For my new prototype, I designed internals, that slide into the tube and hold the electronics in place. I made them in the workshop from MDF. Although my new prototype also serves as a visual model, these internals are not primarily designed to exactly fit the prototypes electronics and do not necessarily represent the internals of the actual product, CyclePole might turn into. This is because of course in such a product the electronics will be different (no Arduino, no branded Mini-Speaker, a bigger battery and so on).
I have started testing with this prototype today and will do final test tomorrow.