Brodhead Pietenpol Association

Original Posted By: Christian Bobka
The recent discussion of 4130 for fittings has me thinkingabout the steel-tube fuselage from the Flying & Glider Manual.I've always had a prejudice that if it isn't wood it isn't reallya Piet. Trouble is, I really enjoy welding, and I understand thatthe steel fuselage is somewhat lighter than the original wood.With a view to adding still more lightness, does anyone knowwhether you could safely go one size thinner on the tubing?I know that 4130 is a lot stronger than the 1025 Bernie used,and the fuselage was overbuilt even with that. However,I'm not enough of an engineer to know how much fiddlingone can do without excessively weakening the structure.Thanks.Owen Davies________________________________________________________________________________Date: Sat, 24 Feb 2001 15:39:58 -0500

Original Posted By: Don Mosher

Original Posted By: Christian Bobka
Christian Bobka prefaced some useful comments with:> Some old articles from early sixties vintage Sport Aviations refer to the> question of 4130 substituting 1025 as used in the early light aircraftsuch> as the Taylortcraft, Aeronca, and Cub. It seems that when in tension, the> 4130 is definitely superior. But when used in compression, then the> buckling of the column becomes the critical factor. (etc.)Yes, thanks. In fact, it was the compressive loads that concerned me.Owen Davies________________________________________________________________________________Date: Sun, 25 Feb 2001 08:51:49 -0500