Brodhead Pietenpol Association

Original Posted By: "Ryan Mueller"
Subject: Pietenpol-List: Magnetic woodNice story Oscar, gives all us in the process of the build something to look forward to.I been down and out of work for the past week , just had knee surgery if not for the no driving thing I would have been back in action sooner. At any rate I been in transition all week from a imp to a limp to a hobble and back to the gimp. The doc said it went really well, as if he was gonna say anythingdifferent? Like, "I really botched it, I guess I should have stayed home today instead of screwing up your knee..... The good news is they let me work from home that helped. If I had to sit home and watch Oprah all I think I would just shoot myself and be done with it once and for all.As it worked out I got a chance to sneak over to the project and get some work done, I got the elevators and rudder about finished short of the metal parts and the horizontal stabilizer is on the bench in the lay out jig up stage. All in all I got some serious building done lately, bum knee and all. Oh yeathe cane thing evokes no sympathy at all from anyone family of outside so no help there. Which is fine with me, ask for nothing and get what you asked for is not a disappointment, its what's expected and if you do get something like help or service its more than you expected making it even better. Simple rule of life I suppose.Ask for nothing, ,expect nothing and anything you receive is a benefit to be cherished.At any rate I been working on the magnet just waiting for my turn to wow the crowds in feats of aeronautical excellence maybe the greatest display of aeronautical skill since the invention of the aeroplane....just thought I would share the adventure with ya,John**************Play online games for FREE at Games.com! All of your favorites, no registration required and great graphics =93 check it out! http://www.games.com?ncid=emlcntusgame00000001)________________________________________________________________________________Date: Sun, 26 Oct 2008 23:17:03 -0500

Original Posted By: owner-pietenpol-list-server(at)matronics.com [mailto:owner-pietenpol-lis
Michael, if you look in the archives under lift struts you will find many questions answered.- As for Jury struts, I ran a stress analysis many years ago examining the need for them.- I don=92t have a copy of it at hand now, but it was published in the BPA Newsletter sometime back in 1996.- It came to the conclusion that Jury struts are necessary to prevent buckling of the lift struts under negative G loads.- You can get some pretty substantial negative G loading from moderate turbulence, or a hard landing.- The jury struts should not be placed at the exact middle of the lift struts to prevent harmonic vibrations.-As for leaving the struts round, there are two reasons not to do that.- One ' they=92re ugly.- Two ' a Pietenpol doesn=92t need any help producing drag ' it makes quite enough on its own, without giving it any help, and a cylinder is one of the highest drag shapes there is (which is why streamlined struts actually produce less drag than round flying wires).- It is quite feasible to make struts with round tubing, with wooden streamlined fairings.- Some Piets (including the Canadian built one that won a Lindy award at OSH 2007) have lift struts made entirely of wood. -Jack PhillipsNX899JP-

Original Posted By: Michael Perez

Original Posted By: "Phillips, Jack"

Original Posted By: Michael Perez

Original Posted By: "Bill Church"
Michael;There is another option as well: use round steel tubing (more efficient and affordable) and then slide on molded plastic streamline fairings that the ultralight guys use. Easier to do than making wooden fairings to streamline the round tubing. These used to be available through SkyTek but I don't see them anymore: http://www.ultralightnews.ca/streamline ... .htmlThese plastic streamline fairings were installed on the prototype M-19 "FlyingSquirrel", which uses round 4130 steel wing lift struts. The airplane cruisesat 75-80MPH and picked up about 5 MPH after installing the streamline fairingson the wing struts only. I'm not saying that it will make that big a differenceon the Piet, but there is a very large drag difference between round tubingand streamlined. It's on the order of 2 to 3x the drag.The jury struts, cabane braces, and gear legs on 41CC are simple round tubing butcabanes and wing struts are streamlined.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Michael,Yes, some builders use aluminum struts. They are generally much cheaper thannew 4130 streamline tubing. Here is one source:http://www.sky-tek.com/struts.htmlAlso check out DJ Vegh's website:http://www.imagedv.com/aircamper/log/im ... 03.htmPaul Poulin, the builder of the Canadian Piet mentioned by Jack, commentedthat he built his wooden lift struts (solid laminated White Ash) and thenweighed them and found them to be slightly lighter than streamlined steellift struts from a Piper Tri-Pacer (I think).I like Jack Phillips' Number One reason not to use round steel tubing as-is.They ARE ugly.Using round steel tubing, faired with wood, and wrapped with tape, thendoped was a typical practice used on aircraft of the same vintage as thePietenpol (see attached detail from Corben Cabin Ace plans).There has been quite a bit of discussion about this stuff in the past. Ifyou've got a bit of time on your hands, check the archives. _____