This base is designed for one 1660 or two 830 tie point breadboards. High quality ones include the BusBoard BB830/BB1660 and the E-CALL EIC-102 (Also sold under a variety of other brands as EIC-102).

The file base 1660-1 cnc.step is meant for machines like a CNC router or CNC mill. It's 4.5mm thick and the prototype was machined from 5mm thick type 5083 aluminium with both sides faced. The mounting holes are 2.1 mm so they are ready for a standard M2.5 tap.

Use M2.5x6 DIN 912 socket head cap screws to fix the PCBs to the base plate.

The files base 1660-1 3dp.step/base 1660-1 3dp.stl are meant for 3D printers and offer another way to make a base for this project. As threads in plastic aren't too durable the screws are fastened to 24 M2.5 nuts embedded in the bottom of the base plate.

Use M2.5x8 DIN 912 socket head cap screws to fix the PCBs to the base plate.

As of now, this has not actually been printed yet

Other types of M2.5 screws with the same length will also work. However it is important that the head size is <=4.5mm. Some module types have the upper copper pour connected to e.g. Ground. A too large screw head could potentially wear through the solder mask and connect the copper plane to the base plate which can lead to issues.