This is a great upgrade for the S4! Took all the shaking out of the top of my CR-10S. I like that that it goes in the back vs the front of the printer. I ordered 500mm carbon rods since they were cheaper and I didn't want to cut them. I had a buddy remix the brace link to make 500mm rods work. I messed up and ordered 10mm inner 12mm outer rods (ooops!). I'll post a remix of the brace links for 8x10 and 10x12 x500mm. The Z-Sync parts worked out great also the belt fit perfectly. Thanks for your work on this design!