Brodhead Pietenpol Association

Original Posted By: Mark Roberts
Subject: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Jeff Boatright

Original Posted By: "x GOYENI "
Subject: Re: Pietenpol-List: Riblett 612 CoG RangePieters Is the 612 the what is used on aeronica?**************A Good Credit Score is 700 or Above. See yours in just 2 easy steps! JulystepsfooterNO62)________________________________________________________________________________

Original Posted By: Mark Roberts
It is true Jeff, I did not remember that today is America's Independence Day.Congratulations to all Americans from the southern South America.Thanks Jeff and Tim for your posts.See you at Brodhead Juan GOYENI________________________________________________________________________________Date: Sat, 4 Jul 2009 16:28:44 -0700Subject: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Mark Roberts
Subject: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Tim Willis

Original Posted By: "Pieti Lowell"
Bill,Just to repeat what others have said, McCormick's would be your best choice. Iwas there about a month ago to pick up some 1/8" Okoume plywood for the Pietand I checked out the sitka spruce at the same time. Very nice boards and theywould work well for you if you're using 3/4" spars.PaulRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Isablcorky(at)aol.com
Mark,I will talk about my 612 at my Brodhead Form ,with 3 years and a number of engineson this foil. If you are under 180 Lbs I will give you a demo you will neverforget, The air foil you show is very close to the 612.Pieti LowellRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: johnwoods(at)westnet.com.au

Original Posted By: johnwoods(at)westnet.com.au

Original Posted By: Jeff Boatright
Thanks so much for the information JW.WillRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Sun, 5 Jul 2009 10:42:50 -0400

Original Posted By:> "Pieti Lowell"
Hi John,Thanks for reposting the spreadsheet with the Riblett numbers - I'm not very adept at using the archive search function. I'd already made a jig for the standard airfoil, but now I'm seriously considering changing.Like several others, I won't be able to be at Brodhead this year, so I'd REALLY appreciate a few comments from Mr. Lowell if he's willing to take the time to answer.My specific questions are:Can someone either describe or point me towards a simple explanation of how to draw out a rib BY HAND (No CAD), from the spreadsheet numbers? I know how to 'loft' boat ribs, but the numerical data for boats is in a significantly different form.Where on the Riblett section (% of Chord, absolute distance, however you want to describe it) do the spars fall? Same as the std. airfoil or is there some variation? I assume that the distance between spars stays as per plans.Thanks!Kip GardnerOn Jul 5, 2009, at 9:24 AM, johnwoods(at)westnet.com.au wrote:>> Pieti,>> With 3 years of flying experience with the 612, would you be able > to comment on the CoG range of this section.> Thanks> JohnW> Perth, W/Australia>> ----- Original Message -----

Original Posted By: Mark Roberts
Subject: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Mark Roberts
Subject: Re: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Mark Roberts
Subject: Re: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Ameet Savant

Original Posted By: Mark Roberts
Subject: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Ryan Mueller
Thanks Ameet,So if I understand you correctly, the positive and negative values are the distances, in inches, above or below an arbitrary y-axis at any given point along the x-axis?That makes sense, and maybe I'm being dense, but I just want to be sure I understand what you are describing.So I guess what's puzzling me is that this airfoil section seems thicker than the standard Piet airfoil? It looks like the thickness at the 25% station is 7.130 inches? The thickness of the std. Piet airfoil is roughly 6.5" at the same point. if I'm figuring this correctly, then some filler may be necessary above or below the spars?Regards,Kip GardnerOn Jul 5, 2009, at 5:33 PM, Ameet Savant wrote:> >>> Kip,>> Plot the "chord" column values on the x-axis.>> for every x- axis value:> Plot the "above" column values on the positive y axis> Plot the "below" column values on the negative y axis>> If you wish to plot to a different size than the 60in shown, use > the the % Chord columns (leftmost three) as they are scaled to one > (1) unit scale. All you have to do is pick the chord length and > that becomes your scaling factor.>> This reminds me of when I was a boy and was learning drafting. The > first thing I wanted to learn was drafting an airfoil and the > drafting process was explained in this Northop Grumman book/manual > about aircraft construction. I drafted my first full scale aircraft > airfoil after reading about it. Since then I have accepted the fact > that a 12in chord is just not going to be enough for a full scale > plane ), but hey, that is the only size paper I had available > then >> Ameet Savant> Omaha, NE>> --- On Sun, 7/5/09, Kip and Beth Gardner > wrote:>>> Can someone either describe or point me towards a simple>> explanation of how to draw out a rib BY HAND (No CAD), from>> the spreadsheet numbers? I know how to 'loft' boat>> ribs, but the numerical data for boats is in a significantly>> different form.>>>> Kip Gardner>>________________________________________________________________________________Date: Sun, 5 Jul 2009 19:01:59 -0500Subject: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: _johnwoods(at)westnet.com.au_ (mailto:johnwoods(at)westnet.com.au)
Subject: Re: Pietenpol-List: AIrfoil can of worms?Back about 3 years ago and on the verge of starting my build I had a chance to visit another builder, I marveled at his project and asked many questions while in the midst of research study and contemplation. During my conversation with that noted award winning Texas builder I came away with a greatpiece of sage wisdom, He said" don't waste you time thinking it, just start building and stop wasting time. he also said that once you begin the build it will all make sense" I took those well placed words and followed theadvice of Hans Vandervort, he certainly knew what he was talking about. When I got home I committed to the build and began now that's not to say I haven't run into a snag here and there and even the dreaded builders block, butgiven a chance you project will speak to you. You just have to listen to her.I been building for the last 3 years and there isn't a day I don't do something to advance my project, knowledge or skill level. I cant think of abetter way to spend the stolen minutes of a work day or the hour and a half commute or the road trip working on my Piet. She's been a real inspiration to meJohnIn a message dated 7/5/2009 8:06:24 P.M. Eastern Daylight Time, rmueller23(at)gmail.com writes:Mark,I would say: turn your energy from plotting Riblett coordinates towards cutting and gluing wood on the rib jig you are going to recieve. The Riblett may be a small improvement on the Piet, and I don't question it's usefulness....but you have a jig coming, and you have a tremendous amount of enthusiam right now. Channel that towards making solid progress on your build.The Piet airfoil, designed by an amateur as it was, has been successfully built and flown by many many people in the past 80 years; safely at that. Don'toverthink this. Just build!RyanOn Sun, Jul 5, 2009 at 5:09 PM, Mark Roberts wrote:Continuing along the journey of discovery, I checked my airfoil plot from yesterday against the plot coordinates from John (thanks again!) and found them to be almost identical. So, I now have a new question about the center line and it's relation to incidence once on the spar... The image attached shows the spars are perpendicular to the baseline. The trailing edge is elevated 1/2" from the baseline. Is this an issue? Or does the wing mount and attachment work out centerline issues when installed? Not sure I am clear here, but I am curious about the spars and whether they should be perpendicular to the median chord line (drawn centered betweenthe LE and the TE) or if they should be perpendicular to the baseline the plot was generated from (see the diagram below).Also, the Full sized Piet Rib Pattern I received does not show a rib riser on the LE of the front spar, or the TE of the rear spar. I drew this 612 rib pattern out the same way. I get it that the spar acts as one BIG riser stick but I still look at it and think one should be there, but I am guessing it is unnecessary...Thoughts? I hope to be starting ribs here soon )MarkPS: Thanks for all of the patience with the questions... On Sun, Jul 5, 2009 at 9:52 AM, Mark Roberts wrote:Thanks John!! I really appreciate the file. I dug through all of the archives and didn't see it, but it wasn't until late in my search that I saw anyattachments at all on any post, so I might have overlooked it in my lack of understanding the archive. Thanks again! I will check my plot.Many thanks!!MarkOn Sun, Jul 5, 2009 at 5:58 AM, wrote:Ooops.. forgot the attachement... JohnW ----- Forwarded Message -----

Original Posted By: Jim
Piet People,612 stuffI know those of you that won't be at Brodhead would like to have a lot of questionsanswered. I think patients will work, as many questions will be asked thatwe now don't even have good answers.But I started with Mr Ribblett in the very early 90s. communicated for a coupleyears, he said that there is much better airfoils than the Piet after I senthim the coordinates. He sent me reams of calculations and curves, and computerread-outs plus his final thinking. I decided to keep the foil close to lookinglike a Piet foil, Ribblitt's second choice. 613.5 his 1St.I laid the numbers on a layout table and they matched the sent profile, exceptfor a very slight shrinkage, It was a start.He suggested I use 33% figure for the CoG to start and let him know what it feltlike. I will need to look over all his letters to check if he changed his thinking.I constructed the 612 just as I built the Piet foil, but added fillers due to theadded height. But since this foil seemed more efficient I shortened each wing12". It works very well, so those of you that are going 612 keep it the samelength as the Piet's foil. if you are concerned about hot weather , heavy loads,altitude or better rate of climb,If you want to live on the edge shorten the wing for a much faster roll rate, anda lot of solo. add HP it will perform very quick.This is an overview , got questions ? will answer the best I know how.Pieti LowellRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Mon, 6 Jul 2009 03:40:41 +0000 (GMT)

Original Posted By: Mark Roberts
Subject: Re: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Tim Willis

Original Posted By: Tim Willis

Original Posted By: "gcardinal"
I'm using the riblett and a built up spar with a top and bottom spruce cap and1/8 ply with spruce blocking between the caps,I made the spars bigger to fit theribs my thinking being that the extra weight in the blocking would be aroundthe same as putting it at the top as a filler.I can't see that this would degrade the strength of the sparCould someone with the knowledge on this, chime in with there thoughts?ThanksCarsonRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: "carson"
Go to Chris Tracy's website www.westcoastpiet.com and look under the "Construction" page where you will find a couple of good articles on built up spars.Greg Cardinal----- Original Message -----

Original Posted By: "Will42"
Subject: Re: Pietenpol-List: AIrfoil can of worms?Mark,I don't believe anyone is making accusation but rather offering advice, as no one wants to see you waste time or loose the great enthusiasm and zeal you have for the project. As you stated the delay and study is more an intellectual journey until the budget comes around, then by all means continueyou're research, questions and analysis. Good preparation makes for a good project. As I believe I speak for most, don't get too caught up on over thinking the project. As soon as the Jig and materials arrive its time to put the research and planning to work. Good luck and happy building. One warning though, the building process can become highly addictive.John**************An Excellent Credit Score is 750. See Yours in Just 2 Easy Steps! yExcfooterNO62)________________________________________________________________________________Subject: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Isablcorky(at)aol.com
"RIB CAPS: I was AMAZED to see a few minutes ago that on the ORIGINAL Piet drawingsfor the rib (dated 3-3-34) there are NO rib caps at all, front or rear ofeither spar. However, I believe everyone builds with several rib caps-- at leastthe two inner ones. Somewhere in the Piet drawings I recall, but cannot nowfind, an "improved rib drawing." On my ribs there is a front rib cap, as youcall it, for both the front and rear spar. My ribs do NOT have a rear rib cap.Looking at pictures of other builds, I see that a few guys have only inner ribcaps, while some have a front rib cap, and some apparently have all four ribcaps. IMO, you will need at least the two inner rib caps to have a more solidbuild than a pure reliance upon compression struts engenders. "I'm lost as to what you are saying here; did you intend to say inner bracing insteadof caps? In a built-up rib, I can't see how one could have a rib, at all,without a rib cap strip.WillRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: "Ed G."
Subject: Re: Pietenpol-List: AIrfoil can of worms?Amen on John's advice, but DON'T stop your mental work. It is a must with the building. Once building you will do as much building while trying to sleep at night, if you are like most of us who will admit it. This Piet building is very addictive. Also, if you begin a Piet, build it at a normal rate(slow) and finally complete it and best of all fly it, you will have an equilivant college education of most of today's institutions of higher learner. When one begins to build a Piet they have no conception as to how manyareas of expertise and allied skills will be involved. Think each problem outcompletely before sanding, cutting or glueing. Learning is actually the correction of mistakes. On a project like this we can't afford to make unnecessary errors. Pardon my interference and soap boxing but I feel very strongon this subject.Corky**************An Excellent Credit Score is 750. See Yours in Just 2 Easy Steps! yExcfooterNO62)________________________________________________________________________________

Original Posted By:> will(at)cctc.net
Hi Will... The origional plans call for nailing through the top and bottom cap strips into the to spars to retain the ribs. I'm guessing this practice came from WW1 planes which weren't expected to have a very long life span. Experience shows that over a long period of time the nails have a tendency to work their way out under the fabric and or rust causing problems later on. So=2C yes=2C the excepted practice has been to add verticles to the rib in order to fasten the ribs to the spars. I added just the inner ones and T-88d them to the spars. Now I wish I had just put a couple nails in each verticle which would make it easier to make adjustments or even replace a rib or a spar in the future. Put in the outer uprights dosen't seem to add anything except weight ( my opinion). Hope that helps...Ed G. > Subject: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Mark Roberts
Already got a response. Thanks everybody!Lorin--------Lorin MillerWaiex N81YXPietenpol next upRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Mon, 6 Jul 2009 12:35:15 -0700Subject: Re: Pietenpol-List: AIrfoil can of worms?

Original Posted By: Mark Roberts
Subject: Re: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: "Richard Schreiber"
H. Riblett's Notes to Me 12/27/91. Ref: GA 3OU-612.Cord, no flaps, 15%, CoG-28% , Center Line of pressure-18". Max, 30%, 16"=24".I can bring much of his notes and calculations to Brodhead for all to ponder, andcopy if you have a copier available. Much of his stuff also covers the GA3OU-613.5, And others.Foe those of you that like to crunch numbers He sent me a basket full.Pieti LowellRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: Roman Bukolt
Subject: Re: Pietenpol-List: Re: AIrfoil can of worms?Mr lowell, I appreciate the material sent but I'm a bit slow. Could you explain a little more in detail those numbers and %s. Thank youCorky**************An Excellent Credit Score is 750. See Yours in Just 2 Easy Steps! yExcfooterNO62)________________________________________________________________________________

Original Posted By: "Jack Phillips"
Someone should record it.twOn Jul 5, 2009, at 5:54 AM, johnwoods(at)westnet.com.au wrote:> ...> I wish I could be at Brodhead to hear Mr Pieti Lowell's forum on > the 612's performance.> ...________________________________________________________________________________

Original Posted By: "Michael Silvius"
Sorry, it has taken me a few days to get through email trail. Did someone record Mr. Lowell's presentation?twOn Jul 7, 2009, at 3:39 PM, Terry Williams wrote:> Someone should record it.>> tw>> On Jul 5, 2009, at 5:54 AM, johnwoods(at)westnet.com.au wrote:>>> ...>> I wish I could be at Brodhead to hear Mr Pieti Lowell's forum on >> the 612's performance.>> ...>>________________________________________________________________________________

Original Posted By: "Pieti Lowell"
I would appreciate any tips out there from those of you who have flown cross country and "packed" for same. I've started trial packing using the front seat and the lap and shoulder harnesses.Looks like it will work, especially avoiding anything that would bind controls. Weight is not an issue but volume of stuff. I suspect there is good advice out there from those of you who have done this before. Besides a minimum of clothes, I'll bring tie downs, a small tent,blanket, sleeping pad, shaving gear, engine oil, camera, money!, cockpit covers to keep my seat dry etc.The important stuff to keep dry I'll put in kayak dry bags. All of it will be bagged.But, some of you have done this before--so--any good tips out there?My route will be around the north end of Lake Michigan and then down the Door Peninsula of Wisconsin to Brodhead, about 375 miles. At the moment I have 27 hours on the plane, landings are getting better and my longest trip thus far has been ~60 miles.I mentioned earliar that my trip is tied to my wife's medical situation. At the moment she is stable and her mom will be coming to stay with her while I'm gone. I can't take the time to go to Oshkosh as well. I have been to Oshkosh with my first plane and have driven to Brodhead twice beore. I am really looking forward to putting faces on the names on e-mails and thanking "you" for your advice and comments in person.Jim Lagowski, NX221PT, just north of Traverse City, Mi.________________________________________________________________________________Subject: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Tim Willis
Corky, I think what Riblett was saying that' 30 % of the 60" cord is 18"' and Littleless than 28 % to Max 40 % gives the figures of 16.8 " to 24 ". That is the only way my simple mind figures these things out, but to prove I'mwrong or right or some thing, I installed the Werner 145 , that put the forwardCoG to 18 ". and as you may know, I flew that combo for 2 years . With my weight,well over 200 Lbs and sitting on 100 Lbs of steel disks, the CoG was closeto 40 " and a lighter engine up front, the Piet also flew . not as well. Wouldnever do tight turns or spins..The more knowledge Pieters can give better answers when they go over all of Riblett'sspecs, that he sent me.I think the 15 % figure is a thickness number fora much deeper airfoil, I think the Piet % is close to10.3 %. This is definedin some of Ribletts letters of which I will try to bring to Brodhead.Pieti LowellRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 8 Jul 2009 22:51:16 -0500 (GMT-05:00)

Original Posted By: Isablcorky(at)aol.com
Subject: Re: Pietenpol-List: Re: AIrfoil can of worms?Thanks Lowell,Please keep me on your mailing list for info on this subject. I am committed to this airfoil for NX241CC. I just want a little float after roundout.Corky**************Dell Studio XPS Desktop: Save up to $400 - Limited Time Offer p:%2F%2Faltfarm.mediaplex.com%2Fad%2Fck%2F12309%2D81939%2D1629%2D3)________________________________________________________________________________

Original Posted By: "899PM"
Subject: Re: Pietenpol-List: Packing for BroadheadA good fly swatter and some "kill those damn flys spray"**************Dell Studio XPS Desktop: Save up to $400 - Limited Time Offer p:%2F%2Faltfarm.mediaplex.com%2Fad%2Fck%2F12309%2D81939%2D1629%2D3)________________________________________________________________________________Subject: Pietenpol-List: Re: Packing for Broadhead

Original Posted By: John Hofmann
Jim,What a great adventure! Hartford (HXF) is a nice stop for cheap fuel and a GREATN/S grass strip. Should be lot's of activity there. No food. About 70 milesto Brodhead from HXF. Skirt the west side of Lake Koshkonong to stay well clearof Madison airspace. One very TALL tower NE of Brodhead to watch for. Lookforward to meeting you. Mike--------PAPA MIKERead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: CozyGirrrl(at)aol.com
In my Cub (which was passed by a Pietenpol last year and I am still irked), that tower and Lake Koshkonong seem to take about eight days to pass. Once past the tower you are to Brodhead in about ten minutes. Figure 60 minutes from Hartford to Brodhead.-john-John HofmannVice-President, Information TechnologyThe Rees Group, Inc.2810 Crossroads Drive, Ste 3800Madison, WI 53718Phone: 608.443.2468 ext 150Fax: 608.443.2474Email: jhofmann(at)reesgroupinc.comOn Jul 9, 2009, at 8:07 AM, 899PM wrote:> >>> Jim,>> What a great adventure! Hartford (HXF) is a nice stop for cheap fuel > and a GREAT N/S grass strip. Should be lot's of activity there. No > food. About 70 miles to Brodhead from HXF. Skirt the west side of > Lake Koshkonong to stay well clear of Madison airspace. One very > TALL tower NE of Brodhead to watch for. Look forward to meeting you. > Mike>> --------> PAPA MIKE>>> Read this topic online here:>> http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: "Pieti Lowell"
> --> Pietenpol-List message posted> by: Kip and Beth Gardner > > Thanks Ameet,> > So if I understand you correctly, the positive and negative> values are the distances, in inches, above or below an> arbitrary y-axis at any given point along the x-axis?> > That makes sense, and maybe I'm being dense, but I just> want to be sure I understand what you are describing.> > So I guess what's puzzling me is that this airfoil section> seems thicker than the standard Piet airfoil? It looks> like the thickness at the 25% station is 7.130> inches?The thickness of the std. Piet> airfoil is roughly 6.5" at the same point. if I'm> figuring this correctly, then some filler may be necessary> above or below the spars?> > Regards,> > Kip Gardner ________________________________________________________________________________Subject: Pietenpol-List: Re: AIrfoil can of worms?

Original Posted By: Tim Willis
> To: pietenpol-list(at)matronics.com> > > "RIB CAPS: I was AMAZED to see a few minutes ago that on the ORIGINAL Piet drawingsfor the rib (dated 3-3-34) there are NO rib caps at all, front or rearof either spar. However, I believe everyone builds with several rib caps-- atleast the two inner ones. Somewhere in the Piet drawings I recall, but cannotnow find, an "improved rib drawing." On my ribs there is a front rib cap, as youcall it, for both the front and rear spar. My ribs do NOT have a rear rib cap.Looking at pictures of other builds, I see that a few guys have only innerrib caps, while some have a front rib cap, and some apparently have all fourrib caps. IMO, you will need at least the two inner rib caps to have a more solidbuild than a pure reliance upon compression struts engenders. "> I'm lost as to what you are saying here; did you intend to say inner bracinginstead of caps? In a built-up rib, I can't see how one could have a rib, at all,without a rib cap strip.> > Will> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 711#251711> > > >> > > Lauren found her dream laptop. Find the PC thats right for you. ________________________________________________________________________________Date: Mon, 6 Jul 2009 12:43:09 -0500 (GMT-05:00)