Brodhead Pietenpol Association

Original Posted By: RAMPEYBOY(at)aol.com
Chuck;Noble undertaking! I wouldn't consider the following to be "errors" in the plans, but they certainly have proven to need updating to make the plane easier to understand how to build.1. Many have pointed out, Mike Cuy in his video especially, that many of the fittings are dimensioned so close that the bolt tabs are too close to the fabric or wood to allow the bolt and nut to be installed readily, much less get a socket and wrench on them. There isn't any exhaustive list of which fittings this applies to, but generally speaking, anything with a mounting tab protruding from a finished surface, could stand to have a bit of extra length.2. Many, many of the clarification questions asked here have to do with "what does 12 gauge fence wire convert to if I'm using 7x19 aircraft cable", and the like. Metal gauges, turnbuckle callouts, tension wire nomenclature, and a few bits and pieces of old-time materials that are scarce or unavailable, such as the streamline tubing that the plans call for. It isn't difficult to cross-reference to a newer material, but it could stand some updating.3. Can anybody explain why the old Flying & Glider manuals show the plywood seat back for the front cockpit, on the FRONT of the framing, while the newer plans show it on the BACK? 41CC is built per plans, with the plywood on the BACK of the framing (facing the rear cockpit) and I'm going to add a cushion to that because it's uncomfortable for the passenger to lean against the framing members.PS- I just started watching Chuck's "Flying NX770CG" video and it is a hoot! Excellent! I will say this, though... Chuck goes through the takeoff roll over and over from several different camera angles and it makes it seem like his airplane requires about 4000 ft. of grass to takeoff from ;o) Every Piet lover has to have this video!Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________

Original Posted By: Waytogopiet(at)aol.com
Subject: Re: Pietenpol-List: building videoIn a message dated 12/18/2005 12:33:24 PM Eastern Standard Time, taildrags(at)hotmail.com writes:PS- I just started watching Chuck's "Flying NX770CG" video and it is a hoot! Excellent! I will say this, though... Chuck goes through the takeoff roll over and over from several different camera angles and it makes it seem like his airplane requires about 4000 ft. of grass to takeoff from ;o) Every Piet lover has to have this video!Where can we get a copy of this video?________________________________________________________________________________

Original Posted By: "Oscar Zuniga"
Well, as long as we're piling onto good old Chuck "Baby Oil" Gantzer with things to think about for his building video, here's more good information. Some is in the way of tips, some gives alternate ways to do the same thing, some is clarification "British style". It's from the UK Piet builders' website, at http://www.pietenpolclub.co.uk/builders ... znotes.htm . On that page if you scroll down to "Chris and Fran Barley's Fuselage Notes" there is some good insight and clarification on some things.On a cold and rainy day you can spend quite a bit of time perusing the photo gallery that the Brits have on their website. Just go to their main page, http://www.pietenpolclub.co.uk/default.htm , and click on 'Photo Gallery'. For something really nifty, look closely at the image on Peter Hill's image page (UK Projects) at http://www.pietenpolclub.co.uk/gallery/ ... m=48&pos=1 to see the tubing bracket that they used to install passenger cockpit shoulder harnesses onto. It conceals behind the pilot's instrument panel, doesn't interfere with any of the cables, and provides a very secure shoulder strap mounting. There is a similar one on G-BYZY utilizing a single-point shoulder harness; see image at http://www.pietenpolclub.co.uk/gallery/ ... m=31&pos=6 or go to the images of G-BYZY.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________

Original Posted By: Rick Holland
I realize I've about worn out my welcome here, but I note one more item that could be mentioned.To locate the mounting position of the elevator bellcrank behind the pilot's seat, on Dwg. #1 (dated 1-19-33 in my plans set), the centerline of the pivot shaft is dimensioned as 7" up from the lower edge of the lower longeron. On Dwg. #4 (dated 2-26-34) the detail of the same bellcrank shows that dimension as 9". Is there a 2" discrepancy, or am I missing something?If you use pulleys under the pilot's seat to direct the elevator cables to the bellcrank (rather than holes drilled in the seat framing), go for the higher mounting location for the bellcrank shaft if you're looking to avoid having the aileron cables rub on the LE of the horiz. stabilizer. As a matter of fact, if anyone is interested in what it takes to change the geometry to eliminate the "pesky elevator cable" problem, I've drawn it up in AutoCAD to illustrate the problem and I can post some images on my website. For those who have the video of Chuck's Piet flying and having fun, watch the elevator cables as Chuck puts his airplane through its paces and he shows you the view out the back. He has some sort of anti-chafe tape on the LE of his HS where the cables contact it. Note also the differential tension (or slack) in the upper and lower cables... all of which can be eliminated by making some slight dimensional changes in the bellcrank and its mounting position. Nevertheless... there is that 2" discrepancy between the mounting locations shown on two different plan sheets.Merry Christmas to all you low 'n' slow fliers...Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________Date: Mon, 19 Dec 2005 20:24:16 -0700

Original Posted By: Rick Holland
From experience I can tell you that raising the bellcrank 1 inch is NOT enoughto allow the cables to clear the stabilizer.Greg Cardinal ----- Original Message -----

Original Posted By: "Philip Miller"
Subject: Re: Pietenpol-List: building video I built my bellcrank to the '34 plans location, Dwg. #4 (dated 2-26-34) with the 9" call out, and used a piece of thick leather on the L.E. of the horizontal stab as the anti-chafe. That's what Oscar saw in the video. I alsoused a piece of hardwood under the seat, where the stick to bellcrank cables change direction...no pulleys. I chose the plans method, because it was simple,it has worked on so many other planes over the years, and didn't want to spend all the time and effort to change the design...just "Git 'er done". It has always been my opinion, however, that if there was one place in the design of the Pietenpol that could be improved, this is it. None of the control surfaces are mass balanced, and the possibility of flutter has always concerned me, especially with so much slack in the lower cable with the flippersin the neutral position. Having said that, I've had my plane over 100 mph indicated in a shallow dive, and with the ASI error removed, it was probably morelike 110 mph. Absolutely NO flutter was indicated, even with the design slack in the lower flipper cable. We (Lynn Knoll and I) were at gross weight,and chasing a confounded streamer of Toilet Paper !! Hey Lynn...did you know we were on a test flight ??? :)Chuck G.NX770CG________________________________________________________________________________

Original Posted By: Rick Holland
1" from the 9" position. Long fuselage. Anti chafe patchwas glued to the LE of the stabilizer.Elevator horns and walking beam were drilled carefullyto maintain a parallelogram in the cable system. No cable slack issuesexcept at very extreme limits and even then it is minimal.Greg CardinalMinneapolis ----- Original Message -----

Original Posted By: Rcaprd(at)aol.com
Group,The interference between the elevator/"flipper" cable and the leading edge of the horizontal stabilizer is not restricted to the Pietenpol. Other early designs, notably the DeHavilland Moths, share this characteristic. Essentially, it isn't a big problem and, in the case of the Pietenpol, can be solved by placing rub strips on the L.E. of the stab. Like Michael Cuy, I use teflon pieces about 1/8"x3/4"x3" screwed to the upper surface of the L.E.The interference noted above, together with cable slackening, was dramatically reduced by restricting the elevator travel. Adjustable stops were welded to the torque tube (in front of and behind the stick) after the first 90 hours of operation, allowing 32 degrees up and 25 degrees down elevator travel. My Piet now has 750 hours on it and this modification has proved to be satisfactory.Generally, when the elevators are at, or near, the neutral position, the upper cable is not in heavy contact with the stabilizer L.E.--at least this is the case with the four different Pietenpols I have flown. Drastically changing the geometry of the elevator (oops, "flipper") circuit, in my humble opinion, really isn't worthwhile.It is a good idea to inspect the forward elevator cables for wear at the torque tube pulleys. The plans call for 2 inch pulleys which are pretty small. Early on, I made the mistake of using aluminum pulleys (I got them "for free") and the cables wore out very quickly. Buying some fibre pulleys solved the problem. Nevertheless, I frequently check the cables at this location. So far, so good!Graham Hansen Pietenpol CF-AUN________________________________________________________________________________