109jb

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Everything posted by 109jb

  1. 109jb added a post in a topic Main gear technical drawings   

    I haven't flown my gear yet, but the design is in this post on my thread.  http://avidfoxflyers.com/index.php?/topic/7354-another-kitfox-iv-rebuild-project/&do=findComment&comment=68547
    This is a thread on my ponderings about the gear and my design of it. http://avidfoxflyers.com/index.php?/topic/7688-fuselage-landing-loads-kitfox-iv-and-cabane-gear/
    The landing gear is shown in this picture. FYI, I'm about ready to get the engine running again, and then small stuff before it flies again.
     

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  2. 109jb added a post in a topic A project with limited time - setting realistic expectations?   

    Do you already have the kit?  If not and you are thinking about ordering a new kit, you won't even get it before next April.  Unless you already have a line on an available kit you would also be hard pressed to find an uncompleted project even.
     
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  3. 109jb added a post in a topic Which is the Widest cockpit and useful load   

    NO, NO, NO. 
    The useful load is the maximum gross weight - empty weight. The maximum gross weight is dictated by many things that all interact together. For more gross weight you might need more wing area, or more horsepower or both, but then you also have to address the structure to carry the additional weight. If you don't know what you are doing, then you could actually make a heavier airplane that has even less useful load. Or worse yet, you could go fly and find out the hard way that the structure isn't up to the task. Unless you have engineering knowledge on how to do this, then you are best off finding an existing design that already fits your needs and has the useful load required rather than trying to redesign one.
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  4. 109jb added a post in a topic Rotax 447 vibration diagnosis   

    So I was able to fly it again after changing the mounts, balancing the prop, and fixing the prop tracking issues. Vibration is still there but definitely much less. On inspection I see that one of the started bolts can touch the firewall with very little effort. I'm thinking this may be the issue and will address.
    I do have a question though. When flying yesterday, operating at about 4000 rpm descending from downwind, the EGT on the front cylinder got much too hot for my liking. Wound up chopping it, descending, and then bringing in power but with more load on the prop to get it down. The descent was not unloading the prop much at all, and on my 582 powered Kitfox would not have been an EGT issue.  After flying I lowered the clip one notch on the jet needle and will try that, it is now at the lowest notch, but I remember on my 582 I went from 11G2 needles to 11K2 needles to correct the midrange lean spot in the 582. Is there a similar change for the 447? It currently has a 15K2 stock needle and stock 2.70 needle jet. perhaps I need a 2.72 needle jet?
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  5. 109jb added a post in a topic Rotax 447 vibration diagnosis   

    Yes. I have a balancer I made for GSC props. One 1/4" washer 6 inches from center can be detected. 
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  6. 109jb added a post in a topic Rotax 447 vibration diagnosis   

    Well, vibration is better, but still there to some extent. I took the prop off and re-varnished the blades, checked balance and set pitch on very flat table. Prop flange checks good on dial indicator and tracking with prop installed is within 1/16". Through all of this, I found that the initial tracking was off 3/4", and balance was a little off but brought into balance using a few additional washers on the hub. Ordered new engine mounts, and it looks like the aluminum angles bolted to the engine block have been rubbing the steel tube mount bolted to the firewall.  I will take a burr and die grinder and put a little relief in when I replace the rubber mounts and see what happens.
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  7. 109jb added a post in a topic Rotax 447 vibration diagnosis   

    The current prop is 60 inches and the ground clearance is marginal in my book. Another reason for slightly larger tires. 64" would be 2" close to ground and would not work IMO. 
     
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  8. 109jb added a post in a topic Rotax 447 vibration diagnosis   

    Thanks. I will check those things out.  Overall I'm really happy with the airplane. It flies really well although it does have a couple little quirks. Visibility over the nose is fantastic on the ground requiring no s-turns at all, but the flat attitude has a drawback. It sits flat enough that a full stall landing would really "hook" the tailwheel and slam the mains on. I'll just have to figure out how tis airplane "wants" to be landed. It wheel lands really well and the ground handling is a piece of cake. In-flight it handles really well except has a lot of adverse yaw which may be due to the non-plans aileron design, but it is easily manageable. Overall I'm really pleased with the airplane because I got it pretty cheap. I'll do what I can with the 447, but eventual plans will be to put a 1/3 Corvair engine on it. I happened to have a Corvair engine project that was for another airplane that didn't pan out, so I'm going to use the Ultravair plans available online and build the 1/3 Corvair for the J3Kitten. I'll be flying it with the 477 until then though.
    Thanks again for the tips. I will let you know what I find.
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  9. 109jb added a topic in Rotax and other engines   

    Rotax 447 vibration diagnosis
    Not really Kitfox or Avid Flyer related because it isn't either but you guys have helped before with tuning on my 582 powered Kitfox so thought I would give this a go here.
    I sold my 582 powered Kitfox 4 and in its place I bought a Rotax 447 powered Hipps J3 Kitten that I've nicknamed "Patches" because of all of the fabric patches I had to put on to make it what I consider airworthy.
    Enough introduction, now to the problem. The engine seems to be running well except that it vibrates. Power is good and getting 6200 RPM in a comfortable climb. The vibration happens at pretty much all RPMs but it is more noticeable at mid-range RPMs. This Rotax 447 is a single carb and the new digital EGT gauge I installed shows the EGTs are running in the 1000 to 1100 deg F range at everything above low speed. The EGT spread between the 2 cylinders when cruising and vibrating is only about 20-30 deg F, and CHTs are about 350 (analog gauge) and appear to be very even. These things have been done or are just other information. New BPR8ES plugs (inverted engine) gapped to 0.015", 2 blade ground adjustable GSC propeller 60" diameter.
    This is what I plan to check next:
    Both prop blade pitch anglesProp balanceProp trackingCylinder compressions for good and evenAny other ideas?
     

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  10. 109jb added a post in a topic Kitfox 4 1050 for sale   

    Sold.  The Kitfox went to a new home today.
     
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  11. 109jb added a post in a topic Kitfox 4 1050 for sale   

    Price reduced to $27,000
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  12. 109jb added a topic in For Sale and wanted, you got it, I want it   

    Kitfox 4 1050 for sale
    FAA finally got the registration to me, so I'm selling the Kitfox 4 1050.  Asking $29,000. Details in the pdf at this link. https://drive.google.com/file/d/1GEExdq3N1pKNp7ydmuPsxSQTRP219fHe/view?usp=sharing
     

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  13. 109jb added a post in a topic Ideal Idle RPM   

    Not a 670, but on my 582, with stock jets I could never get idle below about 2200 rpm without it hammering and running rough. It was way too rich. If I remember right stock idle jets are 55.  After re-jetting I can idle down to about 1700 before it gets rough and that is with 40 or 45 idle jets. I set idle to wherever it will not quit or run too rough on the ground. Right now it is set about 1600 rpm which is fine and smooth until the last part of roll-out on landing and then it starts to hammer a bit and I just bring the throttle in enough to smooth it out.
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  14. 109jb added a topic in For Sale and wanted, you got it, I want it   

    WTB Rotax 582 Ignition coil
    EDIT:  Never mind. I found one an hour away from me.
     
    Went to fly and the ignition check showed one side dead. I switched the 2 coils around and the problem followed the coil, eliminating the stator, pickup and ignition switch. So, my Kitfox is in need of an ignition coil. If anyone has a good used ignition coil for a Rotax 582 they would be willing to sell, let me know. Would like to get it quick because I go in for a surgery on July 11th and would like to get some flights in before I am laid up.  Alternately if someone would loan me one until I can get one elsewhere I'd go for that too.
    Thanks,
    John Brannen
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  15. 109jb added a post in a topic 109JB got another wrecked Kitfox   

    This airplane has a 10 gallon header tank behind the instrument panel that the gauge is hooked to. It only has a 6 gallon wing tank in the right wing. That one has a sight gauge.
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  16. 109jb added a post in a topic 109JB got another wrecked Kitfox   

    Some pictures while flying today.
     



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  17. 109jb added a post in a topic 109JB got another wrecked Kitfox   

    Got some pictures of the airplane in the sunshine yesterday.
     





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  18. 109jb added a post in a topic Ridgerunner for sale on barnstormers   

    No n-number anywhere on it. With the 582 I doubt it is under the 254 lb for ultralight. Would either have to fly illegal, or would probably be hell to try to get an airworthiness and registration for it.
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  19. 109jb added a post in a topic mark1VHH wing ribs   

    Aircraft spruce has 12 ply 6mm birch plywood
    https://www.aircraftspruce.com/catalog/wppages/finnishbirch.php
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  20. 109jb added a post in a topic 582 thoughts   

    If it was kept inside a heated building I would not have problem with it as it isn't likely that it got a bunch of condensation and corrosion in it.  I just got my 582 on the kitfox I rebuilt running again. Not sure exactly how long the 582 gray head sat but it was at least 7 or 8 years. Has 200 TT on it. Sat in an unheated shed in northern Illinois so much worse than you describe.  It has been running fine for about 10 flight hours now. What I had to do on this one was replace the end crankshaft seals as it would leak from them.  For any unknown 2- stroke I would do the following:
    Do a pressure test of the engine. This involves removing and plugging the exhaust, removing and plugging the carbs, Plugging the pulse port, and then using a low pressure gauge, pressurize the engine to about 5 or 6 psi. It should not leak more that about 1 psi in 5 minutes. If it does there is a leak that needs to be fixed. 
    Mine leaked at the end crank seals so I had to split the case and replace the seals.  While it was apart, I decarboned the pistons, checked the crank and bearings, and put it back together. It really depends on how handy you are if this is within your abilities.  I have been messing with engines of all types about 45 years so wasn't concerned.  I also had a snowmobile that had a Rotax 580 in it (1993 Ski-doo grand touring 2-up). The sled engine is pretty much identical to the airplane 582 with a few minor exceptions. That sled engine had 7,000 miles on it and was 20 years old when I sold it and was still running strong.  
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  21. 109jb added a post in a topic 109JB got another wrecked Kitfox   

    The airplane is running great now and I got a chance to make a short flight today and made a couple videos. Both are actually the same portion of today's flight but one is the 360 degree version that you can pan around in. The 360 video is still processing in youtube but should pop up soon.
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  22. 109jb added a post in a topic Evaporated fuel residue   

    Definitely not as fast as denatured alcohol, if really at all.  In the old days I used to use auto gas as cleaning solvent for carb parts and it never did very good at removing varnish from carb bowls and such. Denatured alcohol on the other hand dissolves old gas and varnish almost immediately. Since I discovered this I always have some on hand and use it for cleaning carb parts where I used to use stuff like berrymans dip tank, mineral spirits, etc.
    That said, On the kitfox I recently rebuilt there is a 6 gallon fiberglass wing tank that had/has a bunch of gunk in it from evaporated car gas. Not knowing if the denatured alcohol would harm the fiberglass, I decided to cap the outlet line and put in 3 gallons of 100LL with hopes that flying around and letting that 100LL slosh around in there will dissolve that junk. For now I am flying it only on the 10 gallon polyethylene tank between the instrument panel and firewall until I can get the wing tank clean enough to flow uncontaminated 100LL from it. I unfortunately have no place I can get ethanol free car gas, so that tank will only see 100LL for now.
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  23. 109jb added a post in a topic WTB 8" wheels   

    A pair just popped up on TeamKitfox.
    Douglas 8" wheels (teamkitfox.com)
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  24. 109jb added a post in a topic 109JB got another wrecked Kitfox   

    Update:
    The floats from my spare 912 carbs worked great. Was still seeing high EGT n the old Westach dual EGT gauge, but everything else said I should be OK. I decided to buy a new digital dual EGT from GlowShift. Got it installed today and was able to fly for about 1.5 hours. The EGTs were fine. Pretty much any level or climb RPM and I was seeing about 1100 deg F, about 1150 in a slight descent.  I was seeing 1300 at times with the old gauge.
    Brings up a question though. With my DIY hacman, I can get about 50 deg F rise on EGT. Seems like that is a little weak.  I can change my orifice for one with a smaller hole but before I did that I wanted to see what others get.
    Thanks,
    John B
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  25. 109jb added a post in a topic 109JB got another wrecked Kitfox   

    Well, the 912 carb floats worked fine in the 582. I got a chance to fly it a little yesterday and it ran fantastic. Only up about 45 minutes because of weather but it was enough that I think a little more prop pitch and all will be dialed in.
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