When I wired up the MPCNC’s tool length probe, I planned to reinforce the wiring with a dab of epoxy. What I didn’t notice in my enthusiasm, alas, was the opening from the rear to the front in each pin slot:
Which let the epoxy flow completely through the connector:
So I cut the mess off and applied heatstink tubing on each wire, just like I should have in the first place.
Now you know the rest of the story …
I really dislike pin headers as cable connectors, but that’s what the Protoneer CNC board uses:
It’ll be Good Enough if I don’t do anything else particularly stupid.
The Smell of Molten Projects in the Morning 
I appreciate that you post your mistakes as well as successes. I’ve lost track of how many times I’ve pulling one like that. My latest was hanging a picture frame with slightly offset keyhole mounting slots. Having been caught by such things before, this time I made many measurements and calculated offsets from reference points and whatnot. In the end the picture was perfectly level, but 1.5 inches too low! No idea why. Fortunately I could just redo the holes higher and the frame covered the first pair. That mystery remains unsolved because there are so many other projects ahead to do (and maybe redo).
Yeah, it’s nice to know other people goof too. I made two symmetrical goofs. When I installed my bathtub, I made it parallel to the floor, which was not level, so there was always a puddle in one corner. When I hung a TV on the wall, I made it level, instead of parallel to the ceiling, so there was a visible angle. Double oops.
I know a guy who made the classic mistake of wallpapering a room by working around it while carefully aligning each strip, rather than distributing the misalignments. By the time he got back to the starting point at an archway, the strips were off by nearly an inch and, of course, the paper had a strong vertical pattern.
So he shimmed the side of the arch by an inch to match the paper pattern. He figured the next owner would discover the shims and decide he was a genius-grade paperhanger for somehow making the pattern match the existing misalignment …
I’m wearing that tee-shirt, too. I did a major update/upgrade on my system, and lost the printing. Eventually, I realized that the 64/32 bit multilib setup had been deleted by the upgrade. Unfortunately, I installed the wrong package and my /bin directory went away, so I had to go back to the install DVD. More mishaps later, and I’m sort-of up to speed on upgrades and multilib, with a keen appreciation for Slackdocs. Couldn’t quite talk myself into getting a dedicated 32 bit box as a print server…(Brother has very limited support for Linux, but it’s a great printer for my purposes.)
My father deliberately hung pictures Just Slightly Off(tm), specifically to drive our fussier relatives nuts: they’d know something wasn’t quite right, but couldn’t figure out what. Worked perfectly!
He’d also paint each wall of a room with different color, whenever he got the urge for painting. Turns out varicolored rooms became trendy, so I guess he was just way ahead of his time.
Epoxy-filled connectors will never become trendy, alas …