KR> Wing Skin Reinfrocement/DIVINYCELL FOAM CORES
Glenn, Wicks and Aircraft Spruce usually carry these foams. The company that makes or distributes it used to be in Grand Prairie, Texas. The original Klegicell foam which is the same thing or type of foam came from Europe, Sweden I think it was. One thing you can do with these types of foam is heat it up (like with a heat gun, keep gun moving though or you will begin to melt the foam) bow or bend it around something and let it cool off while holding it in position and it will retain a lot of the shape you desire. If needed get someone to help with the heating while you hold it in the bowed position. I am talking about your turtle back for example or the slight curve to a wing surface. You will be able to make the wing surfaces without heat though, the foam will make that curve easy enough. (Not the leading edges though) You can make your wings the way others have done it including the premolded Diehl skins. Make your ribs out of this same foam, just make them dimensionally less than the thickness of the foam you choose, put a light weight layer of cloth on the inside if you wish but probably not necessary, glue in place with micro or flox mixture then cover the surface with your cloth of choice, fiberglass, carbon fibre, or ? (dynel) : ) . Larry H. From: Martek Mississippi To: KRnet Sent: Friday, October 17, 2008 11:17:10 PM Subject: Re: KR> Wing Skin Reinfrocement/DIVINYCELL FOAM CORES Thank you! This sounds like what I'm looking for to deal with my concerns. Where can I purchase this? Glenn Martin N1333A biloxi, MS ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> Wing Skin Reinfrocement/DIVINYCELL FOAM CORES
Thank you! This sounds like what I'm looking for to deal with my concerns. Where can I purchase this? Glenn Martin N1333A biloxi, MS
KR> Wing Skin Reinfrocement/DIVINYCELL FOAM CORES
Larry Howell wrote: > If you are so inclined to try Divinycell as a core for your wing surfaces, > Divinycell's HT series was developed for aircraft cores. You could choose > their HT50 which is 3.1 lb/ft3.. It has a 100psi compressive strength, 73 > psi shear strength etc. Having thought that carbon fiber skins would eliminate bubbles, and now that I've had Divinycell in my hands, I'd say it's certainly worth a try. I've heard nothing but good stuff about it. The tensile strength of urethane foam is just about non-existent. For those who don't know it, Larry Howell's a professional composite guy... Mark Langford, Huntsville, AL website: www.n5...@hiwaay.net email: N56ML at hiwaay.net
KR> Wing Skin Reinfrocement/DIVINYCELL FOAM CORES
How do those idea sound to my fellow netters, Glenn Martin Glenn, I am with Mark L, lots of time and weight. Sounds like you need to find some honeycomb cores for your wings if you want to go to this much trouble. The honeycomb would accomplish both things for you. The best preference for you in my opinion would be to use 3/16th or 1/4th thick Divinycell foam cores for your wing surfaces. It is light weight, has very high shear strength, and compressive strength compared to urethane foam. You could put a layer of cloth on the interior surface of it but you don't really need to do that with Divinycell foam. I have mentioned this before. I took a piece of urethane foam, Home Depot foam that some have used, and a piece of Divinycell foam that I have used building a Long Eze and a Defiant. I laid up a single layer of bidirectional cloth on all three. The urethane and HomeDepot insulation rigid foam both are extremely weak in shear strength. I was able to take a hold of the edge of the cured glass cloth and rip it right off of the foam with no effort at all. I could not tear the cloth off of the Divinycell foam. The difference in the 3 is MASSIVE!!! It does cost more to purchase Divinycell foam as compared to urethane but it will also cost a lot of money for the carbon fibre you are talking about laying down in the V-grooves. If you are so inclined to try Divinycell as a core for your wing surfaces, Divinycell's HT series was developed for aircraft cores. You could choose their HT50 which is 3.1 lb/ft3.. It has a 100psi compressive strength, 73 psi shear strength etc. You may have figured out by now that I am a huge fan of Divinycell foams. I have used and tested a lot of different kinds of foams in an attempt to find a cheap strong foam but I have given up and submitted to Divinycell, there just is Nothing better right now!! Get a small piece and test it for yourself as compared to other types of foam then you will agree with me. Just my opinion of course. Larry H.
KR> Wing Skin Reinfrocement
Sounds like more weight, and more work, for very little benefit. CF layups would be plenty strong. I built my elevator with CF, and it can chop wood. Ron Smith KR2SSXL Buckeye Arizona mercedesm...@yahoo.com http://ronsmith.myphotoalbum.com/albums.php --- On Fri, 10/17/08, Martek Mississippi wrote: From: Martek Mississippi Subject: KR> Wing Skin Reinfrocement To: "KRnet" List-Post: krnet@list.krnet.org Date: Friday, October 17, 2008, 12:08 PM I have noticed on the KR2 I just purchased that the wings are not as stout as I would like. When I moved the wings to the storage area I could hear the foam under the fiberglass cracking with moderate handling, which I don't care for at all. Mark L's decision to layer the wings using a fiberglass-foam-carbon fiber sandwich is the common sense solution, but in order to insure that my new wings will handle the rigors of being taken on and off regularly , I am considering an additional step. In this step, prior to laying up the outer layer of CF, I will put a crosshatch of 3/4" wide Vee grooves in the outer layer of foam, and then fill those grooves with a layer of CF, which would form a grid of reinforcing angles UNDER the outer skin when that is applied. It seems like a reasonable extra bit of work to do for some extra peace of mind. I'm also going to add four 1/4 inch threaded inserts into the top of the spars (2 front , 2 rear).That allows me to put Eyebolts into the wings during ground operations and lift them using a boom, thus being able to load, unload and attach the wings by myself without putting stress on the skins. How do those idea sound to my fellow netters, particularly you Mark L? Glenn Martin N1333A, Biloxi, MS
KR> 2009 KR Gathering
The third weekend in Septemberlet's book it.. Mark Jones (N886MJ) Stevens Point, WI Web page: www.flykr2s.com e-mail: flyk...@charter.net - Original Message - From: "Larry&Sallie Flesner" To: "KRnet" Sent: Friday, October 17, 2008 5:10 PM Subject: Re: KR> 2009 KR Gathering At 08:53 PM 10/15/2008, you wrote: >Larry, >What are the dates for the 2009 Gathering? I need to start planning >for it. > >Mark Jones (N886MJ) + Mark, What sounds good? Third weekend in September again? Larry ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> TO NITRIDE OR NOT?
Personally, I feel nitrating is additional insurance and I would not fly without having a nitrided crank even with the fifth bearing. Why take the chance? It does not cost that much to have it done. Mark Jones (N886MJ) Stevens Point, WI Web page: www.flykr2s.com e-mail: flyk...@charter.net - Original Message - From: "Larry H." To: "KRnet" Sent: Friday, October 17, 2008 4:20 PM Subject: KR> TO NITRIDE OR NOT? From: Mark Jones flyk...@charter.net Have our prayers all been answered with the fifth bearing? I sure hope so but only time will tell. Mark Jones Hi Mark J & L, I purchased a Corvair engine from Larry Flesner during Mt Vernon 2008. I will be building this engine for aircraft use one of these days, after I see how all you 5th bearing guys hold up. I am wondering what any of you 5th bearing flyers think about the "necessity to nitride the crank" with the addition of the 5th bearing? My thinking is if the previous basic problem was bending loads breaking non nitrated and nitrated cranks then what good is nitriding? Since you Marks have noticed major differences in the operating smoothness of your engines during all phases of flight with the added 5th bearing, maybe there is no need to go to the expense of that crank process. Just wondering what you think about this. Thanks Larry H. After almost two full months since my crank breakage, "Six Mike Juliet" flew again this morning with the new Dan Weseman fifth bearing installed. ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> To nitride or not?
I think for 100 dollars its a little extra piece of insurance I wouldnt mind having. _ Want to read Hotmail messages in Outlook? The Wordsmiths show you how. http://windowslive.com/connect/post/wedowindowslive.spaces.live.com-Blog-cns!20EE04FBC541789!167.entry?ocid=TXT_TAGLM_WL_hotmail_092008
KR> 2009 KR Gathering
At 08:53 PM 10/15/2008, you wrote: >Larry, >What are the dates for the 2009 Gathering? I need to start planning >for it. > >Mark Jones (N886MJ) + Mark, What sounds good? Third weekend in September again? Larry
KR> Wing Skin Reinforcement
Thanks all That tells me some info I needed. I do have damage to the wings and cowling that need repair, but it sounds like I can do the repairs and get her flying again using the standard techniques. Afterwards, using my idea, I will try some tests on small prototype Glass-Foam-CF sandwich sections and see what the difference is. If it's to my satisfaction, I'll do that with a set of new airfoils. The old ones are RAF-48. I'm still going to add the lifting attachments though, as my trailer will have a boom which should allow me to easily and quickly attach the wings without putting any undue stress on the wings. The time spent attaching the wings has been a common complaint and I think I can improve on that, as I don't intend to hanger her, but keep her in an enclosed, vented trailer. The weight of the wings isn't the problem, the bulkiness is. BTW..To clarify: the crosshatch of Vee grooves are lines at an approx. 60 degree angle to each other, extending from spar to spar, cut INTO and bonded to the foam used for the skin form. I am STILL using the sandwich construction Mark L uses. Each parallel groove is spaced 10-12 inches apart (Think of the pattern between the spars, top of each X to Fwd spar, bottom of each X to Aft spar, 10-12 inches between the center of each X). The inside of the CF angle would then be filled with foam again, pretty much impregnating the CF angle into the original foam form except for some material which would used to bond it to the skin (think little flaps of CF to each side of the groove). I don't expect the weight penalty to be substantial. I need to make a drawing. A picture speaks a thousand words. I'm not good with CAD, but it looks like I'll be learning. Glenn Martin KR2 N1333A Biloxi ,MS > Just between you and me, I have about two square feet of lower wing >that's pure mush because my right wheel pant got ripped off and stuffed >into >it when I landed 20 yards short of the runway on my second crank break. >I've been flying it that way for nine months now, although I plan to fix it >over the winter, if I can quit flying for long enough. Mark Langford, Huntsville, AL mail: N56ML "at" hiwaay.net website: www.N56ML.com ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> TO NITRIDE OR NOT?
From: Mark Jones flyk...@charter.net Have our prayers all been answered with the fifth bearing? I sure hope so but only time will tell. Mark Jones Hi Mark J & L, I purchased a Corvair engine from Larry Flesner during Mt Vernon 2008. I will be building this engine for aircraft use one of these days, after I see how all you 5th bearing guys hold up. I am wondering what any of you 5th bearing flyers think about the "necessity to nitride the crank" with the addition of the 5th bearing? My thinking is if the previous basic problem was bending loads breaking non nitrated and nitrated cranks then what good is nitriding? Since you Marks have noticed major differences in the operating smoothness of your engines during all phases of flight with the added 5th bearing, maybe there is no need to go to the expense of that crank process. Just wondering what you think about this. Thanks Larry H. After almost two full months since my crank breakage, "Six Mike Juliet" flew again this morning with the new Dan Weseman fifth bearing installed.
KR> Ray Allen Trim System - Maintenace tip
OK I asked the following: > Has anyone had any operational problems with their Ray-Allen (MAC) > elevator trim? Now the elevator trim is acting up - works fine on the > ground including run up, but refuses to work in the air. Any body have any > suggestions? Just so you will know if you experience the same in the future - check your grounds - clean them and make sure they are tight - I did and now it works as good as before! Rick Human N202RH Houston, Texas
KR> Wing Skin Reinforcement
Glen wrote: > In this step, prior to laying up the outer layer of CF, I will > put a > crosshatch of 3/4" wide Vee grooves in the outer layer of foam, and > then > fill those grooves with a layer of CF, which would form a grid of > reinforcing angles UNDER the outer skin when that is applied. It > seems like > a reasonable extra bit of work to do for some extra peace of mind. I had to cut some grooves in the foam to get my wing back to the exact shape that I wanted after glassing the bottom half. These were filled with micro and dressed up before I glassed the top. The finish was beautiful when I got them back from the paint shop. About a month after it was at the airport in the summer the grooves started to mirror through the finish and the glass and have never gone away. ( I know you guys had to have seen them) I wouldn't do anything to that foam underneath the glass except keep it perfect and undamaged till the glass is on. > I'm also going to add four 1/4 inch threaded inserts into the > top of the > spars (2 front , 2 rear).That allows me to put Eyebolts into the > wings > during ground operations and lift them using a boom, thus being able > to > load, unload and attach the wings by myself without putting stress > Seems like over kill also. I did one insert of a sort under each wing to thread in a tie down, but at 48 # the wings are only just awkward. I use a creeper that folds up into a seat with a piece of foam on it to support the wing for off and on and can just roll it round on the seat. Joe Horton, Coopersburg, PA. joe.kr2s.buil...@juno.com Click to find information on your credit score and your credit report. http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m2PctQ1UiI45DIbvOZed4UdmHfIHds6ZJpisy6kDEYpMHdO/
KR> Wing Skin Reinfrocement
Glenn Martin wrote: >In this step, prior to laying up the outer layer of CF, I will put a > crosshatch of 3/4" wide Vee grooves in the outer layer of foam, and then > fill those grooves with a layer of CF, which would form a grid of > reinforcing angles UNDER the outer skin when that is applied. It seems > like > a reasonable extra bit of work to do for some extra peace of mind. >How do those idea sound to my fellow netters, particularly you Mark L? That sounds like a two year penalty with regards to flying! Don't forget that fabric covered airplanes aren't exactly "stout", and they fly just fine. Just between you and me, I have about two square feet of lower wing that's pure mush because my right wheel pant got ripped off and stuffed into it when I landed 20 yards short of the runway on my second crank break. I've been flying it that way for nine months now, although I plan to fix it over the winter, if I can quit flying for long enough. It sounds like you have wings now. It's difficult to say without seeing it, but I'd be tempted to finish it and fly it. Now if you want a show plane (and it won't stay that way for long) and don't mind spending a few extra years on it, that may be the way to go. It's your plane and your decision, but a lot of heavy planes got that way for "extra peace of mind"... Mark Langford, Huntsville, AL mail: N56ML "at" hiwaay.net website: www.N56ML.com
KR> Wing Skin Reinfrocement
So the outer skin would only contact 50% of the wing area? Wouldn't there be a bunch of 3/4" squares on the surface that have no support and be prone to damage? Maybe fill the voids with micro and sand smooth but that would be heavy I'd think...I'm an armchair pilot still so I don't really know. -Original Message- From: Martek Mississippi [mailto:rep...@martekmississippi.com] Sent: Friday, October 17, 2008 2:08 PM To: KRnet Subject: KR> Wing Skin Reinfrocement I have noticed on the KR2 I just purchased that the wings are not as stout as I would like. When I moved the wings to the storage area I could hear the foam under the fiberglass cracking with moderate handling, which I don't care for at all. Mark L's decision to layer the wings using a fiberglass-foam-carbon fiber sandwich is the common sense solution, but in order to insure that my new wings will handle the rigors of being taken on and off regularly , I am considering an additional step. In this step, prior to laying up the outer layer of CF, I will put a crosshatch of 3/4" wide Vee grooves in the outer layer of foam, and then fill those grooves with a layer of CF, which would form a grid of reinforcing angles UNDER the outer skin when that is applied. It seems like a reasonable extra bit of work to do for some extra peace of mind. I'm also going to add four 1/4 inch threaded inserts into the top of the spars (2 front , 2 rear).That allows me to put Eyebolts into the wings during ground operations and lift them using a boom, thus being able to load, unload and attach the wings by myself without putting stress on the skins. How do those idea sound to my fellow netters, particularly you Mark L? Glenn Martin N1333A, Biloxi, MS - Original Message - From: "Dana Overall" To: "KRnet" Sent: Friday, October 17, 2008 9:07 AM Subject: KR> Fun Friday Just a heads up to what is available to us in the experimental world. This is an actual shot coming out of Land of Enchantment Flyin this past weekend. Mine shipped yesterday, should be here tomorrow!! http://www.youtube.com/watch?v=QCWf8-rhfzU The following is a synthetic approach of an ILS. The GRT unit superimposes the HITS (highway in the sky) square boxes instead of the localizer/GS needles and you simply fly through the boxes. http://www.rocket-boys.com/images/GRT_SAP_HITS.wmv Let this thing load before you play it. If you are using dial up, forget it!! I post these just to motivate all builders. We in the experimental world continue to have access to the best of the best at an affordable price. Anybody care to guess what a certified unit would cost to do what this unit does? Life is good. Keep gluing, I'll keep pounding. Dana Overall 1999 & 2000 National KR Gathering host Richmond, KY i39 RV-7 slider "Black Magic" Flying..well sorta, useta, kinda Barrett Precision O 360 A1A Hartzell C2YR-1BFP/F7497-2 http://rvflying.tripod.com/blackmagic.jpg http://www.youtube.com/watch?v=MMi05-WU2D0#GU5U2spHI_4 http://rvflying.tripod.com do not archive _ You live life beyond your PC. So now Windows goes beyond your PC. http://clk.atdmt.com/MRT/go/115298556/direct/01/ ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> Wing Skin Reinfrocement
I have noticed on the KR2 I just purchased that the wings are not as stout as I would like. When I moved the wings to the storage area I could hear the foam under the fiberglass cracking with moderate handling, which I don't care for at all. Mark L's decision to layer the wings using a fiberglass-foam-carbon fiber sandwich is the common sense solution, but in order to insure that my new wings will handle the rigors of being taken on and off regularly , I am considering an additional step. In this step, prior to laying up the outer layer of CF, I will put a crosshatch of 3/4" wide Vee grooves in the outer layer of foam, and then fill those grooves with a layer of CF, which would form a grid of reinforcing angles UNDER the outer skin when that is applied. It seems like a reasonable extra bit of work to do for some extra peace of mind. I'm also going to add four 1/4 inch threaded inserts into the top of the spars (2 front , 2 rear).That allows me to put Eyebolts into the wings during ground operations and lift them using a boom, thus being able to load, unload and attach the wings by myself without putting stress on the skins. How do those idea sound to my fellow netters, particularly you Mark L? Glenn Martin N1333A, Biloxi, MS - Original Message - From: "Dana Overall" To: "KRnet" Sent: Friday, October 17, 2008 9:07 AM Subject: KR> Fun Friday Just a heads up to what is available to us in the experimental world. This is an actual shot coming out of Land of Enchantment Flyin this past weekend. Mine shipped yesterday, should be here tomorrow!! http://www.youtube.com/watch?v=QCWf8-rhfzU The following is a synthetic approach of an ILS. The GRT unit superimposes the HITS (highway in the sky) square boxes instead of the localizer/GS needles and you simply fly through the boxes. http://www.rocket-boys.com/images/GRT_SAP_HITS.wmv Let this thing load before you play it. If you are using dial up, forget it!! I post these just to motivate all builders. We in the experimental world continue to have access to the best of the best at an affordable price. Anybody care to guess what a certified unit would cost to do what this unit does? Life is good. Keep gluing, I'll keep pounding. Dana Overall 1999 & 2000 National KR Gathering host Richmond, KY i39 RV-7 slider "Black Magic" Flying..well sorta, useta, kinda Barrett Precision O 360 A1A Hartzell C2YR-1BFP/F7497-2 http://rvflying.tripod.com/blackmagic.jpg http://www.youtube.com/watch?v=MMi05-WU2D0#GU5U2spHI_4 http://rvflying.tripod.com do not archive _ You live life beyond your PC. So now Windows goes beyond your PC. http://clk.atdmt.com/MRT/go/115298556/direct/01/ ___ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
KR> Fun Friday
Just a heads up to what is available to us in the experimental world. This is an actual shot coming out of Land of Enchantment Flyin this past weekend. Mine shipped yesterday, should be here tomorrow!! http://www.youtube.com/watch?v=QCWf8-rhfzU The following is a synthetic approach of an ILS. The GRT unit superimposes the HITS (highway in the sky) square boxes instead of the localizer/GS needles and you simply fly through the boxes. http://www.rocket-boys.com/images/GRT_SAP_HITS.wmv Let this thing load before you play it. If you are using dial up, forget it!! I post these just to motivate all builders. We in the experimental world continue to have access to the best of the best at an affordable price. Anybody care to guess what a certified unit would cost to do what this unit does? Life is good. Keep gluing, I'll keep pounding. Dana Overall 1999 & 2000 National KR Gathering host Richmond, KY i39 RV-7 slider "Black Magic" Flying..well sorta, useta, kinda Barrett Precision O 360 A1A Hartzell C2YR-1BFP/F7497-2 http://rvflying.tripod.com/blackmagic.jpg http://www.youtube.com/watch?v=MMi05-WU2D0#GU5U2spHI_4 http://rvflying.tripod.com do not archive _ You live life beyond your PC. So now Windows goes beyond your PC. http://clk.atdmt.com/MRT/go/115298556/direct/01/
