Extends your shower post by 50mm.

The post has a nominal diameter of 10 mm and is slightly conical. 

For stability: 

• Print with lots of walls (maybe 5?). 
• Make sure that your slicer has enough top/bottom layers configured so that the screw hole is solidly connected to the bottom hole as this gives extra strength. They should not be connected by infill
• If above is met, I think infill does not really play a big role. I chose the slicer default which is 20%
• I was not sure whether a FDM print is sufficiently stable (at the change of the cross section), so you can screw in a 4x40mm screw from the top. 

V1 is the version printed as shown in the pictures. It works as shown. but sits slightly higher than I expected. 

V2 has 0.1mm more diameter. If I will reprint in case of failure, I will reprint V2. I recommend printing V2

Remixes are welcome and can start here in onshape