After breaking the original window winder, I opted to design and print a replacement part for my car. I took a photo of the original winder spline, added it as a raster layer with Siemens NX8.5 and then traced with the spline tool to reproduce it, as I couldn't accurately determine it's original dimensions.

Using calipers to determine the rest of the winder dimensions, making some changes to help with printing, e.g. the handle part being printed as one piece.

Two versions exist, one that closer replicates the original and requires support material to print, and another that can print flat on the bed.

The rotating knob is printed in place and requires no assembly, to do this a few test prints on the tolerances were required, especially determining the minimum required separation distances and overhang amounts.

The entire project was done in Siemens NX8.5 supplied as part of my undergraduate degree. The winder has lasted over a year in constant use!