Sunday, August 31, 2014

Project CNC making parts for Project 3D Printer

Successfully installed new lead screws, new bed and new spindle mount on my CNC. Did a rough calibration of the x and y axis, manually leveled the bed and then fine tuned the calibration for all 3 axis.

My top speeds for x and y axis are fairly high but z axis is still the limiting axis. Any faster than about 14in/min and the z-axis stepper squeals and stutters – resulting in a lot of missed steps. After a bit of research I found a few issues that may be causing this:
  1. stepper motor resonance
  2. lead screw (likely to be less of a problem when I change to acme screw on z-axis)
  3. GRBL
Some good links on this issue:

It looks like I won't be able to get faster moves until I finish my rebuild of the frame and spindle mount/carriage (including swapping the z-axis lead screw with an Acme screw). I have tried tweaking the acceleration and max speeds but when I push it a bit for better performance the Z-axis seems to loose steps when retracting resulting in a number of pocket cuts being to deep.

Finally done with both sides of the Z-axis on the 3D Printer and will be cutting out the X-axis shuttle

Cutting X-axis shuttle tonight, tried this afternoon and GRBL stalled (first time ever).  Already re-cut acrylic for mount for extruder out of acrylic.  Lining up printer bed on Y-axis and designing cuts for securing drive belts on X and Y axii.