---------------------------------------------------------- KIS-List Digest Archive --- Total Messages Posted Tue 08/17/10: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:57 AM - Re: Aileron/Elervator Trim .. (Graham Brighton) 2. 05:04 AM - Re: Aileron/Elervator Trim .. () 3. 01:59 PM - Elevator Trailing Edge () 4. 03:11 PM - Re: Elevator Trailing Edge (Graham Brighton) 5. 03:34 PM - Re: Elevator Trailing Edge (ALFRED ROSA) ________________________________ Message 1 _____________________________________ Time: 04:57:52 AM PST US From: "Graham Brighton" Subject: Re: KIS-List: Aileron/Elervator Trim .. Hi Jesse, Thanks for reporting ur experience with ur elevator mod ... I have wondered a lot about how changing the elevator trailing edge from the original stepped shape to a knife edge would work out .... would be good to hear what others have experienced as well .. Graham .. ----- Original Message ----- From: Flyinisfun@aol.com To: kis-list@matronics.com Sent: Tuesday, August 17, 2010 12:33 AM Subject: Re: KIS-List: Aileron/Elervator Trim .. Hi Scott and Graham, I extended the elevator by about 1 1/2" and brought the trailing edge to a knife edge. I had a null spot in neutral position and flew for some time with about a quarter of an inch offset in the trim tab to give me stick pressure. I realized that the knife edge was a problem, causing the null of about 1" deflection before I got any real movement in the plane's attitude and any feel in the stick. I sanded off the knife edge until I had about an 1/8" blunt edge and believe it or not I now have a feel in the stick. If Rich is watching this and OC would you agree this is a realistic evaluation? I can now feel the change of the elevator upon immediate movement and have not done anything else to the plane that would have any effect on the C.G. I've thought about sanding a little more off but maybe not. Jesse Wright ________________________________ Message 2 _____________________________________ Time: 05:04:49 AM PST US From: Subject: Re: KIS-List: Aileron/Elervator Trim .. 8/17/2010 Hello Jesse, You wrote: 1) "If Rich is watching this and OC would you agree this is a realistic evaluation?" Yes. There is extensive experience available about the effects of creating a blunt trailing edge on a control surface. Here is just one extract via google: http://www.homebuiltairplanes.com/forums/aircraft-design-aerodynamics-new-technology/7123-blunt-trailing-edge-question.html 2) "I've thought about sanding a little more off but maybe not." Remember the old adage that goes: "If it ain't broke, don't fix it." There are some structual considerations in sanding more off the trailing edge. 'OC' Baker Says: "The best investment we can make is the time and effort to gather and understand knowledge." ====================================================== ----- Original Message ----- From: Sent: Monday, August 16, 2010 10:33 AM Subject: Re: KIS-List: Aileron/Elervator Trim .. > Hi Scott and Graham, > > I extended the elevator by about 1 1/2" and brought the trailing edge to a > knife edge. I had a null spot in neutral position and flew for some time > with about a quarter of an inch offset in the trim tab to give me stick > pressure. I realized that the knife edge was a problem, causing the null > of > about 1" deflection before I got any real movement in the plane's attitude > and any feel in the stick. I sanded off the knife edge until I had about > an > 1/8" blunt edge and believe it or not I now have a feel in the stick. > > If Rich is watching this and OC would you agree this is a realistic > evaluation? I can now feel the change of the elevator upon immediate > movement > and have not done anything else to the plane that would have any effect > on > the C.G. I've thought about sanding a little more off but maybe not. > > Jesse Wright > ________________________________ Message 3 _____________________________________ Time: 01:59:29 PM PST US From: Subject: KIS-List: Elevator Trailing Edge 8/17/2010 Hello Graham, You wrote: "...changing the elevator trailing edge from the original stepped shape to a knife edge......" I don't understand your words "..from the original stepped shape.." for the elevator trailing edge. My reading of the construction manual has the trailing edges of the top and bottom elevator fiberglass skin moldings being glued directly to each other as they meet. The result, looking at it from a side view, is a flat sided # isosceles triangle with the trailing edge being the thickness of the two fiberglass skins plus any adhesive ("a good coat of resin" in the words of the manual) holding those edges together.* Where does the "stepped shape" term arise from? Thanks. 'OC' Baker Says: "The best investment we can make is the time and effort to gather and understand knowledge." #PS: Flat sided being very important since I discovered (in my effort to extend the trailing edge of the elevator) that any other shape (concave in my original case) could result in a significant trimming effect on the elevator. *PS: Hence my warning against sanding the trailing edge to far forward lest one sand away the area being held together by the resin. =================================================== ----- Original Message ----- From: "Graham Brighton" Sent: Tuesday, August 17, 2010 7:56 AM Subject: Re: KIS-List: Aileron/Elervator Trim .. Hi Jesse, Thanks for reporting ur experience with ur elevator mod ... I have wondered a lot about how changing the elevator trailing edge from the original stepped shape to a knife edge would work out .... would be good to hear what others have experienced as well .. Graham ================================================================ .. ----- Original Message ----- From: Flyinisfun@aol.com To: kis-list@matronics.com Sent: Tuesday, August 17, 2010 12:33 AM Subject: Re: KIS-List: Aileron/Elervator Trim .. Hi Scott and Graham, I extended the elevator by about 1 1/2" and brought the trailing edge to a knife edge. I had a null spot in neutral position and flew for some time with about a quarter of an inch offset in the trim tab to give me stick pressure. I realized that the knife edge was a problem, causing the null of about 1" deflection before I got any real movement in the plane's attitude and any feel in the stick. I sanded off the knife edge until I had about an 1/8" blunt edge and believe it or not I now have a feel in the stick. If Rich is watching this and OC would you agree this is a realistic evaluation? I can now feel the change of the elevator upon immediate movement and have not done anything else to the plane that would have any effect on the C.G. I've thought about sanding a little more off but maybe not. Jesse Wright ________________________________ Message 4 _____________________________________ Time: 03:11:24 PM PST US From: "Graham Brighton" Subject: Re: KIS-List: Elevator Trailing Edge Hi Back OC ... Yep think i have goofed up .... The Ailerons and Flaps have a 'Stepped' trailing edge ..that obviously works fine ... But i have long wondered how the airflow characteristics work there ... (as compared with a more common knife edge trailing edge ... ) But due being too busy with too much 'other stuff ' and only having a very small brain .. i mistakenly transposed my aileron/flap puzzlement onto the Elevator trailing edge question . Will be at the Hanger tomorrow and will double check ...but am sure u are rite that the elevator trailing edge is different than the other control surface trailing edges .. Sorry for my confusion ...! Graham .. ----- Original Message ----- From: Sent: Wednesday, August 18, 2010 6:57 AM Subject: KIS-List: Elevator Trailing Edge > > 8/17/2010 > > Hello Graham, You wrote: "...changing the elevator trailing edge from the > original stepped shape to a knife edge......" > > I don't understand your words "..from the original stepped shape.." for > the elevator trailing edge. > > My reading of the construction manual has the trailing edges of the top > and bottom elevator fiberglass skin moldings being glued directly to each > other as they meet. The result, looking at it from a side view, is a flat > sided # isosceles triangle with the trailing edge being the thickness of > the two fiberglass skins plus any adhesive ("a good coat of resin" in the > words of the manual) holding those edges together.* > > Where does the "stepped shape" term arise from? Thanks. > > 'OC' Baker Says: "The best investment we can make is the time and effort > to gather and understand knowledge." > > #PS: Flat sided being very important since I discovered (in my effort to > extend the trailing edge of the elevator) that any other shape (concave in > my original case) could result in a significant trimming effect on the > elevator. > > *PS: Hence my warning against sanding the trailing edge to far forward > lest one sand away the area being held together by the resin. > > =================================================== > ----- Original Message ----- > From: "Graham Brighton" > To: > Sent: Tuesday, August 17, 2010 7:56 AM > Subject: Re: KIS-List: Aileron/Elervator Trim .. > > > Hi Jesse, > Thanks for reporting ur experience with ur elevator mod > ... I have wondered a lot about how changing the elevator trailing edge > from the original stepped shape to a knife edge would work out .... would > be good to hear what others have experienced as well .. > > Graham > > ================================================================ > . > ----- Original Message ----- > From: Flyinisfun@aol.com > To: kis-list@matronics.com > Sent: Tuesday, August 17, 2010 12:33 AM > Subject: Re: KIS-List: Aileron/Elervator Trim .. > > > Hi Scott and Graham, > > I extended the elevator by about 1 1/2" and brought the trailing edge to > a knife edge. I had a null spot in neutral position and flew for some > time with about a quarter of an inch offset in the trim tab to give me > stick pressure. I realized that the knife edge was a problem, causing the > null of about 1" deflection before I got any real movement in the plane's > attitude and any feel in the stick. I sanded off the knife edge until I > had about an 1/8" blunt edge and believe it or not I now have a feel in > the stick. > > If Rich is watching this and OC would you agree this is a realistic > evaluation? I can now feel the change of the elevator upon immediate > movement and have not done anything else to the plane that would have any > effect on the C.G. I've thought about sanding a little more off but maybe > not. > > Jesse Wright > > > ________________________________ Message 5 _____________________________________ Time: 03:34:39 PM PST US Subject: Re: KIS-List: Elevator Trailing Edge From: ALFRED ROSA By "stepped" I think he's referring to a squared off trailing edge (blunt). I made my elevator with a 1/8 to 3/16 squared off trailing edge. I don't think you should go any thicker than that. Also, increasing the chord 1 1/2 to 2 inches is a good idea. Best way to increase the chord is along the chord line. See Bob Reed's web site for pics on how I did it. Al Rosa Al On Tue, Aug 17, 2010 at 4:57 PM, wrote: > > 8/17/2010 > > Hello Graham, You wrote: "...changing the elevator trailing edge from the > original stepped shape to a knife edge......" > > I don't understand your words "..from the original stepped shape.." for the > elevator trailing edge. > > My reading of the construction manual has the trailing edges of the top and > bottom elevator fiberglass skin moldings being glued directly to each other > as they meet. The result, looking at it from a side view, is a flat sided # > isosceles triangle with the trailing edge being the thickness of the two > fiberglass skins plus any adhesive ("a good coat of resin" in the words of > the manual) holding those edges together.* > > Where does the "stepped shape" term arise from? Thanks. > > 'OC' Baker Says: "The best investment we can make is the time and effort to > gather and understand knowledge." > > #PS: Flat sided being very important since I discovered (in my effort to > extend the trailing edge of the elevator) that any other shape (concave in > my original case) could result in a significant trimming effect on the > elevator. > > *PS: Hence my warning against sanding the trailing edge to far forward lest > one sand away the area being held together by the resin. > > =================================================== > ----- Original Message ----- From: "Graham Brighton" < > gbrighton@skymesh.com.au> > To: > Sent: Tuesday, August 17, 2010 7:56 AM > Subject: Re: KIS-List: Aileron/Elervator Trim .. > > > Hi Jesse, > Thanks for reporting ur experience with ur elevator mod ... > I have wondered a lot about how changing the elevator trailing edge from the > original stepped shape to a knife edge would work out .... would be good to > hear what others have experienced as well .. > > Graham > > ================================================================ > . > ----- Original Message ----- From: Flyinisfun@aol.com > To: kis-list@matronics.com > Sent: Tuesday, August 17, 2010 12:33 AM > Subject: Re: KIS-List: Aileron/Elervator Trim .. > > > Hi Scott and Graham, > > I extended the elevator by about 1 1/2" and brought the trailing edge to a > knife edge. I had a null spot in neutral position and flew for some time > with about a quarter of an inch offset in the trim tab to give me stick > pressure. I realized that the knife edge was a problem, causing the null of > about 1" deflection before I got any real movement in the plane's attitude > and any feel in the stick. I sanded off the knife edge until I had about an > 1/8" blunt edge and believe it or not I now have a feel in the stick. > > If Rich is watching this and OC would you agree this is a realistic > evaluation? I can now feel the change of the elevator upon immediate > movement and have not done anything else to the plane that would have any > effect on the C.G. I've thought about sanding a little more off but maybe > not. > > Jesse Wright > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kis-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/KIS-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kis-list Browse Digests http://www.matronics.com/digest/kis-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.