- Joined
- Jan 12, 2017
- Messages
- 570
Thinking (obsessing?) still about a possible spiral-wound geodetic fuselage, but it occurs to me that this jig concept might make sense for a range of fuselage builds (even steel tube?), where keeping things square and true is key.
Early practitioners of geodetic wood fuselage construction remarked that a good (internal) jig is necessary to deny the natural tendency of spiral winding to twist the formers. The recommended practice seems to have been to build a temporary, "conventional" truss braced box structure, to which the fuselage bulkheads could be clamped, with the internal jig removed after the two opposing helical windings have been installed.
How about the idea of taking advantage of today's engineered wood products to serve (perhaps with some modification) as the internal jig?
Specifically, engineered wood floor joists, such as Weyerhauser's TJI joists (essentially I-beams) are available with a height from 9.5" up, and are manufactured to very tight specs. They are also available in lengths not normally found for dimensional lumber.
Seems to me the engineered wood I-beam would naturally resist twist, but imagine how stiff it would be if we boxed it in with thin ply webbing across the flanges, both sides.
I know some homebuilders have had good results using such engineered would joists to build long, perfectly level work tables.
Just wondering if we can do much more with this product.
Early practitioners of geodetic wood fuselage construction remarked that a good (internal) jig is necessary to deny the natural tendency of spiral winding to twist the formers. The recommended practice seems to have been to build a temporary, "conventional" truss braced box structure, to which the fuselage bulkheads could be clamped, with the internal jig removed after the two opposing helical windings have been installed.
How about the idea of taking advantage of today's engineered wood products to serve (perhaps with some modification) as the internal jig?
Specifically, engineered wood floor joists, such as Weyerhauser's TJI joists (essentially I-beams) are available with a height from 9.5" up, and are manufactured to very tight specs. They are also available in lengths not normally found for dimensional lumber.
Seems to me the engineered wood I-beam would naturally resist twist, but imagine how stiff it would be if we boxed it in with thin ply webbing across the flanges, both sides.
I know some homebuilders have had good results using such engineered would joists to build long, perfectly level work tables.
Just wondering if we can do much more with this product.
