Original Posted By: Richard DeCosta
I recommend to all builders and dreamers of Pietenpols, to get Mike's video.Got it yesterday and only thru half, but it's a great, down to earth,informative tape.I've already gotten oodles of ideas from it. Good work, Mike.Now I've got a question,,,I'm making my cowling, and wondering what you didto the alum. around the openings to finish the edge? I've seen some justroll the edge, and others roll a piece of wire for roundness.thanks,walt evans-----------------------------------------------------Click here for Free Video!!http://www.gohip.com/freevideo/________ ... ______Date: Fri, 14 Jul 2000 05:04:06 -0700 (PDT)
Pietenpol-List: Bravo, Mike Cuy!
Re: Pietenpol-List: Bravo, Mike Cuy!
Original Posted By: fishin
The wire in the rolled edge is not for "roundness" but adds quite a bit ofstrength. Without the wire, the best you can do is double the aluminumback over itself. Once it is flattened, the edge is no stronger than itwas in the first place.The rolled edge is not as hard as it looks. Get a piece of hard wire (nottoo soft!) maybe 3/16" or slightly less. On big biplanes, I use 1/4", butthat is too big for a Piet. Figure out how much metal it takes to roll allthe way around the wire. For 1/4", I think is it about 3/4", for 3/16", Iwould guess 1/2". Cut your sheet metal with that much extra all the wayaround the cockpit opening, and draw a line where the finished edge shouldbe. Take a long piece of square hardwood (1"x1" or something) and cut a narrowslot in the end of it to the 1/2" (or whatever) depth so that it is a tightfit on the metal. Then round over one outside edge so that the point isabout the same radius as the wire you are using (I'll explain why in asecond). Working around the cockpit opening, gradually bend the flange up. It iseasier to bend the flange to the outside so that the wire ends up on theoutside of the metal rather than the inside. Once the padding is on, youcannot tell the difference anyway (it is on the outside of most of the old1920's biplanes). When the flange gets to 90 degrees, one side of thehardwood tool would be flat against the metal, this is why you round offone side, so that you can bend the flange past 90 degrees and make theinside radius of the bend about the same size as your wire.At this point, you may need to trim some of the metal because ofstretching. If you have too much excess, the metal will not roll tightlyaround the wire. Too little, though, and it will not hold the wire infirmly.Now you are ready to install the wire. There are two ways to do this, yourchoice. I personally put the metal on a jig or tie it with safety wire sothat it is in the approximate shape it will be on the airplane. I thenbend the wire to shape to fit in the flange. I have friends, however, wholeave the metal flat on a table, install the wire flat, and bend the entirepiece to fit the airplane after the wire is installed. Personally, I donot like this method because it makes the metal harder to install without"scalloping" because it wants to spring back, but with the smaller wiresize on a Piet, it may be perfectly "doable".Once the wire is laid into the channel, bend the flange on around the wiretightly. I use a pair of well-worn smooth-jawed duckbill pliers and workit around gradually. (you WILL have blisters, though!) If you have judgedthe length of the excess just right, when the metal gets around so that ittouched itself, it takes a slight "pop" to make it tuck under the edge ofthe wire. I do this with a light tack hammer and a sharpened piece ofwood. Once the metal tucks underneath the edge of the wire, it is amazinghow stiff the edge is.Having said all of this, I am not sure what different ways people are doingtheir Piets. I have seen some with no reinforcing at all, which may be OK,too. On a homebuilt, I have also taken a piece of hard aluminum tubing,bent it to shape, and riveted it to the edge of the metal. This is verystrong, too, but the hard tubing is a bear to bend into a complex shape.How's his for an answer to a question that you didn't even ask? If anyoneis interested, and this is too confusing, I can try to make up a couple ofdrawings of what I am talking about.________________________________________________________________________________Date: Fri, 14 Jul 2000 08:26:44 -0500
The wire in the rolled edge is not for "roundness" but adds quite a bit ofstrength. Without the wire, the best you can do is double the aluminumback over itself. Once it is flattened, the edge is no stronger than itwas in the first place.The rolled edge is not as hard as it looks. Get a piece of hard wire (nottoo soft!) maybe 3/16" or slightly less. On big biplanes, I use 1/4", butthat is too big for a Piet. Figure out how much metal it takes to roll allthe way around the wire. For 1/4", I think is it about 3/4", for 3/16", Iwould guess 1/2". Cut your sheet metal with that much extra all the wayaround the cockpit opening, and draw a line where the finished edge shouldbe. Take a long piece of square hardwood (1"x1" or something) and cut a narrowslot in the end of it to the 1/2" (or whatever) depth so that it is a tightfit on the metal. Then round over one outside edge so that the point isabout the same radius as the wire you are using (I'll explain why in asecond). Working around the cockpit opening, gradually bend the flange up. It iseasier to bend the flange to the outside so that the wire ends up on theoutside of the metal rather than the inside. Once the padding is on, youcannot tell the difference anyway (it is on the outside of most of the old1920's biplanes). When the flange gets to 90 degrees, one side of thehardwood tool would be flat against the metal, this is why you round offone side, so that you can bend the flange past 90 degrees and make theinside radius of the bend about the same size as your wire.At this point, you may need to trim some of the metal because ofstretching. If you have too much excess, the metal will not roll tightlyaround the wire. Too little, though, and it will not hold the wire infirmly.Now you are ready to install the wire. There are two ways to do this, yourchoice. I personally put the metal on a jig or tie it with safety wire sothat it is in the approximate shape it will be on the airplane. I thenbend the wire to shape to fit in the flange. I have friends, however, wholeave the metal flat on a table, install the wire flat, and bend the entirepiece to fit the airplane after the wire is installed. Personally, I donot like this method because it makes the metal harder to install without"scalloping" because it wants to spring back, but with the smaller wiresize on a Piet, it may be perfectly "doable".Once the wire is laid into the channel, bend the flange on around the wiretightly. I use a pair of well-worn smooth-jawed duckbill pliers and workit around gradually. (you WILL have blisters, though!) If you have judgedthe length of the excess just right, when the metal gets around so that ittouched itself, it takes a slight "pop" to make it tuck under the edge ofthe wire. I do this with a light tack hammer and a sharpened piece ofwood. Once the metal tucks underneath the edge of the wire, it is amazinghow stiff the edge is.Having said all of this, I am not sure what different ways people are doingtheir Piets. I have seen some with no reinforcing at all, which may be OK,too. On a homebuilt, I have also taken a piece of hard aluminum tubing,bent it to shape, and riveted it to the edge of the metal. This is verystrong, too, but the hard tubing is a bear to bend into a complex shape.How's his for an answer to a question that you didn't even ask? If anyoneis interested, and this is too confusing, I can try to make up a couple ofdrawings of what I am talking about.________________________________________________________________________________Date: Fri, 14 Jul 2000 08:26:44 -0500
Re: Pietenpol-List: construction order
Original Posted By: Michael D Cuy