QUBD Twoup Gantry replacement

I have heard so much good things about StefanBurger's Gantry replacement, to fix variety problems of original TwoUp designs. (http://www.thingiverse.com/thing:248059).

However, it was very difficult for me to print them with the my original TwoUp printer. After a few dozen of attempts, I decided to design my own.


- Lower height in printing ( somehow, my original TwoUp started causing number of problems after z-axis reaches 1 inch above )
- Shorter print time (so, I can easily repeat printing if something goes wrong )
- Almost no sagging by tightening screws

The new gantry holds the timing belt a bit farer from the extruder holder. So, I added a stretched belt holder (original http://www.thingiverse.com/thing:218670)

The hardware used in this modification are

- M3 x 25mm 9 pcs
- M3 x 30mm 1 pcs ( tighten the z-axis holder toward top-left stepper motor hold)
- M3 nuts 6 pcs
- 3/8"-16 inch nut 1 pcs