KR> Throttle cables
Thanks god the rotax 912 does'nt need a mixture mechanic,only a choke cable! After 15 years using a push-pull friction knob on my Kitfox I made a simple throttle quadrant with bowden cables ,very comfortable and quick to use. Herbert F?rle, German Kr Hier ist ein Link zu ?P1040875.JPG? in meiner Dropbox: https://www.dropbox.com/s/lkfstdqji9w17rg/P1040875.JPG?dl=0 Von meinem iPad gesendet
KR> Spar and WAF stress analysis
the conclusion of the German Test of the Kr Spar and WAF's calculated by Otto Bartsch is: Any reliable built Kr with a MTOW of 1050 pounds is a 4,2 G's plane with a 1,45 safety factor,or a 3,8 G 's x 1,6 plane! Otto Bartsch assured me,that the calculation was carried out somewhat conservative ! Herbert F?rle German Kr Von meinem iPad gesendet
KR> center spar analysis
Hello netters,over here in Germany ,I had to do a spar and WAF load test for my Kr. Mr. Otto Bartsch from the OUV(the German association for experimentals and a aerodynamic ingeneer at Messerschmitt Boelkow Blohm (MBB) did a very simple but efficient Job.To demonstrate the strength of the spars he did not covered them with plywood.He also wanted to see If the bolts would split the wood under high loads. The complete test was very successful. The very slightly bent on the WAF's ( pic far right) was the result of a not calculable load (more than 7 g's supposed by Otto Bartsch) caused by an aprupt stop of the loading shovel.To prevent this bending under very high loads,Otto Bartsch recommended to switch to an one bolt systhem.I hope that the documentation is instructive on the basis of the fotos . Herbert F?rle, Gemany Kr https://www.dropbox.com/s/jvxw8xdz990kwn0/SWScan00013.BMP?dl=0 Von meinem iPad gesendet
KR> Landing Speeds
...thanks Colin for the pretty good youtube sequenzes- very educational and motivational ! The manner how you will land the Kr is called in Germany as "Lufthansa landings".That goes back as Lufthansa still Ju 52, DC3 and other tailwheeler planes used. My Altiport instructor in the Swiss Alps always told me that If a Plane's wheels touch the ground for the first time,it may not be able to fly,which methode whatever one chooses! With my Kitfox(tailwheeler) I have hundret of times practiced both versions ( tail up,tail down)and have found, that a nearly 3 point landing ( a little "behind the wheels") takes less treck.The best way for an individual decision is called: practice,practice,practice!An old philosophie sayes: "flying" means "land the plane safely",no matter the way you'll choose. Von meinem iPad gesendet
KR> Taxi testing
...I'm absolutely the opinion of Marks recommendations! Any theories,which can be read in books and magazines are good for the head but not for the hands.Therefore,it is essential to coordinate theory and practice.As Mark said,it is very controversial to find a suitable human/Pilot. Before I flew my Kitfox the first time,I faced the same decision.I completet about fifty landings in a citabria with a very experienced instructor,reminded me on my successful take offs with my Fisher Koala and last but not least on the countless flights with a taildragger motorglider .This whole experience- package caused me to be my own testpilot,Tanks good,with success! I have no fear , to do it again with my Kr! Herbert Fuerle German Kr2s Von meinem iPad gesendet
KR> Fuel injection-megasquirt
this Bing carb. are standard carbs on Rotax 912 Engines (very successful!!) They are also used on BMW motorcycles. Beside my Kr ,I restored a Pelican Ul with a Global half VW engine and replaced the old Stromberg cadb. and mounted a Bing carb. Works fine ! Herbert Fuerle German Kr Von meinem iPad gesendet
KR> Hours to build
..400$ and 40hours? - Even a miracle needs more time! I built mine from scratch,nearly finished- appr. 2300 hours +. I think with prefab. parts ( it depends how many of them) it could be done in 650 to 1000 hours. Herbert Fuerle German Kr2s Von meinem iPad gesendet
KR> KR-2S cabin width
I'm a 185 pounder and 5'10" high and I fit (with a "cloned " passenger )resonable comfortable in my 40" wide Kr! When I widened my fuselage ,I put back the 40" to the shoulder area.Therefore I had to put back the straight line of the longerons a little ( 10-12 inch). Therby,making the turtle deck was a bit tricky,because it had to be spherical in this area.(due to the slightly curved longerons). Of course the Kr2s is a comfortable single seater also with plenty of storage. I would not recommend to build a "Kr 1 s" because then you will lose the mentioned advantages of a two seater. And finaly ,to build a single seat "Kr1s" with an emty weight of about 400 to 450 pounds is almost impossible. Herbert German Kr2s Von meinem iPad gesendet
KR> Kr Plans
..Randy Moore offers his Kr Plans for 3000.00? Is it possible that the decimal dot is on the wrong place ? I think one left is ok. Herbert German Kr Von meinem iPad gesendet
KR> iMonitor App
Oscar,.what a good idea! I remember when Mark visited Germany and I watched his pictures, he posted on his site.But unfortunately it did'nt worked out to meet him at my home. How ever,when any one plans to visit Germany ,especially Bavaria ,let me know! I'm proud to show you the" hot spots" of my country and of course my nearly finished Kr! You very welcome! Herbert German Kr Von meinem iPad gesendet
KR> iMonitor App
I use my iPad mini(64 GB) very successful for navigation with the Air Navigation Pro app installed.It works very fine with the extern Gps receiver GNS 2000.I read Mark Langford's post with the description of the imonitor app and I'm very interested to install it on my iPad.I searched the net and had to recogniced that this App is not available at the german Appstore yet. Mark,is it possible to find out, when this App is available over here in Gemany or Europe? Many thanks, Herbert
KR> Bellyboard
any Test,however it is performed,gives a lot of informations! The aerodynamic principles are always the same ,also in the case of the hot" bellyboard -drag" discusion.For me it's important the location of the board and I think the place underneath the rearspar is very well chosen ( far enough behind the CG ,to give the Kr a small amount of direction stability like a dragchute and the waketurbulences does'nt hit the HS !) I 'm convinced,a board without holes are more effectiv ( one big waketurbulence produce more drag compared to many small ones). I'm also think,a big advantage of the bellyboard is the fact ,that you can lower the nose of the Kr on final for better sight( wether you have to push or pull the stik )! Herbert German Kr builder . Von meinem iPad gesendet
KR> Bellybrake
..my bellyboard turns down to about 80 deg. and after talking to some aerodynamicists and some practical trials I decided to let the board without holes. The tests I made are very simple.I took a foamsheet ( 1 meter x 1 meter x 5 mm) ,fixed 5 strings to the edges and the center with a weight (about 100 grams ) and used my "parachute" as testdummy. I dropped the dummy from my ten meter high rooftop (5 trials without holes and 5 trials with holes) and compared the times I measured. It was easy to recognice that the board without holes always gone down slower ! There was a big difference how they sank down.The board without holes tumbled much more than the Board with the holes (due to the holes,of course) Happy New Year again,Herbert, German Kr Bilder Von meinem iPad gesendet
KR> To all netters
Merry christmas and a healthy and peaceful new year and of course countless save landings to the whole Kr family, Herbert Fuerle German kr2s Von meinem iPad gesendet
KR> ...to read posts from prior years
.I don'nt know what I have to do ,to read posts from prior years! Any help is welcome, Kindly regards,Herbert Von meinem iPad gesendet
KR> Jabiru's in Kr2s.
...I made a very simple calculation : 1100 rpm's comply with about 52 mp/h,when you use a 54 inch Prop.I supose, your approaching speed on short final is about 25-30 more. That means, with the powersetting you use at the final,the prop does'nt produce thrust,he'll brake you. Maybe a naive opinion ,but I also use Mark's procedure on each approach with each craft! Sincerely, Herbert Von meinem iPad gesendet
KR> Bellybrake
...Can anyone of the experienced "bellybrakers"explane ,what kind of bellybrake are the most efficent brake is. .Is it useful to make holes in the brakeshield or not ? what is the most efficent deploying angle of the board ? My bellyboard is mounted just under the rearspar and actuated by a electro-spindle with two alternately switches to limit the braketravel. Any helpful discusion is welcome, Sincerely, Herbert Von meinem iPad gesendet
KR> Pressure testing my wing tanks
when all this methodes does'nt help fill the tank with lipo-batteries and switch to electro-flying! HF. Von meinem iPad gesendet
KR> VG's on my Kr
...the reason way I plan to install VG's on my Kr is to prevent loosing aileron effectivety in some worse flying situations. For example,when you must handle a forced landing after an enginefailure,or you approaching a short airfield with a small pattern.I think it's always an adventure to have a small package of safety in your mind in such unpleasant cases!! Herbert F?rle Von meinem iPad gesendet
KR> Probably a simple way to lower the stallspeed
http://www.youtube.com/watch?v=tYl2gLwLnwA I will do that on my Kr in the area of the alerons toward the wingtips and probably on the bottom of the HS. Von meinem iPad gesendet
KR> Subscribe for posting to to the list
Von meinem iPad gesendet
KR> Weight of 5048 wing vs. 5046 Noob questions
when you make a weight calculation for the wings,I think it does'nt matter what kind of airfoil you use for your kr .( I approve all thoughts of Mark Langford's reply).A very important point is the choice of the wood what you use for the spars, or the entire airframe.(you know that Sitka Spruce is much lighter than Douglas Fir).Also a big difference in weight is,how accurate you work on your wings(not only the wings,I mean general on the entire airframe).Ongoing with the first glue-joints right through the way you glass the entire surfaces.You must know ,there are many ways to save-or add weight to your project! Good luck for your decisions whatever you make!
KR> VE layup
hello netters,i am not sure that put on peel ply as the final layer to reach a smooth surfaces is the best, or a good solution.A employee of Schempp-Hirth,the famous glidermanufacturer,told me that they use only peel ply in areas where aditional layers are connected ,after the layups before are cured ,to save time-consuming sanding.After you weted out the glas-layers and try to lay up peel ply,in most cases it will be neccessary, to ad small amounts of resin to roll-,or squeeze on the peel--and this ads weight.The better way, to get a smooth surface,is to lay up a very light glas-ply with a different wafe (ie.linen-wafe).This lay up will be weted by the remaining resin.A further adventure of this way(I did it and i swear by this method) is ,when you smooth down the surface later on,you have a exact reference image of your glas lay ups due to the different fill directions.( you avoid to sand down the structural lay ups) My conclusion of this method is:you ad strength and earn safety and save weight!!
KR> Rectangular boat building
...beside all the discribed adventures,a big adventure is,not to get a "Banana-boat---and the aerodynamics improve in the wingroot to the fuselage area(you can keep the radius very small--ie.1/2inch or less)
KR> Ailerons
..can anyone tells me the average counterweight of a plansbuilt aileron balancearm for the new 16% airfoil wing? Thank's Herbert Fuerle
KR> Reminiscences
Hello Kr-family,does anyone of you kowes Roy Marsh and David Christensen?I had the chance to meet both of them(Roy Marsh at sun'n fun,David Christensen later on at Oshkosh) and all two gave me the inspitation for building my Kr.I've never heared something from these two fellows.Further I know that Roy sold his famos Kr2s and i saw it at the Krnet.How ever,I only want to know to awake memories!
KR> mmicro balloon
When I have done the bodywork on my Kr I've got the best results by mixing resin and micro ballons (no matter what epoxy-resin you use)at first, to a very dry mixture(no chance to squeeze on to the surface).Then add "household- alcohol"(in germany it is called Spititus-about 90-95% alcohol)to get a slurry mixture. It's easy to squeeze this micro slurry on to the surfaces.It takes a little longer to harden. Never take this mixture for structural bonding!! The adventure of the hardened mixture is a very good and smooth sanding condition and it doesn't give cracks later on!(it stays smooth and flexible all the time). Avoid taking vinyl-esther or polyester resin.This resin gets harder and harder by the time and you will get cracks later on.For small repairs on a finished surface you can use "top coat" (most boat manufacturer use "gel coat"in their molds before they continue with the glass layers ,or "top coat" when they working on a moldless item).Both products are based on polyesther and need a special primer to continue with epoxy resin! To get a good surface and stay light on a moldless wing ,the best way is, to start with a very good preparation of your foamshape.That causes in a minor amount of micro and resin for your lay up and finaly just as little micro for sanding the surface to its color condition. Once again,using colered (most white) "top coat" as described ,results in unwanted highweight and cracks later on, due to it's uncontrolled thickness.
KR> testmessage
only a test mssage from Herbert Fuerle
KR>Need help on the best epoxy to use with micro balloons.
When I have done the bodywork on my Kr I've got the best results by mixing resin and micro ballons (no matter what epoxy-resin you use)at first, to a very dry mixture(no chance to squeeze on to the surface).Then add "household- alcohol"(in germany it is called Spititus-about 90-95% alcohol)to get a slurry mixture. It's easy to squeeze this micro slurry on to the surfaces.It takes a little longer to harden. Never take this mixture for structural bonding!! The adventure of the hardened mixture is a very good and smooth sanding condition and it doesn't give cracks later on!(it stays smooth and flexible all the time). Avoid taking vinyl-esther or polyester resin.This resin gets harder and harder by the time and you will get cracks later on.For small repairs on a finished surface you can use "top coat" (most boat manufacturer use "gel coat"in their molds before they continue with the glass layers ,or "top coat" when they working on a moldless item).Both products are based on polyesther and need a special primer to continue with epoxy resin! To get a good surface and stay light on a moldless wing ,the best way is, to start with a very good preparation of your foamshape.That causes in a minor amount of micro and resin for your lay up and finaly just as little micro for sanding the surface to its color condition. Once again,using colered "top coat" as described results in unwanted weight and cracks later on, due to it's uncontrolled thickness.
