Assemble the tensioner, idler pulley and printed axle as before. Screw on the tension nut and pop the result it into the tensioner housing. 

Next time we’ll square, size and align the frame and rail, and add the y axis belts. Monday, maybe!
https://cdn.masto.host/mastodonart/media_attachments/files/112/615/838/789/964/490/original/2e8066c3ce5bec6a.jpeg
https://cdn.masto.host/mastodonart/media_attachments/files/112/615/839/042/825/341/original/09fa9432064fe780.jpeg