Yesterday I glued the shaft once more. I had made a little flat spot on the shaft to let the epoxy fill that and make this turn the shaft.
I inserted the shaft into the Lama today and I actually made it fly
It flew for half a battery before the lower insert came loose once more and made me land quite quickly
Now I have made a larger flat area on the lower insert and will glue it again.
I still believe the carbon pipe has the strength. It seems more and more that the problem will be to make the lower shaft insert gluing last.
I'll be on to the next experiment.