Tensioning the belt
The belt you just routed has slack in it. The tensioner arm - a black piece with a metal wheel and two T-nuts - installs at the end of the bar, wraps the belt around its wheel, and is pushed outward to pull the belt tight. A tight belt means crisp, accurate prints.This part uses T-nuts again and the number 4 Allen wrench.
Step-by-step
1
Loosen the T-nuts
Crack each T-nut screw just enough to rotate the nuts to vertical so they can enter the rail slot. Do not loosen more than needed.
2
Wrap the belt on the wheel
Lift the loose belt and slip the tensioner’s metal wheel underneath it, so the belt wraps around the wheel before the piece goes into the track.
3
Slide it into the track
Insert the vertical T-nuts into the end of the bar’s slot so the piece sits flush.
4
Push out and tighten
Push the tensioner outward to pull the belt tight, and while holding it there, tighten both T-nut screws with the number 4 Allen wrench to lock it.
The tensioner is locked into the end of the bar, the belt has no more slack, and the print head moves left and right smoothly with no looseness.