The basic idea of this concept is pretty simple: We are using two carriages (in German: Schlitten) which lie on one another where the contact surface is a plane in the angle of 15 degrees to the table. Pushing the lower carriage to the left will force the upper carriage to move upwards.
For moving the lower carriage a simple and therefore cheap screw with an M6 thread is needed. One rotation about its own axis will move the lower carriage about 1 mm and thus the upper carriage about 0.25 mm. For the guideway (in German: Führung) we should use steel bolts which aren't expensive as well. We should be able to print all the other components with the 3D printer.
If desired I can deliver more technical drawings with correct measurements but I guess this is not needed at the moment as we will re-design this approach anyway.
You can download the model here: Media:Microscope-case-jakob-sketchup-model.zip. Note that you need Google SketchUp to open the file.