Adding the Second Extruder for the Wanhao Duplicator 4S in Cura 3.6.0

February 12, 2019

I’m trying to get my friend’s Wanhao Duplicator 4S up and running for him as he was having some issues with it.  It’s been a real challenge at times and part of it seems to be that it’s an unpopular model that is already fairly outdated.  Cura at least surprised me in that it had a profile for the Duplicator 4S when adding a printer however it seemed to have some issues.

The first issue is that only one extruder works.  There seems to be no option for adding or enabling another one. When I scanned some forums and google groups discussions everyone was saying just to make your own custom profile and it would let you add as many as you want.  Sure, that would work but I was looking for a cleaner solution.

After a bit of digging and poking around in the installation folder this is what I came up with.

First I took a peek in C:\Program Files\Ultimaker Cura 3.6\resources\definitions.  With Cura closed I opened up wanhao_d4s.def.json for edit in Notepad++.  You’ll see machine_extruder_trains under metadata, you’ll want to copy the row in there and replace 0 with 1 so that it looks like this:

    "machine_extruder_trains": {
        "0": "wanhao_d4s_extruder_0",
        "1": "wanhao_d4s_extruder_1"

Also make sure you don’t forget to add a comma between the two values.

Next you’re going to go up a level and then into the extruders folder (C:\Program Files\Ultimaker Cura 3.6\resources\extruders). You should see a wanhao_d4s_extruder_0.def.json file in there, copy it and name it wanhao_d4s_extruder_1.def.json. Now open it up in Notepad++.

    "id": "wanhao_d4s_extruder_1",
    "version": 2,
    "name": "Extruder 2",
    "inherits": "fdmextruder",
    "metadata": {
        "machine": "wanhao_d4s",
        "position": "1"

    "overrides": {
        "extruder_nr": { "default_value": 1 },
        "machine_nozzle_size": { "default_value": 0.4 },
        "material_diameter": { "default_value": 1.75 }

In this case you’re just swapping the 0 for 1 on on the Id, position and extruder_nr default value, then updating the name to Extruder 2.

From there I opened Cura up again, the first time I did it I got an error saying there was a corrupt profile. It ended up being a typo in my file but I mention this because once you get it right you’ll know because there will be no error when you start Cura. But once you get Cura opened up add a new printer using the Wanhao Duplicator 4S profile and you’ll now have two extruders available!

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  1. First of all, thanks for this post. Clearest I have found untill now…..I tried it in cura 4 and it works………some questions remain:
    Thats it? If you do this, you can start printing right away with cura, or do you need to edit other configs? What distance did you use for the second extruder…..

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