Recently, I finally received the dual extruder, but was disappointed to find almost no instructions and very little documentation as to how to create a two-color print. I figured it out and was able to print a small decorative box as shown below. It took a bit of trial and error, primarily because of the absence of documentation and I am writing this in the hope that it will help other users. (There is somewhat of an outline at Dual Material Slicing Quick Guide | Snapmaker Wiki but I did not find it very helpful.)
The first step is to design the box. There are various programs you can use for this. I have only used FreeCAD and Fusion 360, and strongly prefer the latter, so that is what I used here.
Here is an outline of the process, then I will go into more detail after.
• Create two bodies in Fusion 360, one to be used for the left extruder the other for the right extruder.
• Export each body to a stl file.
• Import the two stl files into Luban as objects.
• Associate each object with an extruder, one with the left the other with the right. Choose the extruder filaments.
• Align the objects.
• Generate the G-code, etc.
So here are the details.
In Fusion 360 or whatever CAD program you are using, create the box. I am assuming you know how to do that but will briefly illustrate the steps I took in Fusion 360.
To get the box to have a distinctive two-color design, I drew a spline curve on the side of the box as you see here:
Next, I used the Fusion 360 “Split Body” command to split the top part of the box from the bottom along the curve defined by the spline. As a result, I now had two bodies. I renamed them to Box Top and Box Bottom.
Finally, we need to export the two bodies to two stl files for use by Luban. I called these files “Box Top.stl” and “Box Bottom.stl”.
Now move over to Luban and import the “Box Bottom.stl" file and then import the “Box Top.stl” file. Luban imports the top next to the bottom and things should look something like what is below. (I moved and rotated the box for purposes of illustration.)
Next click on the filament settings in the upper right-hand corner to choose your desired filaments (PLA Black for left and PLA White for right in my case) so that it looks like this:
And now back to the object list, and open the pulldown by clicking on the “R” in the Box Top row to change the top to use the Right (white in my case) extruder:
After making this change to use both extruders you will see the addition of a column (or dowel) on the canvas in the printing area. This is called the “Prime Tower” and it is added automatically (unless you have changed the defaults) by Luban when both extruders are to be used. If you go back to using just one extruder the Prime Tower will disappear. To learn more about the Prime Tower, its purpose, and alternatives, open the print settings for the Left Extruder and go to the Dual Extrusion Helper section. Next click on the Prime Tower setting and you will see some very informative help.
Now comes a key step that is not documented anywhere that I can find and that is to align the two objects. Start by selecting both (all) objects with Ctrl-A. Luban shows the overall volume of the two selections with axis renderings at the eight exterior corners of the objects. Note also that two command icons in the toolbar are now available and no longer greyed out: Align and Group.
Click Align, and presto! The two objects have been aligned. Which is further reflected in the Object list which now has “Group 1” and is no longer showing the two separate objects:
Click on the right pointing triangle at the left to expand Group 1 and see the objects in it:
After this it is straightforward to generate the G-code and print the box.
