Simple lampshade that can easily be modified by adjusting the 2 sketches in FreeCad that form the basis for this for your own needs. The way it is supposed to work is by wedging the clamping ring into the base of the lampshade. Because of the friction of the printing lines it clamps tighly onto a cylinder. There is some wiggle room, but might be advisable to measure twice and try some test rings first before commiting to the full print.
My mother recently bought this medusa hair type lamp without any shades and my father hated having to look straight into the lightbulbs. So I figured this might be a nice "reason" to learn some FreeCAD. My first ever attempt at any CAD software and even coming from oldschool Blender I found it a steep learning curve.
If you change the height and width radically do not forget to adjust the radius of the pipe and it's curve for the cooling holes. The current airhole diameter and curve were adjusted exactly so there is no possible way or angle that you can see the lightbulb through them, as per my fathers explicit wishes.
The current wallthickness are specifically designed for 2 walls of 0.8 linewidth, so they print in about 4 hours even at 30 to 40mm/s.