If you've ever had to hold a scope or meter probe on a circuit board with one hand, while typing or doing something else with the other, then this print is for you!
This model combines a hollow ball-and-socket chain, combined with a base with a slot to clamp on a PCB board (default is 1.6mm, but can be changed in the .scad file) and a pin-holding probe tip. Print as many of the ball_socket.stl model (chainSocket() module) as needed to reach across the board. Print one of the ball_socket_pcb_clip.stl model ( pcbClip() module) to hold it onto the edge of a PCB. Print one of the ball_socket_probe.stl model (probePinTip() module) to add to the end.
After assembling the base, chain and tip, strip a few mm off the end of a length of wire-wrap wire and insert at right-angles into the end of the tip (will probably need to clear the hole a bit), then insert a straight pin to capture the wire and provide a connection to the pin. Stretch out the chain and lace the wire through the holes in each link. Strip the other end for clipping by a scope or meter.
The long, thin strip holding the tip is to provide the necessary spring tension to keep the pin-probe held down. If it cannot be flexed against the board w/o movement in the chain, then the tightness factor will have to be increased, or more filament used when printing.
I used PLA with a 0.4mm tip, 0.2mm layers - smaller could make for prettier parts. Depending on your printer, you may need to vary the "TIGHTNESS_FACTOR" global to tighten up the chain, or make it easier to snap together.
Update 4/3/19: reduced TIGHTNESS_FACTOR to 0.93, for a stiffer chain.