The better X line tension-er for Printrbot Simple alpha release.

thingiverse

The Alpha Release of this custom-designed tensioner does not limit the full range of X-axis travel, mounting on the side of the print bed mounting plate. Suitable for left or right side mounting, installation involves using a 3mm screw (25mm long) and a 3mm nut with a built-in spring tensioning feature for increased line tightness. The tensioner also includes a separate slider to prevent line twisting during the tightening process. The goal is to ensure fast and easy adjustments. An update on 9/29/2013 introduced "XTensionerchutev2wings.stl" featuring wings that help secure the part to the board, preventing deformation during printing. A couple of small posts were added for attaching an indicator needle to display line tightness. Slicer settings include no bridging, a 0mm brim (to prevent the spring from gluing together), three skirt loops, and a distance of 0mm from the object with a one-layer skirt height. Further updates addressed slippage issues, recommending changing acceleration settings in Repetier-Host v0.90c to 100 for X, Y, and Z axes, proper stepper motor preparation (using a diamond bit, superglue, and nylon pull zip tie), and switching to 150lb test kevlar weaved kite line instead of the factory fishing line. The use of acrylic for printing surfaces is suggested, along with adjusting extruder height for optimal part adhesion. A recent update on 10/9/2013 mentions experimentation with vinyl-coated steel cable and noting that the plastic spring shows signs of fatigue. Overall, the tensioner design offers ease of tensioning and improved print quality.