I've done it this way:
Load part one from the plater window.
Select this part, right click on it and choose "settings" ( or use the settings button of the plater )
A new window pops up and there is another "load part" button. Click it and select all the other parts you want to combine.
Close the window and voilá there they are.
You can also set different extruders in this settings menu.
Edited 1 time(s). Last edit at 01/18/2017 07:09AM by o_lampe.