This is certainly not my design but from an old copy of WoodenBoat mag. It will be of interest to boat builders but it is quite handy for birds mouth mast and spars.
In the book "Router magic" by Bill Hylton, there is a plan and instructions on how to build an open ended router lathe, that you can use to build masts, but also flutes, barley twists, using a template, etc
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