---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Fri 03/12/10: 22 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:24 AM - Re: New builder already needs help (helspersew@aol.com) 2. 04:34 AM - Re: New builder already needs help (gcardinal) 3. 05:15 AM - Re: Circuit breakers (Barry Davis) 4. 05:58 AM - Re: New builder already needs help (Jack Phillips) 5. 06:50 AM - converting an A65 to an A75 (Oscar Zuniga) 6. 06:56 AM - differeneces between C75 and C85 (Oscar Zuniga) 7. 07:16 AM - Re: New builder already needs help (Michael Perez) 8. 08:52 AM - Re: New builder already needs help (Myron Anderson) 9. 09:00 AM - Re: New builder already needs help (Bill Church) 10. 09:21 AM - Re: log your test maneuvers (Rick Holland) 11. 09:34 AM - Re: Re: New builder already needs help (Rick Holland) 12. 12:55 PM - 1/2" web idea. Spar options--one man's method (Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]) 13. 01:14 PM - Re: 1/2" web idea. Spar options--one man's method (taildrags) 14. 01:42 PM - Re: 1/2" web idea. Spar options--one man's method (Dan Yocum) 15. 01:54 PM - Re: Re: 1/2" web idea. Spar options--one man's method (Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]) 16. 02:50 PM - Re: Re: Purchased an Engine (Dale Johnson) 17. 05:44 PM - Re: 1/2" web idea. Spar options--one man's method (David Paule) 18. 06:37 PM - Re: 1/2" web idea. Spar options--one man's method (Dan Yocum) 19. 07:33 PM - Re: 1/2" web idea. Spar options--one man's method (David Paule) 20. 07:49 PM - Re: Re: 1/2" web idea. Spar options--one man's method (Dick N) 21. 09:06 PM - Re: 1/2" web idea. Spar options--one man's method (Baldeagle) 22. 09:59 PM - Re: Re: New builder already needs help (Mike Whaley) ________________________________ Message 1 _____________________________________ Time: 03:24:39 AM PST US Subject: Re: Pietenpol-List: New builder already needs help From: helspersew@aol.com Myron, Went with the 1" for authenticity. (Purist) The routing surely creates a LOT of expensive sawdust to sweep up. Dan Helsper Poplar Grove, IL. -----Original Message----- From: Myron Anderson Sent: Thu, Mar 11, 2010 10:25 pm Subject: Pietenpol-List: New builder already needs help After years of lurking about the matronics site, going to Oshkosh and drea ming about building an airplane I have taken the plunge. My plans arrived today and I am now officially building a piet. While planning my first order to Aircraft Spruce and pouring over the plan s and some builders web sites I have a question about spar size. I have seen several mentions of the spar width of =C2=BE inches and the plans sh ow spar width of 1 inch with some sections routed for weight savings. I was going to order section of spar to aid in rib jig construction and to test fit the ribs onto to check for consistency of my build. I figured I would use the section of spar later for the center section if I decided to go with the three piece wing. What width spar are you using? Myron Anderson Plans in hand and preparing to make ribs. ======================== =========== -= - The Pietenpol-List Email Forum - -= Use the Matronics List Features Navigator to browse -= the many List utilities such as List Un/Subscription, -= Archive Search & Download, 7-Day Browse, Chat, FAQ, -= Photoshare, and much much more: - -= --> http://www.matronics.com/Navigator?Pietenpol-List - -======================== ======================== =========== -= - MATRONICS WEB FORUMS - -= Same great content also available via the Web Forums! - -= --> http://forums.matronics.com - -======================== ======================== =========== -= - List Contribution Web Site - -= Thank you for your generous support! -= -Matt Dralle, List Admin. -= --> http://www.matronics.com/contribution -======================== ======================== =========== ________________________________ Message 2 _____________________________________ Time: 04:34:13 AM PST US From: "gcardinal" Subject: Re: Pietenpol-List: New builder already needs help Spar size is builder's choice. 3/4" will be less expensive to purchase. Decide on your spar size and then build the ribs accordingly. Greg Cardinal Minneapolis ----- Original Message ----- From: Myron Anderson To: pietenpol-list@matronics.com Sent: Thursday, March 11, 2010 10:25 PM Subject: Pietenpol-List: New builder already needs help After years of lurking about the matronics site, going to Oshkosh and dreaming about building an airplane I have taken the plunge. My plans arrived today and I am now officially building a piet. While planning my first order to Aircraft Spruce and pouring over the plans and some builders web sites I have a question about spar size. I have seen several mentions of the spar width of =BE inches and the plans show spar width of 1 inch with some sections routed for weight savings. I was going to order section of spar to aid in rib jig construction and to test fit the ribs onto to check for consistency of my build. I figured I would use the section of spar later for the center section if I decided to go with the three piece wing. What width spar are you using? Myron Anderson Plans in hand and preparing to make ribs. ________________________________ Message 3 _____________________________________ Time: 05:15:30 AM PST US From: "Barry Davis" Subject: RE: Pietenpol-List: Circuit breakers Looking at the AeroMax Corvair Service and Operations Manual, the wiring diagram shows a 3amp Breaker between the A/B switch(we used a ON/ON switch) and the coils (one for each coil). That is the way we did ours. I always pull these out if there are a lot of kids around and I can't watch the Big Piet every minute. Barry Davis Big Piet NX973BP The pic shows the switch and breakers labled "P" and "E" for points and electronic (also marked the coils P&E, every little bit helps later on). The 40amp breaker is for the alternator. Hope this helps. -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of skellytown flyer Sent: Thursday, March 11, 2010 7:34 PM Subject: Pietenpol-List: Circuit breakers --> if any of you have installed circuit breakers to your coils on Corvair conversions I'd like to hear what you used.I have the coil switcher with 2 coils and 2 ignition switches.but I'm thinking at a minimum I will install individual panel mounted fuses that can be easily changed from the seat.no doubt should get breakers but then I am still a tightwad and with the dual coils if one shorts it probably wouldn't stay reset anyway.what's the opinions? and what kind of amp rating? Raymond Read this topic online here: http://forums.matronics.com/viewtopic.php?p=290065#290065 ________________________________ Message 4 _____________________________________ Time: 05:58:41 AM PST US From: "Jack Phillips" Subject: RE: Pietenpol-List: New builder already needs help =BE=94 is plenty, and considerably cheaper and ligther than 1=94 Jack Phillips NX899JP Raleigh, NC _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Myron Anderson Sent: Thursday, March 11, 2010 11:25 PM Subject: Pietenpol-List: New builder already needs help After years of lurking about the matronics site, going to Oshkosh and dreaming about building an airplane I have taken the plunge. My plans arrived today and I am now officially building a piet. While planning my first order to Aircraft Spruce and pouring over the plans and some builders web sites I have a question about spar size. I have seen several mentions of the spar width of =BE inches and the plans show spar width of 1 inch with some sections routed for weight savings. I was going to order section of spar to aid in rib jig construction and to test fit the ribs onto to check for consistency of my build. I figured I would use the section of spar later for the center section if I decided to go with the three piece wing. What width spar are you using? Myron Anderson Plans in hand and preparing to make ribs. ________________________________ Message 5 _____________________________________ Time: 06:50:28 AM PST US From: Oscar Zuniga Subject: Pietenpol-List: converting an A65 to an A75 >From my upcoming article on the small Continentals in Contact! Magazine: ====================== In order to obtain ten additional horsepower by turning the A65 at 2600 RPM rather than at 2300, Continental changed several things related to cooling and lubrication. The cap ends of the rods were drilled with 1/16 holes to provide additional squirt lubrication for the cylinder walls, the exhaust valves were changed to stellite-faced (a cobalt-chromium alloy with increased hardness and a high melting point), and the undersides of the pistons were made with a waffle pattern for additional cooling. The wrist pins were also changed to a smaller diameter, although it is possible to create a pseudo-A75 from an A65 by simply changing the valves and drilling the connecting rods to allow the engine to operate at the higher RPM without changing pistons, rods, or wrist pins, but engine life and cooling may suffer. Once again, minor changes to ignition timing and carburetion differentiate the higher-horsepower engine from its predecessor. The external appearance is unchanged, and other than by examining the engine data plate, it is not possible to distinguish one engine from the other. While many A65s have been made to operate at the higher engine speed by simply changing propellers to obtain A75 performance, one must understand that the Continental engineers had reasons for implementing the various changes to the engine to achieve certification at the higher horsepower, and countless hours of operation in all sorts of aircraft and configurations brought to light the weaknesses that led to the changes in later engines. ==================== If you have a certified engine, the conversion must be done according to the Continental book procedure and the logs signed off accordingly, or otherwise you have an experimental engine. Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 6 _____________________________________ Time: 06:56:30 AM PST US From: Oscar Zuniga Subject: Pietenpol-List: differeneces between C75 and C85 Also from my upcoming article in Contact!, referring to the jump from the A-series (O-170) to the C-series (O-190): ================ The C75 and C85 introduced cylinders and pistons with a new bore diameter of 4-1/16 to the series, increasing displacement to 188 cubic inches and thus the O-190 designation. With the increased bore and displacement, the C75 could achieve rated power at an A65-like engine speed of 2275 RPM. The jump from the C75 to the C85 was very easily achieved by simply changing the venturi and main jet in the Stromberg carb (or by using an approved model of Marvel-Schebler carb similar to those that would later be used in the C90 and O-200 engines) and operating the engine at 2575 RPM. =================== Oscar Zuniga Air Camper NX41CC San Antonio, TX mailto: taildrags@hotmail.com website at http://www.flysquirrel.net ________________________________ Message 7 _____________________________________ Time: 07:16:17 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: New builder already needs help I am using 3/4" solid. ________________________________ Message 8 _____________________________________ Time: 08:52:29 AM PST US From: "Myron Anderson" Subject: Pietenpol-List: Re: New builder already needs help Thanks All, Since the price of spars are the same at Aircraft Spruce I have decided to go with the 1 inch spar and do the routing. My order is in for the rib materials and looking forward to getting started. Myron Anderson Danville, IN Subject: Re: New builder already needs help From: helspersew@aol.com Date: Fri Mar 12 - 3:24 AM Myron, Went with the 1" for authenticity. (Purist) The routing surely creates a LOT of expensive sawdust to sweep up. Dan Helsper Poplar Grove, IL. -----Original Message----- From: Myron Anderson > Sent: Thu, Mar 11, 2010 10:25 pm Subject: New builder already needs help After years of lurking about the matronics site, going to Oshkosh and drea ming about building an airplane I have taken the plunge. My plans arrived today and I am now officially building a piet. While planning my first order to Aircraft Spruce and pouring over the plan s and some builders web sites I have a question about spar size. I have seen several mentions of the spar width of =C2=BE inches and the plans sh ow spar width of 1 inch with some sections routed for weight savings. I was going to order section of spar to aid in rib jig construction and to test fit the ribs onto to check for consistency of my build. I figured I would use the section of spar later for the center section if I decided to go with the three piece wing. What width spar are you using? Myron Anderson Plans in hand and preparing to make ribs. ________________________________ Message 9 _____________________________________ Time: 09:00:42 AM PST US Subject: Pietenpol-List: Re: New builder already needs help From: "Bill Church" Myron, If you purchased the full set of Pietenpol plans (including the three-piece wing plan), you will see both versions of the spar (1" thick, and 3/4" thick). The original design was 1" thick, with routed sections to reduce weight. This was the spar drawn in the FGM drawings as well as in the 1933/34 Improved Air Camper drawings. Later, BHP switched to a 3/4" thick spar, with NO routed sections. The 3/4" spar is only shown in the drawing for the three-piece wing. The 3/4" non-routed spar has approximately 90% the strength of the routed 1" spar (in simple bending). Both have been proven to be more than adequate in strength. Which one to use is strictly up to you. Your ribs can be built to accommodate the 1" spar, and then, later, if you decide to use 3/4" spars, just add 1/2" wide, 1/8" plywood spacer shims at each rib location. Or, if you know for certain that you want to use the 3/4" spar, build your ribs to suit, and eliminate the little bit of extra weight and work of the shims. Bill C. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=290119#290119 ________________________________ Message 10 ____________________________________ Time: 09:21:03 AM PST US Subject: Re: Pietenpol-List: log your test maneuvers From: Rick Holland Or his checkbook. On Thu, Mar 11, 2010 at 7:29 PM, Gene & Tammy wrote: > > > That's what you hope the other guy has when he taxis into ya. > Gene > ----- Original Message ----- From: "Jeff Boatright" > To: > Sent: Thursday, March 11, 2010 12:14 PM > Subject: Re: Pietenpol-List: log your test maneuvers > > >> >> What's insurance? >> >> >> >> >> >> > > > -------------------------------------------------------------------------------- > > > Checked by AVG - www.avg.com > 21:50:00 > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 11 ____________________________________ Time: 09:34:35 AM PST US Subject: Re: Pietenpol-List: Re: New builder already needs help From: Rick Holland Either size works fine. I think someone on this group who routed his 1" spars collected and weighted the shavings he routed out to see how much weight he saved, came to less than a pound I believe. Can be found in the archives. rick On Fri, Mar 12, 2010 at 12:00 PM, Bill Church wrote: > > Myron, > > If you purchased the full set of Pietenpol plans (including the three-piece wing plan), you will see both versions of the spar (1" thick, and 3/4" thick). The original design was 1" thick, with routed sections to reduce weight. This was the spar drawn in the FGM drawings as well as in the 1933/34 Improved Air Camper drawings. Later, BHP switched to a 3/4" thick spar, with NO routed sections. The 3/4" spar is only shown in the drawing for the three-piece wing. The 3/4" non-routed spar has approximately 90% the strength of the routed 1" spar (in simple bending). Both have been proven to be more than adequate in strength. > Which one to use is strictly up to you. > Your ribs can be built to accommodate the 1" spar, and then, later, if you decide to use 3/4" spars, just add 1/2" wide, 1/8" plywood spacer shims at each rib location. Or, if you know for certain that you want to use the 3/4" spar, build your ribs to suit, and eliminate the little bit of extra weight and work of the shims. > > Bill C. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=290119#290119 > > -- Rick Holland Castle Rock, Colorado "Logic is a wreath of pretty flowers, that smell bad" ________________________________ Message 12 ____________________________________ Time: 12:55:39 PM PST US From: "Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]" Subject: Pietenpol-List: 1/2" web idea. Spar options--one man's method Myron, Group----here is how I did my spar and how I would do it again propo sed in the attached sketch. I did a cost analysis of both methods and it was pretty much a wash as I re call with the proposed method being way less work by not having to route out U-channels in those upper an d lower 'caps'. Mike C. ________________________________ Message 13 ____________________________________ Time: 01:14:40 PM PST US Subject: Pietenpol-List: Re: 1/2" web idea. Spar options--one man's method From: "taildrags" Mikee- Wouldn't a dado blade on a table saw make much quicker work of the channels in the spar caps than a router would, to accept the spar webs? -------- Oscar Zuniga San Antonio, TX Air Camper NX41CC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=290145#290145 ________________________________ Message 14 ____________________________________ Time: 01:42:55 PM PST US From: Dan Yocum Subject: Re: Pietenpol-List: 1/2" web idea. Spar options--one man's method Has anybody done the finite element analysis on the strength provided by this method, Mike's second, in his picture? I was pondering this just last night... On 03/12/2010 02:48 PM, Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation] wrote: > Myron, Group----here is how I did my spar and how I would do it again proposed in the attached sketch. > > I did a cost analysis of both methods and it was pretty much a wash as I recall with the proposed method > being way less work by not having to route out U-channels in those upper and lower 'caps'. > > Mike C. > > -- Dan Yocum Fermilab 630.840.6509 yocum@fnal.gov, http://fermigrid.fnal.gov "I fly because it releases my mind from the tyranny of petty things." ________________________________ Message 15 ____________________________________ Time: 01:54:57 PM PST US From: "Cuy, Michael D. (GRC-RXD0)[ASRC Aerospace Corporation]" Subject: RE: Pietenpol-List: Re: 1/2" web idea. Spar options--one man's method Oscar, Yes, a dado blade would have worked much faster on making those U channels but I did not have one at the time so used my router. The beauty of gluing those four strips of spruce to each corner of the 1/2" spar web is that you don't need to dado or route anything. Mike C. ________________________________ Message 16 ____________________________________ Time: 02:50:22 PM PST US From: "Dale Johnson" Subject: Re: Pietenpol-List: Re: Purchased an Engine Shad There are other . The jets in the carb are larger also. Dale > [Original Message] > From: shad bell > To: > Date: 3/11/2010 7:47:51 PM > Subject: Re: Pietenpol-List: Re: Purchased an Engine > > > I think the only physical difference between the a-65 nad a-75 was the addition of a oil passage drilled in the rods (at the bearing caps) for better lubrication, I also believe that a 65 can be modified to a 75. I looked a buying a luscomb a few years back, and was studying up on it. > > Shad > > > > > ________________________________ Message 17 ____________________________________ Time: 05:44:40 PM PST US From: "David Paule" Subject: Re: Pietenpol-List: 1/2" web idea. Spar options--one man's method Finite element analysis isn't necessary. Hand analysis would be considerably easier and as accurate. As it turns out, the two ways to build that spar are equivalent. With the first approach, there doesn't seem to be a technical reason to make the dado 3/4" deep. All that's needed is to locate the web and provide enough glue area to ensure a firm bond. Since most glues likely to be used will be stronger than the wood in in-plane shear, a person could even glue the caps to the web without the dado, if they hold the position while clamping. But a nominal small dado would be better. Smaller dados would let the builder make the web shallower, too, and therefore probably cheaper. David Paule > > Has anybody done the finite element analysis on the strength provided by > this method, Mike's second, in his picture? I was pondering this just > last night... ________________________________ Message 18 ____________________________________ Time: 06:37:32 PM PST US From: Dan Yocum Subject: Re: Pietenpol-List: 1/2" web idea. Spar options--one man's method David, On 03/12/2010 07:43 PM, David Paule wrote: > > Finite element analysis isn't necessary. Hand analysis would be > considerably easier and as accurate. I admit, the "finite element analysis" bit was tongue-in-cheek. I'm much more of a back-of-the-envelope or napkin type of guy. > > As it turns out, the two ways to build that spar are equivalent. Would these both be equivalent, or nearly so, to the 1"-wide-routed-out method prescribed by BHP? I get that the glue joint would be stronger than the wood, but would the overall strength of the resulting I-beam be equivalent to a solid piece of wood that's scalloped out? Thanks, Dan > > With the first approach, there doesn't seem to be a technical reason to > make the dado 3/4" deep. All that's needed is to locate the web and > provide enough glue area to ensure a firm bond. Since most glues likely > to be used will be stronger than the wood in in-plane shear, a person > could even glue the caps to the web without the dado, if they hold the > position while clamping. But a nominal small dado would be better. > Smaller dados would let the builder make the web shallower, too, and > therefore probably cheaper. > > David Paule > > >> >> Has anybody done the finite element analysis on the strength provided >> by this method, Mike's second, in his picture? I was pondering this >> just last night... > > -- Dan Yocum Fermilab 630.840.6509 yocum@fnal.gov, http://fermigrid.fnal.gov "I fly because it releases my mind from the tyranny of petty things." ________________________________ Message 19 ____________________________________ Time: 07:33:54 PM PST US From: "David Paule" Subject: Re: Pietenpol-List: 1/2" web idea. Spar options--one man's method If the net cross-sections are the same and if the wood's grain is running the same direction, then they are equivalent. I don't know what the original routed section is so I can't comment about that. David Paule >> As it turns out, the two ways to build that spar are equivalent. > > Would these both be equivalent, or nearly so, to the 1"-wide-routed-out > method prescribed by BHP? I get that the glue joint would be stronger > than the wood, but would the overall strength of the resulting I-beam be > equivalent to a solid piece of wood that's scalloped out? > > Thanks, > Dan > ________________________________ Message 20 ____________________________________ Time: 07:49:39 PM PST US From: "Dick N" Subject: Re: Pietenpol-List: Re: 1/2" web idea. Spar options--one man's method Oscar Thats how I did mine. Dick N. ----- Original Message ----- From: "taildrags" Sent: Friday, March 12, 2010 3:14 PM Subject: Pietenpol-List: Re: 1/2" web idea. Spar options--one man's method > > Mikee- > > Wouldn't a dado blade on a table saw make much quicker work of the > channels in the spar caps than a router would, to accept the spar webs? > > -------- > Oscar Zuniga > San Antonio, TX > Air Camper NX41CC > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=290145#290145 > > > ________________________________ Message 21 ____________________________________ Time: 09:06:28 PM PST US Subject: Pietenpol-List: Re: 1/2" web idea. Spar options--one man's method From: "Baldeagle" The "Spirit of St. Louis" spars are done like Mike's second sketch. 1/2" web, 3/4" corner pieces, total 2" thick at top and bottom of spar. Good enough for Lindbergh and 450 gallons of gasoline. - Read this topic online here: http://forums.matronics.com/viewtopic.php?p=290171#290171 ________________________________ Message 22 ____________________________________ Time: 09:59:13 PM PST US From: "Mike Whaley" Subject: Re: Pietenpol-List: Re: New builder already needs help When I worked for Steen Aero, the company airplane (Hale Wallace's last Skybolt, N3HW) had routed spars. While it's never had problems, Hale and others agreed (after the fact) that it was a fundamental mistake to do this. In the end you only save a very small amount of weight (I think it was under 2 lbs, even for a biplane), and it can (potentially) significantly reduce the rigidity of the spars. You also risk messing up while doing the routing process and converting the piece to very expensive scrap wood!! Obviously it's worked on many aircraft over the decades, but really, why risk it for such a miniscule advantage and high potential cost? I'd say that if you really want the beefiness of 1" spars but the lighter weight of 3/4" spars, you'd be better off making your spars 7/8" thick, without routing them. Or not worrying about it and going with the 1"... seems to me that the spar is one of those things where a little extra strength really isn't a bad thing at all, and the weight difference would be better made up on other things. On my project, I believe I'll probably end up with laminated spars, as this reduces the chances of a hidden defect buried in the wood, you can use shorter wood pieces, they weight the same, they fail progressively rather than completely at once (hopefully that will never be an issue!) and they are more warp-resistant. Strength is at least as strong as a solid spar, and with the tests from the Skybolt laminated spars, it was found they were usually about 25% stronger than the solid versions. Mike Whaley MerlinFAC@cfl.rr.com ----- Original Message ----- From: "Rick Holland" Sent: Friday, March 12, 2010 12:31 PM Subject: [piet] Re: Pietenpol-List: Re: New builder already needs help > > Either size works fine. I think someone on this group who routed his > 1" spars collected and weighted the shavings he routed out to see how > much weight he saved, came to less than a pound I believe. Can be > found in the archives. > > rick > > On Fri, Mar 12, 2010 at 12:00 PM, Bill Church wrote: > > > > Myron, > > > > If you purchased the full set of Pietenpol plans (including the three-piece wing plan), you will see both versions of the spar (1" thick, and 3/4" thick). The original design was 1" thick, with routed sections to reduce weight. This was the spar drawn in the FGM drawings as well as in the 1933/34 Improved Air Camper drawings. Later, BHP switched to a 3/4" thick spar, with NO routed sections. The 3/4" spar is only shown in the drawing for the three-piece wing. The 3/4" non-routed spar has approximately 90% the strength of the routed 1" spar (in simple bending). Both have been proven to be more than adequate in strength. > > Which one to use is strictly up to you. > > Your ribs can be built to accommodate the 1" spar, and then, later, if you decide to use 3/4" spars, just add 1/2" wide, 1/8" plywood spacer shims at each rib location. Or, if you know for certain that you want to use the 3/4" spar, build your ribs to suit, and eliminate the little bit of extra weight and work of the shims. > > > > Bill C. > > > > > > > > > > Read this topic online here: > > > > http://forums.matronics.com/viewtopic.php?p=290119#290119 > > > > > > > > > > > > > > > > > > > > > > > > > -- > Rick Holland > Castle Rock, Colorado > > "Logic is a wreath of pretty flowers, that smell bad" > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.