Activity Stream

Activity Stream



  1. lostman added a post in a topic Hall Vortex generators   

    Any time you can get the boundary layer thicker (thicker is good) it helps overall to reduce pressure drag. With the wider cockpit that the Pursang has I can't help but wonder if there disrupted airflow, which would reduced effectiveness of the tail group or at least very cause very turbulent air. Thus installing them over the top of the skylight may help increase the boundary layer, reduce the pressure drag and allow better and hopefully less disrupted air flow to the rudder and elevator....at least that's my theory.
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  2. High Country added a post in a topic LIFT STRUT TEST   

    Thanks for putting this up Ed, I've been thinking about my lift struts lately as I have the original 3/4" struts and am looking for the best way to go. Been thinking about just cutting the tubes about 6-8" from the ends and sliding 7/8" - 1" tubing over the stubs and welding it all back in place. seems to be the easiest way to strengthen them. I think the ends are supposed to be strong enough. what are you guys' thoughts? If I have to build them both from scratch I'm thinking it might be good to add a rod end to both sides...
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  3. dholly added a post in a topic Hall Vortex generators   

    Ok, help me out here. Why is this a good idea?
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  4. lostman added a post in a topic Hall Vortex generators   

    I just installed a full set of VG's that I made to the top of my under cambered wing. I extended them across the top of the skylight as well. I forgot to count them but there is a bunch installed now. I ended up making 24 more to finish the job. I did the math and knew how many I needed but I used the 24 before to install under the tips and horizontal stabilizer.
     
    I should be able to fly tomorrow morning and see what results I get out of these. The next step will be to make fairings for the fuel caps. I'll write up a different thread for that one after reading about what they may help with.
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  5. lostman added a post in a topic VG's on underside of HH wing   

    Randy,
     
    How did you attach your current VG's? I take it you used something a little more than temporary? I have my methods but I'm wondering what you did.
     
    I got all my VG's installed on top of my wing yesterday but we've had terrible weather the past two days. It should be good tomorrow for testing though.
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  6. akflyer added a post in a topic Model A cable brake rudder pedals   

     
    He did   hence him sending a check for the parts HC could find
     

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  7. EDMO added a post in a topic Model A cable brake rudder pedals   

    Sounds like you need to PM High Country and see if he can find his?
    EDMO
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  8. EDMO added a topic in Files and Forms   

    LIFT STRUT TEST
    Attached is copy of Kitfox lift strut test.  Note that the Kitfox 2 used 7/8" diameter struts.
    The thumbnail is large, and when you click it gets larger - someone can resize it if need be - I donno how!
    EDMO
    Also NOTE:  I don't think there was any wood on the struts for this test!   But, this was a test in tension, and not in compression.

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  9. akflyer added a post in a topic Wing Strut Wood   

    http://www.avidfoxflyers.com/index.php?/topic/264-m-t-o-w-modifications/?p=1010
     
    This is a previous discussion that Doug posted up.  It goes deep into the max weights and the reported testing.  I know I have seen pictures and write ups of the load tests someplace on the web and I will see if I can dredge them up.
     

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  10. akflyer added a post in a topic Wing Strut Wood   

     
    The one rod end I have just had a stack of washers in there to take up the space.  It has held up just fine for 600 hrs that I know of
     

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  11. EDMO added a post in a topic Wing Strut Wood   

    Randy,
          I was the one who posted the strut tests - could have been Kitfox tests - anyway, I cant find it in files and forms, or other places - Cant remember what title I put on it - I think that Doug wanted to copy it
    - I will look in my books and if I can find it, I will post it again and let you know.
          If the standard rod end lasted up to 15 Thousand pounds, then I presume it is safe to use it - I would be gone by 15 g's anyway!
    The rod end is for a 1/4 inch bolt.   The same size is used on the 1700 gw Magnum......so, figure?
    One thing I might add:  When the strut end was changed to a rod end, they narrowed the space on the Spar fittings to match the rod ends.   Would a spacer or two work for that with the old Spar fittings?
    EDMO
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  12. akflyer added a post in a topic Wing Strut Wood   

     
    The AD (Avid Directory) states that the wood fairings add strength under compression loads.  I upped my struts to 1" X.058" so I could use the Kitfox PVC fairings.  They added a lot of weight, but also helped a bunch in cruise and climb.  My original struts had the wood fairings, but they were not bonded well nor sealed well and they rusted out BAD under the wood.  As I use the plane on floats the last thing I wanted was wood fairings that hold moisture!
     
    Here are the AD's that I have and AD 007 is the one that talks about the counterweights and the wood fairings.
    Avid AD's.pdf
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  13. SuberAvid added a post in a topic Wing Strut Wood   

    There was a KF at Birchwood with 2X4's for lift struts (wish I had a picture of it now).  Of course that was after the heavy snow we had that year collapsed the struts.      Obviously the lift struts will take a lot more in tension (pos. G's) than in compression ( neg. G's).  The question is, that is the weakest link?  I had heard the same thing about the wood fairings being a required structural necessity and I am sure they add some strength but one would have to see the calculations to see if they are the weakest element in the system of the wing.  The rod end apears to be a weak link and I need to try to find some information of the alllowable working load for them in tension and compression.  Does anyone have that?  I would like to read the strut test information Ed mentions also if anyone knows where that is located.  It may save me the effort and expense of cutting up my 7/8 lift struts and welding in 1" tube.  The 1/4 " lift strut attach bolt have been mentioned as possible weak links as well but they are in double shear loading verses single tension/compression loading so I don't think they are the weakest link but need to check them. 
     
    Ed, your right, it only needs to be as strong as needed with a reasonable SF (1.5).  Anything else is just extra weight.
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  14. EDMO added a post in a topic Stewart Systems paint?   

    Nice paint job - wish I could get someone to spray mine like that.
    EDMO)
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  15. EDMO added a topic in Close Call's and dumb stunts   

    Skydiver nearly hit by Meteor!
    This was on the news today - Just goes to show that jumping out of a perfectly flying airplane is STUPID!
    EDMO
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  16. Trackwelder added a post in a topic Wing Strut Wood   

    I believe after lookingat steve wittmans Buttercup and Tailwind Plans, that the Jury struts are taking the need for the wood fairings extra buckling strength out of the picture, I remember the amount of load that an unsupported Avid A model wing could take and believe that you could get away without the fairings. That said, the aerodynamics mean that some sort of fairing needs to be on there.
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  17. EDMO added a post in a topic Wing Strut Wood   

    Someone said that Dean Wilson flew the early (3/4?) struts at 1500 TOW (without spar inserts?) and they held - then they went to 7/8 and now at 1 inch with spar inserts - I can't see a piece of wood that probably only stiffens them fore and aft, with most of the stress being up and down, doing much good.  Good engineering has a safety factor of 150% - Don't you think that Dean is a good engineer - and look at how much stronger we make struts now.
    I think all the wood or fiberglas fairings (and Joey's Lexan) are good for, is drag reduction.
    The strut tests on the 7/8 was posted on here - may be in "files and forms" - and they held to about 15,000 lbs - and the rod end failed.
    Yes, that was 15 Thousand - Not a misprint!
    EDMO
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  18. Trackwelder added a post in a topic Model A cable brake rudder pedals   

    I found the PM and sent the check, if it doesn't cover postage let me know, I don't want you helping me out to cost you anything.
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  19. thebriman added a post in a topic Classic IV Restoration   

    Excellent work!  I especially like your tail upgrades!
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  20. SuberAvid added a post in a topic VG's on underside of HH wing   

    Ed,  You're right, with the IFA I can fly at 90mph at 4000 rpm or 3600 rpm.  The boost/vacuume gage I put on is really worthless, just not acurate or fine enough to be of use, so the best way I have found to judge the load on the engine is with the fuel flow gage.
     
    Mike, I think your right, just installing them on the outboard half of the wing would probably accomplish almost the same thing since that is where the most drag would be and it might lessen the slight loss of roll authority.  I might do that on my next set of wings.
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  21. thebriman added a post in a topic Wing Strut Wood   

    I know of a Kitfox 4-1200 without them.  The wings are still there.
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  22. lostman added a post in a topic Ice Fishing   

    Looks like you've hit a couple things! Glad it's still holding up at least until you pull it off for summer (or in your case, not snow) flying.
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  23. lostman added a post in a topic The 180.. saving a ramp mummy   

    The 180 is family and is already not a cheap little kid!
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  24. Av8r3400 added a post in a topic Wing Strut Wood   

    The Yahoo group is almost a non issue any more.  Any relevant data is nearly gone.
     
    I have seen that conversation, too.  I wanted to join, but decided against.
     
    As Joey said, if the wood is really structural, than my Mangy Fox should have folded in the first 200 hours of it's life without them.  They add 8-10 mph in cruise.  To me that makes them pretty useful, but I don't think mandatory.
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  25. C5Engineer added a post in a topic Wing Strut Wood   

    I've seen them without and Kitfox sells a retrofit kit just for those. This is strictly my opinion but if that wood glued on there makes the difference of my wings folding or not I am really scared to go flying again!! It does add some rigidity but I don't think it's that much.
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