Electronics Robot arm 3D-printing

I need 4 stepper motors for the Robot arm (X, Y, Z arm and extruder) and 1 stepper motor to rotate tubes.
My old electronics have only 4 stepper motor connections.
So I use now the Arduino Mega 2560 R3 control board, the Ramps 1.4 board, the 2004 LCD board and 5 drivers A4988.
The power supply unit is a Techsolo Micro ATX 12V- 400W.
Also the box http://www.thingiverse.com/thing:1437311 modified.

Used for Robot arm 3D- printing http://www.thingiverse.com/thing:1725519

Look here. https://www.thingiverse.com/thing:3846234