From: To: Subject: krnet Digest 29 Jan 2003 21:51:06 -0000 Issue 616 Date: Wednesday, January 29, 2003 1:51 PM krnet Digest 29 Jan 2003 21:51:06 -0000 Issue 616 Topics (messages 14730 through 14744): Re: Epoxy on wood? 14730 by: Justin 14736 by: Edwin Blocher Re: What plywood? 14731 by: Frank Ross 14732 by: klodhopper.iVillage.com 14740 by: Tony Rogers Plywood 14733 by: Eric Evezard 14742 by: Sky Rider KR's, Materials and Lee Robbins 14734 by: Scott Cable 14741 by: Sky Rider 14744 by: Sutstoy.aol.com Re: KR1s and in-line engines 14735 by: Daren Cogdon 14738 by: WMartensJr.aol.com KR1 undercarriage 14737 by: Daren Cogdon Re: uncertified wood in aircraft. 14739 by: Robert X. Cringely Is there an easy way to take the wings off? 14743 by: Bjbcljdb.aol.com Administrivia: To subscribe to the digest, e-mail: To unsubscribe from the digest, e-mail: To post to the list, e-mail: ---------------------------------------------------------------------- Date: Wed, 29 Jan 2003 09:14:22 -0600 To: KRnet@mailinglists.org From: Justin Subject: Re: KR> Epoxy on wood? Message-ID: <3E37EFCD.9050903@socal.rr.com> --------------050108040006060209050206 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit You all have changed my mind. I will now change it. What is opinion abour birch??? I put it through the same boiling water test and it held up the same as mahagony. Is there anyways to get the plywood off or should I just make another fuseside? I am making this plane from Duglas Fur so it will cost me about $20 for another side. Justin Scott Cable wrote: >Justin, >Do you have a death wish? My heart sank when I read you started building your KR from materials bought from Home Depot. Check this out, go to a hobby store or a craft store that sells plywood for model airplane and boats. Look at the same thickness of plywood of what you bought over at Home Depot, and closely compare the two, and you will notice that the model airplane plywood is 5 to 7 plys, you'll also notice that the HD plywood is only 2 or 3 plys. House construction grade plywood is made from pine trees. Aircraft plywood is made from birch or mahogany trees, pine is soft wood, and does NOT have the density or nearly half of the strength of aircraft grade wood. Also take note that you will see a label on the plywood at the craft or Hobby shop: "Not for Aircraft Use" >Which means, that even though it is hardwood multiply plywood, it has NOT been qualified or certified for aircraft use. Aircraft grade materials are expensive mainly because of the qualification process REQUIRED by the FAA for use on an aircraft. Using anything else but qualified materials is foolhardy and just asking for trouble. >Try this, go over to Home Depot and pick up a length of 1 x 2 of pine, see how far you can bend it without breaking. Now try it on a piece of of like section and length on any piece of hard wood (poplar, maple or oak). You'll notice that it takes a significant increase of effort to bend the hardwood. ( if you can). >Do you know why plywood is much stronger than the same thickness of non-laminated (dimensional lumber) wood? Because the grain of the different layers are opposite from the ply adjacent to it. A crack or failure in one ply cannot readily propagate to the next ply. Dimensional lumber will allow a crack or failure to easily propagate throughout the entire length >This is the same reason why composites work, actually, plywood is a composite also, but that's another discussion.... >So you can see that given the same thickness of material, the more sheer panels or plys, the stronger the result will be. Compare the differences between 1/4 , 1/2, & 3/4 inch plywood. The plys are all basicly the same thickness, the thicker plywood just has more plys. Do you know why architects specify a certain thickness of plywood in their designs? It's because they are requiring the floor or roof structure to carry a certain load, in sheer, between the structural members. >The plywood fuselage sides on the KR is required to carry a certain amount of sheer load between the fuselage structural members also, but the loads are many times greater in magnitude than that of a house. > The plans are very specific about the type and thickness AND grade of the material REQUIRED to handle this load. Ken Rand had an Engineering degree when he designed the KR, and also a really sharp guy on top of it. Justin, PLEASE read your manual, and please use only qualified materials that are specified in the manual. That means no dime store, or hardware store hardware, and that means no materials bought from Home Depot. > As an aviator, you have a responsibility to operate your craft in a manner that does not jepordise the safety and well being of yourself and others, both in the air and on the ground. As an aircraft constructor, you have the same reponsibilities. Please be responsible and destroy any parts you constructed with unqualified materials. It's the right thing to do. > Mark Jones wrote: Justin >Ronevogt@aol.com wrote: >Im almost doen with the second fuselage side but i have jigged up > > >>the first side and it looks nice. I used homedepot exter plywood on the >>outside.... >> >> >> > > >You did what??? The plywood you get at Home Depot is far inferior to >AIRCRAFT GRADE PLYWOOD. What about the weight? Is it 3/32? What type wood is >it? I know some of you guys like to save money and cut corners but >remember...your life depends on how you build your plane. Justin...you need >to re-think this decision.... > > >Mark Jones (N886MJ) >Wales, WI USA >E-mail me at flykr2s@wi.rr.com >Visit my KR-2S CorvAIRCRAFT web site at >http://mywebpage.netscape.com/n886mj/homepage.html > > > > > >--------------------------------------------------------------------- >To post to the list, email: krnet@mailinglists.org , NOT "reply all" > >To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org >For additional commands, e-mail: krnet-help@mailinglists.org > >See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp >or http://www.bouyea.net/ for the Word files > > >Scott Cable >KR-2S # 735 >Livonia, MI >s2cable1@yahoo.com > > >--------------------------------- >Do you Yahoo!? >Yahoo! Mail Plus - Powerful. Affordable. Sign up now > > --------------050108040006060209050206-- ------------------------------ Date: Wed, 29 Jan 2003 12:27:00 -0600 To: From: "Edwin Blocher" Subject: Re: KR> Epoxy on wood? Message-ID: <00d201c2c7c4$08bfcc20$0201a8c0@computer> Justin, The price difference between Sitka Spruce and Douglas Fir looks like a lot but spread that over the whole airplane cost and it is minimal. Spend the extra $$, get the weight savings, and feel safe about it. Birch plywood (Aircraft grade) is acyually stronger than Mahogany but weighs 2# per 3/32", 4X8 foot sheet more. ED Ed Blocher Santa Rosa Beach, FL eblocher@earthlink.net ----- Original Message ----- From: "Justin" To: Sent: Wednesday, January 29, 2003 9:14 AM Subject: Re: KR> Epoxy on wood? > You all have changed my mind. I will now change it. What is opinion > abour birch??? I put it through the same boiling water test and it held > up the same as mahagony. > > Is there anyways to get the plywood off or should I just make > another fuseside? I am making this plane from Duglas Fur so it will cost > me about $20 for another side. > > Justin > > Scott Cable wrote: > > >Justin, > >Do you have a death wish? My heart sank when I read you started building your KR from materials bought from Home Depot. Check this out, go to a hobby store or a craft store that sells plywood for model airplane and boats. Look at the same thickness of plywood of what you bought over at Home Depot, and closely compare the two, and you will notice that the model airplane plywood is 5 to 7 plys, you'll also notice that the HD plywood is only 2 or 3 plys. House construction grade plywood is made from pine trees. Aircraft plywood is made from birch or mahogany trees, pine is soft wood, and does NOT have the density or nearly half of the strength of aircraft grade wood. Also take note that you will see a label on the plywood at the craft or Hobby shop: "Not for Aircraft Use" > >Which means, that even though it is hardwood multiply plywood, it has NOT been qualified or certified for aircraft use. Aircraft grade materials are expensive mainly because of the qualification process REQUIRED by the FAA for use on an aircraft. Using anything else but qualified materials is foolhardy and just asking for trouble. > >Try this, go over to Home Depot and pick up a length of 1 x 2 of pine, see how far you can bend it without breaking. Now try it on a piece of of like section and length on any piece of hard wood (poplar, maple or oak). You'll notice that it takes a significant increase of effort to bend the hardwood. ( if you can). > >Do you know why plywood is much stronger than the same thickness of non-laminated (dimensional lumber) wood? Because the grain of the different layers are opposite from the ply adjacent to it. A crack or failure in one ply cannot readily propagate to the next ply. Dimensional lumber will allow a crack or failure to easily propagate throughout the entire length > >This is the same reason why composites work, actually, plywood is a composite also, but that's another discussion.... > >So you can see that given the same thickness of material, the more sheer panels or plys, the stronger the result will be. Compare the differences between 1/4 , 1/2, & 3/4 inch plywood. The plys are all basicly the same thickness, the thicker plywood just has more plys. Do you know why architects specify a certain thickness of plywood in their designs? It's because they are requiring the floor or roof structure to carry a certain load, in sheer, between the structural members. > >The plywood fuselage sides on the KR is required to carry a certain amount of sheer load between the fuselage structural members also, but the loads are many times greater in magnitude than that of a house. > > The plans are very specific about the type and thickness AND grade of the material REQUIRED to handle this load. Ken Rand had an Engineering degree when he designed the KR, and also a really sharp guy on top of it. Justin, PLEASE read your manual, and please use only qualified materials that are specified in the manual. That means no dime store, or hardware store hardware, and that means no materials bought from Home Depot. > > As an aviator, you have a responsibility to operate your craft in a manner that does not jepordise the safety and well being of yourself and others, both in the air and on the ground. As an aircraft constructor, you have the same reponsibilities. Please be responsible and destroy any parts you constructed with unqualified materials. It's the right thing to do. > > Mark Jones wrote: Justin > >Ronevogt@aol.com wrote: > >Im almost doen with the second fuselage side but i have jigged up > > > > > >>the first side and it looks nice. I used homedepot exter plywood on the > >>outside.... >> > >> > >> > > > > > >You did what??? The plywood you get at Home Depot is far inferior to > >AIRCRAFT GRADE PLYWOOD. What about the weight? Is it 3/32? What type wood is > >it? I know some of you guys like to save money and cut corners but > >remember...your life depends on how you build your plane. Justin...you need > >to re-think this decision.... > > > > > >Mark Jones (N886MJ) > >Wales, WI USA > >E-mail me at flykr2s@wi.rr.com > >Visit my KR-2S CorvAIRCRAFT web site at > >http://mywebpage.netscape.com/n886mj/homepage.html > > > > > > > > > > > >--------------------------------------------------------------------- > >To post to the list, email: krnet@mailinglists.org , NOT "reply all" > > > >To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org > >For additional commands, e-mail: krnet-help@mailinglists.org > > > >See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp > >or http://www.bouyea.net/ for the Word files > > > > > >Scott Cable > >KR-2S # 735 > >Livonia, MI > >s2cable1@yahoo.com > > > > > >--------------------------------- > >Do you Yahoo!? > >Yahoo! Mail Plus - Powerful. Affordable. Sign up now > > > > > > ------------------------------ Date: Wed, 29 Jan 2003 09:12:04 -0800 (PST) To: KRnet@mailinglists.org From: Frank Ross Subject: Re: KR> What plywood? Message-ID: <20030129171204.97517.qmail@web40909.mail.yahoo.com> --- Justin wrote: > I am using 1/8" plywood from home depot. > Justin Justin (and Kevin) Like my best friend says: "I want to die like my father, not like my mother, screaming in the passenger seat." I have to throw more plywood on this fire. These guys are trying to save your life. It's that simple. You may find non- "aircraft grade" plywood that will work, but not at home improvement stores like "Home Depot". That wood will be less expensive, but much heavier, and weaker. Covering it with fiberglass won't help, either. That will make it heavier, but will only postpone your visit to the autopsy room a short time. The difference isn't only in the quality of the glue (which is what you are testing with the steam and water tests). It is also in the type of wood and the number of layers it is made of. Aircraft grade has more layers of higher grade (tested) and lighter weight lumber pushed closer together. That makes it stronger. There are no gaps between the pieces that make up the interior layers. That's what Don Reid means when he says there are more 'voids' in non-aircraft grade plywood. Those voids can kill you. Aircraft grade is lighter, stronger and safer. That is why it costs more, too, unfortunately. 'Exterior' simply means it has glue which will withstand moisture better than 'interior'. Another 'experimenter' built a KR-2 a few years ago with PVC pipe for spars. Seemed like a great idea. It flew. It got certified. Then he killed himself and his passenger when the spars failed. Spinning toward the ground with no chance of recovery is not a fun way to end your life. We are not flaming you, we are trying to keep you from going down in flames. There's a big difference. Frank Ross in San Antonio, TX, USA __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com ------------------------------ Date: Wed, 29 Jan 2003 09:13:37 -0800 To: From: Cc: Subject: Re: KR> What plywood? Message-ID: ------=_NextPart_000_F24D_01C2C776.B4F971B0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Oops, I see I reversed names in that last message. Sorry about that. That's what comes from only knowing everyone from emails and websites. I shore wish more of us could make it to the gathering. Brad _______________________________________________________________ Sign up for FREE iVillage newsletters . From health and pregnancy to shopping and relationships, iVillage has the scoop on what matters most to you. <-----Original Message-----> > > From: klodhopper@iVillage.com > Sent: 1/29/2003 9:01:29 AM > To: KRnet@mailinglists.org > Subject: KR> What plywood? > > I logged on this morning just to say much the same thing Justin has said > after reading some of the messages late last night. > > One additional thought. Kevin indicated he planned to add a fiberglass > cover over the wood. Has anyone done the math to say that his boat will > not be as strong or stronger then per plans. Since he hasn't identified > the resin and style of glass, carbonfiber, or kevlar he plans to use, > obviously not. > > From my reading, it seems that the original concept of the KR was to > make an affordable aircraft. Over the years we have migrated towards > aircraft quality materials and higher expense, I would guess because of > the environment. There is less legal liability in specifying tested > aircraft materials in the plans and, except in the experimental area, > the mindset of the whole aviation community is certified everything. > > Kevin, I hope you have thought about what you are building. Airplanes > are unforgiving. There have been more than a few builders and volunteer > test pilots (friends of builders) killed by experimental aircraft > falling out of the sky on the first flight due to failures of various > parts. I am not willing to risk a friend so will test my own and do not > have a death wish so am being cautious. So much so that I am going to > trash a boat I bought with controls installed because I don't have > confidence in the workmanship. It doesn't have any safety defects that I > am aware of, I just don't have the confidence of having built it myself > and have decided to build my own. > > Brad Glasco > China Lake, CA > > > > _______________________________________________________________ > Sign up for FREE iVillage newsletters . > From health and pregnancy to shopping and relationships, iVillage > has the scoop on what matters most to you. > > <-----Original Message-----> > > From: Kevin > Sent: 1/29/2003 5:18:13 AM > To: KRnet@mailinglists.org > Subject: Re: Re: KR> What plywood? > > Wow! What kind of fire alarm has been set off here? Seems it is > similar to the one I set off a > couple > of months ago when I first came onto this site. There are those who > think that "Aircraft" quality > only comes from some government stamp. Not so and has been proven for > years. Do your homework, study > what the standards are, talk to the people at the FAA and the EAA. > Study the history of what > airplanes have been built of in the past. You would be surprised at > what they say. > > I had an old friend that said you couldn't use anything but DOM steel > tubing. When he mentioned that > he knew that to the tech counselor in Oshkosh he corrected him and > said welded seam tubing is fine > if > it meets the load requirements. > > When we buy wood stamped "aircraft", what does that mean? Buy EAA > books on wood. Study what it is > all > about. There is nothing that says you cannot get an airplane licensed > though you used materials > bought from somewhere other than an aircraft supply house. > > I guess what amazes me about this group is the fact that Ken Rand > built the KR with unproven > aircraft > construction materials, and yet we are giving this kid hell for doing > the same thing. Ken had to > prove that these materials were airwothy himself. I have read people > were so concerned about the > construction that he actually walked out the wing panel to prove its > strength. Many postings have > been put up here about the use of a Corvair engine. I believe this is > a good thing, but it is all > EXPERIMENTAL. Build carefully, read and get advice from the > appropriate places, and test, test, > test. > > Let the grilling begin....... > > Kevin. > > > -------Original Message------- > From: Justin > Sent: 01/28/03 10:31 PM > To: KRnet@mailinglists.org > Subject: Re: KR> What plywood? > > > I am using 1/8" plywood from home depot. It is exterier and I have put > it through tests just as i tested the mahogany. The results will be in > tommorow. The homedepot plywood held together in boiling water over > night and still didnt deform. Though it was weaker when streesed but > im > sure all wood is? Give your opinion. > > Justin > > jim @ synergy design wrote: > > >Justin, Please tell us you are not using 1/4 inch cdx!!!!!!!!!!(that > is > the thinnest You can get at H.D. around here) . If you have somehow > gotten > hold of 1/8 luan door skins, that is just as bad. Of course you could > just leave the wings off, and put a sail on it.:-). Are you using A/C > spruce > for the framework? What kind of glue? Are you related to the long lost > Hennie ? ( look it up in the net archives) . All kidding aside, If you > can' t > afford to use the proper materials and methods , and you become a lawn > dart, It reflects poorly on all of us. If you just have the itch to > fly, try > Hang Gliding. There is nothing better than looking down on a 182 from > 17,999 ft' ;-) . Good Luck, Jim Sporka > > > > > > > --------------------------------------------------------------------- > To post to the list, email: krnet@mailinglists.org , NOT "reply all" > > To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org > For additional commands, e-mail: krnet-help@mailinglists.org > > See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp > or http://www.bouyea.net/ for the Word files > > > > --------------------------------------------------------------------- > To post to the list, email: krnet@mailinglists.org , NOT "reply all" > > To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org > For additional commands, e-mail: krnet-help@mailinglists.org > > See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp > or http://www.bouyea.net/ for the Word files > > . ------=_NextPart_000_F24D_01C2C776.B4F971B0-- ------------------------------ Date: Wed, 29 Jan 2003 12:43:01 -0800 (PST) To: KRnet@mailinglists.org From: Tony Rogers Subject: Re: KR> What plywood? Message-ID: <20030129204301.16025.qmail@web10103.mail.yahoo.com> Justin I'm not flaming you, but I feel I've got to let you know a couple facts I've discovered working with various plywoods over a number of years. I'm a mechanical engineer and I've build several plywood boats and am now getting ready to start a full-size aircraft. Several of my boats have used 1/8" plywood and I didn't have much money to spare, so I tried using exterior grade plywood instead of the marine grade in carefully selected areas. The surfaces were both covered with fiberglass cloth to seal. The results were right off the bench were less than ideal, finish wise. Over the couse of a year the wood surface began to flake (not delaminate) and lift off areas of glass (with wood attached). Then I got a good smack from a sail boat's boom and the wood failed along a void down the length of the panel. Upon careful de-construction of the wood, I found several loose knots as well as the voids (up to 1/2" wide and full length). The glue never failed, but the wood came apart, taking the fiberglass with it and under stress, the voids allowed the outer layers to fail. You're doing a good job testing the glue on the wood you're using, but that's not what will fail. If you want to save a bit of money, use marine grade plywood. It's not the same quality as aircraft (no scarf joints), but at least the wood is selected to take epoxy well and the core layers are solid (not butt-joint gaps and no knots). Additional note: If there's a chance the plane will see moisture (condensation, rain, etc), seal all surfaces of the wood. Experience has shown me that moisture will get into "sealed" compartments and lead to failure of the wood. Tony Rogers Portland, OR --- Justin wrote: > I am using 1/8" plywood from home depot. It is exterier and I have put it through tests just as i tested the mahogany. The results will be in tommorow. The homedepot plywood held together in boiling water over night and still didnt deform. Though it was weaker when streesed but im sure all wood is? Give your opinion. > Justin __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com ------------------------------ Date: Wed, 29 Jan 2003 19:52:14 +0200 To: "KR MAIL" From: "Eric Evezard" Subject: Plywood Message-ID: <007901c2c7bf$43456ee0$f4ce07c4@erick> ------=_NextPart_000_0076_01C2C7CF.EB989BC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Netters, One never really knows what sins are being concealed in commercial = plywood,even although the two outer faces are perfect.The layers in = between may have serious defects which will increase with aircraft = use.Shine a strong lamp on one face and look from the other side.Do not = be surprised to see a full length /width gap of 1/8 ins. where the = layers are poorly but jointed.High quality ply will have been scarf = jointed and there will be no voids.Use certified aircraft plywood at all = times is my advice.I built my one sailplane with all wood imported from = USA and after 18 years the aircraft and myself are still in one piece. Best Regards, Eric Evezard South Africa ------=_NextPart_000_0076_01C2C7CF.EB989BC0-- ------------------------------ Date: Wed, 29 Jan 2003 13:42:49 -0800 (PST) To: KRnet@mailinglists.org From: Sky Rider Subject: Re: KR> Plywood Message-ID: <20030129214249.66222.qmail@web11601.mail.yahoo.com> --0-1959906904-1043876569=:66060 Content-Type: text/plain; charset=us-ascii I once worked in a plywood manufacturing plant in California...making both exterior and interior, and I am familiar with how it is done, if that will help anyone...I will do my best to answer any questions. Tony Eric Evezard wrote:Hi Netters, One never really knows what sins are being concealed in commercial plywood,even although the two outer faces are perfect.The layers in between may have serious defects which will increase with aircraft use.Shine a strong lamp on one face and look from the other side.Do not be surprised to see a full length /width gap of 1/8 ins. where the layers are poorly but jointed.High quality ply will have been scarf jointed and there will be no voids.Use certified aircraft plywood at all times is my advice.I built my one sailplane with all wood imported from USA and after 18 years the aircraft and myself are still in one piece. Best Regards, Eric Evezard South Africa --------------------------------- Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now --0-1959906904-1043876569=:66060-- ------------------------------ Date: Wed, 29 Jan 2003 09:59:03 -0800 (PST) To: KRnet@mailinglists.org From: Scott Cable Cc: aviationmech@aol.com Subject: KR's, Materials and Lee Robbins Message-ID: <20030129175903.68339.qmail@web40812.mail.yahoo.com> --0-1162335572-1043863143=:68030 Content-Type: text/plain; charset=us-ascii Justin, As far as the Douglas Fir goes, again, I must caution you to use only certified materials. Your best bet, the cheapest and safest way to construct your airframe, is to stick to the plans. Build with what is specified in the plans. My fuselage is covered with mahogany, most of the other builders are doing the same. Lee Robbins' KR2 is built with birch plywood. He's been flying his for almost 20 years. Lee has all kinds of wonderful stories about carb ice, GPS's and wood props. and all kinds of things that will make your hair stand on end! You don't fly a KR2 for almost 20 years and not have some interesting things to say about our sport, and our aircraft. My point Justin is this: Lee would advocate only the strict use of certified materials only in the construction of any aircraft. Considering the talent, experience and expertise of Lee, I would recommend that you follow his advise and benefit from his experience. Ask him yourself, I believe his eMail address is: aviationmech@aol.com Justin wrote:You all have changed my mind. I will now change it. What is opinion abour birch??? I put it through the same boiling water test and it held up the same as mahagony. Is there anyways to get the plywood off or should I just make another fuseside? I am making this plane from Duglas Fur so it will cost me about $20 for another side. Justin Scott Cable wrote: >Justin, >Do you have a death wish? My heart sank when I read you started building your KR from materials bought from Home Depot. Check this out, go to a hobby store or a craft store that sells plywood for model airplane and boats. Look at the same thickness of plywood of what you bought over at Home Depot, and closely compare the two, and you will notice that the model airplane plywood is 5 to 7 plys, you'll also notice that the HD plywood is only 2 or 3 plys. House construction grade plywood is made from pine trees. Aircraft plywood is made from birch or mahogany trees, pine is soft wood, and does NOT have the density or nearly half of the strength of aircraft grade wood. Also take note that you will see a label on the plywood at the craft or Hobby shop: "Not for Aircraft Use" >Which means, that even though it is hardwood multiply plywood, it has NOT been qualified or certified for aircraft use. Aircraft grade materials are expensive mainly because of the qualification process REQUIRED by the FAA for use on an aircraft. Using anything else but qualified materials is foolhardy and just asking for trouble. >Try this, go over to Home Depot and pick up a length of 1 x 2 of pine, see how far you can bend it without breaking. Now try it on a piece of of like section and length on any piece of hard wood (poplar, maple or oak). You'll notice that it takes a significant increase of effort to bend the hardwood. ( if you can). >Do you know why plywood is much stronger than the same thickness of non-laminated (dimensional lumber) wood? Because the grain of the different layers are opposite from the ply adjacent to it. A crack or failure in one ply cannot readily propagate to the next ply. Dimensional lumber will allow a crack or failure to easily propagate throughout the entire length >This is the same reason why composites work, actually, plywood is a composite also, but that's another discussion.... >So you can see that given the same thickness of material, the more sheer panels or plys, the stronger the result will be. Compare the differences between 1/4 , 1/2, & 3/4 inch plywood. The plys are all basicly the same thickness, the thicker plywood just has more plys. Do you know why architects specify a certain thickness of plywood in their designs? It's because they are requiring the floor or roof structure to carry a certain load, in sheer, between the structural members. >The plywood fuselage sides on the KR is required to carry a certain amount of sheer load between the fuselage structural members also, but the loads are many times greater in magnitude than that of a house. > The plans are very specific about the type and thickness AND grade of the material REQUIRED to handle this load. Ken Rand had an Engineering degree when he designed the KR, and also a really sharp guy on top of it. Justin, PLEASE read your manual, and please use only qualified materials that are specified in the manual. That means no dime store, or hardware store hardware, and that means no materials bought from Home Depot. > As an aviator, you have a responsibility to operate your craft in a manner that does not jepordise the safety and well being of yourself and others, both in the air and on the ground. As an aircraft constructor, you have the same reponsibilities. Please be responsible and destroy any parts you constructed with unqualified materials. It's the right thing to do. > Mark Jones wrote: Justin >Ronevogt@aol.com wrote: >Im almost doen with the second fuselage side but i have jigged up > > >>the first side and it looks nice. I used homedepot exter plywood on the >>outside.... >> >> >> > > >You did what??? The plywood you get at Home Depot is far inferior to >AIRCRAFT GRADE PLYWOOD. What about the weight? Is it 3/32? What type wood is >it? I know some of you guys like to save money and cut corners but >remember...your life depends on how you build your plane. Justin...you need >to re-think this decision.... > > >Mark Jones (N886MJ) >Wales, WI USA >E-mail me at flykr2s@wi.rr.com >Visit my KR-2S CorvAIRCRAFT web site at >http://mywebpage.netscape.com/n886mj/homepage.html > > > > > >--------------------------------------------------------------------- >To post to the list, email: krnet@mailinglists.org , NOT "reply all" > >To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org >For additional commands, e-mail: krnet-help@mailinglists.org > >See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp >or http://www.bouyea.net/ for the Word files > > >Scott Cable >KR-2S # 735 >Livonia, MI >s2cable1@yahoo.com > > >--------------------------------- >Do you Yahoo!? >Yahoo! Mail Plus - Powerful. Affordable. Sign up now > > Scott Cable KR-2S # 735 Livonia, MI s2cable1@yahoo.com --------------------------------- Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now --0-1162335572-1043863143=:68030-- ------------------------------ Date: Wed, 29 Jan 2003 13:40:38 -0800 (PST) To: KRnet@mailinglists.org From: Sky Rider Subject: Re: KR> KR's, Materials and Lee Robbins Message-ID: <20030129214038.11004.qmail@web11607.mail.yahoo.com> --0-1056701853-1043876438=:10850 Content-Type: text/plain; charset=us-ascii Folks...I have a question about materials also...are there any sources of foam other than aircraft sites...such as buiders materials stores, that would work properly but cost less...and also, my horizontal stab is cracked and chipped...can I gule it back together and add foam to the chipped areas, or do I need to start again...and if I can glue them, what kind of glue should I use... Tony --------------------------------- Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now --0-1056701853-1043876438=:10850-- ------------------------------ Date: Wed, 29 Jan 2003 16:50:53 EST To: KRnet@mailinglists.org From: Sutstoy@aol.com Subject: Re: KR> KR's, Materials and Lee Robbins Message-ID: <77.8869953.2b69a6bd@aol.com> --part1_77.8869953.2b69a6bd_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Tony, The dreaded Home Depot or an upholstery shop is where I would go for foam. Aloha Joe :>}) --part1_77.8869953.2b69a6bd_boundary-- ------------------------------ Date: Wed, 29 Jan 2003 18:28:41 +0000 To: KRnet@mailinglists.org From: "Daren Cogdon" Subject: Re: KR> KR1s and in-line engines Message-ID: Any photos/info on it?? Daz >From: "Howcroft" >Reply-To: KRnet@mailinglists.org >To: >Subject: Re: KR> KR1s and in-line engines >Date: Wed, 29 Jan 2003 13:26:53 +1300 > >Hello, > I know of a kr1 fitted with a Walter Micron inline engine at >Taupo >New Zealand. > > >--------------------------------------------------------------------- >To post to the list, email: krnet@mailinglists.org , NOT "reply all" > >To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org >For additional commands, e-mail: krnet-help@mailinglists.org > >See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp >or http://www.bouyea.net/ for the Word files _________________________________________________________________ Express yourself with cool emoticons http://messenger.msn.co.uk ------------------------------ Date: Wed, 29 Jan 2003 14:22:41 EST To: KRnet@mailinglists.org From: WMartensJr@aol.com Subject: Re: KR> KR1s and in-line engines Message-ID: <102.2506a974.2b698401@aol.com> --part1_102.2506a974.2b698401_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit For those who are interested in the Walter Mikron III engine, here is the web site for their engines. I've had a love afffair with those engines for a long time. http://www.moraviation.com/walter.html I've often thought it would be fun to place one of the larger six cylinder Mikron powerplants in a G10 Aeropony. The G10 is a license produced copy of the Bucker used in Germany before and during the war except it has a Continental engine in it. Putting an inline six would make it look pretty close to an original Bucker with adequate performance. Aeropony site is here: http://www.aeropony.com/ but it isn't loading for me so I don't know the status of the company. Basically they were refurbishing these ex-Eqyptian G10's for sale at a pretty decent price. Walt In a message dated 1/29/2003 1:33:01 PM Eastern Standard Time, darencogdon2@hotmail.com writes: > > Any photos/info on it?? > > Daz > > > > > >From: "Howcroft" > >Reply-To: KRnet@mailinglists.org > >To: > >Subject: Re: KR> KR1s and in-line engines > >Date: Wed, 29 Jan 2003 13:26:53 +1300 > > > >Hello, > > I know of a kr1 fitted with a Walter Micron inline engine at > >Taupo > >New Zealand. --part1_102.2506a974.2b698401_boundary-- ------------------------------ Date: Wed, 29 Jan 2003 18:47:40 +0000 To: krnet@mailinglists.org From: "Daren Cogdon" Subject: KR1 undercarriage Message-ID: Me again Apart from fixed and rearward-retracting undercarriage, has anyone ever fitted up a KR so that the wheels retract OUT towards the wingtips?? _________________________________________________________________ Express yourself with cool emoticons http://messenger.msn.co.uk ------------------------------ Date: Wed, 29 Jan 2003 12:24:29 -0800 To: KRnet@mailinglists.org From: "Robert X. Cringely" Subject: Re: KR> uncertified wood in aircraft. Message-Id: Bernard (NOT "Bernie") Pietenpol built his planes from hemlock he picked out at the local lumber yard. Flybaby and VJ-22 Sportsman plans both specify marine, not aircraft, plywood. I can buy marine plywood at a local lumber yard, though not at Home Depot. We get all worked-up about non-aircraft materials but forget that the foam and glass construction of our KR's isn't approved and literally CAN'T be approved since there is really no testing procedure for such one-off materials. So the plywood came from Home Depot. Has anyone ever seen a plywood failure in a KR that wasn't caused by a crash? Can anyone here cite a fuselage plywood failure they have EVER seen in ANY plane that came about from anywhere near normal use? I had a fuselage plywood failure but it was caused by a roof leak putting about 80 gallons of water in my KR-1. Should that failure concern me? Should it have held 100 gallons of water? The fact is that the fuselage sides are VERY lightly loaded and you could replace that plywood with stuff from Home Depot and it would probably never fail. That doesn't mean we should all buy all our materials at HD. It just means that Justin made a choice, justified that choice by some testing (not enough testing, but again in this case I don't think it really matters) and is completely within the U.S. Experimental rules. Back at Rockford in the 1960s there was a guy named Merle Replogle who had a VW-powered plane called the Gold Bug. You should have seen this thing. It was a wire-braced high wing design much like an Aeronca C-2. The plane was all wood and the wood was from the local lumber yard. It was fabric covered and the fabric was from Pennys (so, by the way, was the fabric on Pete Bowers' Flybaby). The aileron hinges were from the hardware store as were all the screws and bolts. The plane originally flew with three West Bend go-cart engines, but was later re-engined with a 1200cc VW converted exactly like Kenny Rand's original KR-1 engine. It was painted gold using spray cans with plenty of drips. It was the ugliest, draggiest, sorriest plane you've ever seen, but it made it to Rockford at least twice -- in 1967 from Iowa and in 1968 from Arizona after the builder moved there. The trip from Tucson took 5.5 days!. Now to the moral of this story. When this guy arrived at Rockford for the first time in 1967, the EAA folks didn't want to let him in. They didn't want him on the field at all and they SURE didn't want him among the show planes. Worse still, Merle didn't have enough cash to pay the registration fee, which I think back then was $10. Enter stage left EAA president Paul Poberezny who said, in effect, "Let he who is without squawk cast the first AN bolt." Poberezny made them let Merle into the show and he even pulled out his wallet and paid Merle's registration fee. I was 14 years old, my Dad and I were there with our T-18, and I came to understand then that there is room in this sport for all types. Just because people don't do things your way doesn't mean that they are doing it the wrong way. Merle Replogle returned to Rockford in 1968, this time having fitted Gold Bug with flaps. I had no idea why anyone would put flaps on a plane that cruised at 55 and landed at 30 until one windy afternoon Merle pulled on full flaps while in the fly-by pattern. Back then there was no system, so any plane could do a fly-by at any time as long as the airshow wasn't going on. So here were all these Cassutts and Tailwinds and T-18s blasting around the pattern when Merle Replogle put-put-puts into the wind from one end of the runway to the other, drops full flaps, raises the nose, goes into slow flight,a and flies BACKWARDS the full length of the runway. People just stopped and stared. He was going in reverse at perhaps 5 mph and it took about 10 minutes for him to reach the end of the runway. And it was obvious that Merle had added flaps to the Gold Bug specifically for that one moment. I would have done the same thing. Bob -- ------------------------------ Date: Wed, 29 Jan 2003 16:45:08 EST To: KRnet@mailinglists.org From: Bjbcljdb@aol.com Subject: Is there an easy way to take the wings off? Message-ID: <11c.1e01afcd.2b69a564@aol.com> --part1_11c.1e01afcd.2b69a564_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit To whomever: I am needing to take the wings off of my KR2 and need to know if there is any easy way to do it. It seems like the standard ratchet wrench is too big to get in there to take off the 8 bolts on each wing. Also, what do you use to unscrew the gas cap on the wings? It looks like a silver dollar would work, but don't know what else to use. Thanks, George --part1_11c.1e01afcd.2b69a564_boundary-- ------------------------------ End of krnet Digest ***********************************