Hi all,
I have a general question for anyone doing repair of certificated PA-18 (or J3, etc) aircraft: What material thickness are you guys using for ribs on the tail feathers?
I have an old J3 rudder that is pretty much a basket case, and I'm going to rebuild it to basically hang it on a wall. While reviewing the Northland drawings, I see they call out 0.020" thickness ribs--but that thickness material seems pretty hard to find. My local metal supplier doesn't stock it in mild steel (1020) for instance. They stock 26-gauge (0.018") and 24-gauge (0.024"), but nothing in 0.020". So do you guys tend to go a bit lighter than the original drawings, or to the heavier 24-gauage thickness...which is what I would tend to do. For a typical rib the difference between 0.024" and the 0.020" thickness called out on the drawings is less than half an ounce (edit: Per Solidworks)--so you're talking a minimal amount of added weight.
Thus I really do not see an issue using the 24-gauge stuff--and that's what I'm going to use to rebuild this rudder that I have. I was just curious though, and thought I'd ask to see what other folks are doing?
Thanks in advance.
TB
I have a general question for anyone doing repair of certificated PA-18 (or J3, etc) aircraft: What material thickness are you guys using for ribs on the tail feathers?
I have an old J3 rudder that is pretty much a basket case, and I'm going to rebuild it to basically hang it on a wall. While reviewing the Northland drawings, I see they call out 0.020" thickness ribs--but that thickness material seems pretty hard to find. My local metal supplier doesn't stock it in mild steel (1020) for instance. They stock 26-gauge (0.018") and 24-gauge (0.024"), but nothing in 0.020". So do you guys tend to go a bit lighter than the original drawings, or to the heavier 24-gauage thickness...which is what I would tend to do. For a typical rib the difference between 0.024" and the 0.020" thickness called out on the drawings is less than half an ounce (edit: Per Solidworks)--so you're talking a minimal amount of added weight.
Thus I really do not see an issue using the 24-gauge stuff--and that's what I'm going to use to rebuild this rudder that I have. I was just curious though, and thought I'd ask to see what other folks are doing?
Thanks in advance.
TB
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