Duck, Latches like that are one of the options I am toying with. I've used some spring loaded ones in the past that I really like. They sort of take up any slack so you don't have to worry about it breaking the wood. Another option are box latches like this, though I would probably have to bend them to mount them on the curved surface
I've browsed many of the websites including Thomann looking at designs and ideas for joining the segments. Most of them seem to use aluminum or brass sleeves. I am currently working on a wood sleeve design that I can cut on my CNC, though it may require some work on the lathe too. My first thought for gaskets or sealing rings was to get some cork like is used to join segments of woodwind instruments but finding natural cork sheets in the sizes I need is difficult and expensive. I can find plenty of the cork like is used in bulletin boards but I am afraid it will be to crumbly and diffult to wrap around the tenon, especially the smaller ones. I am currently thinking about using crubber like they sell to line vice jaws and as gasket material
That last link was the website (Arbobuilder) that my friend who asked me to make this for him sent me. It may be what inspired him to ask in the first place. I actually used the measurements from that website to create my design. The guy's approach was to make 10' long tapered staves joined with a birds mouth -- like building a wooden mast. Other information on the site is about boats so that is no surprise. Since the staves are tapered that makes it a pretty complex thing to get right and still require significant shaping and carving after glue up. I considered that approach but while working through a segmented design, I came up with my CNC method.
--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.
