Acrilyc Ultimaker V1 rev3

This is an adaptation of the standard Ultimaker drawings, but with some handy features thrown in.

Notes:
-All lettering on the parts has been removed for less clutter in the acryllic version
-Slider blocks have 1mm more depth to improve tension of the belts
-Adjusted the size of the holes in the slider blocks to allow for a smaller kerf in acrylic
-A new construction to set the height of the Z-endstop, either mechanically or optical
-On/off indication next to the button
-Adjusted tabs