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Corrie wrote:
john wrote in message . .. On 30 Jul 2003 16:56:37 -0700, (Corrie) wrote: "MS20001P aluminum hinge is extruded. The closed hinge loops cannot be pulled apart. Furnished with hinge pin. Anodized finish." Thanks. How much stress can it take, though? That's the question. Probably the hinge pin or the rivets holding the plates would be the first to fail at a few hundred pounds, but still... musing I suppose one could order some and find out.... If the specific alloy were known, it could be looked up. http://ourworld.compuserve.com/homep...orhis/T003.htm shows yield and tensile strengths for a number of allows. They tend to be around 30kpsi. The catalog doesn't give the thickness of the flange. Assume it's .1", and the hinge is 6" long, that's .6 sq. in, at 30kpsi.. 18,000 lbs? But some alloys are as low as 5kpsi - that's 3,000 lbs. Impressive for a small hinge, but would it suffice for the application? Marginal at best, I think. The largest hinge at AS&S is just 2" wide, and they all seem to have the same size pin - .089 stainless. That's .006 sq. in. area. I can't find a reference for shear strength for stainless, but taking an optimistic SWAG at 200kpsi (the highest yield strength for drawn ss referenced at http://ourworld.compuserve.com/homep...orhis/T006.htm), that's 200,000 x .006 = 1200 lbs. Not nearly good enough. /musing My guess is that if it's not specifically rated and labeled, it's unknown. Not something to put in a critical area. So, then, back to the original question. Assuming you don't have the ability to extrude a larger piece of aluminum (in order to use a larger pin), how *do* you solve the problem? I really feel like a big dummy, because I may have missed the obvious, and I know that I may have nothing usefull to add after all ... but ... What are these hinges supposed to hold??? pressurized canopy? undercarriage trunion? control surface? some kind of single hinge application? Peter |
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![]() "Peter Dohm" wrote in message ... Corrie wrote: I really feel like a big dummy, because I may have missed the obvious, and I know that I may have nothing usefull to add after all ... but ... What are these hinges supposed to hold??? pressurized canopy? undercarriage trunion? control surface? some kind of single hinge application? Peter Well, the Sisu 1A sailplane used aircraft grade piano hinges in instead of spar root fittings. The right and left wings were joined to each other with 1/16" piano wire inserted through hinges riveted to the upper and lower wing skins. The fuselage was hung from the joined wings. See: http://www.nasm.si.edu/nasm/aero/aircraft/arlington.htm Bill Daniels |
#3
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Peter Dohm asked, quite reasonably
What are these hinges supposed to hold??? The spar. I'm thinking about the possibility of considering the feasibility of investigating a folding wing. The spar would have a hinge installed top and bottom. To fold the wing you remove the bottom pin. GW of the aircraft in mind is ~1500lb. It would need to be able to take 6 g's, hence my concern about strength. The sailplane may have used standard piano hinges, but it was about 500 lbs, and probably not stressed for more than 3 g's. |
#4
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Corrie wrote:
Peter Dohm asked, quite reasonably What are these hinges supposed to hold??? The spar. I'm thinking about the possibility of considering the feasibility of investigating a folding wing. The spar would have a hinge installed top and bottom. To fold the wing you remove the bottom pin. GW of the aircraft in mind is ~1500lb. It would need to be able to take 6 g's, hence my concern about strength. The sailplane may have used standard piano hinges, but it was about 500 lbs, and probably not stressed for more than 3 g's. The Dyke Delta does this with a 1/2" pin that passes through fittings in the top and bottom spar. Max gross is 1950lbs. -- ----Because I can---- http://www.ernest.isa-geek.org/ ------------------------ |
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