Pietenpol-List: Alternate Woods, status report
Posted: Fri Jan 07, 2005 4:20 pm
Original Posted By: "Oscar Zuniga"
Subject: Pietenpol-List: Alternate Woods, status reportI do believe that the wood construction phase of my Piet is now virtually complete. I began in earnest to build Feb. 1, 2002, almost three years ago. Ive tried to use good Douglas Fir, and Basswood plywood wherever possible.Ayear or so ago I compared fuselage weights with someone on the list here, and I came up with 71 pounds, vs 70 pounds for a spruce fuse. I think that both fuses were in about the same condition, but nothing definitve can be drawn fromthese figures.I began work on the wings a summer ago, laminating the spars from Fir, 7 layers. The ribs were of fir, with basswood gussets. Ive been working nearlyevery day(Im retired), so I have to agree with the year and a half estimateas a reasonable time to build the wings(and center section ).So 14 ribs(enough for one side of the wing), weighed very close to 5 pounds.I truly do not believe that it would make a big difference if the pile weighed 4 pounds, or 6. So strength of wood here is not a problem either because the capstrips are so large. Each laminated spar weighed 10 pounds at the start ofconstruction, so I began with 25 pounds of ribs and spars for each wing. Now the ailerons are installed with piano hinges, and the metal fittings,etc. And the wing weighs in at ------- pounds(Ill weigh them soon and report). The wings have really been a pleasure to work on, even if there is a multitude of parts. I built the tailfeathers first, then the fuse, then the CenterSection, finally the wings. Maybe if I built another Piet, I would do the wingsat the beginning.We have a 35 Piet on the airport, which is non-flyable, but interesting. Ithas a two-piece wing, which I am beginning to think is superior to the Vi Kapler design, since the aileron control cables can be run directly to each wing.Im still a little bit perplexed about how one connects the control cables through the Center Section in such a way that they can be easily re-connected.Im amazed at the difference the drag and anti-drag wires make to the rigidity of the wing. I put in some temporary hardware store wires to stiffen thewing while finishing it.The fellow next to me is building a scaled Jenny, and has installed 3/32 cables for the drag and anti-drag braces. He uses Cable Bushings rather than turnbuckles, twisting the cable to achieve the correct tension, after pulling thecable tightly around the Bushing. It is easy to adjust the tension, each half twist tightening the cable by about five pounds. His spec. calls for 35# tension, a figure I think that I will use. I made a set of turnbuckles early on,so cost is not a factor, rather the weight saving and simpler hardware seems to me to be worthwhile.I bought the folded trailing edge at AS&S. Planning to clean the aluminum carefully, then to Epoxy the T.E. to the ends of the ribs with T-88.________________________________________________________________________________
Subject: Pietenpol-List: Alternate Woods, status reportI do believe that the wood construction phase of my Piet is now virtually complete. I began in earnest to build Feb. 1, 2002, almost three years ago. Ive tried to use good Douglas Fir, and Basswood plywood wherever possible.Ayear or so ago I compared fuselage weights with someone on the list here, and I came up with 71 pounds, vs 70 pounds for a spruce fuse. I think that both fuses were in about the same condition, but nothing definitve can be drawn fromthese figures.I began work on the wings a summer ago, laminating the spars from Fir, 7 layers. The ribs were of fir, with basswood gussets. Ive been working nearlyevery day(Im retired), so I have to agree with the year and a half estimateas a reasonable time to build the wings(and center section ).So 14 ribs(enough for one side of the wing), weighed very close to 5 pounds.I truly do not believe that it would make a big difference if the pile weighed 4 pounds, or 6. So strength of wood here is not a problem either because the capstrips are so large. Each laminated spar weighed 10 pounds at the start ofconstruction, so I began with 25 pounds of ribs and spars for each wing. Now the ailerons are installed with piano hinges, and the metal fittings,etc. And the wing weighs in at ------- pounds(Ill weigh them soon and report). The wings have really been a pleasure to work on, even if there is a multitude of parts. I built the tailfeathers first, then the fuse, then the CenterSection, finally the wings. Maybe if I built another Piet, I would do the wingsat the beginning.We have a 35 Piet on the airport, which is non-flyable, but interesting. Ithas a two-piece wing, which I am beginning to think is superior to the Vi Kapler design, since the aileron control cables can be run directly to each wing.Im still a little bit perplexed about how one connects the control cables through the Center Section in such a way that they can be easily re-connected.Im amazed at the difference the drag and anti-drag wires make to the rigidity of the wing. I put in some temporary hardware store wires to stiffen thewing while finishing it.The fellow next to me is building a scaled Jenny, and has installed 3/32 cables for the drag and anti-drag braces. He uses Cable Bushings rather than turnbuckles, twisting the cable to achieve the correct tension, after pulling thecable tightly around the Bushing. It is easy to adjust the tension, each half twist tightening the cable by about five pounds. His spec. calls for 35# tension, a figure I think that I will use. I made a set of turnbuckles early on,so cost is not a factor, rather the weight saving and simpler hardware seems to me to be worthwhile.I bought the folded trailing edge at AS&S. Planning to clean the aluminum carefully, then to Epoxy the T.E. to the ends of the ribs with T-88.________________________________________________________________________________