A quick make, 3d printing threads.

I've had this piece of plastic tube for ages, I use it to protect my small model rocket launch rail rods that need to be kept straight and protected from bends. It has had numerous bits of gaffa tape over each end which had slowly turned it into a sticky mess. I've been trying to get to grips with 3d printing threaded items, it's been a challenge until I realised I was expecting to much by applying machining tolerances to the 3d prints. Once I started under sizing the internal threads by around 0.25mm on the radius I started having some success. So now my rod protecting pipe has a nice end-cap one end and a screw lid on the other and I've learnt some new stuff on the journey!