how to make a combined gcode file (on windows)

Collect all the stl files in a single folder. Together with the program "gcmerge.exe"

download gcmerge

Use cura to create gcode files for each stl file.

In this case 3 gcode files should be created.

Edit the file mergerecept.txt with notepad.

Put the names of the 3 gcode files in the file.

Double click on gcmerge.exe .
Note that this program is only tested with outputs from Cura version 15.04.6

The file "combi.gcode" is created.

Copy this file to your ultimaker sd card.