into GCode ready for 3D printing.  This is commonly known as "Slicing" because the 3D model file, which are "vectors" (mathematical formulae), are turned into geometrical coordinates (x,y,z) layer by layer.  The layers are horizontal and are also called "slices" hence the term "Slicing" your 3D model into GCode.  You can use any open source or commercial 3D modelling and Slicing software with the Educator 3DP as long as it produces standard GCode.

We recommend and support this version of Cura for "Slicing" which is open source.  If you have a Mac or Linux please download Version 15.04.6 from the Cura Site.  This version of Cura has been in use for many years and is easy to use yet complex enough for tweaking your print settings.  It suits an educational environment well. There is a new version of Cura available but we have not started using this yet.

While installing Cura select "other" and just define the printer as "180 x 180"- that way when you use Cura the print bed in Cura will be the same size as the Educator 3DP print bed i.e. 180mm x 180mm.  Please also make sure that the "heated bed" box is checked- otherwise Cura will not display a bed temperature dialogue box.

Once you have installed Cura you can load our Fast PLA Profile or Fast HIPS & ABS Profile (right click and "save link as") into Cura via the "File" menu then "Open Profile".  All the settings are adjusted for quick classroom prints and you can make adjustments from there.

Hovering over the input boxes in Cura brings help a help box that explains what that printing parameter does.  

Start&End Gcode should be in the "Start/End-GCode" TAB of CURA:

You must have the following "start.gcode" in Cura: (in the "Start/End-GCode" Tab)

G21; set to mm

M375;  Load the bed compensation grid from sd card

G90  ;absolute positioning

M82 ;set extruder to absolute mode

G28  ;auto home

G92 E0 ;zero the extruded length

G1 F200 E10 ;extrude 10mm of feed stock

G92 E0 ;zero the extruded length again

You must have the following "end.gcode" in Cura  (in the "Start/End-GCode" Tab):

M104 S0;extruder heater off

M140 S0;heated bed heater off (if you have it)

G91;relative positioning

G1 E-6 F300;retract the filament a bit before lifting the nozzle, to release some of the pressure

G28 ;home all axes

G0 Y170; move the bed forward

M84 ;steppers off

G90 ;absolute positioning

If you have not already setup "Educator 3DP" as your "machine" during the Cura install process then goto the "Machine" menu and then "Add new machine": the only data you need to change from default is a square build area of 180x180 and height of 200mm, 1 extruder, check the heated bed box, and Gcode flavour is RepRap(Marlin/Sprinter).  It should look like the settings below: