DuPont Polarizing Pin Plug

thingiverse

These tiny items fit into Dupont(R)-style pin header housings to prevent plugging it in unless a pin has been omitted in that location. This allows reasonable polarization protection while using common 0.1" (2.54mm) pin headers that normally could be plugged in backwards. This worked great for a 3-conductor cable; I just used a four-position housing and plugged up one of the interior holes. The first picture shows that preventing backwards connection. For a 6-pin cable, I didn't want to add just one position because 7-position housings are uncommon. So I added 2 positions and made a double plug for convenience. This is shown in the second picture. I had been using JST's MHT connectors on the board because they are polarized. But scaling this up proved a problem because the US$40 crimping pliers I found for them requires separate crimp steps for wire and insulation while the US$20 iWiss crimper does the wire and insulation on the DuPont-style pins at the same time. I really don't love crimping, we couldn't find anyone to make our odd cables for us (all that hot-melt is to reinforce the 30ga silicone wires from a slip ring... quite finicky to work with) Near as I can figure out online, these are called DuPont-style connectors because the DuPont chemical company developed them as an application of one of their flame-retardant plastics. The manufacture of them is no longer done by the DuPont company. So, (R)/TM as appropriate on the name DuPont.