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Pietenpol-List: Wing spar questions

Posted: Mon Jan 16, 2006 7:31 pm
by matronics
Original Posted By: "Jack T. Textor"
Subject: Re: Pietenpol-List: Interested in the Smoke....In a message dated 1/16/2006 6:31:36 PM Central Standard Time, kmheidecpo(at)yahoo.com writes:I am seeking some information as to the set-up and design of smoke systems. I have no idea what liquid is used to create smoke nor do I know the location of the liquid port into the exhaust(s) make smoke. I am seeking information forfuture reference and extra-curricular activities to gather necessary parts needed.....(here I come salvage yard...whoopie!)I have though of finding a windshield wiper fluid container that hold a gallon of fluid and carefully stow it inside the fuse with a button on the dashand a filler neck with cap to the outside for ease of filling. For instance, My Honda Element has a nice compact 1 gallon fluid container with pump which couldbe stowed within the plane and controlled with a push-to-talk button located on the stick. Has this been done before? What are other people using for theirsmoke system? Am I just out in left field?KenFargo, NDKen,Ya wanna talk about smoke ?? Lets talk about smoke !!My smoke system consists of an after-market windshield washer pump and tank, plumbing to each exhaust pipe, and wiring to the switch on the power lever. Iisolated / mounted the tank on the upper left motor mount tubing, with a couple layers of rubber strap. I routed the clear tubing to a Tee fitting securedin rubber, to the engine mount, then used 1/8" brass tubing to each of the fittings in the exhaust pipes. I laid out the route of the tubing, marked thepipes, and removed both exhaust pipes. I cut a 1/8" pipe coupler in half, radiused each half to the radius of the pipe, and oxy / accy welded them to the aft pipe of each side. After welded, I drilled one #60 hole through the exhaust pipes. I placed these holes toward the bottom edge of the fittings, theorizing that if oil would lay in there it would gum up. The switch is a pushon / push off button, that is mounted right to the throttle handle. This location allows me to work the smoke without taking my hand off the throttle. I originally thought it would only smoke good at full power, but came to find I don't need much over 1/4 throttle to Smoke 'Em Up !! I can smoke 'em while taxiing, without any problem !! My exhaust pipes point down and away from thefuselage, and even when all the oil doesn't vaporize, the fuselage hardly getsanything on it. I have a couple of squawks on the system, that I have taken careof. 1.) I mounted the tank at about the same level as the fittings on the exhaust pipes, and it always dribbles out the pipes, with a little bit of smokeas a result. Over a period of a couple of hours, it will drain the tank, but I usually 'Smoke em up' before that happens.2.) When I ran the tank empty, and refill it, the pump would cavitate because of the way the line ran from the bottom of the tank to the pump, and Iwould always have to prime the pump, by blowing in the top of the tank. I gotsome strange looks from folks, while I performed this operation !!3.) The tank was too small. It only was big enough to do about 3 smoke runs. I would like to put about a 5 gallon bucket up there on the firewall, butI don't have enough room !!4.) I had to remove the top cowling to re-fill the tank. I'm building a new tank out of fiberglass / West System resin, with a fill tube out to the right side of the cowling. I'll mount it lower on the firewall. This will takecare of all the squawks.5.) I now have been using the new smoke tank, but I have a small leak in the tank. I used West Systems resin for the fiberglass tank, and evidently I didn't get the seam sealed up good enough. I've never had that problem when Iused polyester resin, but it kicks very quickly. The West System gives some time, but it is also quite a bit more expensive. After the warnings about thestuff catching on fire, I'll be repairing the tank before my next flight.Chuck G.NX770CG________________________________________________________________________________Subject: Pietenpol-List: Wing spar questionsDate: Mon, 16 Jan 2006 20:46:44 -0600

Re: Pietenpol-List: Wing spar questions

Posted: Tue Jan 17, 2006 2:28 pm
by matronics
Original Posted By: Jack T. Textor
I don't remember who you were going to order thru so lets review all options. 3/4 with ply caps strips would be fine, but a lot of work.McCormack in Madison should have full cut 1x6 pieces in stock.Wicks Aircraft in Highland, Il. (near St. Louis) should have itAircraft Spruce, of course.Wayne at Midwest Marine Plywood in Eagan, Mn. should have full cut 2x6 sections.Two of those places are within 2 1/2 hours drive of you.Is there a reason you spec 2"x? The wood I have purchased in the past from McCormackhas been over 1" rough cut and I have gotten 7/8 or better finished. The2"x that I have gotten from Midwest Marine Plywood have been 2 1/16" or better.It's a lot of work milling it down.Dick N. ----- Original Message -----

RE: Pietenpol-List: Wing spar questions

Posted: Tue Jan 17, 2006 2:59 pm
by matronics
Original Posted By: "Jack T. Textor"

Pietenpol-List: Wing spar questions

Posted: Tue Jan 17, 2006 3:36 pm
by matronics
Original Posted By:

RE: Pietenpol-List: Wing spar questions

Posted: Tue Jan 17, 2006 7:31 pm
by matronics
Original Posted By: Gene Beenenga

Re: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 12:53 am
by matronics
Original Posted By: Jack T. Textor
Why not use 3/4 inch spars and add a 1x1/8 spruce to the front and back to makeup an I-beam and make the thickness 1 inch. I would think fully facing the sparswith ply would be to much of a weight penalty.Likewise, does anyone know if the 3/4" spars BHP used were routed?Chris TracySacramento, Ca ----- Original Message -----

Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 6:05 am
by matronics
Original Posted By: harvey rule

Re: Pietenpol-List: transportability

Posted: Wed Jan 18, 2006 6:37 am
by matronics
Original Posted By: harvey rule

Re: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 7:00 am
by matronics
Original Posted By: Catdesign
3/4" spars are solid; not routed.Greg Cardinal ----- Original Message -----

RE: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 7:05 am
by matronics
Original Posted By: "Phillips, Jack"

Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 7:12 am
by matronics
Original Posted By: Michael D Cuy

RE: Pietenpol-List: spar idea--sketch attached

Posted: Wed Jan 18, 2006 7:18 am
by matronics
Original Posted By: "Phillips, Jack"

RE: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 12:36 pm
by matronics
Original Posted By: "Bill Church"

Re: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 5:42 pm
by matronics
Original Posted By: Rcaprd(at)aol.com
Subject: Re: Pietenpol-List: Wing spar questionsIn a message dated 1/18/2006 12:55:05 AM Central Standard Time, catdesign(at)intergate.com writes:Why not use 3/4 inch spars and add a 1x1/8 spruce to the front and back to make up an I-beam and make the thickness 1 inch.I used 1/2" X 4 3/4" X 1/8" plywood shims on the fwd & aft face of the spar, at each rib location. I used T88 on everything.Chuck G.NX770CG________________________________________________________________________________

Re: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 6:02 pm
by matronics
Original Posted By: Gene Beenenga
Subject: Re: Pietenpol-List: Wing spar questionsIn a message dated 1/18/2006 12:37:43 PM Central Standard Time, eng(at)canadianrogers.com writes:Anyone out there that has a definitive answer out there?I don't know if there is a difinitive answer, because it's been done so many different ways.I used 3/4" Douglas Fir spars, un-routed. The inboard ribs are Spruce, and all others are Cedar.Chuck G.NX770CG________________________________________________________________________________Date: Wed, 18 Jan 2006 18:30:48 -0600 (GMT-06:00)

RE: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 7:13 pm
by matronics
Original Posted By: "Jack T. Textor"

RE: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 8:04 pm
by matronics
Original Posted By: "Jack T. Textor"

RE: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 9:54 pm
by matronics
Original Posted By: "Jack T. Textor"
I know that weight savings is a very good thing with any plane, but it seemsto me like routing the spars down is just a bad idea with a potential tocause some real problems. With a routed spar, even if you don't affect thevertical bending strength, you do lose a good deal of the available strengthin the fore-aft direction, and this could... potentially... reduce thetortional rigidity of the wing, and contribute to flutter. I know it's beendone for a long time and I don't think it's caused tons of problems, but Ido know of some planes in which routed spars are no longer recommended dueto the potential risk to get a relatively tiny weight reduction. For no morethan a 5 lbs. savings it seems like a bad place to reduce the strength ofyour airframe. Seems like you'd be better off saving weight by, say, cuttinglightening holes in the ply on the sides of the fuselage.That being said, I know that many folks have done it with no problems... notsuggesting anyone should be afraid of a Piet that's got routed spars.-MikeMike Whaley merlin@ov-10bronco.netWebmaster, OV-10 Bronco Associationhttp://www.ov-10bronco.net/----- Original Message -----

Re: Pietenpol-List: Wing spar questions

Posted: Wed Jan 18, 2006 11:11 pm
by matronics
Original Posted By: Mike Luther
Subject: Re: Pietenpol-List: Wing spar questionsIn a message dated 1/18/2006 7:16:10 PM Central Standard Time, jtextor(at)thepalmergroup.com writes:He did say it was NOT vertical grain. Spars must be 1/4 sawn, or they warp.Chuck G.NX770CG________________________________________________________________________________Date: Wed, 18 Jan 2006 21:09:07 -0900

Re: Pietenpol-List: Wing spar questions

Posted: Thu Jan 19, 2006 9:35 am
by matronics
Original Posted By: "Steve Glass"
FYI - Bill Rewey, noted expert on the Pietenpol, who built two of them, built hiswing with 1" solid spars no routing.his current piet has been flying now for over 11 yrs. on a continental A65. It'stravelled the equivalent of 1 1/4 times around the world. He's given ridesto many people particularly wives of Piet builders, to show them how much funthey're going to have when finished. He's flown passengers as large as 240lb.My point is this. don't need to be so fussy about weight saving or rigidityof wing spars. 1" or 3/4". If built with Spruce or Spuce or Fir it'll be strong.The whole plane is over-engineered structurally. Ask William Wynne the"Corvair Authority". He had the opportunity to survive crashing his. But cedar??They make yellow pencils outa cedar and people break them every day whenthey lose their cool.________________________________________________________________________________