RigidBot Z-rod Filament Guard

Snap-on guard to prevent filament from getting tangled in the Z-rod.
Has a generous hole to allow some skewing if your rods are not completely straight. Since the hole passes all the way though, it is easy to align the guard to make sure it doesn't actually touch the rods. This also makes it possible to apply lubrication without removing the guard

**Update 2016-09-13**
Version 2. Stronger frame grip, will not break as easily as version 1. Less travel restriction in Z-axis. Widened guard for