From: owner-krnet-l-digest@lists.teleport.com (krnet-l-digest) To: krnet-l-digest@lists.teleport.com Subject: krnet-l-digest V1 #21 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 Saturday, May 24 1997 Volume 01 : Number 021 ---------------------------------------------------------------------- Date: Wed, 21 May 1997 23:02:24 -0400 From: Carlos Sa Subject: RE: KR: VW Revs and Props Paul, thanks for the correction. My formula should read Vt = SQRT (Vf**2 + (2 * 3.14159 * R * f)**2) Where Vt, Vf = metres/second R = metres f = rotations per second Carlos - ---------- > Hello, Vince > > I think you have to do a vector sum: > > Vt = SQRT (Vf + Vr) CARLOS! - You're close. Vt = SQRT (Vf^2 + Vr^2) I did the same thing and got: Vt = SQRT[(DIA*pi/(12*5280)*RPM*60)^2 + Vf^2] Where: Vt = mph (tip) DIA = in (prop dia) pi = 3.14159 Vf = mph (plane) ------------------------------ Date: Wed, 21 May 1997 23:22:16 EDT From: jscott.pilot@juno.com (Jeffrey E. Scott) Subject: Re: KR: Fuel Tank CofG On Wed, 21 May 1997 18:05:33 -0400 (EDT) JEHayward@aol.com writes: >In a message dated 97-05-18 20:53:08 EDT, you write: > ><< The ideal may be tanks in the leading edge of the outboard wing where at > least the fuel would be "out there" in a crash and on the CofG anyway > (the RV's have this arrangement). I wonder if anyone has put their fuel > in the leading edge? > > I am trying to design a suitable LE wing tank at the moment, any > suggestions will be welcome. >> > > Seems like there was a fellow at the '93 KR fly-in that had a length of 5" >PVC pipe installed along the outer wing spars (I think). He claimed 4gallons per pipe length. >I don't know who it was or how it worked out. > >Jim Hayward > Seems to me that the Grumman Yankee and others of that line used a tubular spar that was hollow and acted as the fuel cells as well. I don't know how PVC reacts with fuel, but a tubular tank either in front or behind the main spar would probably work well. The RV series of aircraft use a leading edge "D" section fuel tank. It should actually be easier to build from glass than from aluminum as in the RVs. Take a look at a local RV builder's plans and/or plane and you'll see a well designed LE fuel cell. In the Diehl wing skin builders instructions, there are plans for building a 7.5 gallon tank that goes from the font spar aft 7 inches and goes from the outer end of the attach fittings to the middle rib of the wing. - ---- Jeffrey Scott jscott.pilot@juno.com See construction of KR-2S N1213W at http://fly.hiwaay.net/~langford/kjeffs.html - ---- ------------------------------ Date: Wed, 21 May 1997 21:25:20 -0600 From: Nick Davidson Subject: KR: RE: Limbach Hi Well the Limbach is German certified ( JAR Part 22 ) and as far as I = know they never persued certification in the US. I have been told that = Australia recognizes JAR Part 22. The last known addresses are listed below. However I have not seen any = advertisements in the rags in many years. I expect the German address = is good. These addresses came from a brochure dated 1993. Limbach Flugmotoren GmbH & Co. Kotthausener Strasse 5 D-5330 Konigswinter 21 Sassenberg, Germany Telephone ( from USA) 011-49-2244-2322 TeleFAX ( from USA) 011-49-2244-6976 ( Parts and Service ) B & B Aviation Attn: R.V. Bud Upton Sand Ridge Airpark 13805 North 152nd East Avenue Collinsville, Oklahoma 74021=20 Telephone 918/372-3528 Fax 918-371-3528 (Marketing and Admin.) Limbach Aircraft Engines USA ATTN: JC Treager c/o 3114 North Sunset Avenue Sand Springs, Oklahoma 74063 Telephone 918-241-5468 Fax 918-245-6910 If you try any of these I would be grateful to hear one way or the other = if you made contact. I bought my L2000EA in 1987 from JC Treager but = have not talked to him since. FYI ... The engine came with engine shop manuals, engine installation = manuel...similar to a firewall forward install instructions, carbureator = oil, spanners ( wrenches ) screw-drivers, and test data from the 10 hour = break in on a dyno. Good luck. Nick - ---------- From: smithr[SMTP:smithr@wadsworth.org] Sent: Tuesday, May 20, 1997 9:56 AM To: krnet-l@teleport.com Subject: KR: Limbach I've been trying to find out about how Limbach has modified the VW to=20 get it certified. Does anyone have any info. on this or a US or=20 European contact address (email, phone or other) for Limbach. I assume=20 Limbach is still in business. Bob Smith ------------------------------ Date: Thu, 22 May 1997 01:14:18 -0400 (EDT) From: MikeTnyc@aol.com Subject: Re: KR: Re: Re: VW Revs and Props >> 2. Don't just consider the still air speed when you're looking at tip >> speed. Your aircraft is moving at considerable speed at max power (you have >> to consider the worst case) and that airspeed is a factor in tip speed as >> well. > > Anyone got a formula for that? * * * > If anyone knows of an equation, send it over! I realize you guys >probably really don't care, but I find it interesting just to look at >the outcome. All I know is that next time I'm cleared for takeoff, I'm gonna check the rpm when I firewall the throttle on the runway and check it again when I'm cruising at full power. Presumably the percentage increase at a given airspeed would be similar to that of other planes at the same airspeed. Of course, the 152's I fly can't cruise anywhere near a KR's speed, but I'll ask other people with faster planes and maybe we can get some data. Mike Taglieri ------------------------------ Date: Thu, 22 May 1997 01:14:16 -0400 (EDT) From: MikeTnyc@aol.com Subject: Re: KR: Re: VW Revs and Props >> So why aren't larger props being used? 52" may have been the limit for >> the retract gear, but I would think a larger one would be desirable on the >> fixed gear without coming dangerously close to the ground. >> >> Mike Taglieri My guess would be ground clearance. The retract gear is a >bit short. I just lifted the >tail up a bit in the driveway and scratched my new prop... . Yeah, that's what I meant. Very few people building KR's now are using the retract gear, and maybe this is why. However, I would think if you build with the fixed gear, you could go to a bigger prop and still have at least as much clearance as the 52" prop gives you with the retract gear. The bigger prop would be more efficient and maybe be able to windmill if the engine dies, so it would be safer to fly without a starter. Mike Taglieri ------------------------------ Date: Thu, 22 May 1997 06:37:29 -0700 From: Tom Crawford Subject: Re: KR: Re: VW Revs and Props MikeTnyc@aol.com wrote: > > >> So why aren't larger props being used? 52" may have been the limit for > >> the retract gear, but I would think a larger one would be desirable on the > >> fixed gear without coming dangerously close to the ground. > >> > >> Mike Taglieri My guess would be ground clearance. The retract gear is a > >bit short. I just lifted the > >tail up a bit in the driveway and scratched my new prop... . > > Yeah, that's what I meant. Very few people building KR's now are using the > retract gear, and maybe this is why. However, I would think if you build > with the fixed gear, you could go to a bigger prop and still have at least as > much clearance as the 52" prop gives you with the retract gear. The bigger > prop would be more efficient and maybe be able to windmill if the engine > dies, so it would be safer to fly without a starter. > > Mike Taglieri Mike, I just got my prop from Ed Sterba. He recommended a 54" diameter prop for a KR with the Diehl tri-gear. Tom Crawford KR2 N262TC Spraying Imron today #:) ------------------------------ Date: Thu, 22 May 1997 07:05:51 -0600 (MDT) From: Ron Lee Subject: KR: Spraying Imron today!!! (No archive) >Mike, > >I just got my prop from Ed Sterba. He recommended a 54" diameter prop >for a KR with the Diehl tri-gear. > >Tom Crawford >KR2 N262TC > Spraying Imron today #:) ^^^^^^^^^^^^^^^^^^^^^^^^ Sounds like TWO KRs are about to leave the nest within the next few weeks! Ron Lee ------------------------------ Date: Thu, 22 May 1997 09:38:34 -0400 From: "Cary Honeywell" Subject: KR: Rear spar advice This is my first post here, so pardon the protocol errors if any. I am finishing a rebuild of a KR-2 initially built in 1977-78. It has seen better days. At some time in the past, an owner has managed to damage the rear spar ends at the wing mounting brackets. Perhaps a frantic attempt to put the wing on ended with the wing backets spearing the spar end and splitting same back into the attach bolt area. This is evident on both left and right sides, top/bottom on one, top on the other. My question: should I do a (12 to 1) angle splice as a repair as recommended by the local EAA types, or would it be easier just to try to pull the spar and replace it? Any suggestions,etc, would be welcome either here or email at cary@storm.ca Thanks. - - Cary Honeywell - KR-2 C-GJMW C-172 C-FRRB ------------------------------ Date: Thu, 22 May 1997 12:23:47 -0400 (EDT) From: Baleco@aol.com Subject: Re: KR: Rear spar advice In a message dated 97-05-22 10:47:12 EDT, you write: << My question: should I do a (12 to 1) angle splice as a repair as recommended by the local EAA types, or would it be easier just to try to pull the spar and replace it? >> Of coarse the clean way to fix this problem is replacement. While you can properly perform a splice, since you appear to be predisposed to replace the spar, why not go for that and be confident that it's up to design strength. There;'s nothing worse than flying an aircraft you don't have confidence in. Marty ------------------------------ Date: Thu, 22 May 1997 15:43:45 -0400 From: Vince Bozik Subject: Re: KR: VW Revs and Props(No Archive) Hey Guys, all of this "Turbo" talk has got me wondering what the heck it would cost. Do any of you have any good guesses? Say, for a VW or Soob? Thanks Vince - -- Vince Bozik - Athens, Georgia Mailto:ICBM@ix.netcom.com ------------------------------ Date: Thu, 22 May 1997 17:57:17 -0700 From: Ted & Louisa Jones Subject: Re: KR: coposite skins David Moore wrote: > > I don't believe dynel is offered anymore, that's why RR went to fiberglass. > I have a copy of the original plans, and yes they call for dynel. > > At 12:53 AM 05/16/1997 -0700, you wrote: > >In a book by Jack Wiley "WORKING WITH FIBERGLASS" it is stated; dynel > >acrylic reinforcing fabric weighs about 1/2 of fibreglass of the same > >thickness, has greater abration resistance, higher tensile strength, > >does not irritate the skin when handling, is easy to work with, easier > >to strech around sharp curves, provides a slick finish when sanded > >better adhesion to wood than fiberglass, polyester and epoxy resins may > >be used,the fabric is easy to wet out. Isn't that the fabric Rand used? > >any kr ditto heads know why glass is used instead of dynel? All > >responses or dialog of this matter is appreciated. > >thanks Gene Gargasz % dave@erienet.net > > > > > > David Moore > Hesperia,Calif. 92345 > Turnkey1@MSCOMM.COM This subject came up several months ago, but apparently my posting was missed. Dynel is available from Defender Industries. They also have an identical (they say) product called Xenol. I recently bought Dynel from Defender for a boat project. I'll try to find their catalog and put their address at the end of this message. Dynel is all the things which are claimed for it except it does not have higher tensile strength than equal size fiberglass cloth, but it does have highly superior abrasion resistance. I believe it does not have as good peal strength, especially with polyester. Dynel is difficult to sand, because of its abrasion resistance. Unless the laminate is carefully wetted out and squeeged down tight and smooth, the weight saving will probably be negated by having to fill the weave with micro or bondo to get a smooth finish. We take advantage of the fuzziness of a Dynel surface to provide non-skid surfaces for decks. (There may be a joke lurking here about fuzzy under-wings.) Aside from the difficulty of obtaining a glassy smooth surface, Dynel is a joy to work with, draping and wetting out very easily. Sorry, my Defender catalog is in the office. I will try to remember to post it tomorrow. Meanwhile, if you can't wait, they are located in central Connecticut south of Hartford (formerly in New Rochelle, New York) and for $.50 you should be able to obtain their phone number from Information. Defender is the marine equilivant of Aircraft Spruce & Specialty Company. The first half-dozen-or-so pages of their catalog has stuff applicable to KR building. The rest is boat hardware, life jackets, etc. It might be interesting to compare their prices, but boat stuff is expensive, too. Hasta manana, Ted Jones ------------------------------ Date: Thu, 22 May 1997 17:15:08 -0700 From: R Covington Subject: Re: KR: Rear spar advice >In a message dated 97-05-22 10:47:12 EDT, you write: > ><< My question: should I do a (12 to 1) angle splice as a repair as > recommended by the local EAA types, or would it be easier just to try to > pull the spar and replace it? >> > > Of coarse the clean way to fix this problem is >replacement. While you can properly perform a splice, since you appear to be >predisposed to replace the spar, why not go for that and be confident that >it's up to design strength. There;'s nothing worse than flying an aircraft >you don't have confidence in. > > > Marty Plus, the rear spars aren't as expensive spruce-wise as the mains.Personally, I am paranoid enough about the normal quality attach points and would probably replace the spar. However, the rear spar is more for torsional strength (so I have read). In that case I don't think your wing would be in danger of falling off on you if you went the repair route. I think you should replace the spar though if there is any doubt in your mind about the quality of going the repair route. It shouldn't cost all that much in time or wood. Robert Covington (who hasn't replaced a spar, or built one by the way yet.Next month!) ------------------------------ Date: Thu, 22 May 1997 23:39:00 EDT From: jscott.pilot@juno.com (Jeffrey E. Scott) Subject: KR: Re: VW Revs and Props > >Tom Crawford >KR2 N262TC >Spraying Imron today #:) ^^^^^^^^^^^^^^^^^^^^^^^ Congratulations Tom! The paint will sure make it look sharp. Just shot mine on Monday. - ---- Jeffrey Scott jscott.pilot@juno.com See construction of KR-2S N1213W at http://fly.hiwaay.net/~langford/kjeffs.html - ---- ------------------------------ Date: Thu, 22 May 1997 22:34:57 -0700 From: Micheal Mims Subject: KR: Propeller RPM There seem to be a concern that we should add a vector of the relative speed of the aircraft to the propeller speed to find our maximum RPM and stay sub sonic. On the aircraft I ran through my spreadsheet I did not figure in the relative airspeed just the prop speed in still air. So I guess what I am trying to say is, the maximum rpm of these production aircraft put the prop tips in the 700+mph range in still air. Does this mean that Piper, Cessna and other manufactures don't figure in the relative speed of the aircraft? and if not, why are we? Is this another excuse to be conservative with our rpm? Sometimes I get the feeling we really over analyze here on the net! :-) _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Thu, 22 May 1997 23:02:48 -0700 From: Micheal Mims Subject: KR: New Soobs Just checked out the Subaru web ( http://www.subaru.com/ ) site to get hp figures on the new engines. They have the following information listed for each engine: Horizontally opposed 4-cylinder, die-cast aluminum-alloy block, and aluminum-alloy heads 16-valve with automatic cam belt tensioner. 1.8 liters (111 cu in) SOHC 115 hp @ 5600 rpm 120 lb-ft @ 4000 rpm 2.2 liters (136 cu in) SOHC 137 hp @ 5400 rpm 145 lb-ft @ 4000 rpm 2.5 liters (150 cu in) DOHC 165 hp @ 5600 rpm 162 lb-ft @ 4000 rpm Horizontally opposed 6-cylinder, die-cast aluminum-alloy block, and aluminum-alloy heads 24-valve dual overhead cam 3.3 liters (202.5 cu. in.) (DOHC) 230 hp @ 5400 rpm, 228 lbs-ft torque @ 4400 rpm Is the 1.8 liter engine of 115 hp the E-82? Or has the engines changed since the E-series? _______________________ ~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Just Plane Nutts mailto:mimsmand@ix.netcom.com http://www.netcom.com/~mimsmand ------------------------------ Date: Fri, 23 May 1997 09:12:50 -0500 From: Paul Eberhardt Subject: Re: KR: VW Revs and Props(No Archive) I bought my soob from Mt. Tech in Oregon. I had originaly ordered a non-turbo with turbo heads and fi. I then changed my mind, and had him throw in a turbo and all related plumbing. He charged me an extra $200. I think he would do the same for $300 for someone who wasn't buying an engine. Talk to Brian 503-650-3686. I have changed my mind on the factory fi, so if someone needs it, make an offer. Paul Eberhardt Vince Bozik wrote: > > Hey Guys, all of this "Turbo" talk has got me wondering what the heck it > would cost. Do any of you have any good guesses? Say, for a VW or Soob? > > Thanks > > Vince > -- > Vince Bozik - Athens, Georgia > Mailto:ICBM@ix.netcom.com ------------------------------ Date: Fri, 23 May 1997 10:43:11 CDT From: "Rex Ellington" Subject: KR: Subaru engines G"Day 1. Many of you seem to know the whole story regarding Subaru engines. I have a question for a close friend. Which engine is in the 1977, yes 77, Subaru Brat?? The reason is this. The engine in this particular unit will run on the well-casing head expansion tank raw gasoline, just like the old Model A, and straight fours we ran in the oil patch on this stuff in the 40-50s. I'm thinking we may need to find a replacement for the one in the Brat. The casing head gas is probably only 70 octane and will diesel when a hot engine is shut down unless you stall it with the clutch. However, the cost of casing head is zero, zip, and it doesn't make sense to buy unleaded regular to run around the lease. 2. I never intended the junk following my name on my e-mails would go on forever. Whoever has the active keyboard, please delete it. My best address is I will spend the long weekend installing a new coil in one of the Eismann mags, along with a blast tube in the engine baffle to keep it cooler, on my T-Craft and a non-TSO'd vertical card compass to augment the whiskey compass that just doesn't like all the bouncing around. 3. Now that the spring semester is over, and I am getting my student's thesis cleaned up, and I am getting Chapter 7 of my management book straightened out, and the final research proposal for the spring is out of the way, I will get back to putting my little bit into the plans review that Mark is doing. 4. I am one engineer who is a crank about good English. People all over the world write better English than the kids I encounter around this campus. I must hold my tongue (i.e., keyboard fingers) or I would be fussing about the things I see in the e-mail. Good English may not get you a new job or advancement, but bad English can damned well keep you from getting it. Rex Ellington ellingto@gslan.offsys.uok.edu/spp/ Rex T. Ellington Science & Public Policy Program Energy Center, 100 E. Boyd Normal OK 73019 ellingto@gslan.offsys.uoknor.edu www.uoknor.edu/spp/ Scroll down to Faculty Associates ------------------------------ Date: Fri, 23 May 1997 09:51:24 -0700 From: Peter Hudson Subject: Re: KR: Retracts removal Dennis Ambrose wrote: > > Hi: > > I'm about to undetake the task of removing the retracts on my newly >aquired KR2. I know that some of you guys have done this, and I was >wondering if someone with this experience would e-mail me directly so >we could discuss the details!! Dennis, I bought my KR kit partially completed. It was in th eboat stage with the retracts installed. It wasn't hard to remove them without a wing center section to get in the way. If your KR is complete you'll have to disassemble down to the springbar and slide it out the end of the wing center section(at least that's my guess) After removal I patched the holes in the fuselage side with a plywood triangular patch nestled between the spar and the diagonal brace there. I then filled the triangular area with PU foam and added a second skin as a doubler over the area. It was probably a little over-kill but since it's right at the main spar so I wanted to be sure. I had to chisle away the original 3 wedges for the main gear mounts. I then plugged the bolt holes through the spar with dowels and added a doubler (with lightning cut outs) to cover the area. I now have the Rand-Robinson spring bar the 3 cast gear fittings installed. I have some pictures and I'm planning to set up a web page for them which will make it more clear. If I were doing it again I'd look at the Dheil gear. good luck - -Peter- ------------------------------ Date: Fri, 23 May 1997 10:06:06 -0700 From: Peter Hudson Subject: KR: Structure Donald Reid wrote: > > There has been a long thread recently conserning wing tanks, wing skin > air loading, spar loading, and related topics. I am an engineer and > have studied aircraft design for a long time and it is difficult to > respond to all of the questions and comments... I too am an aircraft structural engineer type. I've been considering a series of articles for KRonline which at least spell out some basic loads for the KR as we build them (500 lb+ with 1000 lb gross etc.) It wouldn't be a doctrine for modification but more of a look at where there are some margins for change and what should be left alone. I'd love to have someone check my work before publishing any mistakes. > For anyone that is interested, get a book called "Modern Aircraft > Design" by Martin Hollmann... > Don Reid > donreid@erols.com Another excellant text (my favorite in fact) is "Design of Light Aircraft" by Richard Hiscocks ISBN 0-9699809-0-6. I think it's available through wicks or aircraft spruce or from Murphy Aircraft Mfg ltd. Unit #1- 8155 Aitken Rd. Chilliwack, British Columbia, Canada V6G 1Z3 Armed with only this book and a calculator, a novice could analyze everything from the motormount loads to the gust loads on the tail. - -Peter- ------------------------------ Date: Fri, 23 May 1997 13:02:34 -0500 (CDT) From: larry flesner Subject: Re: KR: Fuel Tank CofG >In the Diehl wing skin builders instructions, there are plans for >building a 7.5 gallon tank that goes from the font spar aft 7 inches and >goes from the outer end of the attach fittings to the middle rib of the >wing. > >---- >Jeffrey Scott jscott.pilot@juno.com >See construction of KR-2S N1213W at >http://fly.hiwaay.net/~langford/kjeffs.html >---- > I placed all my fuel in the wings. I built a tank that starts at the inboard end of the outer forward spar and goes all the way to the tip(standard spar). I placed a piece of 1/2 inch foam on the backside of the forward spar and from that point the tank goes 10 inches to the rear. It measured 5.5 inches deep next to the spar and 3.5 inches at the rear(accounting for foam top and bottom). As I recall, the length was 77 inches (I'm going from memory here) so my numbers were something like this 77 x 10 x 4.5(average depth) = 3465 cu. in. Measuring a gallon gas container I determined one gallon to be 264 cu. inches. 3465 / 264 = 13.1 gallon. Accounting for the 3 two inch ribs I should have about 12.5 gallon per tank. I think that when I did my original figures I accounted for the rib loss and my numbers showed 12.5 gallon. I chose wing tank because I didn't like the thought of all that fuel in the fuselage. My tanks are very near the c.g. so I should get very little shift with fuel burnoff and what shift I do get will be forward. I say put your fuel wherever and in whatever you are comfortable with. Just make sure you allow for any changes in your c.g. and do an empty and full weight and balance. Also understand how burnoff will shift your c.g. and fly accordingly. I doubt if any of us are breaking new ground!! It's all been done before. You will paint the word EXPERIMENTAL the same size reguardless how you build it. MAN, AIN'T THIS COUNTRY GREAT!!!!!!! Larry Flesner larryfle@midwest.net P.S. This is not an endorsement to do something stupid like use your blow-up doll passenger for a fuel cell!!! Saaaay, I wonder what kind of range I could get with a Dolly Parton look-a-like!!!!! Probably too much c.g. shift there to be workable. Oh well........... ------------------------------ Date: Fri, 23 May 1997 13:16:22 -0500 From: inet@intellisys.net (brian whatcott) Subject: Re: KR: Fuel Tank CofG At 01:02 PM 5/23/97, Larry Flesner wrote >P.S. This is not an endorsement to do something stupid like use your >blow-up doll passenger for a fuel cell!!! Saaaay, I wonder what >kind of range I could get with a Dolly Parton look-a-like!!!!! >Probably too much c.g. shift there to be workable. Oh well........... > If the water bed mattress is the long-distance drug-smuggler's friend, whose friend is the inflatable Dolly Parton? Regards brian whatcott Altus OK ------------------------------ Date: Fri, 23 May 1997 18:58:00 -0400 (EDT) From: JEHayward@aol.com Subject: KR: Horizontal Stab Ribs While making the ribs for the horizontal stabalizer this afternoon ala Mark Langford's article in the KR Newsletter, I tried transferring the rounded elevator leading edge with a compass from the drawing to the plywood. I found the lower half of the horizontal stabalizer drawing to be off by 1/16" (chord-wise) thicker referenced to the drawn center line. It's off about the center 70 to 80 percent of the drawing. I elected to just "cut down" that portion (by whatever it was off) parallel to the chord. I used a ruler to check equi-distantly from the centerline on the upper and lower halves and marked the lower accordingly and trimmed my rib pieces to match. My question is: should I have done this or increased the "thinner" (upper) half to match the side that was "thicker" (lower). My concern is that left like this, my spar will be 1/16" thinner" (top to bottom) with a resultant lower strength. I know it's not much but my experience doesn't allow much of an educated guess. I'd like to redraw the rib but don't know how they get the airfoil shape with it's constantly changing radius. Anyone run into this before or am I concerned over nothing??? Jim Hayward ------------------------------ Date: Sat, 24 May 1997 02:49:24 -0400 (EDT) From: MikeTnyc@aol.com Subject: KR: Re: Rand fixed gear versus Diehl gear >I now have the >Rand-Robinson spring bar the 3 cast gear fittings installed. > >I have some pictures and I'm planning to set up a web page for them >which will make it more clear. If I were doing it again I'd look at the >Dheil gear. I've never seen any comment here on the relative merits of the Rand Robinson fixed gear versus the Diehl gear, though most people seem to be using the Diehl. Has anybody checked into both of them? Mike Taglieri ------------------------------ Date: Sat, 24 May 1997 07:32:06 -0600 (MDT) From: Ron Lee Subject: KR: Re: Rand fixed gear versus Diehl gear (no archive) At 02:49 97/5/24 -0400, you wrote: >>I now have the >>Rand-Robinson spring bar the 3 cast gear fittings installed. >> >>I have some pictures and I'm planning to set up a web page for them >>which will make it more clear. If I were doing it again I'd look at the >>Dheil gear. > >I've never seen any comment here on the relative merits of the Rand Robinson >fixed gear versus the Diehl gear, though most people seem to be using the >Diehl. Has anybody checked into both of them? > >Mike Taglieri > I will posit an uninformed guess just to see if my knowledge of these two gear is close to accurate. The Rand system has a single piece of material (fiberglass?) that probably attaches to the bottom of the spar. As such, the horizontal piece "may" be a source of drag if it is outside the bottom skin. The Diehl Gear attaches to metal plates that are on the front (and rear?) of the main spar. I suspect that the Diehl gear also places the main wheels in a more forward location which is good in the taildragger configuration. Ron "I am just guessing" Lee No archive since I do not consider this response authoritative!@ ------------------------------ Date: Sat, 24 May 1997 07:32:14 -0600 (MDT) From: Ron Lee Subject: KR: Re: Rand fixed gear versus Diehl gear (no archive) At 02:49 97/5/24 -0400, you wrote: >>I now have the >>Rand-Robinson spring bar the 3 cast gear fittings installed. >> >>I have some pictures and I'm planning to set up a web page for them >>which will make it more clear. If I were doing it again I'd look at the >>Dheil gear. > >I've never seen any comment here on the relative merits of the Rand Robinson >fixed gear versus the Diehl gear, though most people seem to be using the >Diehl. Has anybody checked into both of them? > >Mike Taglieri > I will posit an uninformed guess just to see if my knowledge of these two gear is close to accurate. The Rand system has a single piece of material (fiberglass?) that probably attaches to the bottom of the spar. As such, the horizontal piece "may" be a source of drag if it is outside the bottom skin. The Diehl Gear attaches to metal plates that are on the front (and rear?) of the main spar. I suspect that the Diehl gear also places the main wheels in a more forward location which is good in the taildragger configuration. Ron "I am just guessing" Lee No archive since I do not consider this response authoritative!@ ------------------------------ Date: Sun, 25 May 1997 00:18:18 +1000 From: ginnwj Subject: KR: Diehl Gear Can anyone tell me where the wheel axle of the Diehl main gear is located relative to the vertical front edge of the forward spar for the tailwheel and nosewheel versions? Thanks Bill Ginn Sydney Australia ------------------------------ Date: Sat, 24 May 1997 11:45:38 -0400 (EDT) From: EagleGator@aol.com Subject: Re: KR: Diehl Gear In a message dated 97-05-24 10:21:36 EDT, you write: << Can anyone tell me where the wheel axle of the Diehl main gear is located relative to the vertical front edge of the forward spar for the tailwheel and nosewheel versions? Thanks Bill Ginn Sydney Australia >> I just went out and measured mine (tail dragger) and the center of the gear leg where the axle will attach is 6 7/8 inches forward of the spar. The length of the leg is 24 inches, which is the dimension from the top of the spar to the axle if you are trying to calculate angles. The nose dragger gear actually mounts to the back of the spar and angles back. Be sure if you are going to use the Diehl gear you specify which configuration you are building, they are NOT interchangable. The Scotchply is cut differently. Cheers! Rick Junkin EagleGator @aol.com ------------------------------ Date: Sat, 24 May 1997 11:52:39 -0400 From: Carlos Sa Subject: KR: Prop tip speed I think that the A/C speed has little influence on the propeller tip speed: Assume the propeller tip speed is 700 MPH in still air. If the A/C speed is 150 MPH, the resultant tip speed is SQRT ( 700**2 + 150**2) = 715.89 MPH. This shows that the A/C speed adds 2% to the propeller tip speed (in this example)... Watcha think? Carlos - ---------- From: Micheal Mims[SMTP:mimsmand@ix.netcom.com] Sent: May 23, 1997 01:34 To: krnet-l@teleport.com Subject: KR: Propeller RPM There seem to be a concern that we should add a vector of the relative speed of the aircraft to the propeller speed to find our maximum RPM and stay sub sonic. On the aircraft I ran through my spreadsheet I did not figure in the relative airspeed just the prop speed in still air. So I guess what I am trying to say is, the maximum rpm of these production aircraft put the prop tips in the 700+mph range in still air. Does this mean that Piper, Cessna and other manufactures don't figure in the relative speed of the aircraft? and if not, why are we? Is this another excuse to be conservative with our rpm? Sometimes I get the feeling we really over analyze here on the net! :-) Micheal Mims ------------------------------ Date: Sat, 24 May 1997 11:53:03 -0400 (EDT) From: Baleco@aol.com Subject: Re: KR: Diehl Gear In a message dated 97-05-24 11:48:40 EDT, you write: << I just went out and measured mine (tail dragger) and the center of the gear leg where the axle will attach is 6 7/8 inches forward of the spar. The length of the leg is 24 inches, which is the dimension from the top of the spar to the axle if you are trying to calculate angles. >> Rick, Is your aircraft flying? The measurements you supplied are very valuable considering the lack of help from RR but it'd be reassuring to know that your aircraft is flying or how you arrived at the attach positions you are using. Thanks for taking the trouble to check this out. Marty ------------------------------ Date: Sat, 24 May 97 15:34:33 GMT From: mathewrz@iafrica.com (Rob Matthews) Subject: Fw: RE: Re: KR: inspection covers - -- Rob Matthews Have a nice day South Africa email mathewrz@iafrica.com - ----------------------------Forwarded Message-------------------------------- > Hi Rob > Hope you are keeping well. > Work has tapered off on the KR till after my exams in June > You can forward the following message to the KRnet. > > I wrote some time back when guys were talking about changing the tail and > main plane incidence . In that article, I suggested that someone try to > obtain a copy of the original design file of the KR2 because these changes > were now starting to address design critical factors. By the way if there is > one available I would like to purchase a copy. I was not very happy with the > stability factors of the KR2 and I have redesigned the empennage of the a/c. > I have not changed the RAF 48 wing and we are busy researching the original > test reports for this wing. > > As a proto she was fine and I agree that the a/c has potential for being > cheap, fast and a SAFE a/c, with a little more development. I speak here of > the kind of requirements particular in South Africa were such an aircraft > presently would cost in the region of 30 to 50% of annual disposable income. > > I am glade the issue of the safety belts have been raised, as I have been > pondering about installation of the belts especially with the "g" > requirements and consequently the strength of the attachments. > > I am also concerned about the "bowing" of the rear spar. If this thing is > bowing with a 150lb load, imagine how much bowing you are going to see with > 6g's. By the way my kit is an original from RR ie spruce all the way. > > I am not that familiar with the FAA's Advisory Circular No. 90-89A. but I > shall be conducting my flight test iaw the requirements for JAR > certification. Not that I intend to obtain the certification for the KR,but > to KNOW and have documented the performance and flight characteristics. > > For those interested, my KR2 is lengthened and stabs increased to improve > tail volumes. This in turn will improve the stability of the a/c. I will be > powering it with a direct drive Soob, fuel injected, turbo. > Prepared to address any questions on the work on my plane. > Email: steveb@aviation.denel.co.za > Steve in SA > > ---------- > From: SMTP1@K1 - Server@Servers[] > To: > Cc: > Subject: Fw: Re: KR: inspection covers > Date: Thursday, May 22, 1997 4:45PM > > > -- > Rob Matthews Have a nice day > South Africa > email mathewrz@iafrica.com > ----------------------------Forwarded Message-------------------------------- > > > Ross > > > > The KR has a lot of potential, it is a great shame that Ken Rand isn't > > around to continue the work he started. The plans describe a prototype, > > the plans themselves are prototype standard. The basic concept is still > > the best value for money, however the design needs some improvements, > > particularly with regard to the safety issue of stability. > > > > The seatbelt area also needs addressing as well as a number of other > > areas. However the stability is the most pressing problem and I wonder > > why someone in the aero business hasn't taken up the challenge. As far > > as I can see the first change is to increase the span of the stabilizer > > (which will require engineering work on the structural side). Somehow > > a safe CofG range has to be determined and a flight test is the best > > way to do this. I look forward to hearing from the fellow looking into > > a flight manual for the KR-2, particularly as he is basing it on the > > FAA's Advisory Circular No. 90-89A. > > > > I wonder if anyone has done a serious flight test of a KR-2 using > > 90-89A? > > > > Bill > > Ross Youngblood wrote: > > > > > > ginnwj wrote: > > > > > > > > Robert Lasecki wrote: > > > > > > > > > > I have been concerned since starting to build as to where to place > > > > > inspection covers. Last night I went through the entire set of > > wonderful > > > > > plans and instructions which were not included in the price of my > > "complete" > > > > > KR-2S kit. Nowhere in the documents does it say anything about > > providing > > > > > for any inspection access. I like the idea of clear covers as it > makes > > > > > inspections easier and allows each preflight to be more thorough. Any > > > > > further comments on inspection plates would be quite welcomed. > > > > > > > > These wonderful plans don't even show where to fit seatbelts, so don't > > > > expect details of fancy windows no matter how good an idea they are. > > > > > > > > Just about everything with the KR-2 is builder choice. In other words > > > > a poor set of plans. > > > > > > > > Bill > > > > > > Well, > > > Although I have to agree with you to an extent... you get what you pay > for > > > in a sense. I haven't priced the other VW or Soob based kits recently but > > > at the time the KR was the most economical (or so it seemed). I'd > recommend > > > a Glastar or somthing like this if you want all the details worked out... > > these > > > kits sound terrific... but they are $$$$. > > > > > > -- Ross > > > > > > -- > > > Ross Youngblood > > > KRNET-L administrator > > > mailto:rossy@teleport.com > > > http://www.teleport.com/~rossy/N541RY.htm > > > > > ------------------------------ Date: Sat, 24 May 97 15:35:15 GMT From: mathewrz@iafrica.com (Rob Matthews) Subject: Fw: RE: KR: Wing Design - -- Rob Matthews Have a nice day South Africa email mathewrz@iafrica.com - ----------------------------Forwarded Message-------------------------------- > Try > Darrol Stinton's The Design of the Aeroplane and Design for Flying by David > Thurston > Steveb in SA > ---------- > From: SMTP1@K1 - Server@Servers[] > To: > Cc: > Subject: Fw: KR: Wing Design > Date: Thursday, May 22, 1997 5:01PM > > > -- > Rob Matthews Have a nice day > South Africa > email mathewrz@iafrica.com > ----------------------------Forwarded Message-------------------------------- > > > There has been a long thread recently conserning wing tanks, wing skin > > air loading, spar loading, and related topics. I am an engineer and have > > studied aircraft design for a long time and it is difficult to respond to > > all of the questions and comments. Some are correct and some are partly > > correct, and some are opinions that aren't based on any physical reality. > > > > I don't want to try and preach to anyone, but if you don't know what you > > are doing in making a change to the design, then DON'T DO IT. A KR will > > work just fine as is. I am making a lot of changes, but I have studied > > the required engineering for years (and I still worry that I screwed > > something up). > > > > For anyone that is interested, get a book called "Modern Aircraft Design" > > by Martin Hollmann. Don't bother with Volume II, it isn't worth the > > price. This is not the best reference material, but it does cover a > > large variety of A/C design and should answer an lot of questions. (I > > have no financal interest in the book or publisher). For purchase info, > > check the reference section in the AS&S or Wicks catalogs. > > > > > > -- > > Don Reid > > donreid@erols.com > > > > > ------------------------------ End of krnet-l-digest V1 #21 ****************************