Activity Stream

Activity Stream

  1. Turbo added a post in a topic Building New Wings   

    I've got to agree with Manu here.  It would be dangerous to go beyond the span of the STOL version without a stress analysis.  In my opinion, the STOL version's airfoil has too much camber, which conspires to limit top speed.  I'm not the greatest tailwheel pilot, and am thankful for the lower landing speed with the greater span and area of the STOL  Camber does not translate directly to max lift and low stall speed, but more wing sure does.  I think you're nicely set up to get the best of both wings, cruise speed closer to the smaller speedwing, and a lower stall speed for easier landings, and improved safety if you ever need to make an outlanding when the prop stops turning.  If you have the tri-gear config, or lots of tailwheel experience, and see your bird's primary mission as getting from A to B, and fly in a place where there are lots of good spots for emergency landings, maybe the speedwing is your ticket.  This is what's so great about experimentals!  Of course, we'd all love to see some pics!
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  2. lostman added a post in a topic Not an airplane anymore   

    What is the thin white foam you are using? It looks like it is bending and conforming well to make nice curves without a ton of sanding and making a mess. Looking good. 
     
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  3. Extrados added a post in a topic Avid MK IV build manual   

    Many thanks!!! Akflyer!!
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  4. nlappos added a post in a topic The unquenchable EGT   

    THe main problem is that we all post what we believe, or what we were told, or what we remember, so it becomes clear as mud. Then we say stuff like "wow it's confusing." No it is not confusing, it is as clear as can be, if we bother to just read what the manufacturer said to do. This is from the installation manual, written 19 years ago:
     
     
     

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  5. NorthIdahoAvidflyer added a post in a topic The unquenchable EGT   

    I found two other places where it said to place the probe out 100 mm from the piston skirt on a 582.  I believe you are right that the probes could be close to the specified location and you may not see a lot of temperature difference. When my probes were out at 3.5 inches the EGT's showed over 1300 every time I ran it. Mind you the tips of my probes were still stuck all the way through to the outer edge of the pipe so I could not really tell you what actual placement difference makes. It makes sense to me that if you put the probe in the hotter part of the flame that you will get a higher reading. From gas welding you will learn that the tip of the cone is the hottest part of the flame and the inner cone is the cooler part of the flame. It makes sense that the probe should be placed inside the center of the cone. The goal is to monitor the relationship between the mixture and the heat being exerted on the piston. I will be able to tell you more once I install the new probes how much of a difference tip placement really makes.  
     
     

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  6. efil 01 added a post in a topic Building New Wings   

    engineer turbo will confirm
    but i guess you gain  lift because more suface, and lift because  more reynolds number due to new wing span;
    fast calcul for complete extension :
    wing area is approx 4/3 more so you will gain minimum 1,33 more lift.But it is not completely true because washout reduces lift but on other side with more  stability at the edge of stall
    i guess you to not going longer than standard stol wing because it will change the max momentum at the wing strut liaison, and spar may not support new flexion at Gs avid is certified for. And the tail will not assume whole control if wing area is to big.
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  7. japowell added a post in a topic Building New Wings   

    How much does the flight characteristics change? What are the advantages of doing the extension?  I'am building new flaperons also, so it doesn't matter if I go 2 or three ribs.  What will each give me?
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  8. efil 01 added a post in a topic Building New Wings   

    it is usually ( for stol span) 2x18 or 3x12 per wing, perso i made 1X18 and recover lift by airfoil, so kept short flaps ( a bit extended)
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  9. japowell added a post in a topic Building New Wings   

    Thanks Turbo.  When you do the extension, is it usually just two rib spaces or is it more? 
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  10. efil 01 added a topic in Avidfoxflyers General Hangar   

    control linkage friction
    hi,
    yesterday i made some rigging, i find control colon for stab is not moving freely, there's some friction on the long command going in tail. i've read on manual commands must be tied and not loose, but in this case i really wonder if the air will act on stab to feel micro variations. i'd like input from experienced pls; do i have to trim somewhat or just put some oil ? do i need to have a very light mouvement on control colon? thx
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  11. efil 01 added a post in a topic Manu's Avid C   

    thx turbo, we already have talk here about trim:
    the diff between real tab and stick force mitigation is in case of broken linkage , with tab you can keep control on flying.
     
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  12. Willja67 added a post in a topic Not an airplane anymore   

    Going slowly but still going

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  13. Turbo added a post in a topic Building New Wings   

    Manu, that's what I thought.  Metric sizes!  Japowell, if you decide to extend the span, make sure your span extensions are 6061-T6,, 2024-T3, or 7075-T6.  The alloy of aluminum used is important, as some are much stronger than others.  The 3 listed here are among the best.  The original design uses the first one.  It is the weakest of the 3, but is very corrosion resistent, and is safe, as the wings will take a permanent set if overloaded long before they fail.  
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  14. lostman added a post in a topic Hunting with your Avid, August 2018   

    Awesome pictures as usual Randy. Are you guys using an electric fence around the planes? Are those new wingtips on the Avid? 
     
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  15. Turbo added a post in a topic The unquenchable EGT   

    Wow! Another clear-as-mud discourse on where to drill the damn hole!  It'd be tempting to just get a new Y-manifold with the holes pre-drilled, but for the doubtless exhorbitant price!  Isn't EGT really only about keeping the plugs clean without melting a piston?  If mine read high due to the probes being too far downstream, i reckon it's conservatve if the probe tips are centered in the ducts.  I think I'll validate the latter, then call it good enough!   Thanks for digging into this, Vance!
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  16. Avid Randy added a post in a topic Jab on Barnstormers   

    You have got to be kidding me!  I watch for a Jabiru about every day.  Just put alot of money into some other projects and now one comes up very close!  This is basically in my backyard  (about 1 hr away)
    Vance if you are serious about it and the seller would not be interested in shipping. I would be willing to crate it up for you and ship.  Cheers Randy 
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  17. TJay added a post in a topic Fuel Tank Suppliers   

    I have one Ill sell ya its for a kitfox
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  18. Yamma-Fox added a post in a topic Jab on Barnstormers   

    That's a good report.  Yeah my research might have been lopsided due to the old "negative experience collection pool" effect that internet forums tend to magnify:
    Example: There may be 100,000 Ford 6.0 Diesels out there, 95,000 of them run great and owners never visit the forum.  But the forum has 5,000 reports of head gasket problems so you read that and figure it is a 100% problem when it's actually 5%.
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  19. NorthIdahoAvidflyer added a post in a topic The unquenchable EGT   

    http://www.ultralightnews.ca/exhaustsystems/egt_probelocation.htm
    Here is the link to the article. It’s dated Sept 18. 
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  20. Allen Sutphin added a post in a topic The unquenchable EGT   

    Find a newer engine to look at. The newer engines have prewelded bosses on the manifold in the correct location.
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  21. Turbo added a post in a topic The unquenchable EGT   

    Just to muddy the waters even more, the 1990 build manual says to drill the holes for the EGT probes 4" away from the lower edge of each flange, measured along the bottom centerline of each branch of the "Y" (this is indicated in a sketch).  It also says, in a footnote: "Absolutely precise location of EGT probes is not critical.  The attaching bands will 'effect' {affect} exact location.".  Oh Boy!  It appears likely that new things have been learned since 1990!   My probes are certainly not 38mm out from the flange center, more like 50mm.  So Vance, where did that drawing come from?  Does anybody else want to chime in here?  I've been believing that my EGTs were significant.  I was even contemplating a T-compensated digital gauge to replace my analog ones.  If location of those probes is more critical than it says in my 1990 build manual, I at very least will be more careful about keeping my EGTs away from the 1200F limit.   My probes are about 3-1/8" out from flange bottom, measured along the bottom of the Y branches on centerline.  Any further out, and the bands wouldn't fit.  . 
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  22. japowell added a post in a topic Fuel Tank Suppliers   

    Does anybody make the panel mounted tanks?
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  23. EAA1044Youthbuild added a post in a topic Tail offset for engine rotation   

    Thank you all for the input and suggestions. We have decided to go with a straight tail to accommodate any engine in the future. This part of the restoration was a great exercise for the kids. They got into AC 43.13 to learn the proper way to fabricate gussets for the tubes that were cut. A chapter member then showed them how to weld. Now, on to fuel tank fabrication.....
    Curt
     
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  24. japowell added a post in a topic Avid Flyer Seats   

    Thanks, that looks easy to do.  Looks time consuming but it could be fun.  Thanks
       
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  25. Turbo added a post in a topic Manu's Avid C   

    Very well done!  I look forward to your flight testing, with your improved wings, and this excellent trim installation!  I suspect that the standard Avid trim tab is bigger than it needs to be, so it will be very interesting to see if your "add-on" tab approach works adequately.  I have only a stick-force mitigation setup, similar to JimChuk's, which almost works, but there's no substitute for a real trim system..
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