From: To: Subject: krnet Digest 20 Feb 2002 02:22:43 -0000 Issue 376 Date: Tuesday, February 19, 2002 6:23 PM krnet Digest 20 Feb 2002 02:22:43 -0000 Issue 376 Topics (messages 8855 through 8880): Re: THRUST LINE 8855 by: Philip J. Visconti 8857 by: larry flesner 8858 by: Mark Langford 8859 by: RONALD.FREIBERGER 8864 by: macwood 8867 by: Jerry Mahurin 8868 by: macwood 8869 by: Robert X. Cringely 8877 by: Daniel Heath 8880 by: RONALD.FREIBERGER firewall material 8856 by: Mark Langford fiberglassing technique 8860 by: Larry A. Capps Canopy to canopy bow gaps 8861 by: Dave and Tina Goodman 8862 by: Lynn Hyder Larger Main Wheels 8863 by: Phillip Matheson 8865 by: Frank Ross 8866 by: Mark Langford 8872 by: larry flesner 8875 by: Daniel Heath 8878 by: Frank Ross Bob Cringely re Thrust line 8870 by: Tracy & Carol O'Brien Bob Cringely/Thrust line/pitch trim 8871 by: larry flesner KR-2 Safety issues? 8873 by: Alex Zobell 8874 by: Mark Jones 8876 by: Daniel Heath 8879 by: Frank Ross Administrivia: To subscribe to the digest, e-mail: To unsubscribe from the digest, e-mail: To post to the list, e-mail: ---------------------------------------------------------------------- Date: Mon, 18 Feb 2002 12:51:38 -0500 To: jerrymahurin@charter.net From: "Philip J. Visconti" Cc: krnet@mailinglists.org Subject: Re: KR> THRUST LINE Message-ID: <20020218.125139.-340883.2.viscan@juno.com> Jerry, et al, Thank you for info you supplied. Did I mention that I now have a Revmaster engine ? (Jerry knows because I traded cowling with him and Dan Heath.) I changed to a Polliwagen motor mount I bought from Revmaster. Supposedly, it is similar to original Revmaster mount. The mount, I had previously, was a HAPI and mounting holes were different. Polliwagen mount seems to fit Revmaster engine O.K. Why ask thrust question ??? Tony's "Firewall Forward" got me thinking about it. He suggested that thrust line should be where designer placed it in original plans. However, if some have already changed thrust line, with their different engine installations, I guess I shouldn't worry. Just make sure engine/cowling combination fits properly. Phil ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/. ------------------------------ Date: Mon, 18 Feb 2002 14:55:28 -0600 To: "Philip J. Visconti" From: larry flesner Cc: krnet@mailinglists.org Subject: Re: KR> THRUST LINE Message-Id: <3.0.6.32.20020218145528.008c3d80@mail.midwest.net> >Why ask thrust question ??? Tony's "Firewall Forward" got me thinking >about it. He suggested that thrust line should be where designer placed >it in original plans. However, if some have already changed thrust line, >with their different engine installations, I guess I shouldn't worry. >Just make sure engine/cowling combination fits properly. >Phil +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++== Phil and netters, In my earlier reply, I didn't intend to suggest that builders were changing the thrust line with the different engines. I was speaking about aircraft design in general. The only changes to KR's that I'm aware of is the physical layout of the different engines and mounts maybe changing the vertical thrust line and I believe Mark Langford may have dropped his a couple inches to accommodate the Corvair(correct me if I'm wrong, Mark). I know of no builder that has offset the thrust line horizontally with any of the different engines. The one builder that had to shim his mount (he never said which way) said when he installed the 0-200 the aircraft wanted to roll on the first flight. He had to hold continuous side stick and bring it back in. What the problem was there is beyond me but I suspect it was unique to that airframe or engine installation. He claimed the shims took care of the problem but I suspect it is just hiding a problem somewhere else. By the way, The HAPI (I hope I'm right on this one) mount fits the 0-200. If I have the correct mount here, it's the same one Marty Roberts is using and also the one I have my 0-200 on. I moved mine out with 1 inch spacers on the firewall to help the C.G. with my 24 inch stretch. The spacers also allowed me to use the older pull type starter which my engine had. The original 55 amp alternator could not be used as it hit the mount so I'm using a B&C that I traded for mine. I'm still trying to get the drawing for the adaptor that Marty made so he could install a Nippendenso (SP) , pronounced rice burner, on his. Hope that was all clear enough........... Larry Flesner ------------------------------ Date: Mon, 18 Feb 2002 16:14:00 -0600 To: From: "Mark Langford" Subject: Re: KR> THRUST LINE Message-ID: <00ec01c1b8c9$95cbc020$0100a8c0@cmc3075662a> Larry wrote: > thrust line and I believe Mark Langford may have dropped his > a couple inches to accommodate the Corvair(correct me > if I'm wrong, Mark). It's been a while since I looked at the "plans",. but I remember that actually figuring out where the thrust line is supposed to be is a matter that's left to your imagination. You can infer from the drawings that it might be at the top of the top longeron elevation, but I don't think it actually spells it out anywhere. And if you look at the side view "poster" drawing of the KR2S that's included with the plans, you'd guesstimate that it's about 2" below the longeron. I think it's one of those things where you have to buy an engine mount from somebody, bolt it on, and now you know where your thrust line is! Of course some of those folks who've actually bought engine mounts could probably shed considerable light on this subject, if they would. But I wouldn't want anybody to go out of their way! I will say that the Revmaster cowling looks to have been designed for the thrustline to be located at the top of the top longeron, and that seems to be the way most KRs are constructed. I DID see a drawing in an old Newsletter that showed the thrust line to be about 2" below the longeron's top, but I forget the details. Mine is 2.38" below the top of the longeron, mainly so my mechanical fuel pump and distributor wouldn't require bulges in the cowling. That puts my prop's centerline only 34.6" off the ground, leaving me with only 7-5/8" of prop clearance with a 54" prop. I'll fix that with some 4130 gear leg extensions that'll raise me up 3 more inches. As far as moving the thrust line up or down an inch or two on a KR, I can't see that you'd realize any real differnce in flying qualities, especially compared to all the other variables that individual builders build into these things, stuff like nosegear vs taildragger vs retracts, for example. And nothing like the huge change in CG during every flight that you'd get with a big header tank mounted behind the panel... Mark Langford, Huntsville, Alabama mailto:langford@hiwaay.net see KR2S N56ML at http://home.hiwaay.net/~langford ------------------------------ Date: Mon, 18 Feb 2002 17:19:06 -0500 To: "larry flesner" , "Philip J. Visconti" From: "RONALD.FREIBERGER" Cc: Subject: RE: KR> THRUST LINE Message-ID: I have experience with several airplanes that we mounted the engine "square and in the middle of the cowl opening. They all flew well. The backwards turning VW might benefit from a little offset, but apparently no-one bothers to do so . Ron Freiberger... mailto:ron.martha@mindspring.com -----Original Message----- From: larry flesner [mailto:flesner@midwest.net] Sent: Monday, February 18, 2002 3:55 PM To: Philip J. Visconti Cc: krnet@mailinglists.org Subject: Re: KR> THRUST LINE >Why ask thrust question ??? Tony's "Firewall Forward" got me thinking >about it. He suggested that thrust line should be where designer placed >it in original plans. However, if some have already changed thrust line, >with their different engine installations, I guess I shouldn't worry. >Just make sure engine/cowling combination fits properly. >Phil +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++== Phil and netters, In my earlier reply, I didn't intend to suggest that builders were changing the thrust line with the different engines. I was speaking about aircraft design in general. The only changes to KR's that I'm aware of is the physical layout of the different engines and mounts maybe changing the vertical thrust line and I believe Mark Langford may have dropped his a couple inches to accommodate the Corvair(correct me if I'm wrong, Mark). I know of no builder that has offset the thrust line horizontally with any of the different engines. The one builder that had to shim his mount (he never said which way) said when he installed the 0-200 the aircraft wanted to roll on the first flight. He had to hold continuous side stick and bring it back in. What the problem was there is beyond me but I suspect it was unique to that airframe or engine installation. He claimed the shims took care of the problem but I suspect it is just hiding a problem somewhere else. By the way, The HAPI (I hope I'm right on this one) mount fits the 0-200. If I have the correct mount here, it's the same one Marty Roberts is using and also the one I have my 0-200 on. I moved mine out with 1 inch spacers on the firewall to help the C.G. with my 24 inch stretch. The spacers also allowed me to use the older pull type starter which my engine had. The original 55 amp alternator could not be used as it hit the mount so I'm using a B&C that I traded for mine. I'm still trying to get the drawing for the adaptor that Marty made so he could install a Nippendenso (SP) , pronounced rice burner, on his. Hope that was all clear enough........... Larry Flesner --------------------------------------------------------------------- To post to the list, email: krnet@mailinglists.org , NOT "reply all" To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org For additional commands, e-mail: krnet-help@mailinglists.org See the KRNet archives at http://www.escribe.com/aviation/krnet/ ------------------------------ Date: Tue, 19 Feb 2002 12:20:34 -0000 To: From: "macwood" Cc: Subject: Re: KR> THRUST LINE Message-ID: <000a01c1b93f$ea11d540$d7353c3e@tinypc> Back in the dark ages,when I did my basic aerodynamics, we were taught that the thrust line and the drag component had to form an anticlockwise couple to counter the clockwise couple of lift and c of g. (Centre of lift behind c of g. and thrust below drag) So in theory if you got your thrust line too high you could run into stability problems. ----- Original Message ----- Regards Mac W From: "RONALD.FREIBERGER" To: "larry flesner" ; "Philip J. Visconti" Cc: Sent: Monday, February 18, 2002 10:19 PM Subject: RE: KR> THRUST LINE > I have experience with several airplanes that we mounted the engine "square > and in the middle of the cowl opening. They all flew well. The backwards > turning VW might benefit from a little offset, but apparently no-one bothers > to do so . > > Ron Freiberger... > mailto:ron.martha@mindspring.com > > > -----Original Message----- > From: larry flesner [mailto:flesner@midwest.net] > Sent: Monday, February 18, 2002 3:55 PM > To: Philip J. Visconti > Cc: krnet@mailinglists.org > Subject: Re: KR> THRUST LINE > > > >Why ask thrust question ??? Tony's "Firewall Forward" got me thinking > >about it. He suggested that thrust line should be where designer placed > >it in original plans. However, if some have already changed thrust line, > >with their different engine installations, I guess I shouldn't worry. > >Just make sure engine/cowling combination fits properly. > >Phil > +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++== > > Phil and netters, > > In my earlier reply, I didn't intend to suggest that builders > were changing the thrust line with the different engines. > I was speaking about aircraft design in general. The only > changes to KR's that I'm aware of is the physical layout of > the different engines and mounts maybe changing the vertical > thrust line and I believe Mark Langford may have dropped his > a couple inches to accommodate the Corvair(correct me > if I'm wrong, Mark). I know of no builder that has offset > the thrust line horizontally with any of the different engines. > The one builder that had to shim his mount (he never said > which way) said when he installed the 0-200 the aircraft > wanted to roll on the first flight. He had to hold continuous > side stick and bring it back in. What the problem was there > is beyond me but I suspect it was unique to that airframe > or engine installation. He claimed the shims took care > of the problem but I suspect it is just hiding a problem > somewhere else. > > By the way, The HAPI (I hope I'm right on this one) mount > fits the 0-200. If I have the correct mount here, it's the > same one Marty Roberts is using and also the one I have > my 0-200 on. I moved mine out with 1 inch spacers on > the firewall to help the C.G. with my 24 inch stretch. > The spacers also allowed me to use the older pull type > starter which my engine had. The original 55 amp alternator > could not be used as it hit the mount so I'm using a B&C > that I traded for mine. I'm still trying to get the drawing > for the adaptor that Marty made so he could install a > Nippendenso (SP) , pronounced rice burner, on his. > > Hope that was all clear enough........... > > Larry Flesner > > > > > --------------------------------------------------------------------- > To post to the list, email: krnet@mailinglists.org , NOT "reply all" > > To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org > For additional commands, e-mail: krnet-help@mailinglists.org > > See the KRNet archives at http://www.escribe.com/aviation/krnet/ > > > --------------------------------------------------------------------- > To post to the list, email: krnet@mailinglists.org , NOT "reply all" > > To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org > For additional commands, e-mail: krnet-help@mailinglists.org > > See the KRNet archives at http://www.escribe.com/aviation/krnet/ > ------------------------------ Date: Tue, 19 Feb 2002 08:46:00 -0500 To: "macwood" , From: "Jerry Mahurin" Cc: Subject: Re: KR> THRUST LINE Message-ID: So....how high is TOO HIGH...??? And too high relative to what.....??? Jerry Mahurin Lugoff, SC See our KR2 at http://www.jerrymahurin.com On Tue, 19 Feb 2002 12:20:34 -0000 "macwood" wrote: >Back in the dark ages,when I did my basic aerodynamics, >we were taught that >the thrust line and the drag component had to form an >anticlockwise couple >to counter the clockwise couple of lift and c of g. > (Centre of lift behind >c of g. and thrust below drag) So in theory if you got >your thrust line too >high you could run into stability problems. >----- Original Message ----- Regards Mac W >From: "RONALD.FREIBERGER" >To: "larry flesner" ; "Philip J. >Visconti" > >Cc: >Sent: Monday, February 18, 2002 10:19 PM >Subject: RE: KR> THRUST LINE > > >> I have experience with several airplanes that we mounted >>the engine >"square >> and in the middle of the cowl opening. They all flew >>well. The backwards >> turning VW might benefit from a little offset, but >>apparently no-one >bothers >> to do so . >> >> Ron Freiberger... >> mailto:ron.martha@mindspring.com >> >> >> -----Original Message----- >> From: larry flesner [mailto:flesner@midwest.net] >> Sent: Monday, February 18, 2002 3:55 PM >> To: Philip J. Visconti >> Cc: krnet@mailinglists.org >> Subject: Re: KR> THRUST LINE >> >> >> >Why ask thrust question ??? Tony's "Firewall Forward" >>got me thinking >> >about it. He suggested that thrust line should be where >>designer placed >> >it in original plans. However, if some have already >>changed thrust line, >> >with their different engine installations, I guess I >>shouldn't worry. >> >Just make sure engine/cowling combination fits >>properly. >> >Phil >> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++== >> >> Phil and netters, >> >> In my earlier reply, I didn't intend to suggest that >>builders >> were changing the thrust line with the different >>engines. >> I was speaking about aircraft design in general. The >>only >> changes to KR's that I'm aware of is the physical layout >>of >> the different engines and mounts maybe changing the >>vertical >> thrust line and I believe Mark Langford may have dropped >>his >> a couple inches to accommodate the Corvair(correct me >> if I'm wrong, Mark). I know of no builder that has >>offset >> the thrust line horizontally with any of the different >>engines. >> The one builder that had to shim his mount (he never >>said >> which way) said when he installed the 0-200 the aircraft >> wanted to roll on the first flight. He had to hold >>continuous >> side stick and bring it back in. What the problem was >>there >> is beyond me but I suspect it was unique to that >>airframe >> or engine installation. He claimed the shims took care >> of the problem but I suspect it is just hiding a problem >> somewhere else. >> >> By the way, The HAPI (I hope I'm right on this one) >>mount >> fits the 0-200. If I have the correct mount here, it's >>the >> same one Marty Roberts is using and also the one I have >> my 0-200 on. I moved mine out with 1 inch spacers on >> the firewall to help the C.G. with my 24 inch stretch. >> The spacers also allowed me to use the older pull type >> starter which my engine had. The original 55 amp >>alternator >> could not be used as it hit the mount so I'm using a B&C >> that I traded for mine. I'm still trying to get the >>drawing >> for the adaptor that Marty made so he could install a >> Nippendenso (SP) , pronounced rice burner, on his. >> >> Hope that was all clear enough........... >> >> Larry Flesner >> >> >> >> >> --------------------------------------------------------------------- >> To post to the list, email: krnet@mailinglists.org , NOT >>"reply all" >> >> To UNsubscribe, e-mail: >>krnet-unsubscribe@mailinglists.org >> For additional commands, e-mail: >>krnet-help@mailinglists.org >> >> See the KRNet archives at >>http://www.escribe.com/aviation/krnet/ >> >> >> --------------------------------------------------------------------- >> To post to the list, email: krnet@mailinglists.org , NOT >>"reply all" >> >> To UNsubscribe, e-mail: >>krnet-unsubscribe@mailinglists.org >> For additional commands, e-mail: >>krnet-help@mailinglists.org >> >> See the KRNet archives at >>http://www.escribe.com/aviation/krnet/ >> > > >--------------------------------------------------------------------- >To post to the list, email: krnet@mailinglists.org , NOT >"reply all" > >To UNsubscribe, e-mail: >krnet-unsubscribe@mailinglists.org >For additional commands, e-mail: >krnet-help@mailinglists.org > >See the KRNet archives at >http://www.escribe.com/aviation/krnet/ >