This is another improvement on a design submitted by flurin. The differences between our designs is that I reused the metal plate originally provided with the Ord Bot to prevent any outward flex of the part during heavy tensioning. Additionally, I am using 7xM5 Button Head socket screws and t-nuts to hold the ideler in position. Perhaps a little overkill, but I can guarantee it won't move. Additionally the arms do not limit x-axis travel. I have specifically designed the height of the arms and the recess of the button head screws to ensure that the v-wheels are able to clear them during x-axis transit to the far right. This gives me the maximum build area. The idler pulley uses all original parts from the Ord Bot BOM and the tensioning nuts are two M4x20 socket head cap screws with 2xM4 nuts. You will also require a regular M5 nut for the idler. I recommend six M5x8 nuts for the t-slots. I didnt have any on hand so I cut some longer ones with my dremel. I have designed the support into the STL file for this part, so no support is required. The support broke off like butter for me and I am using PLA. This has worked really well for me. Be careful when putting in the M4 screws for the belt tensioning. I accidentally stripped out the square opening that the nuts are inserted into on my first print because the screw and nut were not aligned properly. If the screw isnt going in easy, dont force it.