Edit: Sep-19-2016: changed the design to metric.
This is a super duper hanger for the Flashforge Creator Pro and similar printers. This design has a few advantage
Printing: print in the orientation of the provided STL file. This orientation will provide the max strength. I printed with ABS, 4 bottom/side/top layers, 0.2mm layers with 0.4mm nozzle, 20% infill and support material from the printing bed to that large round bump.
Materials: M6*90 screw (e.g. https://www.amazon.com/gp/product/B0143ACXD4), 4 X 626 bearings (I prefer the plastic/glass type, search ebay for '626 Plastic Nylon POM Ball Bearings', they turn smoothly, open don't require lubrication, don't rust, and light weight), and an M6 hex nut.
Assembly: debar the spacers and other holes (use a debarring tool such as Shaviv or a large drill bit) insert the bolt into the base, inserts the spacers and bearings insert the end piece and the nut and tighten everything.
Verifying your assembly:
* Make sure that all the bearings turn freely. The spacers are designed with chamfer at their ends to make sure the touch only the center part of the bearings.
* Make sure the end piece is well tighten and that it is pointing up. If it doesn't point up, release it, release, turn the bolt in the base a third of a turn or so and tighten again.