Electrical probe (magnetic)

SummaryThis design is a magnetic probe holder to take contact with a PCB pad in a simple but reliable way. I design it because i needed to connect 8 pads on a single samples and i didn't have enough probes.It uses a single M3 screw to control the rotation of the arm and its contact with the pad. The whole probe has to be positioned manually. My design uses 2 circular 12mm diameter magnets (thicknesses from 2 to 3 mm are ok) to attach to an iron base. Alternatively you can use a thin piece of rigid plastic with a magnet underneath as a base.I made the tip of the probes from 18mm long 0.64mm thick square section contactor legs. The wire is maintained with a drop of hot glue.You can find here 3 vertions of the probe arm: V1, V2 and V4 depending on the number of tips at the end of the arm. In V2 and V4 each tip hah an individual lever to give it some elasticity and ensure a reliable contact. The spacing between tips is the standards 2.56 mm. For a precise installation you can place the tip