The metal lathe that I've owned for a little over a decade now recently quit running.
After some troubleshooting I found that my ON/OFF switch had failed. To be more specific, the plastic housing that contained the metal contacts of the ON/OFF switch is what actually failed.
It appeared that the plastic housing had gotten brittle enough over time that the small tabs that secured the overall component in it's place had just cracked and broken off.
Since my lathe was as old as it was, when I called the seller's customer support I was informed that there was now a version-2 of that same component. Unfortunately for me, that "Version-2" was NOT interchangeable with the older version that came with my lathe back when I bought it new.
They did also have the "Original Version" (so they claimed) but that "Original Version" looked nothing like the ON/OFF switch that had just gone bad on me.
Rather than ordering it and taking the chance of it not fitting I opted to try to just model some replacement parts in my CAD software and then 3D printing them instead.
It took me three separate tries to get them to print out just right but eventually I got them to fit and function perfectly; and all for pennies on the dollar compared to the price of an OEM replacement part.
The factory replacement ON/OFF switch that they had in stock for my specific lathe was now a cylindrical shape. The OEM factory component that had gone bad on me was more of a dual rectangular shape. I most likely could have gotten their OEM replacement component to work even if it didn't fit perfectly but I was afraid of just making more work for myself so, 3D printing saved the day.
My lathe is back up and running again.