Yet another X-tensioner for the PrintrBot Jr. This one allows the user to use handy finger screws to adjust tension. Also the screw cups are to keep from marring the wood surface.
If you look at the before and after cup picture, this fixed the squashed circle/lemon shape(on the left) I was having.
There are sockets for 1/4"20 Hex nuts if one so desires on the inside portion of the tensioner. I just hand twisted the screws in. I tightened the tension nice and snug. I'm using GT2 gears (20 tooth) and matching timing belt.
.3175mm layers (using stock Z threaded rod)
fill density .4/concentric pattern