Geeetech i3

Geeetech i3 is a Prusa-style 3D printer made in China. Variants include the Pro A, Pro B and Pro X.

X-axis belt routing — common assembly mistake

The assembly videos and photographs in Geeetech's instructions for this model contain an error.

The stop collars on the smooth rods (which carry the X-axis motion) should be mounted on the inside, between the two carriages on the Z axes.

The X-axis drive belt is tensioned between the two carriages that ride on the Z rods. This belt tends to pull the Z rods toward each other and therefore deforms the geometry of the Z axis. The Z motors then have to drive mis-aligned rods while fighting against the belt tension, which acts as a brake on rotation.

A schematic of the forces involved (apologies — I'm not a graphic designer):