I wanted to upgrade my UM with direct drives. Problem: You need larger rods for this. Solution: Replace the Rod for 10mm. I printed the parts. I mount them. I printed some parts, to make sure, it works. 1.) Make my own Version of a Rod Spacer 2.) Make my own Version of a Direct Drive 3.) Made the Thing printable without Support 4.) Printed it. Got Screws needed M3x40mm. 5.) Make the Alu plates with the threaded M3 Stopper-ALU-M3.stl 6.) Mount it all on the UM 7.) Tested 8.) Long time testing > 10h printing 9.) Added a Fan Mount to the Steppers http://www.thingiverse.com/thing:193542 10.) Added a Image to the Gallery, how to assemble it. 11.) Create the instructions for this thing. 12.) Very long time testing. > 100h printing etc. If the CNC Coupler does scratch the inside of the Direct Driver Bottom part, use a grinder, to flatten the Screw heads. I tighted the screws, to fix the rods. Then i released them for like 1/4 turn and then i grinded the screw heads so they do not stand out. Tight all screws from the Stepper first, move the CNC coupling in the middle , so there is a space on both sides. then tight the coupling. Try to move the Rods by Hand, and make sure, its not grinding anywhere.