2015/03/17 : Add belt tightener
This is a design for Prusa i3 z-axis upgrade to leadscrew with 4 holes copper nut.
- 4 holes copper nut type.
- Z axis force for nuts is a pushing direction not pulling. More strength.
- Design with LM8UU bottom stopper. LM8UU won't fall out for long term use.
- Design with LM8UU top cover (by nut). LM8UU is held tightly inside. (use M3x20 screw to hold LM8UU from the side on the top)
- Design with LM8UU inner tighten tolerance. Easy to insert LM8UU.
- Idler use 625ZZ or any appropriate bearing with 5mm inner hole. Sscrew is M5x15 with nut.
- Belt tightener required M4x15~20 screw and M4 nut.