KR> CG and the KR2S
> With 6.5 gal fuel in the header tank ( max is 13 gal ) and a passenger, > my > 2S is 2" forward of the rear most CG, and I can tell you that it's a > handful > on take off, the tail drops noticeably. To counter this I increase my take > off speed to 70 mph or top off the fuel tank. > Your results may vary.--I'm 240lbs and the last passenger was > 135 lbs. > > Kenny 6399U > > > - Original Message - > From: "Colin Rainey" > To: > Sent: Saturday, December 31, 2005 7:24 AM > Subject: KR> CG and the KR2S > > >> Bob >> I do not believe that the CG limits were changed for the KR2S from those >> already designed for the KR2. They are still the same, which is why the >> standard modification is to add one bay forward and one bay rear for the >> total stretch. Others are going alittle longer and enlargening the tail >> feathers, but their CG will still need to fall into the same range as >> before. Adjustments are just made as to locating battery and such to >> compensate. I also believe that it is understood that the last 2 inches >> of >> the originally published limits are considered unusable by builders and >> pilots of today... >> >> >> Colin Rainey >> brokerpilot9...@earthlink.net >> __ Kenny, Do you have any idea what your engine weighs? Bobby >> 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> CG and the KR2S
Kenny and Bobby My initial post was in response to a question posed by a builder in reference to whether or not the CG location and limits were different from the original KR2 and the KR2S. I had stated that they were not if both aircraft were built to plans. Kenny your plane being flown within 2 inches of the aft limit basically puts the aircraft at the "sane" limit that all who are informed about the KR2 and S agree on. A quick weight and balance check of the shifting of the CG slightly aft as you take off and begin climb would probably reveal that you are in fact in that last 2 inches during the climb, and so need to take measures to keep the CG forward at all times. I am loading everything that I can that I have to put in the plane anyway in front of the main spar in some way or another. The more weight that I can transfer to right at or just ahead of the spar, the harder it will be to move the CG rearward due to the volume already forward. Also, I plan to have a small fuel cell used when flying with two, behind the seat so that when flying long distance, and draining the header tank, I can re-fill it with 5 to 6 gallons to maintain a safe CG in descent and landing, while manipulating the CG aft while in cruise. Yes there will be 2 pumps to transfer fuel so that I cannot get caught with an out of CG plane... New latch in the new gullwing. Back to sanding the nose bowl to shape... Colin Rainey First National Mortgage Sources Lending Solutions in All 50 States brokerpilot9...@earthlink.net
KR> CG and the KR2S
The problem with these things is that everything you do changes the CG-including leaning forward. Somebody needs to invent a sliding counter weight. ( just kidding) - Original Message - From: "Colin Rainey" To: Sent: Wednesday, January 04, 2006 7:24 PM Subject: KR> CG and the KR2S > Kenny and Bobby > My initial post was in response to a question posed by a builder in > reference to whether or not the CG location and limits were different from > the original KR2 and the KR2S. I had stated that they were not if both > aircraft were built to plans. Kenny your plane being flown within 2 inches > of the aft limit basically puts the aircraft at the "sane" limit that all > who are informed about the KR2 and S agree on. A quick weight and balance > check of the shifting of the CG slightly aft as you take off and begin > climb would probably reveal that you are in fact in that last 2 inches > during the climb, and so need to take measures to keep the CG forward at > all times. I am loading everything that I can that I have to put in the > plane anyway in front of the main spar in some way or another. The more > weight that I can transfer to right at or just ahead of the spar, the > harder it will be to move the CG rearward due to the volume already > forward. Also, I plan to have a small fuel cell used when > flying with two, behind the seat so that when flying long distance, and > draining the header tank, I can re-fill it with 5 to 6 gallons to maintain > a safe CG in descent and landing, while manipulating the CG aft while in > cruise. Yes there will be 2 pumps to transfer fuel so that I cannot get > caught with an out of CG plane... > > New latch in the new gullwing. Back to sanding the nose bowl to shape... > > > Colin Rainey > First National Mortgage Sources > Lending Solutions in All 50 States > brokerpilot9...@earthlink.net > ___ > 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> CG and the KR2S
They do that on Seaplanes, Virg On Wed, 4 Jan 2006 19:42:57 -0500 "Kenneth Wiltrout" writes: > The problem with these things is that everything you do changes the > CG-including leaning forward. Somebody needs to invent a > sliding > counter weight. ( just kidding) > > > > - Original Message - > From: "Colin Rainey" > To: > Sent: Wednesday, January 04, 2006 7:24 PM > Subject: KR> CG and the KR2S > > > > Kenny and Bobby > > My initial post was in response to a question posed by a builder > in > > reference to whether or not the CG location and limits were > different from > > the original KR2 and the KR2S. I had stated that they were not if > both > > aircraft were built to plans. Kenny your plane being flown within > 2 inches > > of the aft limit basically puts the aircraft at the "sane" limit > that all > > who are informed about the KR2 and S agree on. A quick weight and > balance > > check of the shifting of the CG slightly aft as you take off and > begin > > climb would probably reveal that you are in fact in that last 2 > inches > > during the climb, and so need to take measures to keep the CG > forward at > > all times. I am loading everything that I can that I have to put > in the > > plane anyway in front of the main spar in some way or another. > The more > > weight that I can transfer to right at or just ahead of the spar, > the > > harder it will be to move the CG rearward due to the volume > already > > forward. Also, I plan to have a small fuel cell used when > > flying with two, behind the seat so that when flying long > distance, and > > draining the header tank, I can re-fill it with 5 to 6 gallons to > maintain > > a safe CG in descent and landing, while manipulating the CG aft > while in > > cruise. Yes there will be 2 pumps to transfer fuel so that I > cannot get > > caught with an out of CG plane... > > > > New latch in the new gullwing. Back to sanding the nose bowl to > shape... > > > > > > Colin Rainey > > First National Mortgage Sources > > Lending Solutions in All 50 States > > brokerpilot9...@earthlink.net > > ___ > > 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 > > Virgil N. Salisbury - AMSOIL www.lubedealer.com/salisbury Miami ,Fl
KR> CG and the KR2S
At 06:42 PM 1/4/2006, you wrote: >The problem with these things is that everything you do changes the >CG-including leaning forward. Ken + That's true on any aircraft. I once flew the Tripacer on a clear , smooth night for 25 minutes without touching the control yoke. After trimmed in cruise, I could lean forward or back in the seat if the altimeter drifted a bit. A very slight power reduction gave me the decent rate I wanted when arriving at the home airport. I tried to rudder the turn onto downwind and that's when the nose dropped enough that I had to take the wheel. All airplanes play by the same laws of physics. Larry Flesner
KR> CG and the KR2S
OK, all this CG talk has got me thinging. I am getting ready to install wing tip navigation/ strobe lights. They are the Aeroflash units. I think the total weight of the power supply units is 2 lbs. Which is 1 lb per unit. My airplane is a KR-2 (not an S) with a total weight of 672 lbs. I am using a Great Plains VW- 2180. I have a 4.5 gallon header tank with 7.5 gallon wing tanks in each wing feeding the header. the CG location is 7.9 inches. Considering the above and on comparison to your KR, Where are you locating the 2 lbs of strobe power supplies? Jeff York KR-2 Flying N839BG Home page http://web.qx.net/jeffyork40/ My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 Email jeffyor...@qx.net - Original Message - From: "Larry&Sallie Flesner" To: "KRnet" Sent: Thursday, January 05, 2006 7:00 AM Subject: KR> CG and the KR2S > At 06:42 PM 1/4/2006, you wrote: > >The problem with these things is that everything you do changes the > >CG-including leaning forward. Ken > > + > > That's true on any aircraft. I once flew the Tripacer on a clear > , smooth night for 25 minutes without touching the control > yoke. After trimmed in cruise, I could lean forward or back in > the seat if the altimeter drifted a bit. A very slight power reduction > gave me the decent rate I wanted when arriving at the home > airport. I tried to rudder the turn onto downwind and that's when > the nose dropped enough that I had to take the wheel. All > airplanes play by the same laws of physics. > > Larry Flesner > > > > > > ___ > 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> CG and the KR2S
I would be much more concerned with moving the power supplies and the wires between the supplies and the strobe as far from your radio, antenna, and antenna cable as you can. Best place is in the wing tips if you happen to have them removable. Brian Kraut Engineering Alternatives, Inc. www.engalt.com -Original Message- From: krnet-bounces+brian.kraut=engalt@mylist.net [mailto:krnet-bounces+brian.kraut=engalt@mylist.net]On Behalf Of jeffyor...@qx.net Sent: Thursday, January 05, 2006 5:19 PM To: KRnet Subject: Re: KR> CG and the KR2S OK, all this CG talk has got me thinging. I am getting ready to install wing tip navigation/ strobe lights. They are the Aeroflash units. I think the total weight of the power supply units is 2 lbs. Which is 1 lb per unit. My airplane is a KR-2 (not an S) with a total weight of 672 lbs. I am using a Great Plains VW- 2180. I have a 4.5 gallon header tank with 7.5 gallon wing tanks in each wing feeding the header. the CG location is 7.9 inches. Considering the above and on comparison to your KR, Where are you locating the 2 lbs of strobe power supplies? Jeff York KR-2 Flying N839BG Home page http://web.qx.net/jeffyork40/ My KR-2 http://web.qx.net/jeffyork40/Airplane/ to see my KR-2 Email jeffyor...@qx.net - Original Message - From: "Larry&Sallie Flesner" To: "KRnet" Sent: Thursday, January 05, 2006 7:00 AM Subject: KR> CG and the KR2S > At 06:42 PM 1/4/2006, you wrote: > >The problem with these things is that everything you do changes the > >CG-including leaning forward. Ken > > + > > That's true on any aircraft. I once flew the Tripacer on a clear > , smooth night for 25 minutes without touching the control > yoke. After trimmed in cruise, I could lean forward or back in > the seat if the altimeter drifted a bit. A very slight power reduction > gave me the decent rate I wanted when arriving at the home > airport. I tried to rudder the turn onto downwind and that's when > the nose dropped enough that I had to take the wheel. All > airplanes play by the same laws of physics. > > Larry Flesner > > > > > > ___ > 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> CG and the KR2S
Kenny, Colin, Mark, Mark, Dan and group, This is exactly the factor which made me decide to build the KR- the availability of hard, specific data from educated and experienced folks who have the desire to help. This thread will be fied in my wt/bal file. If you have it available, could you each (these are all modified aircraft I think) post the distance from firewall to rudder post. My project is at the boat stage and growing. Happy New Year and Many Thousands of Feet in Altitude! Bob Polgreen
KR> CG and the KR2S
I am not exactly sure, but I can tell you that from firewall to the axle of the tailwheel is 136.125. You can take 4 to 6 inches off that to get back to the rudder post. If I remember, I will measure the difference for you tomorrow, if you need an exact number. Remember, this is a stock KR2. The W & B spread sheet that is available on our site will tell you almost anything you want to know about W & B. The datum on that sheet is the Firewall. Why would you use anything else, as it would be most difficult to change it's location. See N64KR at http://KRBuilder.org - Then click on the pics See you in Mt. Vernon - 2006 - KR Gathering There is a time for building and a time for FLYING and the time for building is OVER. Daniel R. Heath - Lexington, SC ---Original Message--- If you have it available, could you each (these are all modified aircraft I think) post the distance from firewall to rudder post.
KR> CG and the KR2S
Dan, Thanks, I streatched my KrS2 a bit (156" firewall to post) I am looking for the plane with similar dimensions. This entire issue is so critical to stability that all related info is of help. I want to fly two with a certain degree of safety and comfort. I have used the stock dimensions and increased each proportionally to redistribute the weight over the longer dimension. I would like to compare my work to that of builders who are ahead of me. Sorry to hear of your engine problems. You are right to ask for expert help, the freeze up may well be a catastrophic symptom of a much more subtle problem. Good luck. Bob Polgreen
KR> CG and the KR2S
Bob I do not believe that the CG limits were changed for the KR2S from those already designed for the KR2. They are still the same, which is why the standard modification is to add one bay forward and one bay rear for the total stretch. Others are going alittle longer and enlargening the tail feathers, but their CG will still need to fall into the same range as before. Adjustments are just made as to locating battery and such to compensate. I also believe that it is understood that the last 2 inches of the originally published limits are considered unusable by builders and pilots of today... Colin Rainey brokerpilot9...@earthlink.net
KR> CG and the KR2S
>> I do not believe that the CG limits were changed for the KR2S from those already designed for the KR2. They are still the same, which is why the standard modification is to add one bay forward and one bay rear for the total stretch.<< There's only 2" added to the front of the S as opposed to the KR2, if you built them both by the RR plans. If you add a whole 'nuther bay to the front of a KR, you better have a really light engine up there! I know Ed Blocher added 4" to the front of his KR2S, and I'm not sure how he was planning on hanging a Corvair up there. You can modify a KR in many ways, but adding legroom has its limitations! Mine is "stock KR" in front of the main spar, and with the Corvair hanging up there a half an inch from the firewall (and no header tank), my CG is at the forward end of the range. Not that there's anything wrong with that (it sure makes it stable), but if I added 2", 4", or another bay, I'd have to have 30 pounds of lead in the tail (and my backup battery is already back there). Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net --
KR> CG and the KR2S
I agree with Mark that you can only move the firewall forward a couple of inches. I did exactly that as I wanted a little more leg room. When I built the boat and added the 2" forward for legroom, I was dedicated to installing a 2180 VW but then in 1999 at the Lake Barkely Gathering, William Wynne showed up with a Corvair engine mounted on a trailer and after listening to him for most of the day on Saturday, I became a Corvair convert. Then as time went on and I began to learn more and more about how to build an airplane I began to worry about the extra weight of the Corvair sitting 2 inches further out from the CG. Well to make a long story short, I finished the plane and did a W&B with the battery sitting against the forward side of the main spar. The engine it self was as close to the firewall as possible as the nose of my starter is 1/8" off the firewall. The CG calculated in this configuration to be 2.7 inches aft of the forward CG limit fully loaded with pilot and passenger. Not too shabby!!! Then I moved the battery to the firewall and the CG moved forward to 2.3 inches aft of the forward CG limit. Great!! I left the battery on the firewall and have been flying that way ever since. She is a very stable craft that when trimmed will fly hands off for several minutes. As a matter of fact I HAVE flown 4 minutes and thirty seconds without touching the stick but I was having rudder inputs toward the last couple of minutes to help keep her straight & level. Remember, every KR will be different. Factors such as your turtle deck weight, tail feathers weight, etc all make a huge difference whether you will need ballast in the tail or not. Mark Jones (N886MJ) Wales, WI USA E-mail me at flyk...@wi.rr.com Visit my NEW KR-2S CorvAIRCRAFT web site at www.flykr2s.com - Original Message - From: "Mark Langford" To: "KRnet" Sent: Saturday, December 31, 2005 7:54 AM Subject: Re: KR> CG and the KR2S > >> I do not believe that the CG limits were changed for the KR2S from those > already designed for the KR2. They are still the same, which is why the > standard modification is to add one bay forward and one bay rear for the > total stretch.<< > > There's only 2" added to the front of the S as opposed to the KR2, if you > built them both by the RR plans. If you add a whole 'nuther bay to the > front of a KR, you better have a really light engine up there! I know Ed > Blocher added 4" to the front of his KR2S, and I'm not sure how he was > planning on hanging a Corvair up there. > > You can modify a KR in many ways, but adding legroom has its limitations! > Mine is "stock KR" in front of the main spar, and with the Corvair hanging > up there a half an inch from the firewall (and no header tank), my CG is at > the forward end of the range. Not that there's anything wrong with that (it > sure makes it stable), but if I added 2", 4", or another bay, I'd have to > have 30 pounds of lead in the tail (and my backup battery is already back > there). > > Mark Langford, Huntsville, Alabama > see KR2S project N56ML at http://home.hiwaay.net/~langford > email to N56ML "at" hiwaay.net > -- > > > ___ > 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> CG and the KR2S
With 6.5 gal fuel in the header tank ( max is 13 gal ) and a passenger, my 2S is 2" forward of the rear most CG, and I can tell you that it's a handful on take off, the tail drops noticeably. To counter this I increase my take off speed to 70 mph or top off the fuel tank. Your results may vary.--I'm 240lbs and the last passenger was 135 lbs. Kenny 6399U - Original Message - From: "Colin Rainey" To: Sent: Saturday, December 31, 2005 7:24 AM Subject: KR> CG and the KR2S > Bob > I do not believe that the CG limits were changed for the KR2S from those > already designed for the KR2. They are still the same, which is why the > standard modification is to add one bay forward and one bay rear for the > total stretch. Others are going alittle longer and enlargening the tail > feathers, but their CG will still need to fall into the same range as > before. Adjustments are just made as to locating battery and such to > compensate. I also believe that it is understood that the last 2 inches of > the originally published limits are considered unusable by builders and > pilots of today... > > > Colin Rainey > brokerpilot9...@earthlink.net > ___ > 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> CG and the KR2S
> With 6.5 gal fuel in the header tank ( max is 13 gal ) and a passenger, > my > 2S is 2" forward of the rear most CG, and I can tell you that it's a > handful > on take off, the tail drops noticeably. To counter this I increase my take > off speed to 70 mph or top off the fuel tank. > Your results may vary.--I'm 240lbs and the last passenger was > 135 lbs. > > Kenny 6399U > > > - Original Message - > From: "Colin Rainey" > To: > Sent: Saturday, December 31, 2005 7:24 AM > Subject: KR> CG and the KR2S > > >> Bob >> I do not believe that the CG limits were changed for the KR2S from those >> already designed for the KR2. They are still the same, which is why the >> standard modification is to add one bay forward and one bay rear for the >> total stretch. Others are going alittle longer and enlargening the tail >> feathers, but their CG will still need to fall into the same range as >> before. Adjustments are just made as to locating battery and such to >> compensate. I also believe that it is understood that the last 2 inches >> of >> the originally published limits are considered unusable by builders and >> pilots of today... >> >> >> Colin Rainey >> brokerpilot9...@earthlink.net >> _ Kenny,What are you powered with? Thanks, Bobby__ >> 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 >
