From: owner-krnet-l-digest@teleport.com[SMTP:owner-krnet-l-digest@teleport.com] Sent: Tuesday, January 13, 1998 7:52 PM To: krnet-l-digest@teleport.com Subject: krnet-l-digest V2 #12 krnet-l-digest Tuesday, January 13 1998 Volume 02 : Number 012 ---------------------------------------------------------------------- Date: Wed, 14 Jan 1998 01:26:17 +1000 (EST) From: Peter Leonard Subject: Re: KR: NLF Thoughts Since the talk started about the NLF airfoil section I have been wondering how much advantage would be gained by using this section Dons "thoughts" prompted me into doing some calculations myself. I must admit that I'm a bit sceptical about these newer sections and all the claims made about them. So I looked up the Cl/Cd plots for the RAF48 and NLF0115 and transfered the RAF48 plot onto the the NLF plot and straight away you can see the difference between the two curves. Below a Cl of 0.6 the NLF has a lower drag (approx. .002 lower) but above a Cl of 0.6 the RAF48 has lower drag by approx. .002 this is because of the drag bucket that is associated with laminer flow wing sections. Still not convinced that the NLF section would be that much better that the RAF48 I then did some calculations. Firstly I had to make some assumptions, first assumption was, 1. the aircraft would fly at 150mph (220fps) 2. the fuslage and wing were the same for both calculations 3. the wieght of the aircraft, I used 900lbs 4. I had to estimate drag values for the fuselage. The first calculation was to get the lift coefficent(Cl) Cl = weight/(.5*rho*S*fps^2) 900/(.5*.002378*70*220^2) = .22 rho = .002378(ISA conditions) S = wing area fps = feet per second Next the induced drag for the aircraft CDi = eff factor*(Cl^2*)/(pi*AR) 1.25*(.22^2)/(pi*6) = .0032 CDi = induced drag coefficient eff factor =1.25 pi = 3.14 AR = 6 Next the drag at 150mph for the RAF48 section drag = .5*rho*S*fps^2*(CDi+CDf+CDw) .5*.002378*70*220^2*(.0032+.009+.007) = 77lbs CDf = fuslage drag coefficient (assumed) CDw = wing drag coefficient (from Cl/Cd plot) Next the drag at 150mph for the NLF, as above, but we change one parameter the CDw to .005 all other factors remain the same. .5*.002378*70*220^2*(.0032+.009+.005) = 69lbs So we reduced our drag by 8lbs, so how much faster will this mean we can go. By rearanging the above formula so we get speed for 77lbs of drag. fps = sqr root(drag/(.5*rho*S*(CDi+CDf+CDw)) sqr root(77/(.5*.002378*70*(.0032+.009+.005)) = 232fps or 158mph So ok we may go a bit faster but I agree with Don in that there are quite a few other factors to consider. Before you go and change to the NLF section. The Reynolds number must be considered when comparing different sections eg. the Reynolds number for an aircraft with a 48in chord travelling at 150mph at sea level is approx. 5.6 million. Have a look at the NLF Cl/Cd plot and the better of the two Cl/Cd plots is for a Reynolds number of 9 million. Also to get these very low drag figures you must have a wave free surface on your wing with no dirt, bugs etc. Also consider with washout in the wing you are not going to achieve the maximum stated lift coefficient for the section it will be somewhat less for the whole wing. There may be some improvement to be made in the area of washout by doing some calculations using Anderson's formula out of Theory of Wing Sections??? I still believe the RAF48 would be the best all round wing section for the KR2. Peter Leonard PS. I would like read more thoughts like Don's below and someone please check my working above, I'm not infallible. At 08:36 PM 11/01/98 -0500, you wrote: >I had to work this weekend, but it was slow and I had a chance to do >some number crunching on the NLF(1)-0115 airfoil and I want to pass on >what I found. Some of it may be old news and some of it may have a bit >of sense in it. > >I took three airfoils and ran them through an airfoil analysis program >to calculate the lift, drag, and pitch moment data. I used the RAF48, >the NLF(1)-01115, and the NACA 747A315, the one I am using. I did this >so I would have a consistant basis for comparison. The results for the >747A315 agreed pretty well with the published data so I believe that the >comparison will be valid. > >The RAF has the highest lift coefficient and a gentle stall, but high >drag. > >The 747A315 has the lowest drag coefficient, but also the lowest lift >coefficient, so you have to increase wing area for a good landing >speed. It also has the most gentle stall of the three and the lowest >pitch coefficient. > >The NLF has a very good lift coefficient, a reasonable low drag >coefficient, but a very high pitch coefficient and an sharper stall. > > >Then I scaled the wing area, aspect ratio, and taper ratio so that the >plan form and the unflapped stall speeds were the same. Then I scaled >the horizontal stabilizer so that the volume coefficient were the same. >I did this by changing the stab. size, but not the length of the >fuselage. The idea was to model the same fuselage, with the different >wing and tail. > >I looked at design cases of 180mph and 90mph, with full forward and full >aft CG. In all three cases, the neutral stability point was between 34 >and 35 percent of the mean aerodynamic chord. > >What I found was that the wing drag for the 747 was about 5% lower than >the RAF, the 747 required the largest area of the three, since it has >the lowest lift coefficient. The NLF was about 20% lower than the RAF, >since the lift coefficient was almost the same, but the drag was so much >lower. When you add in the drag caused by the tail, the NLF looses some >of its advantage, but only about 5% (net about 15% over the RAF). This >is because the NLF has a much high pitch moment. That means that as the >speed increases, the airfoil wants to pitch nose down. In fact, the >downward tail force at 180mph was about 2.5 times higher on the NLF than >on either of the other two. Up to this point, there were no surprises. > >I did note two things that may be of interest. The NLF runs out of >laminar flow at a relatively low lift coefficient, on the order of >0.65. Since your Vx speed is generally at a lift coefficient of about >1.0, the NLF will have a significantly higher drag during climb. This >translates into a decreased rate of climb. The other thing that is >interesting, at least to me, is that if you size the horizontal >stabilizer for a realistic volume cofficient, at forward CG and high >speed, the tail will/can be well outside of its laminar flow region. In >other words, the elevator may need to work so hard that the drag will >increase dramatically. In certain cases, increasing the tail size would >significantly decrease the drag since the lift coefficient would be in >the laminar region at all times. > >Any question? I will try to answer. > >-- >Don Reid >Bumpass, Va. >mailto:donreid@erols.com >http://www.erols.com/donreid/kr_page.htm > > ------------------------------ Date: Tue, 13 Jan 1998 11:07:59 EST From: rdewees@juno.com (Ron DeWees) Subject: KR: Re: KR Newsletters 1-100 On Mon, 12 Jan 1998 20:28:34 EST BSHADR writes: >In a message dated 98-01-12 17:56:38 EST, Mike wrote: > ><< Gee I wonder if the issues I have (1 - 70) can be copied and >redistributed?? > If they are considered "unavailable" :o) >> >Randy.. I wouod be interested in the old newsletters. I ordered the available ones anb you are rivht about the missing older copies. Let us know what the copy costs and postage will be and I will get it to you ASAP. Ron DeWees, Atlanta, Ga >Mike: > >Ernie Koppe, who published issues 1 through 100 +/-, gave us >permission to >copy and distribute his issues freely with no restrictions. He said >he never >sold the rights of those issues to anybody and as such he was the >rightful >owner (his words). I do think I know were there is a realtively >complete set >that could be set up for copying at a copy shop and anyone who wanted >a full >set could just order them direct. If anyone is interested, please >Email me >direct. Use "KR Newsletters 1 -100" as the subject line so I can >separate >your Email from the other 100+ I get every day. > >Please don't turn this post into a debate on who has the rights to >copy what. >That horse has been sent to the glue/pet food factory a year ago and >can't be >located except for the pet food label I have left from the cat's >dinner >fix'ins last night. (No Oscar - her dinner, NOT MINE!) > >Randy Stein >BSHADR@aol.com > ------------------------------ Date: Tue, 13 Jan 1998 08:12:17 PST From: "Oscar Zuniga" Subject: KR: Mims walked away from it... > >How did you manage to be here to tell us about it? > >Mike Taglieri > Well, I think he finally remembered that if he unbuckled and crawled up under the inst. panel, he could use his weight to bring the c.g. back forward. Alternately ducking under the dash, and then peeking, using hands on the rudder pedal and toes on the yoke, he managed to squeak the fully loaded Twin Otter into a 300-yd. long clearing in the woods! Oscar (irreverent) Zuniga Medford, Oregon ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com ------------------------------ Date: Tue, 13 Jan 1998 11:44:28 -0500 From: "Bob Vermeulen" Subject: KR: Spar question I'm getting ready to glue up my spars and I want to make the holes for ventilating and equalizing the airpressure that might develop in the sealed areas of the spar. Where does everybody locate those holes? In the verticals, and vent out the ends, or in the web, or what? Is an 1/8" hole large enough or too large? What is typically used for preservation inside the spars? A spar varnish, something like MinWax Polyurethane or what? Is there anything that I should avoid. I'm also planning on having our Chapter tech advisor inspect my spars before I close them entirely. Anybody's help would be appreciated. Video Bob ------------------------------ Date: Tue, 13 Jan 1998 12:21:52 EST From: Horn2004 Subject: Re: KR: Spar question =0AIn a message dated 1/13/98 10:49:35 AM, you wrote:=0A=0A<>=0A=0AWhat I did was drill 1/8" holes in the de= ad center of the verticles. I also=0Adrilled the same hole in both end ve= rticles. Prior to closing the spars, I=0Acoated the non-contact surfaces = with 2 coats of spar varnish. I then took some=0Apipe cleaners and dunked= them in spar varnish and then fed them through the=0Abreather holes I dr= illed. I did this again after the first coat had dried to=0Aensure good s= aturation. After all the spar varnish dried, I took heavy copper=0Awire a= nd ran it through each hole to ensure it was clear (I did not leave the= =0Acopper wire in, just used it as a probe). Instead of spar varnish, you= could=0Ause epoxy. The varnish is cheaper and flows better, that=92s why= I used it. MAKE=0ASURE you DO NOT get varnish on any of the spar web con= tact surfaces. Prior to=0Ainstalling the web, I put a heavy coat of T-88 = on all the web contact surfaces=0Aand let it overlap the varnished areas = to ensure a good seal. Use plenty of=0Aepoxy when assembling the spars. Y= ou do not want any starved areas on your=0Aspar glue-ups. =0A=0ASteve Hor= n=0AHorn2004@aol.com=0ADallas, Texas=0A ------------------------------ Date: Tue, 13 Jan 1998 10:00:39 -0800 From: Micheal Mims Subject: Re: KR: Spar question At 11:44 AM 1/13/98 -0500, you wrote: >I'm getting ready to glue up my spars and I want to make the holes for >ventilating and equalizing the airpressure that might develop in the sealed areas of the spar. Where does everybody locate those holes? In the verticals, and vent out the ends, or in the web, or what? Is an 1/8" hole large enough or too large?>>>>> There is probably a hundred ways you could do it, I drilled 1/4 inch holes in my shear web (on the front side) I used epoxy to seal up the inside of my spar. If you use a varnish DO NOT get the varnish on future bond sites. This is why I decided to use epoxy, I thinned it a little with isopropyl alcohol and it went on just fine. I did the same on the inside of my fuselage too. 1/8 inch hole should be large enough, the flow of air due to pressure changes cant be all that great. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 15:06:14 EST From: Willard561 Subject: Re: KR: Re: KR Newsletters 1-100 given the ease and low cost of making cdroms using CD-r media I would vote for putting them on cdrom with a good xref. Bill Higdon ------------------------------ Date: Tue, 13 Jan 1998 12:26:30 -0800 From: Micheal Mims Subject: KR: web site Sorry if this is a repeat! http://www.baicorp.com/aerocrafter/ac_info.htm ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 12:37:38 -0800 From: Micheal Mims Subject: Re: KR: web site And anoter one, http://home.earthlink.net/~kitairbldr/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 16:29:34 EST From: BSHADR Subject: Re: KR: Re: KR Newsletters 1-100 In a message dated 98-01-13 15:16:36 EST, Bill wrote: << given the ease and low cost of making cdroms using CD-r media I would vote for putting them on cdrom with a good xref. >> Bill: We are looking at that option as we speak. Give me a few days to sort it out. Everyone who has asked for a set, hang in there. We'll see if we can make it cheap! After all, that is the reason we like the KR - it is....eeerrrrrrrrr LOWCOST. Randy Stein BSHADR@aol.com Soviet Monica, CA ------------------------------ Date: Tue, 13 Jan 1998 17:50:31 -0500 From: Tom Andersen Subject: Re: KR: Weight Check/ Boat's complete! Micheal Mims wrote: > > At 08:19 PM 1/12/98 -0800, you wrote: > >The boat is done! Well, at least everything in chapter one is finished. > > > >It's at 42 pounds. How I'm doing guys? What weights did anyone else > >record? > > > I think my skinned boat was just under 50 pounds. > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Micheal Mims > Oh My,.......Its 1998!! > > mailto:mikemims@pacbell.net > http://home.pacbell.net/mikemims Did you fellas use mahogany or birch skin and does this include the vertical fin spars? - -Tom ------------------------------ Date: Tue, 13 Jan 1998 14:58:06 -0800 From: Micheal Mims Subject: Re: KR: Weight Check/ Boat's complete! At 05:50 PM 1/13/98 -0500, you wrote: >Did you fellas use mahogany or birch skin and does this include the >vertical fin spars? >-Tom > > Birch and the tail post ony (aft vertical spar) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 16:24:29 EST From: EagleGator Subject: KR: Fwd: Max Calkin This is a multi-part message in MIME format. - --part0_884726669_boundary Content-ID: <0_884726669@inet_out.mail.aol.com.1> Content-type: text/plain; charset=US-ASCII Netters, I got this email and my web browser is down, can anyone help Bob locate Max? Thanks for your help! Cheers! Rick Junkin EagleGator@aol.com St. Charles Mo http://members.aol.com/eaglegator In a message dated 98-01-13 15:55:16 EST, sarce@tri-lakes.net writes: << Subj: Max Calkin Date: 98-01-13 15:55:16 EST From: sarce@tri-lakes.net To: eaglegator@AOL.COM Hi Rick, Bob Sarcione here. I was wondering if you had Max Calkin's e-mail address. He lives close by me and I would like to communicate with him. The info package for the KR2 that I sent for a couple of years ago had a copy of the KR Newsletter in it and it featured Max's second KR2 which was a restoration. I am still wanting the one I told you about in Wisconsin and I would like to get some input from Max., and maybe go see him and his KR2. Thanks, Bob >> - --part0_884726669_boundary Content-ID: <0_884726669@inet_out.mail.aol.com.2> Content-type: message/rfc822 Content-transfer-encoding: 7bit Content-disposition: inline Return-Path: Received: from relay21.mail.aol.com (relay21.mail.aol.com [172.31.106.67]) by air13.mail.aol.com (v37.8) with SMTP; Tue, 13 Jan 1998 15:55:16 1900 Received: from bob.tri-lakes.net (BOB.tri-lakes.net [207.3.81.6]) by relay21.mail.aol.com (8.8.5/8.8.5/AOL-4.0.0) with SMTP id PAA16454 for ; Tue, 13 Jan 1998 15:54:23 -0500 (EST) From: sarce@tri-lakes.net Received: from [207.3.81.177] by bob.tri-lakes.net (NTMail 3.02.13) with ESMTP id sa423298 for ; Tue, 13 Jan 1998 14:54:28 -0600 X-Sender: sarce@mail.tri-lakes.net (Unverified) X-Mailer: Windows Eudora Pro Version 2.1.2 To: eaglegator@AOL.COM Subject: Max Calkin Date: Tue, 13 Jan 1998 14:54:28 -0600 Message-Id: <20542837102842@tri-lakes.net> Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit Hi Rick, Bob Sarcione here. I was wondering if you had Max Calkin's e-mail address. He lives close by me and I would like to communicate with him. The info package for the KR2 that I sent for a couple of years ago had a copy of the KR Newsletter in it and it featured Max's second KR2 which was a restoration. I am still wanting the one I told you about in Wisconsin and I would like to get some input from Max., and maybe go see him and his KR2. Thanks, Bob - --part0_884726669_boundary-- ------------------------------ Date: Tue, 13 Jan 1998 15:22:56 -0800 From: "John Bouyea" Subject: Re: KR: Weight Check/ Boat's complete! My boat is mahogany and the weight included the "stern post" only. The only thing not completed from Chapter One is the tail wheel mounting block. John Bouyea johnbouyea@worldnet.att.net kr2s - laying out the spars for lamination Hillsboro, Oregon > > Did you fellas use mahogany or birch skin and does this include the > vertical fin spars? > -Tom > ------------------------------ Date: Tue, 13 Jan 1998 17:47:30 From: Austin Clark Subject: KR: Diel Gear I got my Diel gear today and I am impressed. These things are heavy duty and the workmanship is great to. It looks like I am going to have to move/modify the 48" rib near the fuselage to mount the brackets. No big deal. The nose gear comes complete with a molded fiberglass fairing to fair to the cowling. The whole shabang cost $1000 including shipping, but I think it was money well spent. Any advice on mounting these would be welcome. Austin Clark Pascagoula, MS http://www.datasync.com/~itac/ ------------------------------ Date: Tue, 13 Jan 1998 18:45:53 EST From: BSHADR Subject: KR: Max Calkin In a message dated 98-01-13 18:28:37 EST, Rick wrote: << Netters, I got this email and my web browser is down, can anyone help Bob locate Max? Thanks for your help! Cheers! Rick Junkin >> Rick: He was not at the last KRKosh in Perry as far as I know. He was at the '96 KRKosh in Pine Bluff. I recall his plane was for sale at that time...anyhow: Max Calkin 14095 Denver Road Omaha, AR 72662 (501) 426-5307 I hope this helps. Randy Stein BSHADR@aol.com Soviet Monica, CA ------------------------------ Date: Tue, 13 Jan 1998 16:07:38 -0800 From: Micheal Mims Subject: KR: composite skins?? (long) Well here is my idea for foam and glass skins,... First you would need your fuselage built up without skins (see my fuselage page). Grab a sheet of Last-A-Foam and hold it up against the side (or bottom if you are making the bottom) of your fuselage. Trace with a marker all around the outside of your fuselage. Lay the foam sheet on a flat surface with the marker side up and trim around the drawing, trim it so that the foam skin will be 1/2 inch larger than the outline. The skin will need to be made from 2 pieces as the foam only comes in 8 foot lengths. This is no problem though as we will build a joggle where the two pieces mate for a 2 inch wide glass tape. With the foam laying on a flat surface apply two layers of 6 oz bid. Apply the bid so the first layer is at a 45 degree angle to the fuselage, this will require cutting ther glass on the bias and will require two or three areas where you will butt the glass up next to each other (do not overlap the glass this will cause bumps in the finished product). Apply the next layer with the fibers on a 45 but so that the butt edges are in the opposite direction as the first layer. Wetout peelply on top of the last layer of glass. Let cure. (these two layers of 6 oz make up the outside skin) Note: Where the two pieces of foam will butt up against each other you will want to sand a nice joggle into the foam before glassing. You can make a joggle 1/16 inch deep and about 1.5 inches wide (fore and aft). This will give you a 3 inch wide 1/16 inch deep area to apply 2 two inch wide tapes to join the 2 pieces that will make up the complete fuselage skin. When you sand this joggle into the foam you do not want to go the full length top to bottom, leave the foam level with the rest of the skin near the top and bottom. This foam will be removed in the future and the skin will bond to the longeron. Your 2 inch wide bid tape will only join the two skins in an area that starts about 3/4 inch from the top to 3/4 of an inch from the bottom. After cure hold the skin up next to the fuselage again and now trace around all the vertical members as well as the longerons. Now lay the skin on a flat surface again and using a x-acto knife cut into the foam along each line (actually about 1/4 inch to the outside of each line, outside meaning the side away from the spruce member), you will want to cut through the foam and down to the outer skin but not through the skin. Next use a scraper to chisel up all the foam between the knife cuts. The idea is to remove all the foam where it will contact the wood structure plus some. This means the foam should be removed all along the top and bottom edges as well as where the vertical members are located. Use some 60 grit sand paper and round all the edges so the inside glass skin will lay over the contoured surface better. Also you will want to lightly sand the area where the inside skin will make contact with the outside skin (glass to glass area) Now lay up your inside skin by applying one layer of 6 oz . Use a paint brush and a stipple motion to help get the glass down into the valleys. This layer will be applied with the fibers running fore and aft. Use peelply in all the future bond sites (where the spruce structure will come in contact with the skin). After cure peel up all the peel ply in the inside and flox into position on the spruce structure. Leave the peelply on the outside skin until you are ready to sand and fill. Of course you will need to remove the peelply if you are applying a glass tape but try to leave most of the peelply on as long as you can to protect the outside skin from drips. You may ask why all the glass to glass areas? Well by making all the areas where the spruce contacts the skin you are transferring the loads to all three layers of glass more effectively and the glass to glass bonds add rigidity and strength to the skin. The skin will be quite stiff but it should contour to the shape of the fuselage with no problems. Advantages?? Should be stronger than plywood Should be lighter than plywood (will be if vacuum bagging is used) Should be less than half the cost of plywood. An additional layer of glass can be added to the front area of the skin for strengthening up the firewall area (see below). A joggle could be made in the outside skin up near the firewall so that 4 or 5 layers of 6 oz bid could be used to tie the 1/4 plywood into the fuselage skins (8 inch wide tapes, 4 inches on the firewall and 4 inches on the skin) This could be done on the sides and the bottom. Better sound insulation. Disadvantages Would require more time to build Is not proven Remember this is only an idea and I have not tried it. So use at your own risk! You can see a jpg image at: http://home.pacbell.net/mikemims/skin.jpg Oh yea, you engineer types feel free to shoot this one down! Cuz I aint no engineer! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 19:14:51 -0500 From: Donald Reid Subject: Re: KR: NLF Thoughts Michele Bucceri wrote: > Just a question about the program you've used. > You speaks about "...airfoil analysis...", "...NLF runs out of laminar > flow..." and " ...gentle stall...", so I guess that you ran a two > dimensional CFD program with boundary layer and post-stall computation. > Is that true? I found one on the web. The URL is on my web page. I went with the default conditions and did not try anything fancy. It is a 2-d panel method. I will be starting a graduate level CFD class tomorrow so the knowledge level will be increasing. > What's your experience with the moment evaluation with CFD programs? > Mine is that they never get the true value. They are very good for > evaluating the lift curve, good for the drag, and poor for the moment. > My be I've ever used bad programs. Not enough data on my part to estimate. After my class work, I will have a better idea. From thin wing theory, the moment coefficient is a function of mean line profile. The NACA 747A315 compared resonably well with the published wind tunnel data. > > Another question. What about airfoil contamination vs laminary flow for > the 747? I've seen the diagrams of this airfoil on Abbot, and it seems > very good, but everytime I see a laminar airfoil with good performance > in the laminar region, and poor performance outside, I get scared. May > be that my scare is because of poor experience. You are right of course. The laminar airfoils do look good on paper and some turn out to less than ideal in the real world. The 747 is supposed to be OK in real life. Time will tell. > Michele Bucceri > E-mail: mailto:michele.bucceri@italtel.it - -- Don Reid Bumpass, Va. mailto:donreid@erols.com http://www.erols.com/donreid/kr_page.htm ------------------------------ Date: Tue, 13 Jan 1998 16:16:50 -0800 From: Micheal Mims Subject: Re: KR: composite skins?? (long) At 04:07 PM 1/13/98 -0800, you wrote: >Well here is my idea for foam and glass skins,... > Oh yea I uploaded all this to the ideas page. Any other ideas out there yall want to share? Ideas page URL: http://home.pacbell.net/mikemims/ideas.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 19:20:35 -0500 From: Donald Reid Subject: Re: KR: NLF Thoughts Peter Leonard wrote: > > Since the talk started about the NLF airfoil section I have been wondering > how much advantage would be gained by using this section Your 8 pound drag reduction is just about what I got, but I was looking at just the wing and stab. drag and neglected any fuselage. That was where I came up with a ~20% reduction in drag. Mine was a 20% reduction in wing drag only, which is the same as your ~10% overall reduction. All of the numbers that I got were in the same ballpark as yours. - -- Don Reid Bumpass, Va. mailto:donreid@erols.com http://www.erols.com/donreid/kr_page.htm ------------------------------ Date: Tue, 13 Jan 1998 20:20:17 EST From: EagleGator Subject: KR: Speed Mods There is a very interesting article in the January edition of Sport Aviation on using "dimple tape" to improve airflow across everything from the prop to the landing gear legs. Here's the meat of it: Dimple tape is applied span-wise to the maximum camber of the prop, wings, and airfoils. The theory is that trailing edge separation and the trailing edge wake characteristics are improved. The improvements cited in the article are on the order of about a 5% increase in speed and a decrease of 50% in prop noise. All this just by just applying dimples to the airfoils in the appropriate place. Definitely something to look at in the wind tunnel tests. If you're interested, the author of the article is Anthony C. Occhipinti, 1353 Lake Ave, Apt A, Metairie, LA. (504)831-1816. Cheers! Rick Junkin EagleGator@aol.com St. Charles MO http://members.aol.com/eaglegator ------------------------------ Date: Tue, 13 Jan 1998 20:13:51 EST From: KR2 616TJ Subject: KR: Construction update. I just added the pictures of my engine upgrade to my web page. On the main page I have changed the KR patch to the engine pictures. I have explainations under each picture of the engine's disassembly so I won't take up space here. I also added Austin Clark's KR Construction page, check it out, nice page. I sent my case off today all $79.57 in shipping for the machine work to be done to accept Steve's Stroker Crank with the larger prop hub bearing. As you can tell it's going from an 1835 to a 2180. I've already got a Revmaster Carb, 4 to 1 tuned exhaust and dual port intakes. I am currently doing my instrument panel wiring, I'm lucky in this regard, as the guy who is doing all the electrical work on the P-38 that was recovered from the Greenland icecap lives about 3 miles from me and I can trade out CPA work for wiring; seeing it's tax season again, I get more wiring. I am working on the engine electrical wiring so that when I get the case back I can at least crank it over. I've been looking forward to that time for 2 years. Due to the weather, I can't do any glassing so I'm doing the finish sanding on the wings in preparation for priming at the first good warm stretch. Sometimes I think I should be on 3M's Christmas card list. Questions: I have a Revflow 32mm floatless card, give me some input, I'm a big boy so if you feel strongly about it let me know. My plans are 1980 plans and did not show the engine mount alum. support. What size alum is everyone using, I'm guessing 6061 is the grade. I gather from the discussions this is bolted to the upper shelf plywood. Since the engine is off, I want to add this over this weekend. Let me know. Let me know about the Revflow.....seriously. Dana Overall Richmond, KY kr2616tj@aol.com http://www.geocities.com/CapeCanaveral/Hangar/7085/ ------------------------------ Date: Tue, 13 Jan 1998 21:17:40 EST From: JEHayward Subject: Re: KR: Spar question In a message dated 98-01-13 11:49:35 EST, you write: << Where does everybody locate those holes? In the verticals, and vent out the ends, or in the web, or what? Is an 1/8" hole large enough or too large? What is typically used for preservation inside the spars? A spar varnish, something like MinWax Polyurethane or what? >> Bob, I used an 1/8" drill bit in the middle of each spar "cell" and on the aft shear web. I coated the inside of the spar with 2 coats of the MinWax Poly. I did find that the 1/8" holes closed up a little with the varnish but didn't seem to be anything to be concerned about. Jim Hayward ------------------------------ Date: Tue, 13 Jan 1998 20:40:37 -0600 From: "Mark Langford" Subject: KR: let's just call it a preference KRFolks, While everyone's busy proving that we're wasting our time on the NLF, I'd like to remind you all that there are a great many decisions regarding our planes that are simply a matter of personal preference. Taildragger vs tri-gear, wing tanks vs header tank, Subaru vs VW, and yes, RAF48 vs the contenders. Each has it's place. Assuming that we "only" get a 5% increase in speed from the NLF over the RAF48, combined with other modifications to the plans (washout, incidence) there is little doubt that there is room for improvement on the top end. To many of you, that doesn't matter one bit, and that's fine. Many will stick with the plans, and have wonderful airplanes that are quick to build and a joy to fly. Personally, I like to be a little different, especially when it comes to my means of transportation. I'm going to build my wing from scratch no matter what airfoil it is or how long it takes. I'm going to the trouble of building large, meaningful flaps that will actually lower my landing speed considerably, probably to something very similar to the RAF48, for a small weight penalty. As for stall characteristics, it's certainly no worse than the 23012, which is used sucessfully by many Wichita machines. One of my primary reasons for building a KR2 is SPEED. My time is very important to me, and the faster I can get somewhere, the happier I am. I could have chosen something like the VP-2, which uses similar construction, materials, and engine. But the mission of that airplane is completely different, focused mainly on slow, safe, pleasure flying. That's great, but just not what I'm looking for in an airplane. And for me, there's a limit to "stall proofing" an airplane. If it takes 3 degrees of washout and a wing that mushes forever before stalling to tell you that you're in trouble, maybe you shouldn't be flying after all. It just depends on what's important to you. I'm one of those lunatics that does little things to my cars to make them a little more efficient. After a while, they add up. Take my '74 Karmann Ghia ( http://fly.hiwaay.net/~langford/ghia2.jpg ) which originally went 0-60 in about 21 seconds. After 24 years of tweaking, it now gets there in 6 flat, surprising many 5.0 liter Mustang owners in the process. My father told me when I bought that car that I should leave it stock, and I'd be a lot happier with it. Well, I've got news for him...I'd have sold that car long ago if it were a stocker. Right now, its one of a kind. To many of you, this is childish stuff. But it's the kind of thing that makes me tick. The last thing I want to do is fuel the flames of another airfoil war or similar on KRNet. Let's just leave it at a "personal preference", OK? Mark Langford, Huntsville, AL email at langford@hiwaay.net KR2S project construction at http://fly.hiwaay.net/~langford ------------------------------ Date: Tue, 13 Jan 1998 18:49:40 -0800 From: Micheal Mims Subject: Re: KR: let's just call it a preference At 08:40 PM 1/13/98 -0600, you wrote: Take my '74 Karmann Ghia ( http://fly.hiwaay.net/~langford/ghia2.jpg ) OK when can I pick it up? :o) Seriously, I am making the changes to my KR for exactly the same reasons. In my mind I see a better way to do certain things (better for me) and that's why I am doing it! My way isn't right or wrong its just my way! I didn't want to wait around for the NLF data so I continued on with the NACA 23015 which looks terrible on paper but seems to fly great! My plane is likely to be pretty fast but that will mostly be due to brute force! The Lyc O-290 has reared its ugly head again and continues to call to me from the corner of the hanger while I am sanding filler! Oh well hang in there Mark, we have been through this before and we will continue to deal with it until our machines take to the skies! Mark,... Some time in 1999 after we get all our bugs worked out I purpose we take a week or two vacation and meet up somewhere for a tour around North America. Kind of a KRnet North American Tour. I am sure we would have no problems finding places to park our Planes and our butts over night. I am willing to bet we could find a few locations to visit just by announcing we off for ???? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 20:17:40 -0700 From: Ron Lee Subject: Re: KR: let's just call it a preference (no archive) >My plane is likely to be pretty fast but that will mostly be due to brute >force! The Lyc O-290 has reared its ugly head again and continues to call to >me from the corner of the hanger while I am sanding filler! > Mike, I am from the engine/airframe compatibility police and it is against all laws of nature to put that engine in a KR. Too much horsepower and speed for any KR gathering. >Mark,... Some time in 1999 after we get all our bugs worked out I purpose we >take a week or two vacation and meet up somewhere for a tour around North >America. Kind of a KRnet North American Tour. I am sure we would have no >problems finding places to park our Planes and our butts over night. I am >willing to bet we could find a few locations to visit just by announcing we >off for ???? >Micheal Mims >Oh My,.......Its 1998!! Psssst, you guys man enough to try some high altitude take-offs and landings? Ron "The Instigator" Lee > > ------------------------------ Date: Tue, 13 Jan 1998 19:32:47 -0800 From: Micheal Mims Subject: Re: KR: let's just call it a preference (no archive) At 08:17 PM 1/13/98 -0700, you wrote: > >>My plane is likely to be pretty fast but that will mostly be due to brute >>force! The Lyc O-290 has reared its ugly head again and continues to call to me from the corner of the hanger while I am sanding filler! >> >Mike, I am from the engine/airframe compatibility police and it is against >all laws of nature to put that engine in a KR. Too much horsepower and speed for any KR gathering. Aw come on man! Let me go fast,... please??? No problemo on the high altitude stuff because if not the Lyc O-290 it will be a turbo something! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 22:03:07 -0600 From: "Mark Langford" Subject: KR: Re: Construction update. Dana Overall wrote: > My plans are 1980 plans and did not show the engine mount alum. support. What > size alum is everyone using, I'm guessing 6061 is the grade. RR sells you two 36" long pieces of 4" x 2.5" x 1/8" 6061-T6511 (call it T6). The bottom angle is supposed to be somehow miraculously expanded to fit the 100 degree angle between the bottom 3.5" x 5/8" firewall cross members, while the upper one connects the top cross member to the deeper of the two upper plywood shelves (the one about 3" below the longeron). Get some 4 x 4 and rip it down to 2.5" on a tablesaw (with a blade that you need an excuse to throw away). Mark Langford, Huntsville, AL email at langford@hiwaay.net KR2S project construction at http://fly.hiwaay.net/~langford ------------------------------ End of krnet-l-digest V2 #12 ****************************