Sometimes a 3D printed design works out well in practise, sometimes it has obviously failed and sometimes you gradually become aware of issues over time. The tool I created to help remove the springs from my tuba valves falls into the third category. It is a set of four joined spikes that I could put over the open valve holes before inverting the tuba and catching the springs as they fell out. However, I’ve realised that the spikes aren’t quite long enough and often end up slipping down the sides of the spikes.

Version two adds 20mm to the end of each spike, which should ensure the springs already sit around them before I turn the instrument upside down. In theory that should solve the problem – tomorrow morning, once the print has finished and the bed cooled down, I’ll be able to move to the practical test and find out for sure.