KR> Vacuum power
Hey Steve The VSI is just hooked to the static line of the altimeter, and airspeed indicator. You can use a venturi that is placed inside the cowling if you want to have it not show outside the plane, but that is going to be the easiest, most reliable way for a KR builder. For both an Attitude Indicator (Artificial Horizon) and Directional Gyro you will need the larger type venturi so that you can produce enough vacuum to run both. The largest venturi AS sells requires a regulator. You should be able to see the fuel in the tube since it has a blue color added, without any ball in the tube. I can just see it melting over time and ending up in the fuel filter or worse Colin Rainey N96TA
KR> WAFs
I have to agree with Don Reid if I understand this thread correctly. My take on it is that the original design has 4 bolts per attach point for a total of 8 per wing side. If this is the way yall (sorry) are doing it, I will YELL hold on! I have been doing the wing attach thing with 4 bolts total per side since I bought mine because the original builder set it up this way. In addition, my spar is carried ALL the way thru the WAFs so that all 4 of my bolts pass thru the WAF AND the spar (WAF spar WAF). The ends of my spars of the stub wing touch the ends of the wing section spars by butting together. I really trust mine, and my DAR agreed that it is the strongest he has seen on a KR2. I have taken my wings off 4 times and will install new AN bolts front and rear for this next install, just on principal. And if I dont understand it, I hope you understand how mine is anyway, LOL Saw a Robinson R44 giving rides today, WHEW! What a scary sight watching that thing fly in the wind! Colin N96TA
KR> Aileron travel
I hate to contradict you Brian, but more travel does not necessarily increase sensitivity, but WILL make for a better roll rate when fully deflected. The sensitivity will be dependent on how much deflection occurs compared to a given amount of stick travel, as compared to an original setup. If the original KR2 gets 5 degrees of deflection for a ½ of movement at the stick, and Robert Pesak is getting the same 5 degrees with every ½ (it will not be this clean since there is differential aileron motion on the original KR design) then he will have the same sensitivity, but just more deflection capable, therefore a higher roll rate. This wont make it more sensitive or harder to fly, but will lead to over controlling if one is in the habit of big control inputs. It also has the potential for being a little bit safer, due to the enhanced slow speed roll control. I personally would not change anything unless you find your ratio of activation greater than the plans call for. Brian sorry to hear about the plane! I was looking forward to giving you some IFR dual soon. Colin Rainey N96TA
KR> ailerons
Differential ailerons are one of the two ways engineers use to control or tune out adverse yaw, caused by both the decrease in drag on the inboard wing and the increase in drag on the outboard wing during a level turn. Friese ailerons like Mark L uses and is common on Cessnas have the hinge part of the aileron extend down below the bottom surface to try and balance the increased drag of the out board aileron, while differential simply deflect less outboard than inboard, as with Piper aircraft. In both cases these changes are mainly aimed at flight speeds at or near cruise speed for their biggest effect at balance. Maneuvering flight causes too much drag and we are lucky that the KR mostly stays coordinated nearly all speeds (at least mine and Larrys). My point being that comparison to most certificated aircraft is only going to be valid or fair for these types of enhancements, if you compare to results at or near cruise. The designers pretty much compromise all other speeds to arrive at what is in highest demand at cruise, and all other speeds need some kind of adjustment. Even their props favor an acceptable climb rate with cruise economy and speed being the primary focus. My KR is fast and stable, and seems to favor high speed cruise over all else. When I was doing a lot of pattern work last year, the tower guys would regularly put me on the big runway with twins, because he knew I would run all over the 152 and 172 crowd. My pattern was smaller and faster. Have fun, back to the work room . Colin N96TA
KR> aileron deflection
Jim I hope you see this reply Just over a year ago, I ran into the same problem, expressed a little differently. When hooked up by plans dimensions and parts, the aileron does not deflect the required or recommended amount of degrees. The two things I did to correct this condition were as follows: 1) I installed a spacer to bring the aileron pushrod into a straight line with the bellcrank end on the aileron, so the pushrod would actuate completely horizontal, instead of at a downward angle. This made the actuation smoother throughout the range of motion. I had sent Dan Heath pictures and he saw bent rods and mis-alignment. I believe the spacer is about ¾ of white plastic between two AN3 washers. 2) Larry Flesner sent me an email detailing how he had taken the aileron bellcrank and re-drilled the connection hole to the stick cable ½ closer to the pivot hole, (which is actually ½ further away from the fuselage) to increase the rate of deflection per amount of stick movement. After making both adjustments, I found my ailerons to be like Larrys and actually have the same sensitivity as the elevator does. True control harmony was achieved. I have 32 hours of flying like that and no complaints. And I do get the recommended 20 degrees up and 10 degrees down now. Colin N96TA
KR> 1835 - 1915cc
Ben I previously had an 1835 with large 2180 jugs for a 1915cc engine with Zenith Carb. I was originally told by two recommended prop people to put on a 52x48 prop, but this killed the power, and restricted rpm to 2100 rpm. I bought a prop on ebay 52x42 and loved it. Solo I was getting 1000 fpm climb thru 3000 feet (I live in Florida so we are always starting near sea level). I did several flights with the new prop very happy and began really enjoying it, and testing speeds etc After about 28 hours I began to test more weight, working up to passenger weights. I reached 120 pounds with full fuel, and me at 200, 15 gallons of fuel, for a total takeoff weight of 1050 pounds. All previous testing had been on similar days to Oscars flight, winter days with temps 50 to 60 degrees F. This particular day was 80 in late February, with a humidity of approximately 85 to 90%, typical of normal summer days in Florida. I originally took off from Sanford with half fuel, because Massey Ranch Airpark (yes the same place WW operates out of) had fuel available to the public for nearly a dollar cheaper per gallon, and was in my test area. So I flew directly there about a 15 minute flight, landed uneventfully and filled up. Fired up, engine run up, and away I went, time now the middle of the day 12 to 1:00. The KR2 accelerated poorly, and would not build sufficient speed to break ground. I always had previously lifted off before mid-field, and this takeoff I was still rolling then. I finally forced the KR2 into ground effect by using a soft field technique, and accelerated with approximately 5 feet of altitude. At ¾ of the field I hit 100 mph, and did a 2 G pull up to clear the trees at the end, and the KR settled into a 150 to 200 fpm climb. I had to maneuver to the west to avoid an antenna which should not have been an issue, but this time was. At 500 feet the engine seemed to gain power, and continued to climb at approximately 450 to 500 fpm. This was my last flight with the 1915cc engine. After this flight, it was my contention that my personal experience and the reports of other pilots through the Krnet confirmed that anything less than 2180cc in power was too little power for two people. I good solo plane could be built on less, say 1835 or 1915cc, and do fine. But a true two passenger plane would need the 2180 or better for weight over 900 pounds. I felt like I had truly tested this engine with 3 different props, and different weights, and found it just too small. I sold it and now have a Corvair that I am finishing the conversion. I am not saying that two cannot fly with an 1835 or 1915. What I am saying is that based on my testing, on any day that is not ideal for making best power, hot humid days, increased elevation, etc the safety margin of performance goes away. In my opinion, and to quote my DAR who has completed 15 aircraft in his lifetime Jack Murphy, Colin, you can never have too much horsepower. Thats why I am putting a Walter turbo-prop where an O-360 used to be on my latest 4 place plane. As always your results will vary . Colin N96TA
KR> AMY progress
Hey Mark J What is AMY PROGRESS? Just curious on Friday. LOL Ok back outside to the plane Colin N96TA
KR> master cylinders
Ok gang I have learned from the original builder that the master cylinders came from C172, and could be McCauley or Cleveland depending on the year and whether the upgrade had been performed or not. Has anyone dealt with these style that look just like a Cleveland model 10-21 but have a plastic center and NO snap ring retainer. I just dont want to break them if I can help it, but they need new o-rings. Thanks in advance again, Colin N96TA
KR> master cylinder o-ring kit
Ok netters I got the master cylinders apart with a home made tool, Oscar referred to it as a spanner wrench. I dont have a better name for it, but its roots are from an adjustable wrench (metric size*) and two M10 1inch grade 8 bolts and nuts. Works great, and will accommodate any sizes from 10mm or approximately ¾ (remember this is a metric adjustable wrench*) to 65mm or approximately 2 5/8. Now I just have to find the matching o-ring kit since this is a 10-21 master cylinder, and Aircraft Spruce only sells kits for 10-34 cylinders. Colin N96TA *Ask the man at Lowes in the tool section where to find this special metric adjustable wrench. HAPPY FRIDAY!
KR> Ethanol
It is my understanding that this why alcohol and straight pump gas has never been endorsed by the FAA: alcohol absorbs water. Water in fuel creates a nightmare of problems from freezing at altitude to low power, etc That is why MOGAS at airports has the same rating in octane but is refined differently. Personally, everything I read leads me to draw the conclusion that the engine of the future in GA aviation will be run on JET A, kerosene. They already have several diesels that run successfully on it, and it is just a matter of time before they eclipse the gas engine with popularity. The slower burning and power making diesel also work wells with props. A light weight version would be perfect for the KR2, Zenair, Vision crowds. But what do I know. I am just a southern mechanic from Georgia Colin Rainey N96TA
