This 33mm (1.3") long cup-tipped pogo pin probe pin is normally used for electronic JTAG uses, but we use them for bots!
Another spring-loaded test Pogo pin - this tip would be particularly useful for making devices that run into each other and you want to electrically link them. Use them with the PPH1 pogo pin holder for quick and easy replacement.
The cup on the tip would be ideal for receiving a pin of some sort. The cup measures 1.5mm (0.059") in diameter, the outer shaft diameter is 1.01mm (0.040"), and overall uncompressed length of 33mm (1.3") with 6.5mm (1/4") travel.