From: owner-krnet-l-digest@lists.teleport.com (krnet-l-digest) To: krnet-l-digest@lists.teleport.com Subject: krnet-l-digest V1 #49 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 Wednesday, June 25 1997 Volume 01 : Number 049 ---------------------------------------------------------------------- Date: Tue, 24 Jun 1997 15:30:58 -0700 From: "David M. Gargasz" Subject: Re: KR: KR longitudinal stability smithr wrote: > > Micheal Mims wrote: > The elevator control is just simply too light! Here are some > > of the changes I have made to hopefully help sensitivity and stability: > > > > 1) Increase horizontal span 5 inches (2.5 each side) > > 2) Tapered horizontal to a 1 inch airfoil section rather than 1/2 inch sq. > > 3) Drilled cable attach holes one inch closer to center on elevator belcrank > > 4) Will only use 15 to 30% of airfoil for CG range > > 5) Considering adding strakes after more research on their effectiveness per > > square foot. (its not a 1 for 1 trade from what I understand) > > > > On above point #3: This sounds good for increasing stick force > (desirable) but in physics you don't get something for nothing. It will > also yield more degrees of elevator deflection per inch of stick > movement. This might not be good if you are trying to reduce pitchiness. > The KR needs both more stick force and (slightly) more stick movement > per deg of elevator deflection. I don't know what will give both. > Possibly a non-linear cam. > > Bob Smith, Albany, NY Hi Bob, After digesting all the information available as to kr2 sensetivity pitch and bank control I'v come to the conclusion that stops will have to be installed to prevent over controling of the ailerons and vertical stab.. The horizontal stab. control should be desensitized by allowing more stick travel. I plan to tame my kr2 by adding 2' shoulders back, adding 6" @ the enjine mount, 40" wide inside at the shoulders, 2' to the main spars allowing 1' more for each flap. Thank you for your opinion. Gene Gargasz Elyria Ohio ------------------------------ Date: Tue, 24 Jun 1997 15:55:13 -0400 (EDT) From: Horn2004@aol.com Subject: Re: KR: Hinge Material Very impressive, Don! Thanks for the information. Steve Horn Horn2004@aol.com Dallas, Texas ------------------------------ Date: Sun, 22 Jun 1997 21:23:00 -0700 From: Donald Reid Subject: Re: KR: Hinge Material David > Hi Don, > With a eye ball conclusion with all this informatio it occured to me > 3/16"x 1 3/4" AN42B-17 steel eye bolts min tensile strength 125,000 psi > [3]@ each with a drilled locked clevis pins for a hinge, with steel back > plates where attached to the dbl 5/8" wood, should do a better job > without any added wieght than the alum. chanel arangement. Any > alignment problems could be solved with washers, the inspection covers > would be smaller. Thank you for your well thought opinion. > Gene Gargasz Elyria Ohio I do agree that this will work. I know that other people have used this method. You didn't mention it, but with this type of hinge, there needs to be two eyebolts on one side of the hinge (typically the stationary part) and one on the other. This keeps the hinge pin from binding. I think Tony Bingelis has something about it in his books. - -- Don Reid donreid@erols.com ------------------------------ Date: Sun, 22 Jun 1997 21:26:46 -0700 From: Donald Reid Subject: Re: KR: Hinge Material Horn2004@aol.com wrote: > > Very impressive, Don! Thanks for the information. > > Steve Horn > Horn2004@aol.com > Dallas, Texas I can just imagine that a few are impressed, a few are saying ... so what... , and a lot are saying ... Oh no, that #$&(#@ engineer is at it again. - -- Don Reid (All dirt roads lead to) Bumpass, Va donreid@erols.com ------------------------------ Date: Tue, 24 Jun 1997 13:39:16 -0700 From: Micheal Mims Subject: Re: KR: KR longitudinal stability At 02:44 PM 6/24/97 -0400, you wrote: On above point #3: This sounds good for increasing stick force >(desirable) but in physics you don't get something for nothing. It will >also yield more degrees of elevator deflection per inch of stick >movement. This might not be good if you are trying to reduce pitchiness. > The KR needs both more stick force and (slightly) more stick movement >per deg of elevator deflection. I don't know what will give both. >Possibly a non-linear cam. > Your right but I plan to leave the stick the stock length. I noticed some builders have cut the stick down in an attempt to decrease the stick sensitivity (give themselves less leverage). Hopefully there will be some sort of happy medium and the longer stick will not cancel out the increased stick pressure. I took measurements from various aircraft at the airport and decided 1 inch will help some. Its one of those things that will be a "wait and see". :-) ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 13:47:31 -0700 From: Micheal Mims Subject: Re: KR: Hinge Material At 09:23 PM 6/22/97 -0700, you wrote: >David >> Hi Don, >> With a eye ball conclusion with all this informatio it occured to me >> 3/16"x 1 3/4" AN42B-17 steel eye bolts min tensile strength 125,000 psi >> [3]@ each with a drilled locked clevis pins for a hinge, with steel back >> plates where attached to the dbl 5/8" wood, should do a better job >> without any added wieght than the alum. chanel arangement. Any >> alignment problems could be solved with washers, the inspection covers >> would be smaller. Thank you for your well thought opinion. >> Gene Gargasz Elyria Ohio Have you priced these eye bolts lately? You could be talking about $80+ worth of eye bolts! They would be a better system than what's currently used (aluminum channel). Did anyone come to any conclusions on why we couldn't hinge the elevators like the ailerons? The AR-5 uses piano hinges on its elevator and it does better than 200mph. If I were to do it again I think piano would be the path I would take. ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 16:51:13 -0400 From: "Cary Honeywell" Subject: Re: KR: Computer Geek Stuff Email (repy) to cary@storm.ca Web page http://www.storm.ca/~cary/ - ---------- > From: David Moore > To: krnet-l@teleport.com > Subject: Re: KR: Computer Geek Stuff 97-06-22 07:36:19 EDT > >>From: computer284@xqkq.netsales1.net (P133 Computer) > >>Reply-to: computer3@netsales1.net > >>To: computer284@xqkq.netsales1.net > >> > >> Only $799! P133 computer/16RAM/1.2GIG/6xCD...>> > >> > >>Netters: > >> > >>Sorry sorry sorry...my face is redder than normal. This post was not > >>intended for KRNet. My brain is slow so I compensate by having very fast > >>fingers!!! > >> > >>I''ll crawl back into my hole now... > >> > >>Randy Stein > >>Santa Monica, CA (but I now think I'll move and not leave a forwarding > >>address...) > >>BSHADR@aol.com Sorry. I just reacted badly. My work Internet account is constantly overflowing with unwanted spam, all saying I have to tell them if I don't want any more. This account is blessed by "anti-spamming" software that seems to work. - - Cary - (ps: if I get another computer, I'll be faced with another divorce!) ------------------------------ Date: Tue, 24 Jun 1997 16:55:42 -0400 From: "Cary Honeywell" Subject: Re: KR: Re: Computer geek info Email (repy) to cary@storm.ca Web page http://www.storm.ca/~cary/ - ---------- > From: Micheal Mims > Hey dude , mistakes happen! You may want watch your language regardless of > how upset you are or you may find yourself removed from the list! > Rebuke accepted with apology. - - Cary - ------------------------------ Date: Tue, 24 Jun 1997 17:00:24 -0400 From: "Cary Honeywell" Subject: Re: KR: Re: Computer geek info Email (repy) to cary@storm.ca Web page http://www.storm.ca/~cary/ - ---------- > From: BSHADR@aol.com > To: krnet-l@teleport.com > Subject: Re: KR: Re: Computer geek info > > > Sorry Cary...Now how 'bout you let it all out and tell me how you really > feel.... :-( > ^^^ Don't be sad. Guess I just a bit sensitive. I've had one account rendered useless due to deliberate spam. Also a bit miffed because I have spent money getting Sitka spruce to re-do my rear spar only to have the joker on the band-saw cut it up all wrong despite specific drawings. Really tough getting that kind of wood up here, and expensive too! Beginning to feel that after 3 years of work I may not ever get this thing off the ground. - - Cary - ------------------------------ Date: Tue, 24 Jun 1997 14:21:44 -0700 From: Micheal Mims Subject: KR: Source for .5 inch 4130 strap Has anyone found a source for the 1/2 inch 4130 strap used to make the aft wing attach fittings? I may locate a metal shop with a hydraulic floor shear and see if they will cut some for me. Or I could just use 1 inch for the aft fittings and 2 inch for the front. ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 17:47:10 -0400 From: Marty Hammersmith Subject: Re: KR: Formula V crash At 03:42 PM 6/24/97 +0000, you wrote: >Did anyone catch the air race crash on the news? It looked like a formula V >race. Two Soneris tried to occupy the same airspace at the same time. >Pretty sad, we are not off to a good start this year as far as airshows go, >three or four crashes already! > >If anyone on the ground gets hurt, airshows could very well be a thing of >the past in the US considering the current philosophy of our elected >officials! All it would take is one experimental aircraft to crash and kill >spectators and we could lose more than airshows! > >________________________________ >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Micheal Mims What? When? Who? I was part of Formula V for a short time up 'tilJim Frank was killed in a demo flight not related to a race. The plan was to fly my two place for a while and help Jim while I earned my commercial then sell the two place Sonerai and build a Sonerai 1 for racing. Jim's been dead a couple years now and was just starting to work on the wife again. If true, this finishes my bid for air racing for good. Any details to the group or via E-mail appreciated! Marty Marty Hammersmith (baleco@worldnet.att.net) ------------------------------ Date: Tue, 24 Jun 1997 15:05:04 -0700 From: Micheal Mims Subject: Re: KR: Re: Computer geek info At 04:55 PM 6/24/97 -0400, you wrote: >> From: Micheal Mims >> Hey dude , mistakes happen! You may want watch your language regardless >of >> how upset you are or you may find yourself removed from the list! >> > >Rebuke accepted with apology. > >- Cary - Cool! If I would have hit the "send" button on some of the email I composed I would have long been removed from this list! Just like dealing with my kids I decided to count to 10 before I hit the "send" or "delete" button. In my kids case selecting "send" is usually a better option! As in send them to their room! :-) ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 15:20:48 -0700 From: Micheal Mims Subject: Re: KR: Formula V crash At 05:47 PM 6/24/97 -0400, you wrote: What? When? Who? I was part of Formula V for a short time up >'tilJim Frank was killed in a demo flight not related to a race. It was on the local news here in LA last night, I guess there was a race at Long Island (could be wrong about location) this weekend and from the amateur video It looked like two Sonerais collided while maneuvering for position, one continued and the other tumbled out of the sky and crashed right in front of the grand stands (300 yards from the stands) and exploded. I am trying to find more information on the net if I do I will post it. ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 18:23:27 -0500 From: Kerry Miller Subject: KR: Formula V Crash Hi, guys, I emailed Michele Boland (owner of the coolest web page in all of aviation) and she said she thought one of them was Jim Vliet's plane, but he wasn't flying. I still don't know who was flying either one. It appears that Jim has, at least temporarily, taken down the Formula V web page. Kerry ------------------------------ Date: Tue, 24 Jun 1997 19:37:12 -0400 (EDT) From: Krwr1@aol.com Subject: Re: KR: REMOVE No more please ------------------------------ Date: Tue, 24 Jun 1997 17:45:12 -0700 From: Peter Hudson Subject: Re: KR: KR longitudinal stability smithr wrote: > > Micheal Mims wrote: > > The elevator control is just simply too light!... > > 3) Drilled cable attach holes one inch closer to center on elevator > > belcrank > On above point #3: This sounds good for increasing stick force > (desirable) but in physics you don't get something for nothing. It > will also yield more degrees of elevator deflection per inch of stick > movement. > The KR needs both more stick force and (slightly) more stick movement > per deg of elevator deflection. > Bob Smith, Albany, NY I'm thinking about moving the attach point out on the elevator to reduce elevator movement then getting back my stick force with springs at the stick. The springs could also be used to augment the trim system (though I still plan on aerodynamic trim for a source of control redundancy). - -Peter- ------------------------------ Date: Sun, 22 Jun 1997 09:59:54 -0500 From: "Rick Hanson" Subject: Re: KR: KR longitudinal stability Question: Would adding a mass balance help longitudinal control? - ---------- > From: smithr > To: krnet-l@teleport.com > Subject: Re: KR: KR longitudinal stability > Date: Tuesday, June 24, 1997 1:44 PM > > Micheal Mims wrote: > The elevator control is just simply too light! Here are some > > of the changes I have made to hopefully help sensitivity and stability: > > > > 1) Increase horizontal span 5 inches (2.5 each side) > > 2) Tapered horizontal to a 1 inch airfoil section rather than 1/2 inch sq. > > 3) Drilled cable attach holes one inch closer to center on elevator belcrank > > 4) Will only use 15 to 30% of airfoil for CG range > > 5) Considering adding strakes after more research on their effectiveness per > > square foot. (its not a 1 for 1 trade from what I understand) > > > > On above point #3: This sounds good for increasing stick force > (desirable) but in physics you don't get something for nothing. It will > also yield more degrees of elevator deflection per inch of stick > movement. This might not be good if you are trying to reduce pitchiness. > The KR needs both more stick force and (slightly) more stick movement > per deg of elevator deflection. I don't know what will give both. > Possibly a non-linear cam. > > Bob Smith, Albany, NY ------------------------------ Date: Tue, 24 Jun 1997 22:05:47 -0700 From: "David M. Gargasz" Subject: Re: KR: Hinge Material Micheal Mims wrote: > > At 09:23 PM 6/22/97 -0700, you wrote: > >David > >> Hi Don, > >> With a eye ball conclusion with all this informatio it occured to me > >> 3/16"x 1 3/4" AN42B-17 steel eye bolts min tensile strength 125,000 psi > >> [3]@ each with a drilled locked clevis pins for a hinge, with steel back > >> plates where attached to the dbl 5/8" wood, should do a better job > >> without any added wieght than the alum. chanel arangement. Any > >> alignment problems could be solved with washers, the inspection covers > >> would be smaller. Thank you for your well thought opinion. > >> Gene Gargasz Elyria Ohio > > Have you priced these eye bolts lately? You could be talking about $80+ > worth of eye bolts! They would be a better system than what's currently > used (aluminum channel). Did anyone come to any conclusions on why we > couldn't hinge the elevators like the ailerons? The AR-5 uses piano hinges > on its elevator and it does better than 200mph. If I were to do it again I > think piano would be the path I would take. > > ________________________________ > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Micheal Mims > Just Plane Nutts > mailto:mimsmand@ix.netcom.com > > http://www.netcom.com/~mimsmand Hi Micheal, The piano hing as mounted on the ailoron allows approx 30 deg. movement 20 deg. up 10 deg. down the hinge pin is located on the up side could that be problems for the stabalizers. The eye bolts per Wicks page 178 are $4.31 each, the cost vs alum is slightly higher but avoid a lot of alignment and binding problems and would wear better no need for oilite bearings. I am greatfull for all the information I have gleaned from your web site especialy your landing gear mounts, canopy, and how to do it instructions thanks again. Gene Gargasz Elyria Ohio ------------------------------ Date: Tue, 24 Jun 1997 21:31:21 From: brian whatcott Subject: Re: KR: A stable design -Tail vol At 06:49 6/24/97 -0700, Ed N. wrote: >>... Take a look at the tail volume of the KR-2 and >>compare it with almost any other aircraft and you will see the first >>source of low longitudinal stability of the KR-2. > >Sure. Compare it to the tail volume of the Zenith line of aircraft desings, >and I think you'll be surprised. > >Ed Newbold >Columbus, Ohio > Here is Pazmany's take on this topic: "It's always convenient to use non-dimensional coefficients for comparative purposes. If we divide tail volume by another 'volume' such as wing area (sq ft) times wing chord ( ft) = cu. ft. we obtain a dimensionless expression called "Tail Volume coefficient". That's horiz tail area times distance from c of g all divided by main wing area times wing chord He offers a table of eleven horizontal tail volume coefficients. If I exclude the two outliers, the remaining aircraft are in the range .371 to .580 ( median .412, mean .445 ) Ed, or anyone else: I don't have the plans: can you tell me the horizontal tail vol coefficient for the KR2 and KR2S please? Regards (Ref: Light Airplane Design - Pazmany) brian whatcott Altus OK ------------------------------ Date: Tue, 24 Jun 1997 19:36:52 -0700 From: Micheal Mims Subject: Re: KR: KR longitudinal stability At 05:45 PM 6/24/97 -0700, you wrote: >I'm thinking about moving the attach point out on the elevator to reduce >elevator movement then getting back my stick force with springs at the >stick. The springs could also be used to augment the trim system >(though I still plan on aerodynamic trim for a source of control >redundancy). > >-Peter- > I gave this some thought too but then my mind went into overdrive thinking about "what if" one of the springs break! And if it did break we all know when it would! I think you would need to mount the springs so that if one broke both would be disabled. I am sure this could be thought out, or you could set it up to use the same spring for both up and down elevator, again something to be thought out is the linkage but I am sure it can be done. I am not sure springs would give you the "feel" you would want though, but then again maybe they would?!? _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 20:56:54 From: Austin Clark Subject: Re: KR: Source for .5 inch 4130 strap Micheal Mims wrote: >Has anyone found a source for the 1/2 inch 4130 strap used to make the aft >wing attach fittings? I may locate a metal shop with a hydraulic floor shear >and see if they will cut some for me. Or I could just use 1 inch for the aft >fittings and 2 inch for the front. > >________________________________ >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Micheal Mims >Just Plane Nutts >mailto:mimsmand@ix.netcom.com > >http://www.netcom.com/~mimsmand > > Micheal - I had no problem getting them sheared at a local fab shop from some scrap 4130 they had. It took me about 20 hours to build them. You'll need a good scribe, center punch and drill press. Mine are built according to plans and I was suprised at the weight of these things. Austin Clark Pascagoula, Mississippi ------------------------------ Date: Tue, 24 Jun 1997 19:47:06 -0700 From: Micheal Mims Subject: Re: KR: Hinge Material At 10:05 PM 6/24/97 -0700, you wrote: The piano hing as mounted on the ailoron allows approx 30 deg. movement 20 deg. up 10 deg. down the hinge pin is located on the up side could that be problems for the stabalizers. > The eye bolts per Wicks page 178 are $4.31 each, the cost vs alum is >slightly higher.................. Yes I think a steel elevator hron would have to be welded up to use along with the piano hinge. It would be simple enough to build but then you would also need to use a cable/push rod setup like I have installed. One change leads to another in this case! As far as the piano hinge only allowing 10 and 20 degrees deflection, you would have to mount it and the elevator main spar to allow the required amount. _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 19:56:09 -0700 From: Micheal Mims Subject: Re: KR: A stable design -Tail vol At 09:31 PM 6/24/97, you wrote: >He offers a table of eleven horizontal tail volume coefficients. >If I exclude the two outliers, the remaining aircraft are in the range >.371 to .580 ( median .412, mean .445 ) > >Ed, or anyone else: I don't have the plans: can you tell me >the horizontal tail vol coefficient for the KR2 and KR2S please? > I cant find my spreadsheet right now but I think a KR2 came out to something like .26 and a 2S was .3 something. _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 22:13:31 -0500 From: "Mark Langford" Subject: Re: KR: A stable design -Tail vol Michael Mims wrote: > I cant find my spreadsheet right now but I think a KR2 came out to something > like .26 and a 2S was .3 something. Can't find where I figured that either (and it's bedtime), but I got .2 something for the S, if I'm not mistaken. Either way, it's WAY out of the ballpark, and certainly tells us something... Mark Langford, Huntsville, AL email at langford@hiwaay.net KR2S construction page at http://fly.hiwaay.net/~langford ------------------------------ Date: Tue, 24 Jun 1997 20:55:37 -0700 From: Micheal Mims Subject: Re: KR: A stable design -Tail vol At 10:13 PM 6/24/97 -0500, you wrote: >Michael Mims wrote: > >> I cant find my spreadsheet right now but I think a KR2 came out to >something >> like .26 and a 2S was .3 something. > >Can't find where I figured that either (and it's bedtime), but I got .2 >something for the S, if I'm not mistaken. Either way, it's WAY out of the >ballpark, and certainly tells us something... Yep its around .26 for the KR2 and .31 for the 2S. These are generous figures, because I did not calculate the true area of the horizontal but rather multiplied the span by the average chord. If I can remember the horizontal area of the KR2 was somewhere around 8 feet and the 2S was a little over 9. They both need to be in the 12 square foot range to be considered acceptable in general aircraft design. Me and Mark Langford and a few others hashed this out about a year ago. This is the reason we both nag about the fuselage needing to be longer or the horizontal area increased or both! Interesting enough if you add 14 more inches to the KR2S and leave the horizontal area as plans you would fall in around .42! Just where it should be! _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts in Irvine Ca. mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Tue, 24 Jun 1997 21:25:57 -0700 From: MARVIN MCCOY Subject: Re: KR: Source for .5 inch 4130 strap Micheal Mims wrote: > > Has anyone found a source for the 1/2 inch 4130 strap used to make the aft > wing attach fittings? I may locate a metal shop with a hydraulic floor shear > and see if they will cut some for me. Or I could just use 1 inch for the aft > fittings and 2 inch for the front. > > ________________________________ > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Micheal Mims > Just Plane Nutts > mailto:mimsmand@ix.netcom.com > > http://www.netcom.com/~mimsmand - ------ I couldn't find any .5 inch either. so I cut the 1.5 inch down to .5 inch on my band saw and cleaned it up on the grinder and belt sander. It takes a good blade but it cut pretty easy. If you can find a shop with a large enough piece they can cut it on a shear. But they can NOT shear it from 1.5 inch stock. Marvin McCoy Seattle, WA. North end of Boeing Field. Mr.Marvin@worldnet.att.net - ------------ ------------------------------ Date: Wed, 25 Jun 1997 01:19:37 -0400 (EDT) From: TANDEM2@aol.com Subject: Re: KR: Formula V Crash so what is the address to the coolest web on earth? ------------------------------ Date: Wed, 25 Jun 1997 02:06:38 -0400 (EDT) From: LVav8r@aol.com Subject: Re: KR: KR longitudinal stability In a message dated 97-06-25 00:42:30 EDT, you write: << smithr wrote: > > Micheal Mims wrote: > The elevator control is just simply too light! Here are some > > of the changes I have made to hopefully help sensitivity and stability: > > > > 1) Increase horizontal span 5 inches (2.5 each side) > > 2) Tapered horizontal to a 1 inch airfoil section rather than 1/2 inch sq. > > 3) Drilled cable attach holes one inch closer to center on elevator belcrank > > 4) Will only use 15 to 30% of airfoil for CG range > > 5) Considering adding strakes after more research on their effectiveness per > > square foot. (its not a 1 for 1 trade from what I understand) > > > > On above point #3: This sounds good for increasing stick force > (desirable) but in physics you don't get something for nothing. It will > also yield more degrees of elevator deflection per inch of stick > movement. This might not be good if you are trying to reduce pitchiness. > The KR needs both more stick force and (slightly) more stick movement > per deg of elevator deflection. I don't know what will give both. > Possibly a non-linear cam. > > Bob Smith, Albany, NY Hi Bob, After digesting all the information available as to kr2 sensetivity pitch and bank control I'v come to the conclusion that stops will have to be installed to prevent over controling of the ailerons and vertical stab.. The horizontal stab. control should be desensitized by allowing more stick travel. I plan to tame my kr2 by adding 2' shoulders back, adding 6" @ the enjine mount, 40" wide inside at the shoulders, 2' to the main spars allowing 1' more for each flap. Thank you for your opinion. Gene Gargasz Elyria Ohio >> I have only limited experience flying homebuilts. The total time I have logged is 1.8 hours and only in an RV-6A. That experience led me to believe that stick force may be what most people are referring to when they talk about sensitivity or longitudinal stability. The RV required very little stick movement in either roll or pitch to accomplish the desired change in attitude. The stick force however made it no problem to limit the controll input. Does anyone on the list have any experience flying both the RV and the KR to make a more objective observation on this? An engineer friend of Jeanette Rand at S&F this year mentioned the stick force problem and suggested a spring system to add it to the elevator controlls. I later flew the RV and felt that without the level of stick force it had, that it would be very easy to over-controll it also. I plan to fly my KR-2S first without any added stick force to see what is the situation and then if necessary add the spring system, unless someone with first hand experience can convince me otherwise. So far that has yet to happen. A longer stick would also help. I am still satisfied with my decision to build the KR-2S. I hope to get the chance to fly a couple of KR's at the gathering so that I can make a more educated observation on this matter. Although there is an abundance of excellent information on this list I must aplogize for not taking everyones ideas as gospel. There seems to be a fair amount of speculation, and that is not necessesarily all bad. I just recomend that you take anything you read regardless of the source with a grain of salt. The people on this list that I put the most confidence in the accuracy of their posts are the people who are already flying. After all the FAA says that the pilot in command is the one who must determine that a flight is conducted safely. Tom Kilgore Las Vegas, NV LVav8r@aol.com KR-2S 2% complete Private Pilot w/instrument & 260 hrs TT ------------------------------ Date: Wed, 25 Jun 1997 01:00:05 -0700 From: David Moore Subject: Re: KR: Source for .5 inch 4130 strap Hey Mike, All I can say is good luck, I built a set of brackets from a sheet of 4130 what a pain, and when I was done I wasn't happy. So I bit the bullet and ordered them from RR. Dave Moore At 02:21 PM 06/24/1997 -0700, you wrote: >Has anyone found a source for the 1/2 inch 4130 strap used to make the aft >wing attach fittings? I may locate a metal shop with a hydraulic floor shear >and see if they will cut some for me. Or I could just use 1 inch for the aft >fittings and 2 inch for the front. > >________________________________ >~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >Micheal Mims >Just Plane Nutts >mailto:mimsmand@ix.netcom.com > >http://www.netcom.com/~mimsmand > > > David Moore Turnkey1@mscomm.com Hesperia, California ------------------------------ Date: Wed, 25 Jun 1997 06:18:34 -0500 From: Kerry Miller Subject: KR: Re: Coolest Aviation Web site... At 01:19 AM 6/25/97 -0400, you wrote: >so what is the address to the coolest web on earth? Sorry, guess I should have put it in the first message. Try this: http://rampages.onramp.net/~micheleb/ and click on the part about aviation. I'm warning you, it may take a while! Keep 'em Flying, Kerry "I own I am not a friend to a very energetic government. It is always oppressive. It places the governors indeed more at their ease, at the expense of the people..." Thomas Jefferson, in a letter to James Madison, 12/20/1787 Kerry Miller kmiller@flash.net http://www.flash.net/~kmiller WD5ABC ------------------------------ Date: Mon, 23 Jun 1997 12:46:35 -0700 From: Donald Reid Subject: Re: KR: KR longitudinal stability Micheal Mims wrote: > I think you would need to mount the springs so that if one broke both would > be disabled. I am sure this could be thought out, or you could set it up > to use the same spring for both up and down elevator, again something to be > thought out is the linkage but I am sure it can be done. > > I am not sure springs would give you the "feel" you would want though, but > then again maybe they would?!? Sport Aviation had an article on control system springs in 1996 (don't know the month) entitled "What's Up With Downsprings?", another in April 1996, and one on center stick vs side stick in Oct 1996. (I copy tech articles and save then in a file for easy reference) As I understand the articles, the springs will change the stick forces and make it easier to control. The same thing by be done by making what is sometimes called an anti-servo tab. This is a trim tab that works backwards from a regular trim tab. As the elevator is displaced, the anti-servo tab moves in the same direction, only more so. This gives a larger force feedback to your arm. I think the KR-100 is set up this way. I also think a Piper stabalator trim tab combines the trim tab and anti-servor tab functions with one tab. FAR23 airworthiness requirements (for certified A/C) say something about control system springs and potential failure. You have to be able to control the aircraft with a failed spring system. The mass balance should reduce the stick forces which will make the controls more sensative. More sensative means easier to overstress the aircraft, less sensative means more forearm strength to control. Pick a happy medium. - -- Don Reid donreid@erols.com ------------------------------ Date: 25 Jun 97 09:07:36 EDT From: "Driessen, Marcel" Subject: KR: AW: Source for .5 inch 4130 strap ---------- Von: 'MAIL@CSERVE ' Gesendet: Dienstag, 24. Juni 1997 17:22 An: Driessen; 'MAIL@CSERVE ' Betreff: KR: Source for .5 inch 4130 strap Sender: owner-krnet-l@teleport.com Received: from desiree.teleport.com (desiree.teleport.com [192.108.254.21]) by dub-img-6.compuserve.com (8.6.10/5.950515) id RAA03863; Tue, 24 Jun 1997 17:22:08 -0400 Received: from localhost (daemon@localhost) by desiree.teleport.com (8.8.5/8.7.3) with SMTP id OAA07588; Tue, 24 Jun 1997 14:21:53 -0700 (PDT) Received: by desiree.teleport.com (bulk_mailer v1.5); Tue, 24 Jun 1997 14:21:51 -0700 Received: (from daemon@localhost) by desiree.teleport.com (8.8.5/8.7.3) id OAA07546 for krnet-l-outgoing; Tue, 24 Jun 1997 14:21:48 -0700 (PDT) Received: from dfw-ix14.ix.netcom.com (dfw-ix14.ix.netcom.com [206.214.98.14]) by desiree.teleport.com (8.8.5/8.7.3) with ESMTP id OAA07528 for ; Tue, 24 Jun 1997 14:21:44 -0700 (PDT) Received: (from smap@localhost) by dfw-ix14.ix.netcom.com (8.8.4/8.8.4) id QAA15975 for ; Tue, 24 Jun 1997 16:21:37 -0500 (CDT) Received: from ppp-206-170-69-15.irvn11.pacbell.net(206.170.69.15) by dfw-ix14.ix.netcom.com via smap (V1.3) id sma014853; Tue Jun 24 16:19:02 1997 Message-Id: <2.2.32.19970624212144.0071b12c@popd.ix.netcom.com> X-Sender: mimsmand@popd.ix.netcom.com X-Mailer: Windows Eudora Pro Version 2.2 (32) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Tue, 24 Jun 1997 14:21:44 -0700 To: krnet-l@teleport.com From: Micheal Mims Subject: KR: Source for .5 inch 4130 strap Sender: owner-krnet-l@teleport.com Reply-To: krnet-l@teleport.com Has anyone found a source for the 1/2 inch 4130 strap used to make the aft wing attach fittings? I may locate a metal shop with a hydraulic floor shear and see if they will cut some for me. Or I could just use 1 inch for the aft fittings and 2 inch for the front. ________________________________ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand Mike, I was not able to find a source for the 1/2" strap #4130 either. People at a local metal shop were so kind to cut the straps (from a sheet) with their hydraulic floor shear. When I told the guys at the shop that those parts were for use on a homebuilt aeroplane they were very enthusiastic and I had to tell them everything about my project. The cutting has cost me $5 (donation for their annual party). Making the fittings by yourself will save you a lot of money (over $200 for the RR-fittings is a lot of those goodies !) and if you work accurate it will be of a good quality too My suggestion: make the first fitting and use this as a template for the other ones. This way if you make the template accurate then all the fittings will be identical. So just tell the guys at your local metal shop that you're building a real plane and they will do everything for you ! Good Luck. Marcel Driessen KR2S-Builder Meerlo, The Netherlands e-mail: driessen@krohne.mhs.compuserve.com ------------------------------ Date: Wed, 25 Jun 1997 08:39:19 -0500 From: "Johnny Galindo" Subject: KR: Night Flight??? I am about to purchase a KR-2 so I was looking at the FAR's and when I saw this, I started wondering what it means to me. what constitutes "otherwise specifically authorized by the Administrator" ?? Sec. 91.319 Aircraft having experimental certificates: Operating limitations. d) Each person operating an aircraft that has an experimental certificate shall-- (1) Advise each person carried of the experimental nature of the aircraft; (2) Operate under VFR, day only, unless otherwise specifically authorized by the Administrator; and (3) Notify the control tower of the experimental nature of the aircraft when operating the aircraft into or out of airports with operating control towers. (e) The Administrator may prescribe additional limitations that the Administrator considers necessary, including limitations on the persons that may be carried in the aircraft. John Galindo WK - (512)339-5394 HM - (512)869-6227 Pager ===== E-Mail to: 1167029@skymail.com or (800)Page-MCI pin 1167029 ------------------------------ Date: Wed, 25 Jun 1997 06:39:52 -0700 From: "John Bouyea" Subject: KR: Re: EAA Northwest Fly-in, Arlington, WA. I'm planning on going as well. I'd like to make it a day trip if we know WHICH day everyone is gathering @ the fire pit. Both Saturday & Sunday have been suggested; is there an agreement as which day will draw the greatest number of attendees? bou KR2S -just glued up the second fuse side... John/Johnna Bouyea johnbouyea@worldnet.att.net - ---------- From: DC4FREE@aol.com To: krnet-l@teleport.com Subject: KR: EAA Northwest Fly-in, Arlington, WA. Date: Sunday, June 22, 1997 7:55 PM KR dudes, Is anyone going to the EAA Northwest Fly-in, Arlington, WA. July 9 thru 12?? If you are going, how about we set up a time and place and all meet to exchange stories, pictures, lies and lay eyeballs on the people we’ll SOON be flying with. Any takers on Saturday, 0900 hrs. around the fire-pit outside the cafe by the Ultralight hangers? Don Wright Everett, WA DC4FREE@AOL.COM - ---------- ------------------------------ Date: Wed, 25 Jun 1997 08:34:28 -0700 From: Ted & Louisa Jones Subject: Re: KR: KR longitudinal stability Donald Reid wrote: > > Micheal Mims wrote: > > I think you would need to mount the springs so that if one broke both would > > be disabled. I am sure this could be thought out, or you could set it up > > to use the same spring for both up and down elevator, again something to be > > thought out is the linkage but I am sure it can be done. > > > > I am not sure springs would give you the "feel" you would want though, but > > then again maybe they would?!? > > Sport Aviation had an article on control system springs in 1996 (don't know > the month) entitled "What's Up With Downsprings?", another in April 1996, > and one on center stick vs side stick in Oct 1996. (I copy tech articles > and save then in a file for easy reference) > > As I understand the articles, the springs will change the stick forces and > make it easier to control. The same thing by be done by making what is > sometimes called an anti-servo tab. This is a trim tab that works backwards > from a regular trim tab. As the elevator is displaced, the anti-servo tab > moves in the same direction, only more so. This gives a larger force > feedback to your arm. I think the KR-100 is set up this way. I also think > a Piper stabalator trim tab combines the trim tab and anti-servor tab > functions with one tab. > > FAR23 airworthiness requirements (for certified A/C) say something about > control system springs and potential failure. You have to be able to > control the aircraft with a failed spring system. > > The mass balance should reduce the stick forces which will make the controls > more sensative. More sensative means easier to overstress the aircraft, > less sensative means more forearm strength to control. Pick a happy medium. > -- > Don Reid > donreid@erols.com Don, please help me out here: I have been under the impression that mass balance in a control surface was used to inhibit flutter by adding weight forward of the hinge to equalize the weight of the control surface forward and aft of the hinge -- or approach equal weights. I had a flutter problem with a leading edge device I patented for sailboats, and the mass balance I added forward of the pivot point solved the problem like magic. As such, the weight is contained out of the airstream or is streamlined to minimize aerodynamic input -- as on the elevator of the P-38, for example (I used to wonder what function those streamlined do-hickies performed). If my assumption is correct, the effect of mass balancing would have no affect on sensativity -- or minimal affect. However, if surface area of an elevator, for example, is added forward of the hinge line, this would most decidedly lighten the load in the control system while having a minimal affect on flutter unless that portion forward also incorporated weights to improve mass balance. What am I missing? Ted Jones ------------------------------ End of krnet-l-digest V1 #49 ****************************