RAMPS 1.3 Case ventilated [OUTDATED]

[2025] This design is outdated for a number of reasons. The OpenSCAD source contains deprecated code, and the resulting STLs have alignment issues that were no issue on +0.4mm layer thickness, but may cause problems on todays quality printers. Feel free to make a remix, and update the source file yourself.
[/2025]

Note this is for the RAMPS 1.3 board and not suited for RAMPS 1.4.

Slight improvements; leveled the board, added powerjacket and repositioned USB hole.

Ventilation added, dimensions based on Sepa MFB25B12 12VDC fan http://nl.farnell.com/sepa/mfb25b12/fan-25mm-12vdc/dp/1217961.

This case is used for a milling machine with relatively slow stepper speeds, no extruderheater and no heated build platform.

The fan is connected to screw terminal D9, with the fan pin assigned to it. Given the fan is quite noisy, I think of adding a thermistor later on and tweak the code so that the Arduino takes care of adaptive cooling.

Ventilation efficiency has not been verified with