A subway tunnel that is free for all :)
Due to problem with strength of the male-end I have added a connector, just print two female ends and us the connector it if you whant.
Updated the entrance parts, the new parts got better clearance to the tunnel for better fitting.
Added the tube split in two parts so it now only requires ~90 mm of z-height. Just glue them together to a full 175 mm tube.
I have printed all parts with supports and 15% infill. I hade some problem with layer delamination on the tunnel but it is easy repaired with some super glue.