Ultracube

This is a very WIP thing. It's supposed to be a heavy duty version of the Hypercube Evolution with linear rails for X and Y, a very solid milled aluminum gantry... also, it's a H-BOT design, rather than a Corexy! I know, right? H-bot suffers from racking when moving along the x-axis! But on lower accelerations it's so small it's hard to even notice it. It will be possible later on to turn it into a CoreXY with some additional parts (i.e: idler holders and x-carriage) I'm yet to design. In that case, it will be possible to use a much thinner plate for the X-gantry, like a 3.175mm instead of 6.35mm, since Corexy doesn't suffer racking around the Z axis.

The gantry plate is designed to fit inside a 300x200 or 300x300 hypercube evolution frame calculated with Scott's original spreadsheet.

The x-carriage can be set up either as a direct drive or as a bowden-style extruder by simply attaching the motor to the frame instead of on the top of the carriage. I like it direct-drive mode beca