Printed in PLA with .25 layers and 60% infill. The bridge is challenging but if your printer is tuned it shouldn't be too much of a problem.I've also added two nuts on the support rail so the idler is held in place but can still move when tensioning.Edit: Changed the shape to octagonal to avoid extreme overhangs before big bridge.y-idler...3mm - 3mm bearing hole for 623y-idler...4mm - 4mm bearing hole for 624Also: There seems to be a design very similar to this in the box_frame repositoryhttps://github.com/josefprusa/Prusa3/blob/master/box_frame/y-drivetrain.scad