Mk4 of the mini tripod with the modifications listed below.
If this works when 3D printed I will add it to the Schools forum.
I have an Ultimaker 2 3D printer on loan for a couple of weeks and decided to build on the modifications suggested by Dave White and simplify the parts to avoid support structures altogether and the end result is excellent. Build time was around 8 hours and the thread fitted together really well without any fettling, just a rub with a candle. The legs should be attached using roll-pins, the screws are temporary and I have yet to epoxy a 1/4" UNC bolt into the cap and glue a rubber washer on the top.
I am very impressed with the Ultimaker 2 3D printer and Cura slicing software. They are both very easy to set up and get printing. In two weeks of almost continuous printing the only problem has been a blocked nozzle. This was easily sorted using the clear online guides and a quick call to their tech support. An excellent product and support.