Original Posted By: Brian Mitchely
I'm joining in on this one a bit. Years ago I too tried to get plansfor the built up spar the Brits have. As far as I as able to find outthere is simply no legal way of doing it and that is the end of that.However EAA has (or had) publications on built up spars. Also there area number successful home built aircraft that use built up spars.Molt Taylor designed aircraft made largely out of cardboard, fiberglassand epoxy. They used a built spar that probably didn't cost a hundredbucks. Zenith Aircraft Company uses built up aluminum spars that are(IMHO) probably cheaper that aircraft quality Sitka Spruce, stronger andweigh less too.The Skypup Ultra-lite does not have the classic beauty of a Piet, but ituses just one built up spar and the removable three piece wing is fullycantilevered. IMHO the Skypup designer is in the same league as BerniePietenpol. A simple straight forward design using commonly availablematerials. Only this man is a professional aeronautical engineer. Ifanyone wants to see something about it there is a video called"Machnone" on youtube that shows a lot of the construction methodologyof the Skypup. I bought a set of plans from the designer's son just tosee how it was constructed. (Over the years I have collected a numberof plans for the same reason.) Due to personal responsibilities that Ihave, building my own Piet is not possible so I stand on the sidelineswishing others well. Hopefully, someone will be inspired by all that is out there on low costbuilt up spars and the sky will be darkened with Pietenpol Air Campersbeing flown by happy pilots before too long.Back to lurking,Bob B.________________________________________________________________________________Date: Tue, 17 Nov 2009 07:16:35 -0800 (PST)
Pietenpol-List: built up spars
Re: Pietenpol-List: Black Max brakes on my Piet
Original Posted By: hvandervoo(at)aol.com
Well, I don't see how procuring the UK plans is against the law in any way; Jim Wills just doesn't want to sell them to anyone here. If you were to acquire a set it would be against his wishes, but I highly doubt you would be breaking any laws.As far as holding Zenith spars up as an example of a strong, high quality design....you may want to reconsider that: http://www.eaa.org/news/2009/2009-11-12 ... aspThey've developed such a tendency to shed their wings/break up in flight that the FAA has seemingly done all they can to require or strongly recommend no further flight until an extensive package of mods are completed on existing aircraft, and will not issue airworthiness certificates for any new aircraft that do not have the mods. Too bad for the Zenith guys...RyanSent from my mobile deviceOn Nov 17, 2009, at 5:32 AM, baileys wrote:>> I'm joining in on this one a bit. Years ago I too tried to get plans> for the built up spar the Brits have. As far as I as able to find out> there is simply no legal way of doing it and that is the end of that.> > Zenith Aircraft Company uses built up aluminum spars that are> (IMHO) probably cheaper that aircraft quality Sitka Spruce, stronger > and> weigh less too.>>________________________________________________________________________________Subject: Re: Pietenpol-List: Black Max brakes on my PietDate: Tue, 17 Nov 2009 10:29:17 -0500
Well, I don't see how procuring the UK plans is against the law in any way; Jim Wills just doesn't want to sell them to anyone here. If you were to acquire a set it would be against his wishes, but I highly doubt you would be breaking any laws.As far as holding Zenith spars up as an example of a strong, high quality design....you may want to reconsider that: http://www.eaa.org/news/2009/2009-11-12 ... aspThey've developed such a tendency to shed their wings/break up in flight that the FAA has seemingly done all they can to require or strongly recommend no further flight until an extensive package of mods are completed on existing aircraft, and will not issue airworthiness certificates for any new aircraft that do not have the mods. Too bad for the Zenith guys...RyanSent from my mobile deviceOn Nov 17, 2009, at 5:32 AM, baileys wrote:>> I'm joining in on this one a bit. Years ago I too tried to get plans> for the built up spar the Brits have. As far as I as able to find out> there is simply no legal way of doing it and that is the end of that.> > Zenith Aircraft Company uses built up aluminum spars that are> (IMHO) probably cheaper that aircraft quality Sitka Spruce, stronger > and> weigh less too.>>________________________________________________________________________________Subject: Re: Pietenpol-List: Black Max brakes on my PietDate: Tue, 17 Nov 2009 10:29:17 -0500
RE: Pietenpol-List: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
...with one minor correction....the FAA warning is for the 601XL model,which is a long wing with no center section. Both the 601HD & HDS models areperforming just fine, with no concerns. They both have an 8' center section.Still...as you say...too bad for the Zenith guys...Gary BootheCool, Ca.PietenpolWW Corvair Conversion, mountedTail done, Fuselage on gear(15 ribs down.)-----Original Message-----
...with one minor correction....the FAA warning is for the 601XL model,which is a long wing with no center section. Both the 601HD & HDS models areperforming just fine, with no concerns. They both have an 8' center section.Still...as you say...too bad for the Zenith guys...Gary BootheCool, Ca.PietenpolWW Corvair Conversion, mountedTail done, Fuselage on gear(15 ribs down.)-----Original Message-----
Re: Pietenpol-List: built up spars
Original Posted By: Tim Willis
> RE: Pietenpol-List: built up spars
Original Posted By: airlion
Pietenpol-List: Re: General Pietenpol questions
Original Posted By: "K5YAC"
As a new forum member I have some questions regarding building this aircraft. Tobegin with I'm a rusty low time pilot with time in the usual Cessnas and Piperaircraft including some instrument time in a 180 Archer. No tail dragger timealthough I would certainly get this prior to flying any homebuilt project.I'm currently reviewing a number of project possibilities including the Fly Babyand the Piet, the advantage with the Piet being the 2 place configuration. (Both similar build times ) How difficult is this aircraft to fly? and is it ahand-full on the ground?Years ago back in the 70's I built a large RC model of this aircraft that I enteredin the Canadian Scale Nationals in Calgary. Frankly I was less than impressedwith the flight characteristics. It was difficult to balance with the shortnose moment, a bear to handle on the ground with that narrow gear, being proneto ground loops and dragging a wing tip, especially in a cross-wind. In theair it was particularly touchy in pitch and not pleasant to fly. I realize it is difficult to compare the flight characteristics of a model to fullsize ( Reynolds numbers etc. ) but they both have that narrow gear and almostno dihedral, in fact in head-on flight pics the aircraft appears to havezero dihedral.Any thought on these comments? I love the aircraft and would consider poweringit with a C-85 or possibly a Corvair, the photos of the British G-BUCO are especiallyinspiring.Thx for the help,Nigel Jones, BC, Canada--------Nigel R. JonesRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: General Pietenpol questions
As a new forum member I have some questions regarding building this aircraft. Tobegin with I'm a rusty low time pilot with time in the usual Cessnas and Piperaircraft including some instrument time in a 180 Archer. No tail dragger timealthough I would certainly get this prior to flying any homebuilt project.I'm currently reviewing a number of project possibilities including the Fly Babyand the Piet, the advantage with the Piet being the 2 place configuration. (Both similar build times ) How difficult is this aircraft to fly? and is it ahand-full on the ground?Years ago back in the 70's I built a large RC model of this aircraft that I enteredin the Canadian Scale Nationals in Calgary. Frankly I was less than impressedwith the flight characteristics. It was difficult to balance with the shortnose moment, a bear to handle on the ground with that narrow gear, being proneto ground loops and dragging a wing tip, especially in a cross-wind. In theair it was particularly touchy in pitch and not pleasant to fly. I realize it is difficult to compare the flight characteristics of a model to fullsize ( Reynolds numbers etc. ) but they both have that narrow gear and almostno dihedral, in fact in head-on flight pics the aircraft appears to havezero dihedral.Any thought on these comments? I love the aircraft and would consider poweringit with a C-85 or possibly a Corvair, the photos of the British G-BUCO are especiallyinspiring.Thx for the help,Nigel Jones, BC, Canada--------Nigel R. JonesRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: General Pietenpol questions
Original Posted By: "David Paule"
Interesting background (similar to my own) and good questions Nigel. I am a newbuilder and do not have any flight time in this airplane yet, but surely someonewill be along soon to give you an experienced perspective. G-BUCO also caught my eye very early in the decision making process. I'll be readingthe mail.--------Mark - working on wingsRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Interesting background (similar to my own) and good questions Nigel. I am a newbuilder and do not have any flight time in this airplane yet, but surely someonewill be along soon to give you an experienced perspective. G-BUCO also caught my eye very early in the decision making process. I'll be readingthe mail.--------Mark - working on wingsRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
Re: Pietenpol-List: General Pietenpol questions
Original Posted By: "Gene & Tammy"
Having built a Fly-Baby many years ago, I'd think that the Pietenpol would be the clear choice for these reasons:1. It's got that second seat.2. Fly-Baby performance is often not that much different than the Pietenpol, certainly not enough to be a deal-breaker, for the same engine. There are some Fly-Bablys, though that are cleaned up and can cruise faster. The Fly-Baby is probably easier to reduce drag on.3. The Pietenpol can be built slightly lighter.4. The visibility is better in the Pietenpol, if you don't use the Ford with the upright radiator.5. The Pietenpol might be slightly more robust. The struts help. The Fly-Baby has flying and landing wires.While the Fly-Baby does have folding wings, they are a bit awkward and aren't used that often, generally speaking. Still, they are there and that might make a difference.David Paule>> As a new forum member I have some questions regarding building this > aircraft. To begin with I'm a rusty low time pilot with time in the usual > Cessnas and Piper aircraft including some instrument time in a 180 Archer. > No tail dragger time although I would certainly get this prior to flying > any homebuilt project.>> I'm currently reviewing a number of project possibilities including the > Fly Baby and the Piet, the advantage with the Piet being the 2 place > configuration. ( Both similar build times ) How difficult is this aircraft > to fly? and is it a hand-full on the ground?>________________________________________________________________________________
Having built a Fly-Baby many years ago, I'd think that the Pietenpol would be the clear choice for these reasons:1. It's got that second seat.2. Fly-Baby performance is often not that much different than the Pietenpol, certainly not enough to be a deal-breaker, for the same engine. There are some Fly-Bablys, though that are cleaned up and can cruise faster. The Fly-Baby is probably easier to reduce drag on.3. The Pietenpol can be built slightly lighter.4. The visibility is better in the Pietenpol, if you don't use the Ford with the upright radiator.5. The Pietenpol might be slightly more robust. The struts help. The Fly-Baby has flying and landing wires.While the Fly-Baby does have folding wings, they are a bit awkward and aren't used that often, generally speaking. Still, they are there and that might make a difference.David Paule>> As a new forum member I have some questions regarding building this > aircraft. To begin with I'm a rusty low time pilot with time in the usual > Cessnas and Piper aircraft including some instrument time in a 180 Archer. > No tail dragger time although I would certainly get this prior to flying > any homebuilt project.>> I'm currently reviewing a number of project possibilities including the > Fly Baby and the Piet, the advantage with the Piet being the 2 place > configuration. ( Both similar build times ) How difficult is this aircraft > to fly? and is it a hand-full on the ground?>________________________________________________________________________________
Re: Pietenpol-List: General Pietenpol questions
Original Posted By: "njones"
Nigel, where in BC are you?I have a Piet with a one piece wing, which has no dihedral. The Piet is a joy to fly IF you enjoy open cockpit flying. It is stable in the air and on the ground. The Piet is not prone to ground looping. Just a good, all around easy and gentle plane to taxi, fly and land. Mine has the A 65 with a 76 X 38 prop and I'm very happy with the cruise and climb. From what I see, the only folks that are not happy with the Piet are the ones that try to make it into something it was never ment to be. The Piet is a slow, draggy, windy and delightful airplane and the only change you can make to it, is to take out the delightful. If you do build one, built it by the plans and build it light. You won't be sorry.GeneN502R in rainy Tennessee----- Original Message -----
Nigel, where in BC are you?I have a Piet with a one piece wing, which has no dihedral. The Piet is a joy to fly IF you enjoy open cockpit flying. It is stable in the air and on the ground. The Piet is not prone to ground looping. Just a good, all around easy and gentle plane to taxi, fly and land. Mine has the A 65 with a 76 X 38 prop and I'm very happy with the cruise and climb. From what I see, the only folks that are not happy with the Piet are the ones that try to make it into something it was never ment to be. The Piet is a slow, draggy, windy and delightful airplane and the only change you can make to it, is to take out the delightful. If you do build one, built it by the plans and build it light. You won't be sorry.GeneN502R in rainy Tennessee----- Original Message -----
RE: Pietenpol-List: General Pietenpol questions
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Nigel,With sufficient tailwheel time I don't think you'll find a Pietenpoldifficult to handle. Its ground handling is quite docile, as long as youare not bothered by not being able to see anything straight ahead.It is not a particularly easy airplane to land, due to its very high drag.When approaching power off, I find the best speed to be 55 mph on shortfinal. The flare has to be timed very well, because the time betweenbeginning the flare at 55 mph and stalling at 35 is approximately 1-2seconds. However, if you carry a bit of power, the flare can be extendedsomewhat, making it a bit easier to land. Directional control is not aproblem, any more than in any other taildragger. I have flown mine in a 25knot direct crosswind, and while not enjoyable, the plane could handle it.Flying in such wind is work, and I don't recommend it unless you have nochoice (like landing at Oshkosh in strong crosswinds).As for the narrow gear, if you think it is too narrow, make it wider. Iwidened mine a bit, to a width of 7 feet between the wheels. Still narrowerthan a Cub (with its 10' tread), but certainly not a handful. Narrow geardoes not necessarily make a plane difficult to handle on the ground. I havean RV-4 as well as the Pietenpol. The RV-4 has much narrower gear than thePiet, but is absolutely the easiest plane to land I've ever flown, includingall tricycle gear types.No dihedral? No problem. The parasol configuration adds substantialstability, but if you're looking for the stability of a Cessna 210, lookelsewhere. On a glass smooth day, my Pietenpol will fly hands off forminutes at a time. It will fly feet off for maybe as long as a second ortwo. Stability in yaw is not a strong suit.It flies like exactly what it is - a 1929 airplane design. It is very mucha rudder airplane, with lot's of adverse yaw. You do have to fly it, sotime in a Cherokee or a Cessna is not much of a prep. Try to get some timein a J-3, to get more of a feel for what a Piet is like.Is it enjoyable to fly? Very much. I have not flown a Fly Baby, so I can'tcompare the two. Of planes I have flown, the closest in feel to a Pietenpolis probably a 1934 Fairchild 22. Again, lots of drag, lots of adverse yaw,and lots of fun.Good luck with your decision. I had the same choice to make (with theVolmer Sportsman thrown into the mix as well). I chose the Pietenpol andhave never regretted my choice. If you haven't decided by next July, Isuggest you make the trip to Brodhead, Wisconsin for the annual Pietenpolgathering and take a ride in one.Jack PhillipsNX899JPRaleigh, NC-----Original Message-----
Nigel,With sufficient tailwheel time I don't think you'll find a Pietenpoldifficult to handle. Its ground handling is quite docile, as long as youare not bothered by not being able to see anything straight ahead.It is not a particularly easy airplane to land, due to its very high drag.When approaching power off, I find the best speed to be 55 mph on shortfinal. The flare has to be timed very well, because the time betweenbeginning the flare at 55 mph and stalling at 35 is approximately 1-2seconds. However, if you carry a bit of power, the flare can be extendedsomewhat, making it a bit easier to land. Directional control is not aproblem, any more than in any other taildragger. I have flown mine in a 25knot direct crosswind, and while not enjoyable, the plane could handle it.Flying in such wind is work, and I don't recommend it unless you have nochoice (like landing at Oshkosh in strong crosswinds).As for the narrow gear, if you think it is too narrow, make it wider. Iwidened mine a bit, to a width of 7 feet between the wheels. Still narrowerthan a Cub (with its 10' tread), but certainly not a handful. Narrow geardoes not necessarily make a plane difficult to handle on the ground. I havean RV-4 as well as the Pietenpol. The RV-4 has much narrower gear than thePiet, but is absolutely the easiest plane to land I've ever flown, includingall tricycle gear types.No dihedral? No problem. The parasol configuration adds substantialstability, but if you're looking for the stability of a Cessna 210, lookelsewhere. On a glass smooth day, my Pietenpol will fly hands off forminutes at a time. It will fly feet off for maybe as long as a second ortwo. Stability in yaw is not a strong suit.It flies like exactly what it is - a 1929 airplane design. It is very mucha rudder airplane, with lot's of adverse yaw. You do have to fly it, sotime in a Cherokee or a Cessna is not much of a prep. Try to get some timein a J-3, to get more of a feel for what a Piet is like.Is it enjoyable to fly? Very much. I have not flown a Fly Baby, so I can'tcompare the two. Of planes I have flown, the closest in feel to a Pietenpolis probably a 1934 Fairchild 22. Again, lots of drag, lots of adverse yaw,and lots of fun.Good luck with your decision. I had the same choice to make (with theVolmer Sportsman thrown into the mix as well). I chose the Pietenpol andhave never regretted my choice. If you haven't decided by next July, Isuggest you make the trip to Brodhead, Wisconsin for the annual Pietenpolgathering and take a ride in one.Jack PhillipsNX899JPRaleigh, NC-----Original Message-----
Pietenpol-List: General Pietenpol questions
Original Posted By: Dan Yocum
Jack wrote:>The flare has to be timed very well, because>the time between beginning the flare at 55 mph>and stalling at 35 is approximately 1-2 seconds.>However, if you carry a bit of power, the flare>can be extended somewhat, making it a bit easier>to land.All very true, but I actually like the fact thatwhen you start the flare, you're committed to landthe airplane and there isn't much float to speak of.The time in the landing phase in taildraggers thathas always been the most nervous for me is thatperiod where the wing is in a relatively high angleof attack and near the stall, nose is up, wheelsaren't on the ground yet, and airspeed is scrubbingoff. It's when the airplane gets wobbly and thecrosswind has its way. Rudder effectiveness isdropping off, so is aileron so you're busy stirringthe pot with the stick and your feet are moving tothe tempo that is needed to stay straight. So to me,the fact that the Piet doesn't mess around once youstart the flare is a good thing. The "wobbly period"is kept to a very minimum, which saves my nerves.The airplane is, to me, a delight to fly but youhave to enjoy low, slow, breezy, antique styleflying where the wood and fabric are part of theexperience and the instrument panel is almost nota factor at all. Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________Date: Tue, 17 Nov 2009 20:51:10 -0600
Jack wrote:>The flare has to be timed very well, because>the time between beginning the flare at 55 mph>and stalling at 35 is approximately 1-2 seconds.>However, if you carry a bit of power, the flare>can be extended somewhat, making it a bit easier>to land.All very true, but I actually like the fact thatwhen you start the flare, you're committed to landthe airplane and there isn't much float to speak of.The time in the landing phase in taildraggers thathas always been the most nervous for me is thatperiod where the wing is in a relatively high angleof attack and near the stall, nose is up, wheelsaren't on the ground yet, and airspeed is scrubbingoff. It's when the airplane gets wobbly and thecrosswind has its way. Rudder effectiveness isdropping off, so is aileron so you're busy stirringthe pot with the stick and your feet are moving tothe tempo that is needed to stay straight. So to me,the fact that the Piet doesn't mess around once youstart the flare is a good thing. The "wobbly period"is kept to a very minimum, which saves my nerves.The airplane is, to me, a delight to fly but youhave to enjoy low, slow, breezy, antique styleflying where the wood and fabric are part of theexperience and the instrument panel is almost nota factor at all. Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________Date: Tue, 17 Nov 2009 20:51:10 -0600
Re: Pietenpol-List: built up spars
Original Posted By:
You can also go here:http://www.westcoastpiet.com/construction.htmAnd find a couple of good articles if you want to figure out your own.....Greg C.----- Original Message -----
You can also go here:http://www.westcoastpiet.com/construction.htmAnd find a couple of good articles if you want to figure out your own.....Greg C.----- Original Message -----
Re: Pietenpol-List: built up spars
Original Posted By: Dan Yocum
Re: Pietenpol-List: General Pietenpol questions
Original Posted By: Jeff Boatright
RE: Pietenpol-List: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com [mailto:owner-pietenpol-list-server(at)matronics.com] On Behalf Of Tim Willis
Hi Guys,I have put a couple of jpegs on the web site of my notes. Check out the wing spar construction page on http://www.cpc-world.comCheersPeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Hi Guys,I have put a couple of jpegs on the web site of my notes. Check out the wing spar construction page on http://www.cpc-world.comCheersPeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
> RE: Pietenpol-List: built up spars
Original Posted By: Matt Dralle
Pietenpol-List: Re: built up spars
Original Posted By: "Peter W Johnson"
vk3eka(at)bigpond.net.au wrote:> ...Check out the wing spar construction page on http://www.cpc-world.comPeter's box-spar sketches joined together in single picture and cleaned in Photoshop:Read this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/boxs ... __________
vk3eka(at)bigpond.net.au wrote:> ...Check out the wing spar construction page on http://www.cpc-world.comPeter's box-spar sketches joined together in single picture and cleaned in Photoshop:Read this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/boxs ... __________
RE: Pietenpol-List: Re: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Ivan,Nice work. I'll put this one on my web site rather than the other two. Isthat OK?CheersPeter-----Original Message-----
Ivan,Nice work. I'll put this one on my web site rather than the other two. Isthat OK?CheersPeter-----Original Message-----
Pietenpol-List: Re: built up spars
Original Posted By: Jim
vk3eka(at)bigpond.net.au wrote:> Ivan,> > Nice work. I'll put this one on my web site rather than the other two. Is> that OK?> > Cheers> > Peter> --Of course it is OK! I want to build this spar, and I'm trying to do a CAD versionof it, but don't tell anyone yet!
If I manage to finish it, I'll post ithere. and you can also ad that to your site.Regards,IvanRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 18 Nov 2009 21:24:27 +0000 (GMT)
vk3eka(at)bigpond.net.au wrote:> Ivan,> > Nice work. I'll put this one on my web site rather than the other two. Is> that OK?> > Cheers> > Peter> --Of course it is OK! I want to build this spar, and I'm trying to do a CAD versionof it, but don't tell anyone yet!
If I manage to finish it, I'll post ithere. and you can also ad that to your site.Regards,IvanRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 18 Nov 2009 21:24:27 +0000 (GMT)RE: Pietenpol-List: Re: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Done,Thanks IvanPeter-----Original Message-----
Done,Thanks IvanPeter-----Original Message-----
Pietenpol-List: built up spars
Original Posted By: "Peter W Johnson"
Thanks, everyone, for the info and leads on thebuilt-up spar. Of the articles posted on theWestcoastpiet site, note carefully the informationgiven in the addendum to the article that ran yearsago in the old EAA Design Manuals (which I am veryfortunate to have at least some of). Referring toI-shape compared to box beams, there are distinctadvantages. The UK built-up spar with its C-shapeas a compromise between the I-beam and the full box,has some of the advantages of both. Note, however,that the I-shape is inherently more resistant tohaving the web buckle, which is why the UK spar hasvertical stiffeners between the capstrips at eachrib position.To take the I-shape to what I would call "elegantoverkill", consider the spars on Mike Cuy's wing.Refer to the sketches and photos of his wings andspars that Mike provided on the Westcoastpiet site.In essence, since Mike's spars use a solid 1/2"spruce web, he has the best of all worlds in thathe has essentially a 1" square top and bottom flangeto take the tension and compression loads and a solid1/2" web of spruce for shear. With that thickness(as opposed to, say, using 1/8" or even 1/2" ply forthe web), his spar does not require stiffeners toprovide buckling resistance for the web. Note thephotos of Mike's wing before covering... there areno vertical stiffeners at each rib. It is hell forstout and, as I say, "elegant overkill". It coulddoubtless be engineered to a slimmer profile but itis clean and effective. However, there is still thecost of that spruce in straight, clear lengths.For us cheapskates still trying to use thinner andless expensive stock and either scarfing or laminatingthings so we don't have to use long expensive pieces ofclear wood, and trying to use plywood for the web ratherthan spruce planks, the approach becomes one ofengineering a built-up section with equivalent strength.This is where I am right now, and Jim Markle knows why ;o)Meanwhile, 41CC soldiers on... putting grins on facesall over south Texas as the C75 begins to break in andpull stronger with every passing flight.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________
Thanks, everyone, for the info and leads on thebuilt-up spar. Of the articles posted on theWestcoastpiet site, note carefully the informationgiven in the addendum to the article that ran yearsago in the old EAA Design Manuals (which I am veryfortunate to have at least some of). Referring toI-shape compared to box beams, there are distinctadvantages. The UK built-up spar with its C-shapeas a compromise between the I-beam and the full box,has some of the advantages of both. Note, however,that the I-shape is inherently more resistant tohaving the web buckle, which is why the UK spar hasvertical stiffeners between the capstrips at eachrib position.To take the I-shape to what I would call "elegantoverkill", consider the spars on Mike Cuy's wing.Refer to the sketches and photos of his wings andspars that Mike provided on the Westcoastpiet site.In essence, since Mike's spars use a solid 1/2"spruce web, he has the best of all worlds in thathe has essentially a 1" square top and bottom flangeto take the tension and compression loads and a solid1/2" web of spruce for shear. With that thickness(as opposed to, say, using 1/8" or even 1/2" ply forthe web), his spar does not require stiffeners toprovide buckling resistance for the web. Note thephotos of Mike's wing before covering... there areno vertical stiffeners at each rib. It is hell forstout and, as I say, "elegant overkill". It coulddoubtless be engineered to a slimmer profile but itis clean and effective. However, there is still thecost of that spruce in straight, clear lengths.For us cheapskates still trying to use thinner andless expensive stock and either scarfing or laminatingthings so we don't have to use long expensive pieces ofclear wood, and trying to use plywood for the web ratherthan spruce planks, the approach becomes one ofengineering a built-up section with equivalent strength.This is where I am right now, and Jim Markle knows why ;o)Meanwhile, 41CC soldiers on... putting grins on facesall over south Texas as the C75 begins to break in andpull stronger with every passing flight.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________
RE: Pietenpol-List: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Oscar,Don't forget also that the UK Piets (and mine) have a full "D" section fromthe top of the front spar over the leading edge to the bottom of the frontspar. Makes for a really strong spar..PeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Oscar,Don't forget also that the UK Piets (and mine) have a full "D" section fromthe top of the front spar over the leading edge to the bottom of the frontspar. Makes for a really strong spar..PeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Re: Pietenpol-List: Re: General Pietenpol questions
Original Posted By:
You got it good up there. :-)Down here in Vancouver it's heavy rain and so windythe Ferries have been cancelled.Clif>> PS, to Gene in "rainy Tennessee", we are in Salmon Arm at the north end of > the Okanagan Valley, right on Shuswap Lake.>> Nigel>> --------> Nigel R. Jones________________________________________________________________________________
You got it good up there. :-)Down here in Vancouver it's heavy rain and so windythe Ferries have been cancelled.Clif>> PS, to Gene in "rainy Tennessee", we are in Salmon Arm at the north end of > the Okanagan Valley, right on Shuswap Lake.>> Nigel>> --------> Nigel R. Jones________________________________________________________________________________
Pietenpol-List: Re: built up spars
Original Posted By: "ivan.todorovic"
Mr VI used the 90 Deg, from the cord line as Mr R. suggested. He also suggested 1 Deg.angle of incidence on the 612. I would go with 1/2 Degree AoI, I also havethe short version Piet, My long version worked well with 1-1/2deg.Pieti LowellRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: built up spars
Mr VI used the 90 Deg, from the cord line as Mr R. suggested. He also suggested 1 Deg.angle of incidence on the 612. I would go with 1/2 Degree AoI, I also havethe short version Piet, My long version worked well with 1-1/2deg.Pieti LowellRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: built up spars
Pietenpol-List: Re: built up spars
Original Posted By: "ivan.todorovic"
Ivan,Comments embedded.........Please check if I've messed the dimensions for the front spar on thedrawings below.................all look good.Maybe it is a stupid question, but better safe than sorry: spar face withfull plywood web goes in the wing-tip direction for both spars, front andrear, right? There is a small drawing near the right edge of your sketchthat made me uncertain about that.................do you mean the grain of the plywood? If so yes main grainis along the length of the sparOne other thing: vertical stiffeners position on the spar inside edge wouldneed a hint or two, there are several dimensions (7 1/2), (1/2 + 8 1/2) thatare a bit confusing.................Not sure what you mean here, the wing join ends are 7 1/2",the center (wing spar strut fitting) 25 1/2", the wing tip 4 1/2". There isblocking at each wing rib position, pulley fixing position and compressionstrut fitting.................Does all that help?CheersPeter________________________________________________________________________________Subject: Pietenpol-List: Re: built up spars
Ivan,Comments embedded.........Please check if I've messed the dimensions for the front spar on thedrawings below.................all look good.Maybe it is a stupid question, but better safe than sorry: spar face withfull plywood web goes in the wing-tip direction for both spars, front andrear, right? There is a small drawing near the right edge of your sketchthat made me uncertain about that.................do you mean the grain of the plywood? If so yes main grainis along the length of the sparOne other thing: vertical stiffeners position on the spar inside edge wouldneed a hint or two, there are several dimensions (7 1/2), (1/2 + 8 1/2) thatare a bit confusing.................Not sure what you mean here, the wing join ends are 7 1/2",the center (wing spar strut fitting) 25 1/2", the wing tip 4 1/2". There isblocking at each wing rib position, pulley fixing position and compressionstrut fitting.................Does all that help?CheersPeter________________________________________________________________________________Subject: Pietenpol-List: Re: built up spars
RE: Pietenpol-List: Re: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Ivan,Sorry, check out page 6 of the build pictures. They show the ply side on theinside of the wing.CheersPeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Ivan,Sorry, check out page 6 of the build pictures. They show the ply side on theinside of the wing.CheersPeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Pietenpol-List: Re: built up spars
Original Posted By: gliderx5(at)comcast.net
Re: Pietenpol-List: Re: built up spars
Original Posted By: gliderx5(at)comcast.net
Ah, Ivan, When you say "tip" do you mean the "leading edge",or front of the wing?> Peter,when you build the whole front spar, and the spar box has so called "U" shape, do you rotate the bottom of the letter "U" towards the tip of the wing, not towards the rear spar?>> Regards,> Ivan________________________________________________________________________________Date: Fri, 20 Nov 2009 02:26:13 +0000 (UTC)
Ah, Ivan, When you say "tip" do you mean the "leading edge",or front of the wing?> Peter,when you build the whole front spar, and the spar box has so called "U" shape, do you rotate the bottom of the letter "U" towards the tip of the wing, not towards the rear spar?>> Regards,> Ivan________________________________________________________________________________Date: Fri, 20 Nov 2009 02:26:13 +0000 (UTC)
Re: Pietenpol-List: Re: built up spars
Original Posted By: Robert Ray
Subject: Re: Pietenpol-List: Re: built up spars
Subject: Re: Pietenpol-List: Re: built up spars
Pietenpol-List: Re: built up spars
Original Posted By: "Peter W Johnson"
Sorry for the delay, day job stuff turned 1 day I've promised into 1 week.Peter, please check all the dimensions on the attached drawings for the front spar,before I draw the rear spar. Only thing that is left unclear to me is thesize of the plywood on the upper side of the center section - does it cover itcompletely?Regards,IvanRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/fron ... __________
Sorry for the delay, day job stuff turned 1 day I've promised into 1 week.Peter, please check all the dimensions on the attached drawings for the front spar,before I draw the rear spar. Only thing that is left unclear to me is thesize of the plywood on the upper side of the center section - does it cover itcompletely?Regards,IvanRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/fron ... __________
RE: Pietenpol-List: Re: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Ivan,Very good! The only thing I can say is that at the root of the spar, thefront ply is 7 1/2" not 9 1/2", although it would not make a lot ofdifference (make sure you varnish the inside before gluing the ply inplace!).The center section is constructed in exactly the same way as the main spars,full 1/8" ply one side, partly covered on the other.CheersPeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Ivan,Very good! The only thing I can say is that at the root of the spar, thefront ply is 7 1/2" not 9 1/2", although it would not make a lot ofdifference (make sure you varnish the inside before gluing the ply inplace!).The center section is constructed in exactly the same way as the main spars,full 1/8" ply one side, partly covered on the other.CheersPeterWonthaggi Australiahttp://www.cpc-world.com-----Original Message-----
Pietenpol-List: Re: built up spars
Original Posted By: Matt Dralle
Pietenpol-List: Re: built up spars
Original Posted By: "Peter W Johnson"
OK, Peter, I've got it.I hope I'll draw the rear spar as soon as I get some time. My plans arrived lastweek, I've bought a set of Grega plans from James Thursby (Thank's to Matronicslist for finding the available set), and now I'm in "finding wood" phase.There is no "Aircraft spruce" or shops like that here where I live, as a meterof fact the spruce doesn't grow on this continent, I have to actually call andgo search the lumberyards (go ahead, laugh). Last but not least - I have todraw this modification for Riblett I'm planing to build... Busy time ahead.One more question: This additional width of the spars also needs to make a roomfor the spar in the rib wider, but in which direction? On both sides symmetricalto the center of the spar, or on the inside of the wing, further from theleading and trailing edge? Regards,IvanRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
OK, Peter, I've got it.I hope I'll draw the rear spar as soon as I get some time. My plans arrived lastweek, I've bought a set of Grega plans from James Thursby (Thank's to Matronicslist for finding the available set), and now I'm in "finding wood" phase.There is no "Aircraft spruce" or shops like that here where I live, as a meterof fact the spruce doesn't grow on this continent, I have to actually call andgo search the lumberyards (go ahead, laugh). Last but not least - I have todraw this modification for Riblett I'm planing to build... Busy time ahead.One more question: This additional width of the spars also needs to make a roomfor the spar in the rib wider, but in which direction? On both sides symmetricalto the center of the spar, or on the inside of the wing, further from theleading and trailing edge? Regards,IvanRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________
RE: Pietenpol-List: Re: built up spars
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Ivan,My Pietenpol plans show the front spar as 1 1/8" and the rear at 1". Theseare the same dimensions as the UK plans (7/8" caps with 2 x 1/8" ply for thefront and 3/4" caps with 2 x 1/8" ply on the rear).I made my ribs first and followed Bernard's plans. I didn't change anythingto get them to fit the box spars.CheersPeter-----Original Message-----
Ivan,My Pietenpol plans show the front spar as 1 1/8" and the rear at 1". Theseare the same dimensions as the UK plans (7/8" caps with 2 x 1/8" ply for thefront and 3/4" caps with 2 x 1/8" ply on the rear).I made my ribs first and followed Bernard's plans. I didn't change anythingto get them to fit the box spars.CheersPeter-----Original Message-----
Re: Pietenpol-List: Re: built up spars
Original Posted By: Ryan Mueller
Subject: Re: Pietenpol-List: Re: built up spars
Subject: Re: Pietenpol-List: Re: built up spars
Pietenpol-List: Re: built up spars
Original Posted By: Matt Dralle
Ryan,Your second option seems logical to me. Luckily, Peter has the original box-sparplans in his possession, we will see what the designer of Piet box-spar thinksabout that detail.Ivan[quote="Ryan Mueller"]Ivan,At least with the actual Pietenpol plans, when dealing with ribs and differentspar widths (original 1" routed, 3/4" solid, etc) you want to maintain the 273/4" dimension (if my memory is correct) between the front and rear spar, as thiscorresponds to the cabane struts coming off the fuselage.Or you could think of it as the rear face of the front spar and the front faceof the rear spar being immovable, as constants. If you are going to increase ordecrease spar width you would "move" the front face of the front spar, or therear face of the rear spar and adjust your ribs accordingly. Again, this iswith the Pietenpol plans; your mileage may vary with the Grega Plans.RyanOn Sat, Nov 28, 2009 at 4:51 AM, ivan.todorovic wrote:> > > OK, Peter, I've got it.> > I hope I'll draw the rear spar as soon as I get some time. My plans arrivedlast week, I've bought a set of Grega plans from James Thursby (Thank's to Matronicslist for finding the available set), and now I'm in "finding wood" phase.There is no "Aircraft spruce" or shops like that here where I live, as a meterof fact the spruce doesn't grow on this continent, I have to actually calland go search the lumberyards (go ahead, laugh). Last but not least - I haveto draw this modification for Riblett I'm planing to build... Busy time ahead.> > One more question: This additional width of the spars also needs to make a roomfor the spar in the rib wider, but in which direction? On both sides symmetricalto the center of the spar, or on the inside of the wing, further from theleading and trailing edge?> > > Regards,> Ivan> > > > > Read this topic online here:> > > http://forums.matronics.com/viewtopic.p ... 198#275198 (http://forums.matronics.com/viewtopic.p ... 198#275198)> > > > > > > > > ==========> ="_blank">www.aeroelectric.com> ooks.com" target="_blank">www.buildersbooks.com> et="_blank">www.homebuilthelp.com> ="_blank">http://www.matronics.com/contribution> le, List Admin.> ==========> st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List> ==========> http://forums.matronics.com> ==========> > > > > > Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Sun, 29 Nov 2009 00:04:37 -0800
Ryan,Your second option seems logical to me. Luckily, Peter has the original box-sparplans in his possession, we will see what the designer of Piet box-spar thinksabout that detail.Ivan[quote="Ryan Mueller"]Ivan,At least with the actual Pietenpol plans, when dealing with ribs and differentspar widths (original 1" routed, 3/4" solid, etc) you want to maintain the 273/4" dimension (if my memory is correct) between the front and rear spar, as thiscorresponds to the cabane struts coming off the fuselage.Or you could think of it as the rear face of the front spar and the front faceof the rear spar being immovable, as constants. If you are going to increase ordecrease spar width you would "move" the front face of the front spar, or therear face of the rear spar and adjust your ribs accordingly. Again, this iswith the Pietenpol plans; your mileage may vary with the Grega Plans.RyanOn Sat, Nov 28, 2009 at 4:51 AM, ivan.todorovic wrote:> > > OK, Peter, I've got it.> > I hope I'll draw the rear spar as soon as I get some time. My plans arrivedlast week, I've bought a set of Grega plans from James Thursby (Thank's to Matronicslist for finding the available set), and now I'm in "finding wood" phase.There is no "Aircraft spruce" or shops like that here where I live, as a meterof fact the spruce doesn't grow on this continent, I have to actually calland go search the lumberyards (go ahead, laugh). Last but not least - I haveto draw this modification for Riblett I'm planing to build... Busy time ahead.> > One more question: This additional width of the spars also needs to make a roomfor the spar in the rib wider, but in which direction? On both sides symmetricalto the center of the spar, or on the inside of the wing, further from theleading and trailing edge?> > > Regards,> Ivan> > > > > Read this topic online here:> > > http://forums.matronics.com/viewtopic.p ... 198#275198 (http://forums.matronics.com/viewtopic.p ... 198#275198)> > > > > > > > > ==========> ="_blank">www.aeroelectric.com> ooks.com" target="_blank">www.buildersbooks.com> et="_blank">www.homebuilthelp.com> ="_blank">http://www.matronics.com/contribution> le, List Admin.> ==========> st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List> ==========> http://forums.matronics.com> ==========> > > > > > Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Sun, 29 Nov 2009 00:04:37 -0800
Pietenpol-List: Re: built up spars
Original Posted By: "ivan.todorovic"
That is waaay too cool. Wow!--------Mark - working on wingsRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: built up spars
That is waaay too cool. Wow!--------Mark - working on wingsRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: built up spars
Original Posted By: amsafetyc(at)aol.com
Attached are three drawings of the built box-spar for Piet Air Camper. Many Thanksto Peter W. Johnson for all the info from the original (UK designed) plans.Grega builders may expect their version in the future, together with adequate Riblettrib-jig plans (31" GN-1 spar distance, different leading edge constructionetc.). Not to bother Pietenpol builders with things not related to them, I'veformed Grega GN-1 group on Yahoo,http://groups.yahoo.com/group/GregaGN1/and all things Grega-specific and non-Pietenpol related I will post there. Feelfree to join.Regards,Ivan TodorovicRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/boxs ... __________
Attached are three drawings of the built box-spar for Piet Air Camper. Many Thanksto Peter W. Johnson for all the info from the original (UK designed) plans.Grega builders may expect their version in the future, together with adequate Riblettrib-jig plans (31" GN-1 spar distance, different leading edge constructionetc.). Not to bother Pietenpol builders with things not related to them, I'veformed Grega GN-1 group on Yahoo,http://groups.yahoo.com/group/GregaGN1/and all things Grega-specific and non-Pietenpol related I will post there. Feelfree to join.Regards,Ivan TodorovicRead this topic online here:http://forums.matronics.com/viewtopic.p ... ttachments: http://forums.matronics.com//files/boxs ... __________
Pietenpol-List: Re: built up spars
Original Posted By: "ivan.todorovic"
Has anyone done any structural analysis of any ofthe Piet spars... either the stock solid spruce, orthe routed, or the built-up in any configuration?I'd like to compare notes on some calculations thatI've done.thanks.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________Subject: Pietenpol-List: Re: built up spars
Has anyone done any structural analysis of any ofthe Piet spars... either the stock solid spruce, orthe routed, or the built-up in any configuration?I'd like to compare notes on some calculations thatI've done.thanks.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________Subject: Pietenpol-List: Re: built up spars
Pietenpol-List: Re: built up spars
Original Posted By: airlion