This is a collection of cranks for an RV / Trailer window mechanism with a 5/16 or 8mm spline shaft. The variations relate to the length of the stem at the back as some are embedded in windows a bit more than others. Two of the versions don’t require the knob. Printed mine in ABS then covered with copper and aluminum powder mixed with acetone. I am sure they will work well painted or left plain.
The knob needs a 3/32 x 3/8 or 3mm x 10mm bolt. There is a spot for the nut as well if you want to pause the print and drop one in but I discovered the bolts thread in nice and strong without.
Prints best at resolutions at .3 mm or under lest the splines get a bit fuzzy.