Original Posted By: "flea"
Thanks guys, I do appreciate your advice. I had never heard of HTS 2000 or anyof the other aluminum brazing rods until today. I just found it interestingthat it seems to be so strong. As for the aluminum control horns I really havent done any serious analysis ordestructive testing to confirm that 6061 will stand up to the same stresses thatformed sheet metal will. I do know that 6061-T6 claims to have a tensile strengthof 42,000psi and a yield strength of 35,000psi. Hardly the characteristicsof 4130 steel, but much more than my 1/2 spruce aileron spars would allow.I really didnt think about the annealing that would take place during theheating of this material. I know that welding aluminum is acceptable, but notin structural assemblies. I suppose TIG is the most effective and least harmfulmethod (to the material), but oxy-acetylene is supposed to be acceptable too,although it would distribute even more heat over a wider area. Again, I understandthis to mean non-structural assemblies like fuel tanks, cowlings, etc.,as even TIG welding will soften the welded area to 6061-O (tensile 18,000psi,yield 8,000psi). Ive also read that the assembly could be heat treated torestore its strength. Im not certain about this but I guess Ill need to considerthat too if I want the full rated strength of T6. Ive seen a couple of different aircraft that use aluminum control horns. One exampleis on a Pietenpol that was built by a local EAA member. Ill pick his brainas to how he affixed his tabs and dealt with annealing. Perhaps he did nothingat all, or maybe he will enlighten me on his approach. I do know thishe has many hours on his airplane (his 5th) and is a well respected builder, evenin the Pietenpol community. Im not saying that as a dig at anyone, I am onlystating it to point out that I chose to duplicate some of his features becauseI figured that he knew what he was doing (an assumption), and because theylook pretty cool. As for the weight of these items, I assume that you are comparing1:1 dimensions for these materials. The example I studied has lighteningholes, which I also plan to implement. I know, I know there are probably1000 arguments for or against the lightening holes too. Well, hopefully I canprovide some answers after my next discussion with this fellow. Thanks again for the comments. They sure do help get the ideas flowing, and helpme formulate better questions when discussing these issues with others.--------Mark - working on wingsRead this topic online here:
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http://forums.matronics.com//files/p926 ... ___Subject: Pietenpol-List: Re: Grega GN-1 plans