CNC3018 spindle mount

thingiverse

The original spindle holder was introducing a lot of runout and wobbling. My goal was to use this CNC3018 for PCB milling and I needed a decent precision, so I decided to redesign the spindle holder and Z-axis sledge. Before you print, check your CNC3018-like machine if it fits this design. I know there are many variations of this machine with LMUU10 bearings on the Z-axis instead of LMUU08 and different bearing spacing. In this project, the spacing between linear bearing centers is 38mm, which kinda explains why the trapezoidal screw has to be cut in order to fit in between. Required items: - 2x LM08LUU linear bearings (45mm long) - 1x Trapezoidal screw TR8x4 (check with your machine) with anti-backlash nut (needs to be cut and ground to fit inside the Z-axis sledge) - 3x Hex M6 screw, nut, and washer - AC glue You need to fix the trapezoidal screw with a spring and anti-backlash nut inside the sledge. Then check it with the trapezoidal rod if it fits properly, mechanical alignment, and so on. Put the small lid (z_axis_locker.stl) on the trapezoidal screw opening and fix it with glue to the sledge. Make sure the glue does not get to the screw thread. Same thing for the linear bearings - apply glue to the inner walls of the linear bearing holes and push the bearings inside, making sure to align them equally from both sides of the sledge. Wait for the glue to dry. With this design, I was able to mill PCBs with accurate-enough precision for my DIY projects. You can see example videos and photos of the PCB making process here: https://www.youtube.com/watch?v=OzJ_bb20_9I https://photos.app.goo.gl/vLs5gWqZPQQpVirQ8 Any creative comments and questions are welcome.