X Axis motor mount for Anet A8 or Prusa i3

thingiverse

This is a thorough overhaul of "thing" 1428253 using Fusion 360 from scratch. I used a slight teardrop shape at the top (when printing) of the horizontal holes to prevent sagging on the bridging at the top of the holes. Additionally, I applied 1mm fillets at all corners, so the printer wouldn't have to slow down or overrun tight corners. These changes allowed for significantly tighter tolerances than the original design. The holes are now 8.18mm (originally 8.6), although some light bearing oil was needed to slide the rods in smoothly. Linear bearing holes are slightly tighter too (15.08 vs. 15.2). There are numerous cosmetic and functional changes. After printing, you'll likely want to sand the bottom (which will be the top when flipped). I used 600 sandpaper for this purpose. This is to address any curling or warping that may have occurred during printing. You'll want those large nuts for the z-axis screws to be as level as possible. All of the screws and nuts in my design are 3mm in size. I repurposed a leftover 45mm screw from my printer for the pulley/thumbscrew. I also used 3mm locknuts, although plain nuts should work too. ### Printing * Depending on your printer, use either the standard Left/Right files which have 45mm spacing between rod axes, or the 44mm/46mm variants of those files. * Do not use supports * Enable <code>Avoid crossing perimeters</code> or equivalent so you don't have any garbage to clean up where the rods or linear bearing go. * The *test_fit.stl* file can be used to check how tight the fit is with your printer and slicer settings. The hole in this file is the normal (8.18mm) size. ### Assembly After inserting the horizontal rods, rotate both of them in place (simultaneously) to relieve any stress on your Z-axis rods. Then tighten the two outer screws on the "tensioner" just enough that it begins to separate. This ensures that the horizontal rods are providing the belt tension (and not your Z-axis). ### Updates: * I added a second version of the right side that is slightly looser than the left side, in case you don't want to struggle to slide the rods across. It is 8.32mm instead of 8.18mm. * Made the screw holes for the endstop switch a little bigger * Added a small shape for test-fitting just the hole * Added variations with 44mm and 46mm rod spacing (vs. standard 45mm)