From: Majordomo@teleport.com[SMTP:Majordomo@teleport.com] Sent: Monday, December 08, 1997 12:39 PM To: john bouyea Subject: Majordomo file: list 'krnet-l' file 'v01.n080' -- From: owner-krnet-l-digest@lists.teleport.com (krnet-l-digest) To: krnet-l-digest@lists.teleport.com Subject: krnet-l-digest V1 #80 Reply-To: krnet-l-digest Sender: owner-krnet-l-digest@lists.teleport.com Errors-To: owner-krnet-l-digest@lists.teleport.com Precedence: bulk krnet-l-digest Sunday, August 24 1997 Volume 01 : Number 080 ---------------------------------------------------------------------- Date: Fri, 22 Aug 1997 08:08:55 -0500 From: kr2builder@juno.com (Richard E Pitman) Subject: Re: KR: Wing Attach Fittings On Thu, 21 Aug 1997 21:12:27 -0700 Micheal Mims writes: >At 08:57 PM 8/21/97 -0700, you wrote: >Those really aren't lightning holes. They are used to "control" the >amount >>of load being transferred to the spar cap material and the strain >>(elongation) that the metal plates will undergo. > > >OK I guess I will go buy a uni bit and drill those structural >lightning >holes! :o) > >Are those uni bits strong enough to drill .125 inch 4130? Or should >I plan >on going through two or three? >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Micheal Mims >Just Plane Nutts in Irvine Ca. >mailto:mimsmand@ix.netcom.com >http://www.netcom.com/~mimsmand > > \ / > _\/\/_ >_____/_//\\_\_____ > > F-117 > > Michael, I started my holes with a center punch, then proceeded to use a slf centering starter bit (it has a fancy name, but I can't remember it right now) and then to a 1/4 " bit. Then use the uni-bit. May I suggest that you buy the titanium coated one. It doesnt cost as much as 3 regulars, but will last longer. Also use a slow spped on the drill press and use lots of lubricant. Don't force the bit into the metal, but just ease it in and let the bit do it's work. When you are turning out nice long curls, you have it right. Also invest in a set of countersinks for the chamfers. Mine look professionally made, and I "ain't" no professional. PS if you have a machinist buddy use his, pocket the savings, and buy us a beer at the gathering Ricky Pitman KR2 Builder Marion, Arkansas E-Mail to: KR2Builder@juno.com Web Page: http://pw2.netcom.com/~rnricky/Ricky/Default.htm ------------------------------ Date: Fri, 22 Aug 1997 07:50:14 -0500 From: kr2builder@juno.com (Richard E Pitman) Subject: Re: KR: Monte's Newsletter On Thu, 21 Aug 1997 16:54:36 -0500 "Mark Langford" writes: >KRNetHeads, > >I've been meaning to write a few words on the KR Newsletter. >Realizing >that I may be one of the only subscribers left on KRNet, I thought I'd >let >you know that under Monte's watch it has improved dramatically with >more >and better submissions, and a much more professional look. And I >still >get a kick out of his sense of humor. We even got the August issue in >August! > >Having said that, I can't help but wonder how he managed to devote the >entire front page to the upcoming KR Gathering and Randy's forum >efforts >without a single mention of KRNet. I've written twice asking him to >put a >plug for KRNet in his newsletter, but to no avail. Could it be >competition? Surely he's not intentionally depriving his readers of >THE >best source of KR information and technical support... > > I guess I'll have to submit an article to him, with my website URL >buried >in it. I hope if a program is being printed, that it will include >instructions on how to subscribe to KRNet. If nobody's doing a >program, >let me know, and I'll see what I can come up with. > >Mark Langford, Huntsville, AL >email at langford@hiwaay.net >KR2S project construction at http://fly.hiwaay.net/~langford > I am glad to hear that Monte is now doing the Newsletter. I will resubscribe just to hear his stories. He is also a good source of information. My subscription had been renewed with Earl, when it (the newsletter) stopped coming. Besides, I don't have a computer in the bathroom (yet) and it can be used twice in their. Please provide the new address and subscription rate. If enough of us subscribe/resubscribe AND tell him that we heard about it here, maybe he will return the favor. Ricky Pitman KR2 Builder Marion, Arkansas E-Mail to: KR2Builder@juno.com Web Page: http://pw2.netcom.com/~rnricky/Ricky/Default.htm ------------------------------ Date: Fri, 22 Aug 1997 08:31:37 -0700 From: Micheal Mims Subject: Re: KR: weight and balance At 06:13 AM 8/22/97 -0700, you wrote: My CG is rather foreword, I know this has been debated a lot, but >what has been decided is a good range? The plans say 8-16" behind L.E., >and I remember people saying not to use the last 2". Well maybe you should consider yourself lucky! Remember the numbers in the plans are a starting point, you as a test pilot as supposed to figure out what your comfortable with in the CG range. The 16 inches aft of the leading edge is comes from the figure 35% and I wouldn't go that far! 30% airfoil is good enough for test flying! ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Fri, 22 Aug 1997 11:10:37 -0700 From: Peter Hudson Subject: Re: KR: Wing Attach Fittings Don's right again. The extra holes are very important to the load distribution. It spreads the load between the bolts much more evenly rather than having it all bunch up on the end fasteners. It's important for them to be of increasing diameter along the fitting too. - -Peter- Donald Reid wrote: > > Micheal Mims wrote: > > AS for the lightning holes, what lightning holes? :o) Seriously > > how much weight can you save on these? 10 oz? > Those really aren't lightning holes. They are used to "control" the > amount of load being transferred to the spar cap material and the > strain(elongation) that the metal plates will undergo. > Don Reid > donreid@erols.com ------------------------------ Date: Fri, 22 Aug 1997 20:03:03 -0600 From: jscott.pilot@juno.com (Jeffrey E Scott) Subject: Re: KR: weight and balance On Fri, 22 Aug 1997 06:13:05 -0700 Tom Crawford writes: >Well, N262TC finally made it to the airport. I did a preliminary weight >and balance and the results are what I expected. >Mine is a KR2 built to plans with a few minor modifications- removable >front deck and fuel tank, all factory premolds, Deihl wing skins and >Tri-gear, Cleveland brakes, lights and strobes for night VFR, full >interior, nice finish (Imron), COM radio, type 4 engine with starter, >alternator, dual ignition- Mag and Compufire ignition, Ellison TBI. > >And the final weight- 659 lbs. >Actually I was hoping for something under 600, but not really expecting >it. My CG is rather foreward, I know this has been debated a lot, but >what has been decided is a good range? The plans say 8-16" behind L.E., >and I remember people saying not to use the last 2". With my bird, I >dont think this will be a problem, I may have to do some juggling to get >more weight in the back. > >Tom Crawford >tomc@afn.org >Gainesville, FL > Congratulations Tom!!! It's a great feeling to finally get it painted and to the airport. Sounds like a really sharp bird. I'll look forward to seeing it at the '98 Gathering. As far as the balance of the plane goes, you don't care what it calculates out to on the ground in a non-flying configuration. You only care about the balance of the plane in any configuration in which it might be flying. The CG on mine REQUIRES a minimum of a 105 pound pilot to get the plane into the CG range. (not a problem for me at 250) I found during my test flying program that the farther forward the plane was loaded in the CG range the more docile the plane became. This was especially true for landing. As I pushed the CG range aft, I found that the longitudinal stability became less stable and I had to work a bit harder to avoid overcontrolling the landing. My advice (although unsolicited) would be to keep your CG as far forward as you can, but keep it within the 8 - 14+ inch limit (yes I know I trimmed about 2 inches off the limit) for all fuel and load configurations you might encounter during a flight. Good luck with the upcoming first flight. Bring your pictures to the Gathering! - ------- Jeff Scott - Los Alamos, NM jscott.pilot@juno.com See N1213W construction and first flight at http://fly.hiwaay.net~langford/kjefs.html & http: //www.thuntek.net/~jeb/krpage.htm ------------------------------ Date: Fri, 22 Aug 1997 19:35:18 -0700 From: Micheal Mims Subject: Re: KR: weight and balance At 08:03 PM 8/22/97 -0600, you wrote: My advice (although unsolicited) would be to keep your CG as far forward as you can, but keep it within the 8 - 14+ inch limit (yes I know I trimmed about 2 inches off the limit) for all fuel and load configurations you might encounter during a flight. > > Now I am starting to think I didnt mount the landing gear far enough ahead of the main spar! Dang it! Oh well I guess I can always park it like a EZ! :-) My axles are 4.5 inche forward of the front face. Hope this is enough! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand \ / _\/\/_ _____/_//\\_\_____ F-117 ------------------------------ Date: Fri, 22 Aug 1997 22:11:43 -0500 From: "Mark Langford" Subject: Re: KR: weight and balance Michael Mims wrote: > My axles are 4.5 inche forward of the front face. Hope this is enough! I'm right in the middle of mounting my gear legs, and decided to drill only one hole thru them to bolt them to the casting, so that I can pivot them forward if required when the plane is almost finished. I'll just clamp them meanwhile. Mark Langford, Huntsville, AL email at langford@hiwaay.net KR2S project construction at http://fly.hiwaay.net/~langford - ---------- > From: Micheal Mims > To: krnet-l@teleport.com > Subject: Re: KR: weight and balance > Date: Friday, August 22, 1997 9:35 PM > > At 08:03 PM 8/22/97 -0600, you wrote: > My advice (although unsolicited) would be to keep your CG as far forward as > you can, but keep it within the 8 - 14+ inch limit (yes I know I trimmed > about 2 inches off the limit) for all fuel and load configurations you might > encounter during a flight. > > > > > > Now I am starting to think I didnt mount the landing gear far enough ahead > of the main spar! Dang it! Oh well I guess I can always park it like a EZ! > :-) > > My axles are 4.5 inche forward of the front face. Hope this is enough! > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Micheal Mims > Just Plane Nutts in Irvine Ca. > mailto:mimsmand@ix.netcom.com > http://www.netcom.com/~mimsmand > > \ / > _\/\/_ > _____/_//\\_\_____ > > F-117 > ------------------------------ Date: Fri, 22 Aug 1997 20:37:54 -0700 From: Micheal Mims Subject: Re: KR: weight and balance At 10:11 PM 8/22/97 -0500, you wrote: >I'm right in the middle of mounting my gear legs, and decided to drill only one hole thru them to bolt them to the casting, so that I can pivot them forward if required when the plane is almost finished. I'll just clamp >them meanwhile. > Good Idea! As the Native Alaskans used to say "white man always tinking!" translation; tinking = thinking ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand \ / _\/\/_ _____/_//\\_\_____ F-117 ------------------------------ Date: Sat, 23 Aug 1997 05:53:17 -0700 From: Tom Crawford Subject: Re: KR: weight and balance Ron Lee wrote: > > Sounds like another bird will soon be flying. Wonderful!!!! Do you have > numbers on the CG with you alone on board? > > Ron Lee > > At 06:13 97/8/22 -0700, you wrote: > >Well, N262TC finally made it to the airport. I did a preliminary weight > >and balance and the results are what I expected. > >Mine is a KR2 built to plans with a few minor modifications- removable > >front deck and fuel tank, all factory premolds, Deihl wing skins and > >Tri-gear, Cleveland brakes, lights and strobes for night VFR, full > >interior, nice finish (Imron), COM radio, type 4 engine with starter, > >alternator, dual ignition- Mag and Compufire ignition, Ellison TBI. > > > >And the final weight- 659 lbs. > >Actually I was hoping for something under 600, but not really expecting > >it. My CG is rather foreward, I know this has been debated a lot, but > >what has been decided is a good range? The plans say 8-16" behind L.E., > >and I remember people saying not to use the last 2". With my bird, I > >dont think this will be a problem, I may have to do some juggling to get > >more weight in the back. > > > >Tom Crawford > >tomc@afn.org > >Gainesville, FL > > > > Ron, I had to guess the station for pilot and pax as I was alone at the time. I couldnt read the scales while sitting in the plane. Monday I will drag my wife out with me and get the exact numbers. For now, with a full tank, 12 gallons, and just me aboard, the CG is still 3 inches in front of the foreward range. Part of the ?problem? is that I weigh 145 pounds after a big lunch. I saw in an old newsletter an article by M.M. He used 6-15" on his plane. If I used those numbers, with the above conditions, I would only be about 1" in front. Maybe if I ate a really big lunch? I still need to mount my ELT- it weighs over 2 lbs. I will experiment with mounting it as far back as I can. Tom "crunching the numbers" Crawford tomc@afn.org Gainesville, FL ------------------------------ Date: Sat, 23 Aug 1997 06:01:38 -0700 From: Tom Crawford Subject: Re: KR: weight and balance Jeffrey E Scott wrote: > > On Fri, 22 Aug 1997 06:13:05 -0700 Tom Crawford writes: > >Well, N262TC finally made it to the airport. I did a preliminary weight > >and balance and the results are what I expected. > >Mine is a KR2 built to plans with a few minor modifications- removable > >front deck and fuel tank, all factory premolds, Deihl wing skins and > >Tri-gear, Cleveland brakes, lights and strobes for night VFR, full > >interior, nice finish (Imron), COM radio, type 4 engine with starter, > >alternator, dual ignition- Mag and Compufire ignition, Ellison TBI. > > > >And the final weight- 659 lbs. > >Actually I was hoping for something under 600, but not really expecting > >it. My CG is rather foreward, I know this has been debated a lot, but > >what has been decided is a good range? The plans say 8-16" behind L.E., > >and I remember people saying not to use the last 2". With my bird, I > >dont think this will be a problem, I may have to do some juggling to get > >more weight in the back. > > > >Tom Crawford > >tomc@afn.org > >Gainesville, FL > > > > Congratulations Tom!!! It's a great feeling to finally get it painted > and to the airport. Sounds like a really sharp bird. I'll look forward > to seeing it at the '98 Gathering. > > As far as the balance of the plane goes, you don't care what it > calculates out to on the ground in a non-flying configuration. You only > care about the balance of the plane in any configuration in which it > might be flying. The CG on mine REQUIRES a minimum of a 105 pound pilot > to get the plane into the CG range. (not a problem for me at 250) I > found during my test flying program that the farther forward the plane > was loaded in the CG range the more docile the plane became. This was > especially true for landing. As I pushed the CG range aft, I found that > the longitudinal stability became less stable and I had to work a bit > harder to avoid overcontrolling the landing. My advice (although > unsolicited) would be to keep your CG as far forward as you can, but keep > it within the 8 - 14+ inch limit (yes I know I trimmed about 2 inches off > the limit) for all fuel and load configurations you might encounter > during a flight. > > Good luck with the upcoming first flight. Bring your pictures to the > Gathering! > ------- > Jeff Scott - Los Alamos, NM > jscott.pilot@juno.com > See N1213W construction and first flight at > http://fly.hiwaay.net~langford/kjefs.html & http: > //www.thuntek.net/~jeb/krpage.htm Jeff, Thanks for the advice. At this point, all advice and encouragement are warmly accepted. I found a fellow in Fernandina Beach that has offered to give me some stick time in his KR on Sunday. Tom "preflight jitters" Crawford tomc@afn.org Gainesville, FL ------------------------------ Date: Sat, 23 Aug 1997 05:24:07 From: Ron Lee Subject: Re: KR: weight and balance >I had to guess the station for pilot and pax as I was alone at the time. >I couldnt read the scales while sitting in the plane. Monday I will drag >my wife out with me and get the exact numbers. >For now, with a full tank, 12 gallons, and just me aboard, the CG is >still 3 inches in front of the foreward range. >Part of the ?problem? is that I weigh 145 pounds after a big lunch. >I saw in an old newsletter an article by M.M. He used 6-15" on his >plane. If I used those numbers, with the above conditions, I would only >be about 1" in front. Maybe if I ate a really big lunch? > >I still need to mount my ELT- it weighs over 2 lbs. I will experiment >with mounting it as far back as I can. > >Tom "crunching the numbers" Crawford >tomc@afn.org >Gainesville, FL > Tom, are you saying that with just you on board the CG is 3" forward of the forward limit? IE, that you are OUTSIDE of the CG range? I would have to use your weight with my CG numbers but that seems unlikely. You may want to converse with someone who just finished that CG stuff, like Jeff, to make sure you have not made a math problem or measurement boo-boo. Ron Lee ------------------------------ Date: Sat, 23 Aug 1997 08:14:08 -0700 From: Micheal Mims Subject: Re: KR: weight and balance At 05:24 AM 8/23/97, you wrote: >Tom, are you saying that with just you on board the CG is 3" forward of the forward limit? IE, that you are OUTSIDE of the CG range? I would have to use your weight with my CG numbers but that seems unlikely. You may want to converse with someone who just finished that CG stuff, like Jeff, to make sure you have not made a math problem or measurement boo-boo. > >Ron Lee > > He could be close, depending on what size tank and the fact he is running a type 4, those guys are a bit heavier then the type 1s. Some are reported to weigh as much as 225 pounds firewall forward. At least he is outside the range in the right direction! :o) Keep in mind those numbers are a starting point, if he finds he likes the way it flies with the CG an inch or two forward then that's where he sets his limits. IF he continues to add weight until he no longer likes the way it handles (PIOs on landing and while in cruise flight) then he has found the aft limit for his plane. Remember its called a "test flight period" If my bird is one or two inches forward with full fuel and pilot (me) after its complete, I will be stoked! Keep in mind this condition will last only until a few gallons of fuel are burned off and then he's more than likely back in the normal (published) range. Mike "test pilot of way too many overloaded planes" Mims ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand \ / _\/\/_ _____/_//\\_\_____ F-117 ------------------------------ Date: Sat, 23 Aug 1997 12:06:06 From: Ron Lee Subject: Re: KR: Forward CG (Was: weight and balance) >Keep in mind those numbers are a starting point, if he finds he likes the >way it flies with the CG an inch or two forward then that's where he sets >his limits. IF he continues to add weight until he no longer likes the way >it handles (PIOs on landing and while in cruise flight) then he has found >the aft limit for his plane. > >Mike "test pilot of way too many overloaded planes" Mims >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Micheal Mims There has been some discussion of the problems of flying with a too far aft CG. Are there any concerns with it forward of the current "recommended" limit? If so, how are those concerns impacted within the range we are talking about (1-3" forward of the current limit)? Ron Lee ------------------------------ Date: Sat, 23 Aug 1997 11:18:35 -0700 From: Micheal Mims Subject: Re: KR: Forward CG (Was: weight and balance) At 12:06 PM 8/23/97, you wrote: >There has been some discussion of the problems of flying with a too far CG. Are there any concerns with it forward of the current "recommended" limit? If so, how are those concerns impacted within the range we are talking about (1-3" forward of the current limit)? > >Ron Lee > Well running out of elevator control at slower speeds and having the nose come down hard is a bummer! Not being able to rotate a tricycle gear airplane is another bummer. CG forward = more stable but less efficient CG aft = less stable more efficient By far being aft is more dangerous than over gross or being forward. Here is a quote from the Pilots Handbook or Aeronautical Knowledge. "Loading in the tail heavy condition has a most serious effect upon longitudinal stability, and can reduce the airplanes capability to recover from stalls and spins. Another undesirable characteristic produced from tail heavy loading is that it produces VERY light stick forces. This makes it easy for the pilot to over control and overstress the airplane." Gee,..... does any of that sound familiar? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand \ / _\/\/_ _____/_//\\_\_____ F-117 ------------------------------ Date: Sat, 23 Aug 1997 13:33:40 -0500 From: brian whatcott Subject: Re: KR: Forward CG (Was: weight and balance) At 12:06 8/23/97, you wrote:... >There has been some discussion of the problems of flying with a too far aft >CG. Are there any concerns with it forward of the current "recommended" >limit? If so, how are those concerns impacted within the range we are >talking about (1-3" forward of the current limit)? > >Ron Lee > > Running out of aft stick at takeoff and bonking a nosegear on landing are two hazards that come to mind - preferable to a stall/spin that just won't go away... Regards brian whatcott Altus OK ------------------------------ Date: Sat, 23 Aug 1997 14:42:10 -0400 (EDT) From: JEHayward@aol.com Subject: Re: KR: Monte's Newsletter In a message dated 97-08-21 19:44:08 EDT, you write: << I've been meaning to write a few words on the KR Newsletter. Realizing that I may be one of the only subscribers left on KRNet, I thought I'd let you know that under Monte's watch it has improved dramatically with more and better submissions, and a much more professional look. And I still get a kick out of his sense of humor. We even got the August issue in August! >> I agree it IS better but I would still have to wait 2 months to get an answer to any question I might want answered where as here the answers are forthcoming within a day or so. Yep, my subscription is good thru next year and I still look forward to getting each issue just to see what else might be happening. Jim Hayward ------------------------------ Date: Sat, 23 Aug 1997 15:07:41 -0400 (EDT) From: JEHayward@aol.com Subject: Re: KR: Monte's Newsletter In a message dated 97-08-21 19:44:08 EDT, you write: << Having said that, I can't help but wonder how he managed to devote the entire front page to the upcoming KR Gathering and Randy's forum efforts without a single mention of KRNet. >> Especially when it looked like it was word for word from a portion of a post on the KRNet a few weeks ago. That was disappointing. Jim Hayward ------------------------------ Date: Sat, 23 Aug 1997 15:12:17 From: Ron Lee Subject: KR: Forward CG Based on the two replies about forward CG, it would seem that for initial flight testing, weight should be ADDED to move the CG into some mid-range point, then REMOVE weight until the desired forward CG limit was reached, based upon flight tests. Ron ------------------------------ Date: Sat, 23 Aug 1997 17:26:05, -0500 From: PQAL25A@prodigy.com ( FRED D LEWIS) Subject: Re: KR: Can a fresh PPL handle it ? I have a whopping 12 hours in a Skyhawk and that will double NEXT WEEK when I add ten more!! I have sent away for the KR-1 plans. Even amonst different Skyhawks, there are small differences. I am thinking that when I get my KR-1 built, I will go back to school - that is -- I will have to re-learn turns-around-a-point, stalls, climbs, etc. in a plane that goes significantly faster than a Skyhawk. I was planning to teach myself, by using an uncontrolled airport in the off-hours. How much shop floor space do I need to build a KR-1? I live in an apartment, and I'll likely have to rent a space somewhere. Fred Lewis ------------------------------ Date: Sat, 23 Aug 1997 17:46:51 -0400 From: dennis ambrose Subject: Re: KR: Need help with KR Operating Handbook???? At 09:14 PM 8/21/97 -0700, you wrote: >At 10:48 PM 8/21/97 -0400, you wrote: >>Mike: >> >>Maybe with proper permission, (copyright and all) you could post it on your >site and we all could get it from you? >> >> Just a thought. Dennis (in Toronto) > > >Well if you get the proper permission to download it , try: > >http://members.aol.com/peggeykerl/writever.exe > >its a self extracting zip file. Thanks Mike! Regards Dennis. ------------------------------ Date: Sat, 23 Aug 1997 15:44:39 -0600 From: cartera@cuug.ab.ca Subject: Re: KR: Forward CG (Was: weight and balance) Micheal Mims wrote: > > At 12:06 PM 8/23/97, you wrote: > >There has been some discussion of the problems of flying with a too far > CG. Are there any concerns with it forward of the current "recommended" > limit? If so, how are those concerns impacted within the range we are > talking about (1-3" forward of the current limit)? > > > >Ron Lee > > > > Well running out of elevator control at slower speeds and having the nose > come down hard is a bummer! Not being able to rotate a tricycle gear > airplane is another bummer. > > CG forward = more stable but less efficient > CG aft = less stable more efficient > > By far being aft is more dangerous than over gross or being forward. Here > is a quote from the Pilots Handbook or Aeronautical Knowledge. > > "Loading in the tail heavy condition has a most serious effect upon > longitudinal stability, and can reduce the airplanes capability to recover > from stalls and spins. Another undesirable characteristic produced from > tail heavy loading is that it produces VERY light stick forces. This makes > it easy for the pilot to over control and overstress the airplane." > > Gee,..... does any of that sound familiar? > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Micheal Mims > Just Plane Nutts in Irvine Ca. > mailto:mimsmand@ix.netcom.com > http://www.netcom.com/~mimsmand > > \ / > _\/\/_ > _____/_//\\_\_____ > > F-117 Hi Mike, Sure does sound familiar. My CofG is 1 1/2" forword of the front limit and I still did not think that it was enough this was empty. So I relocated my small motorcycle battery from behind the seat to the firewall but it did not make all that much difference because it was too close to the CG. With full tank of fuel and myself in the seat it moved back to 3" behind the forward limit. Anyway to flies great! Your "right on" in your analysis, Mike. - -- Adrian VE6AFY cartera@cuug.ab.ca http://www.cuug.ab.ca/~cartera ------------------------------ Date: Sat, 23 Aug 1997 15:24:11 -0700 From: Micheal Mims Subject: Re: KR: Can a fresh PPL handle it ? At 05:26 PM 8/23/97 -0500, you wrote: >How much shop floor space do I need to build a KR-1? I live in an >apartment, and I'll likely have to rent a space somewhere. >Fred Lewis > Well up to this point I have built a oversized KR2S in a single car garage, it has been tight but it was doable. I need to move now to a location that will allow me to start the wings. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand \ / _\/\/_ _____/_//\\_\_____ F-117 ------------------------------ Date: Sat, 23 Aug 1997 20:49:10 -0700 From: Donald Reid Subject: KR: Wing attachment fittings Someone made the mistake of asking for the whole story on wing attachment fittings. If you don't want to be bored with engineering stuff, then hit the DELETE button. As background, the main spar wing attachment fittings are 0.125 thick 4130 steel, 16 total, all exactly alike. There are two on each spar cap, one on the front face and another on the rear face, with 8 3/16" bolts passing through the spar cap material and holding the plates together. The wing removal is by 3/8" bolts that hold the outer spar and center section spar together. Those of you without plans will just have to try and visualize all this. The through bolts are arranged in two parallel rows. The first pair is 7/8" from the end of the spar cap. There is a 1 1/2" bolt to bolt spacing along the length of the spar cap in the direction of the applied load. There is a 1" bolt to bolt spacing across the direction of the applied load. (These are all center-to-center distances, not edge to edge) The outer section of the main spar has spar caps that are 1 15/16" wide, with 3/32" spruce faces on both sides. The following data is from ANC-5, Strength of Aircraft Elements. The term ultimate bearing strength means that is the maximum that the bolt will carry. At this point, there would be fiber failure in the wood by crushing and grain splitting. minimum allowable spacing based on center of hole bolt size ultimate bearing to end center to center load (lb) of wood center to edge 3/16" 1,100 13/16" 15/16" 3/8" 1/4" 1,700 1-1/8" 1-1/4" 1/2" (rounded up to the nearest 1/16") With 8 3/16" bolts, the wing attachment fitting pair will only transfer 8,800 lbs to the spar cap without failure. The first pair is 7/8" from the end of the spar cap, which is 1/16" more that the minimum. These bolt holes can not be safely enlarged, otherwise the minimum distance would be be met. The center to center spacing on the others is 1-1/2". These can be enlarged one size without violating any minimums. The load is applied to the fitting pair at the 3/8" bolt. The metal will carry the stress to the first pair of 3/16" bolts. Some of that stress will be "transferred" to the wood in the spar cap and the rest will continue along the metal fitting to the next pair of through bolts. The next pair will transfer more stress to the wood, and so on. (A real structural engineer will probably be shaking his head at this point but I am going to keep it simple) In the ideal design, each bolt/wood interface will load up equally. If they don't, some will be more heavily stressed than others. They would fail first and cause a cascade failure that would be at an overall value lower than the ideal. When a material is stressed by some force, it undergoes a strain (deformation). Pull on a rubber band and it stretches. Pull really hard on a piece of steel and it stretches as well. When two materials are joined together like the wooden spar caps and the wing attachment fittings, the stress/strain relationship must be considered. The wood will stretch more that the steel under the same load. The only way to control the application of the stress into the wood in this configuration is by making the steel "less strong" the farther away from the applied load. That is why the "lightening" holes in the fittings get bigger as they get farther away from the applied load. There are alternate ways to make this type of fitting that perform the same function. The easiest is probably thin plates that are added on to make the thickness progress along the length of the fitting. Since the KR uses two parallel rows of through bolts, a fitting that looks like the letter U could work. Some people build airplanes so they can fly, some just like to build then, some like the engineering and design, and some people are like me and enjoy all of it. - -- Don Reid Long winded in Bumpass, Va donreid@erols.com ------------------------------ Date: Sat, 23 Aug 1997 21:55:00 -0700 From: Micheal Mims Subject: Re: KR: Wing attachment fittings At 08:49 PM 8/23/97 -0700, you wrote: >The only way to control the application of the stress into the wood in this >configuration is by making the steel "less strong" the farther away from >the applied load. That is why the "lightening" holes in the fittings get >bigger as they get farther away from the applied load. > Outstanding !! it totally made sense to me! Please don't hesitate to send your explanations to me, I am always on the lookout for more data! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand \ / _\/\/_ _____/_//\\_\_____ F-117 ------------------------------ Date: Sun, 24 Aug 1997 06:34:16 -0700 From: Tom Crawford Subject: Re: KR: Forward CG Ron Lee wrote: > > Based on the two replies about forward CG, it would seem that > for initial flight testing, weight should be ADDED to move the > CG into some mid-range point, then REMOVE weight until the > desired forward CG limit was reached, based upon flight tests. > > Ron Dont get me wrong, I do not intend to fly the plane until the C of G is within limits. I will need all the help I can get on that first flight! #:-) I was merely sharing my data to promote intellectual stimulation and exchange of ideas. As Mike said, this is the starting point. Now I will start tweaking. Tally Ho! Tom Crawford tomc@afn.org Gainesville, FL N262TC ------------------------------ Date: Sun, 24 Aug 1997 06:46:23 -0700 From: Tom Crawford Subject: KR: C of G Something I discovered that I thought I might share. While doing my Cof G measurements, I compared my numbers to those of someone with a type 1 and found something interesting. Same exact plane, same motor mount, acc. case, front bearing, prop, and spinner. The distance from the tip of the spinner to the firewall on the type 1 was 34.5 inches. The same distance on my type 4 is 38.5 inches. Have you seen all the type 1's with the 2 inch spacers between the engine and the mount? Tom Crawford tomc@afn.org Gainesville, FL N262TC ------------------------------ Date: Sun, 24 Aug 1997 09:10:42 -0700 From: bmsi@ix.netcom.com Subject: Re: KR: Wing attachment fittings Don, If you'll write it I'll read it! This is good stuff! Donald Reid wrote: >The wood will stretch more that the steel under the same load. To make sure my visualizer is in order. I understand the strength of the wood is along the fibers in bending. Is that what you mean by stretch? >then, some like the engineering and design, and some people are like me >and enjoy all of it. Me Too! > -- > Don Reid > Long winded in Bumpass, Va > donreid@erols.com Bruce S. Campbell Tampa bmsi@ix.netcom.com ------------------------------ Date: Sun, 24 Aug 1997 08:32:47 -0500 From: Bobby Muse Subject: Re: KR: Can a fresh PPL handle it ? At 08:10 PM 8/21/97 +0700, you wrote: > >For the sake of people in in my category i.e' the wannabee KR builders' without any flying experience , can the KR flying people give us an intelligent guess.. approximately how many hours of flight trainning and experience should one have before attempting to fly his own >KR as a hobby.? > >Agreed that KR dual time is important, but how many hours of it will be considered >sufficient? > > > >Please bear with the fact that such stupid questions are repeated now and then here. >I belong to a category of people who are new to flying and building. > >Words of advise direct from the experienced KR flyers who have had not much flying >experience earlier to their KR, will be greatly appreciated and thanked. > >bye > >Palani > Palani, I guess I fit into the area of an experienced KR pilot that did not have much flight experience before I flew my own KR. I obtained a pilots license because I wanted to build and fly my own airplane. In 1972 I started taking flying lessons and became a private pilot 59 days later with a total flying time of 43hrs. I flew my KR(N122B) a little over twenty years later at which time I had a total a total of 71 total flying hours(that's 28 hours spread out over 20 years). I'm not sure how much flying time is needed to prepare you for your KR. I practiced(slow and high speed taxi) on the ground for three months before I finally got enough nerve up to leave the ground. I flew with three different flight instructors in three weeks and everyone told me to go fly my KR because I was really....I keep on just perpecting my taxi. When I I finally did leave the ground I dipped once and that was it. I was then a KR pilot. I have felt at home in my KR ever since. When your really and you know that you are ready for the KR then ther will be no problem flying your KR. But you really need to learn to fly in some other aircraft type first. The KR is problem to fly, but will be flying it all the time. Since the day I first flew my KR, I haven't flown any other type aircraft. IT'S GREAT! By the way, I how have 264hrs in my KR. Bobby Muse(N122B) bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Sun, 24 Aug 1997 09:00:00 -0500 From: Bobby Muse Subject: Re: KR: weight and balance At 06:13 AM 8/22/97 -0700, you wrote: >Well, N262TC finally made it to the airport. I did a preliminary weight >and balance and the results are what I expected. >Mine is a KR2 built to plans with a few minor modifications- removable >front deck and fuel tank, all factory premolds, Deihl wing skins and >Tri-gear, Cleveland brakes, lights and strobes for night VFR, full >interior, nice finish (Imron), COM radio, type 4 engine with starter, >alternator, dual ignition- Mag and Compufire ignition, Ellison TBI. > >And the final weight- 659 lbs. >Actually I was hoping for something under 600, but not really expecting >it. My CG is rather foreward, I know this has been debated a lot, but >what has been decided is a good range? The plans say 8-16" behind L.E., >and I remember people saying not to use the last 2". With my bird, I >dont think this will be a problem, I may have to do some juggling to get >more weight in the back. > >Tom Crawford >tomc@afn.org >Gainesville, FL > Tom, It sounds like you have a winner. Enjoy! Bobby Muse(N122B) bmuse@mindspring.com Wimberly, TX ------------------------------ Date: Sun, 24 Aug 1997 09:00:02 -0500 From: Bobby Muse Subject: Re: KR: weight and balance At 05:53 AM 8/23/97 -0700, you wrote: >I had to guess the station for pilot and pax as I was alone at the time. >I couldnt read the scales while sitting in the plane. Monday I will drag >my wife out with me and get the exact numbers. >For now, with a full tank, 12 gallons, and just me aboard, the CG is >still 3 inches in front of the foreward range. >Part of the ?problem? is that I weigh 145 pounds after a big lunch. >I saw in an old newsletter an article by M.M. He used 6-15" on his >plane. If I used those numbers, with the above conditions, I would only >be about 1" in front. Maybe if I ate a really big lunch? > >I still need to mount my ELT- it weighs over 2 lbs. I will experiment >with mounting it as far back as I can. > >Tom "crunching the numbers" Crawford > Don't forget the battery. It's a real heavyweight that you can move backwards. Bobby Muse(N122B) bmuse@mindspring.com Wimberly, TX ------------------------------ End of krnet-l-digest V1 #80 ****************************