IgorNC - a random numerically controlled contraption with a dual printing head

Mechanics

Comprises three (almost) identical linear actuators built around C-beams with machined end caps

All mechanics are maximally over-engineered to compensate for a poorly conceived and inherently unstable gantry design.

endplates are machine 8mm aluminium
transition fit for NEMA17 motor journals
press fit for flanged bearings
3 NEMA17 steppers with integrated ~500mm leadscrews
all 3 axes differ in gantry plates only, but use otherwise interchangable components

Print head

dual head
1.75mm bowden extruders (Titan from E3D)
internal air guide creates a directed planar sheet of air
printed ABS duct for better heat resistance
flexible TPU adapter improves fan connection to the duct

blower components	blower outlet

Print bed

print area is 360x360mmm

First iteration

bakelite heated bed
overengineered kinematic mounts: machined, hardened, and surface ground V-Blocks locating on cap screw heads :D

Second iteration

machined from 6mm aluminium, heater fully recessed
removable magnetic print surface from Ender 5 Plus
rigidly bolted to the X gantry to reduce vibrations

Electronics and control

Duet 2 WiFi controller
350W power supply
custom laser-cut enclosure
NC emergency switch
NO customizable control buttons
NO reset button (unfortunately, Duet 2 uses a dedicated pin for that, so has to be hard-wired)

Settings and macros

Homing

Homing is done switch-less using stall detection.

Bed probing

Currently done by detecting contact between print head and a steel feeler gauge :D

Bed leveling

G29.1 allows loading an interpolated height map for a given temperature using RepRap firmware support for "meta-commands".

Macros

triggerX.g allow customizing button actions, e.g. the "Green" button will resume print if paused, or print last file again if not currently printing.

load.g/unload.g provide parametrized macros to simplify filament management.

ig248/igornc