Epoxy granite and CNC
A CNC mill with an epoxy-granite gantry — slowly taking shape as the new piece of workshop kit :)
CNC mill with an epoxy gantry
The new piece of workshop kit is slowly taking shape :)
The mill's working envelope will be X: 50cm Y: 50cm Z: 45cm
- "wet Chinese spindle" 2.2KW with ER20 collet
- servo motors
P3 Sanyo Denki750W SGDM-08 Yaskawa 200V - Yaskawa step/dir SGDP-08 servopacks
- Mach3 control via the CSMIO Ethernet controller
- linear rails THK SRS20/HSR25
The gantry is poured from epoxy mixed with quartz in varying grain sizes — filler-to-resin ratio around 15-20% (resin is Epidian 61 with the slow PAC hardener — ~3 hours to set, over a week to fully cure at ~20°C).
The base is a 100x60cm scraping table. The whole stack damps vibrations beautifully and is plenty stiff (the plan is to mill aluminium and acrylic).
Currently on the bench: tweaking the Y axis, building the Z axis, and wiring the control box.
Y axis changes done — the carriage spread is now 34cm wide, while still keeping a full 50cm travel over the table. The Z axis will be appropriately wide-set.
Now it's time to design the Z axis and to align the angles and parallelism of all the surfaces.
With the table aligned to 0.02mm, time for the gantry.
