NeoDue Part 1 - Duet Wifi for GRR Neo by Mechanotronikum

Last crawled date: 3 years, 1 month ago

Since my Neo did benefit a lot from Thingiverse (special thanks to Kakadu for his E3D upgrade and his table stiffener, and for stueckl for his inductive Z endstop); I wanted to give something back, so here is part one of my "NeoDue" upgrade, where I have replaced the old Printrboard with a Duet Wifi (and a display, but that is part 2).
To change the electronics board, you need
a Duet Wifi board
one of each of the three 3D parts printed out on your Neo
two M3 x 20 mm (or longer) screws to mount the board holder to the fan outlet
two M3 nuts to mount the fan again
five Ø2.9...3 mm x 6mm screws for plastic (for the cover part and the Duet Wifi)
Hints for mounting:
remove board cooling fan and old Printrboard electronics
change the cable paths as shown in the pictures (you will need to make the wires of the Z motor, the Z sensor and the main power cable ca. 10 cm longer; the others do fit)
turn the extruder motor as shown in the picture so that the connector faces up
assemble board holder (halter_leiterplatte.stl), faceplate (blende.stl) and cover piece (schutzhaube.stl) using the short screws
if you like to add some extra safety against oil dripping onto the board whenever you oil your linear bearings, use some tape to cover the gap between the board holder and the cover piece.
now mount the assembly to the fan outlet hole using the two M3 screws.
mount fan onto protruding screws on backside of fan outlet hole and secure with M3 nuts. Caution: blowing direction = towards z axis, i.e. the opposite direction as before! The ribs on the board holder will direct the airflow so that the steppers get the cooling they need. Works fine on my machine so far.
cutout left plastic cover of Neo to fit the faceplate
now mount board
don't forget to secure the wires again
For setting up of the board please refer to Duet documentation - just some short remarks:
I run the Duet with 19.5V as the original (I did change however the power supply to a 230W one when I changed the print head, so I cannot guarantee if the original Neo supply will provide the power needed)
the connectors of the steppers and the endstops can be left as they are; but you might want to switch to an NPN endstop if you currently use the inductive endstop from stueckl. (A PNP endstop requires quite a bit of additional electronics: first, you need to add a separate voltage stabilizer for the sensor, e.g. for 9V. Then add a 2,2k resistor between Duet Z endstop input pin and ground pin, and add a second resistor between sensor output and Duet Z endstop input pin, thus creating a voltage divider which needs to provide 3V at the endstop input pin if the sensor is active. The resistance of that second resistor needs to be calculated accordingly. An NPN sensor is much easier to connect, just add a BAT43 diode as mentioned in the Duet Wiki.)
the steppers work fine on my machine if I let them run with 500...600mA.