So a big shout out to juanmol from Thingiverse for the 3D model. Conveniently sliced into 14 sections, with two holes through every part, the 3D print was floorless.
I originally tried 5mm doweling but found this to be too sloppy as a fit allowed flex during the initial mockups… I didn’t want to introduce flex as this would add pressure to the joins.
I settled on two 6.2mm fibre glass rods for stability but did have to do a bit of sanding to get them to slide into place easily.
6mm holes do not allow 6.2mm rods to slide in – obvious aye!
I used a two part superglue just to give me a few seconds of slide when joining the parts. Slop in the shaft from my eager sanding was addressed by introducing some lightweight filler.