Milling directly on the aluminum bed of the CNC 3018 Pro Router is a sure way to ruin your machine quickly. To prevent this and as a fixture method for holding PCBs I made a wasteboard with a 10×6 matrix of 1/4″-20 mounting holes. As with my previous project write up this project was completed in the distant past so the details below are as best as I can remember.
I chose 1/2″ (12.7mm) thick MDF as the material to make the wasteboard from as it was readily available at the local big box hardware store and its uniformity makes machining it easy. I cut out 300mm x 180mm blanks using a table saw, this dimension is the same as the extruded aluminum bed that this wasteboard will be mounted to.
The wasteboard will be mounted to the extruded aluminum bed using 1/4″-20 flat head bolts that have countersunk holes drilled into the corners of the wasteboard. I went with inch bolts since that is what I could find at the hardware store.
The t-slot nuts to use with the extruded aluminum bed are generally metric so I machined my own 1/4″-20 t-slot nuts using a manual milling machine.
Having had my fill of manual machining I set about making the CNC 3018 Pro finish up the wasteboard by machining its own mounting holes for the 1/4″-20 tee nuts. This was done using a 1/8″ end mill. The wasteboard was mounted upside down on the extruded aluminum bed with a 1/4″ piece of plywood underneath it as a wasteboard for the wasteboard. This was a dusty and loud operation that takes a long time and is best done in a garage or outside on a nice warm day. Compressed air is also useful for after machining is done to dust off the CNC 3018.
Design files can be found here: GitHub. Before running the gcode please inspect it to make sure your machine will behave. wasteboard.gcode was generated recently using FreeCAD 1.0. XY zero is the center of the wasteboard and Z zero is the top surface of the wasteboard. wasteboard_bottom.gcode was the original file I used.
SD Perry 