Wednesday, June 6, 2018

Root 3 CNC - Adding the Spindle Mount to the Z-Axis

The 80mm Spindle Mount Assembly connects to the Z-Axis via the MGN12c linear bearing blocks, as well as the 8mm threaded trapezoidal lead screw.  Start the process by adding a 24-tooth 8mm 3M HTD pulley to the lead screw and securing it with a set screw.





Roughly set the spindle mount assembly in place.  Thread the lead screw though the top mount, through the spindle mount assembly, then finally through the bottom mount.  If your 3D Parts are a little warped/missized like mine were, you will need to drill out the holes on the spindle mounts a bit, to ensure they align with the MGN12c blocks.



To fasten the assembly to the MGN12c blocks, the following parts were used:

  • 16x M3 x 12mm screws (0.5mm threads)
  • 16x M3 lock washers
  • 16x M3 washers



The following picture is out of sequence (it was taken while testing part fittings/alignment) but is the only photo I have which demonstrates how the inner screws are fastened.  A Wiha precision screwdriver is inserted through the front of the 3D printed assembly to tighten the screw.  To help with alignment, another screwdriver was used as leverage to move the small M3 screws/washers into position before tightening.



Proceed with fastening all 16 screws.  For my build, I completed the 8 outer screws before attempting the inner screws.




Once fully attached, the trapezoidal lead screw can be cut to length.  Mark the appropriate location, and then use a hacksaw to remove the excess length.  Use a file on the finished cut to knock down any sharp edges.







1 comment:

  1. The BOM calls for 20T pulley for Z, any reason you went for 24?

    ReplyDelete