Brodhead Pietenpol Association

Original Posted By: "Christian Bobka"
Friends-Some of you have asked for an update on my Piet since Brodhead so, here it is.I copied the intact half of John Greenlee's Ray Hegy prop onto my Red Oak/Mapleblank. John's prop was 76x44, mine is 2" shorter hence the pitch comes out abit higher. I have studied several sources about prop-building and can say withauthority that no two prop makers use the same data to arrive at their pitchnumbers. Some use half diameter, others use 2/3 diameter and some use the tip!!!Even the formulas that should be the one constant are interpreted differently.The point is; if you're looking for a prop, try to find what someone (or a lotof someones) are having success with and go with that. I measured my Falcon propthat was stamped 74x42 and the pitch came out to be 51" based on another sources'formulas!!!! Even the Sensenich at 44" pitch was more like 48". So whosefigures do you use? My advice is that unless you are willing to make severalprops, go with the crowd or copy a known quantity like I did.Now- the prop that I have made seems like it is a little better in the climb andcruises at a given speed at 50 rpm less than the Sensenich. Sounds like a winner,right? BUT the outside air temp is about 35 degrees cooler than when I flewto Brodhead so the jury is still out on performance until I can duplicatethe 90 degree days of summer. Of course by that time I should have a lot morehours on the "A" and that will help, too. I am very happy that I built (copied) my new prop. It certainly isn't any worsethan the two previous ones and it's one more thing that I can say is home-made.Makes me feel independent and "accomplished" but best of all, it gets me backinto the sky!Larryps. I found out that keeping the forward cockpit cover in place while flying (tryingto stay warm!) seems to create a lot more turbulence for the pilot. My nextstep is to take off the front windshield and see what effect that has.________________________________________________________________________________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Larry, I there anything special about this Hegy prop like the shape? Couldyou send a picture of either the busted up one or the new one?I might want to duplicate the busted up one as well...chris bobka-----Original Message-----

Original Posted By: Dave and Connie

Original Posted By: Isablcorky(at)aol.com
For those of us lucky enough to have flying Piets I have a question, actually two 1. are most of the Piets out there using cabane struts of the length shown in the plans?? and 2.Does standard length give adequate room for average size, nimble people to get in and out of the front pit without too much whineing. I'm getting ready to order tubing. I'd rather not lengthen them because that would raise the center of drag which might aggrevate any tail heavy tendancys that Piets with light engines are famous for. I know some guys have lengthened them.I guess I just need to know if it's really necessary. All opinions respected of course. TIA Ed G.>From: "LAWRENCE WILLIAMS" >Reply-To: pietenpol-list(at)matronics.com>To: "Jim Kinsella" , "John Greenlee" >, "Lou Larson" , "Michael >Madrid" , "Michael D Cuy" >, "Skip Gadd" , "Steve >Eldredge" , "Donny Emch" , >"Pietenpol-List Digest Server" >Subject: Pietenpol-List: Piet update>Date: Sun, 20 Oct 2002 22:08:38 -0400>>>Friends->>Some of you have asked for an update on my Piet since Brodhead so, here it >is.>>I copied the intact half of John Greenlee's Ray Hegy prop onto my Red >Oak/Maple blank. John's prop was 76x44, mine is 2" shorter hence the pitch >comes out a bit higher. I have studied several sources about prop-building >and can say with authority that no two prop makers use the same data to >arrive at their pitch numbers. Some use half diameter, others use 2/3 >diameter and some use the tip!!! Even the formulas that should be the one >constant are interpreted differently.>The point is; if you're looking for a prop, try to find what someone (or a >lot of someones) are having success with and go with that. I measured my >Falcon prop that was stamped 74x42 and the pitch came out to be 51" based >on another sources' formulas!!!! Even the Sensenich at 44" pitch was more >like 48". So whose figures do you use? My advice is that unless you are >willing to make several props, go with the crowd or copy a known quantity >like I did.>Now- the prop that I have made seems like it is a little better in the >climb and cruises at a given speed at 50 rpm less than the Sensenich. >Sounds like a winner, right? BUT the outside air temp is about 35 degrees >cooler than when I flew to Brodhead so the jury is still out on performance >until I can duplicate the 90 degree days of summer. Of course by that time >I should have a lot more hours on the "A" and that will help, too.>I am very happy that I built (copied) my new prop. It certainly isn't any >worse than the two previous ones and it's one more thing that I can say is >home-made. Makes me feel independent and "accomplished" but best of all, it >gets me back into the sky!>>Larry>>ps. I found out that keeping the forward cockpit cover in place while >flying (trying to stay warm!) seems to create a lot more turbulence for the >pilot. My next step is to take off the front windshield and see what effect >that has.>>Choose an Internet access plan right for you -- try MSN! http://resourcecenter.msn.com/access/pl ... __________

Original Posted By: Kip & Beth Gardner
Subject: Re: Pietenpol-List: Cabane surveyEd,I went 2" longer as ala Mike Cuy. I like the additional room and especially the vision. About the extra drag, don't even consider it as a Piet is a Piet and like most water vessels it has a definite hull speed and no matter what you do to it power or minimize drag you will probably still fly low and slow and have a ball. My next Piet, if you believe in that reincarnation stuff, I will use round tubes for all struts and streamline with balsa and dacron. Lindbergh did it that way why not PietersCorky with 41CC and 9 hrs of test time behind it.________________________________________________________________________________Date: Wed, 23 Oct 2002 19:19:55 -0400