For about $320AUD you can get a CNC milling machine delivered in kit-form. I’m going to use mine for etching circuit board prototypes, and maybe cutting a bit of acrylic. It also came with a 500mw laser and safety glasses, but I will be sticking with milling for now.

picture of filing cast aluminium parts

#1: Use a file to tidy up the cast aluminium parts, removing any rough edges left by the casting processes.

picture of sliding t-slot nuts into aluminium channel

#2: Add one of the smaller cap head screws, washers and t-slot nuts to each side of a right-angle connector. These t-slot nuts slide into the extruded profiles and tightened in position.

picture of building boxy a shape

#3: Take two 300mm lengths of extruded aluminium and the two 220mm lengths. Attach with right angle connectors into a boxy 'A' shape, with the crossbars separated by 55mm.

picture of building base

#4: Take the two 330mm lengths of extruded aluminium and attach two 300mm lengths. This time, separating the crossbars by 28mm. You will need to tighten the top crossbar in place before positioning the lower.

picture of building base

#5: Take the last 300mm length of extruded aluminium and use it to enclose the base.

picture of attaching the two assemblies

#6: Using six of the right-angle connectors, attach the two assemblies to make an L shape. With the upright intersecting the base at the middle crossbar. Double check to make sure everything is square and true, and ensure your connectors are well tightened.

picture of attaching 3D-printed strut

#7: Using more of the smaller cap head screws and t-slot nuts, add the 3D-printed struts to further reinforce the L shape. The t-slot nut will slide into the channel, just ensure it has rotated 90 degrees when tightened in place. Be careful not to over-tighten the screws here as you can crack the 3D-printed part.

picture of larger t-slot nuts

#8: During construction of the build platform, use the larger cap head screws and t-slot nuts to attach components.

picture of attaching linear bearings to the build platform

#9: Attach the linear bearings 20mm from the edge of the build platform. Use two of the 330mm smooth rods to help get everything aligned. Spend a bit of time here to get things as precise as you can, it will help ensure that the platform can slides smoothly. Again, be careful not to over-tighten and crack the 3D-printed parts.

picture of attaching nut-mount to the build platform

#10: Attach the nut-mount to the build platform, 100mm from the edge.

picture of attaching nut-mount to the build platform

#11: Insert one of the springs into the nut mount. Thread the screw into the ball nut, compressing the spring till the nut flange sits flush with the nut-mount. Thread the screw into the nut-mount to hold everything in place.

picture of adding oil to the smooth rods

#12: Drop a couple of dots of fine machine oil on the smooth rods, and ensure everything moves fluidly.

picture of attaching the build platform to the base of the frame

#13: Using the brackets and smaller t-slot nuts, attach the build platform to the base of the frame. Take care to ensure that the round rods are parallel and that the platform moves freely.

picture of attaching stepper motor to the steel mount.

#14: Using the smallest screws, attach a stepper motor to the steel mount and attach the blue coupling.

picture of attaching stepper motor to the frame.

#15: Using smaller t-slot nuts and screws, attach the stepper motor and idler bearing to the base of the frame. I found it easier to flip the mill on its side to get a good alignment.

picture of adding spring to z-axis assembly.

#16: Add a spring to the 3D printed z-axis assembly and thread the screw and ball nut into position.

picture of adding smooth rod.

#17: Add 340mm smooth rod, position mounts, adding screws and t-slot nuts.

picture of attaching second stepper motor.

#19: Assemble the second stepper motor mount and attach to the mill gantry.

picture of fitting idler bearing

#20: Fit the idler bearing and ensure that all fittings have been been correctly tightened.

picture of adding aluminium heatsinks

#21: Add the small aluminium heatsinks to the stepper drivers.

picture of adding aluminium heatsinks

#22: Add cap-screws, small plastic grommets and t-slot nuts to the control board.

picture of mounting control board

#23: Mount the control board to the mill gantry.

picture of wiring the spindle

#24: Wire the spindle motor down to the control board.

picture of wiring the stepper motors

#25: Wire the stepper motors down to the control board, the one on the spindle mount gets routed to the Z-channel. The motor on the gantry get routed down to the X-channel. The motor on the base of the mill gets routed over to the Y-channel.

picture of wiring organisation

#26: Using hot glue and cable ties, organise the wiring down the channels of the extruded aluminium profiles.