Activity Stream

Activity Stream



  1. EDMO added a post in a topic Lexan turtledeck   

    If you are just wanting a rear window, you have a choice of bending Lexan or using aluminum sides and Lexan for the flat top.  Another option is to use Lexan for the top and sides and join them with aluminum angle.
    Lexan can be bent over a form using heat lamps or a heat gun - I think about 265 to 275F is the max temperature.
    The turtledeck is supposed to slip under the skylight, so you put the same thickness spacer as the Lexan turtledeck under the trailing edge of the skylight and a strip of aluminum under that.
    EDMO
    I like the light bronze for turtledeck and windows, and the dark for the skylight, but you can also get the light and dark green tints.
    • 0


  2. Av8r3400 added a post in a topic Lexan turtledeck   

    "Plexiglass" will not bend to make one of these, it will crack and break.  "Lexan" is bendable enough to break corners like this.
     
    The newer Kitfoxes (4-SS) that have these use a different style flapperon hanger on the wings that flexes much less than the extended ribs tails of an Avid or early Kitfox.  The bearings on the horn end of the flapperons are critical on the Avid style flapperons to keep them rigid and free of flutter.  Therefore, retrofitting a newer style Kitfox model will not work.  The bearings need to be snug.
     
    I think Joey has one on his Avid, but I don't know where he got it from or how it's configured.
    • 0


  3. Trackwelder added a topic in Technical tasks   

    Lexan turtledeck
    I have seen the plexiglass or lexan tinted turtledecks on Kitfoxes, does anyone make them for Avids, or  has anyone tried to make them from Big Box Store Plexiglass? I have heard conflicting stories about using what is available locally does anybody have experience? I had planned on using a hot wire and bending it to fit, I have also been told that it can be bent on a brake, but mine is only 40 inches and not long enough.
          While on the topic, I planned to use .125 inch for the turtle deck, does the cabin roof need to be that thick or could I get away with less?
    • 12 replies
    • 2,454 views


  4. Av8r3400 added a post in a topic rotax radiator flush   

    Flush with distiller water, or distiller water Dextron (pink) mix.

    I wouldn't use anything else.
    • 0


  5. FoxDB added a post in a topic Avid B model to MK4 Elevator upgrade   

    So Joey,
    VG's on wings next?
    Dave
    • 0


  6. EDMO added a post in a topic Cant open Avid Manual series...Can Someone give strut attach measurements?   

    Luke,
         I understand what you are saying - I have studied this somewhat - an engineer with all the figures could probably come up with some positive figures on it.  I have talked to one of the design engineers who did some work for Dan Denny on the early Kitfoxes, but we didn't get into this in our discussions.  So far, I have never heard of a gull-wing Avid or Kitfox! 
    EdMO
    • 0


  7. Luked added a post in a topic Cant open Avid Manual series...Can Someone give strut attach measurements?   

    Hey Ed,
     
    I'm not an expert, and I don't know what the thinking was in the design decisions. Something may have lead them to re-think their earlier assumptions. Here is my understanding of a strut braced wing in simple terms off the top of my head.
     
    The part of the wing past the upper strut attachment is the easiest to understand because it's just cantilevered. All things being equal, the longer that section becomes, the more bending stress it will experience near the strut attach (the point of highest bending for that section). So, if you make the wing longer but leave the strut attached at the same distance from the root, the spar gets higher bending stress at that point.
     
    The part of the wing that goes from the wing root to the strut attach point is a little more complicated. It's like a simply supported beam except that it has that cantilever section extending out to one side, and the strut is applying a compression force to it (when G load is positive). To get into the stresses on this part of the wing, you would want to do a shear and bending diagram (and free body diagram showing the strut forces), but basically, all things being equal, you can say the following. If the length of this section is increased, bending stress at the middle will be increased, and resistance to compression (buckling) will decrease.
     
    The last thing to think about is the strut angle. As you move the strut upper attach point farther from the wing root, the angle of the strut becomes flatter. This part is hard to explain because you can't make as many simple blanket statements about it. A flatter strut angle means that a larger component of the force in the strut is compressing the wing spar, but as you move the strut out on the wing, it decreases the vertical force component needed to support the plane's weight because more of that vertical load is shifted to the wing root attach point. Also, the longer the strut, the less resistance it has to compression loads (negative Gs). It's kind of a balancing act.
     
    Add to this that airplanes are loaded in many different ways as they fly through the air and make different maneuvers. The ailerons (flaperons for us) add additional up or down force at times for example.
     
    Anyway, I've rambled enough. I hope I don't come off sounding like too much of a know it all jerk. This stuff is probably not that interesting to a lot of people. I like to talk about it though, and learn all I can. I probably misstated one of two things, so please let me know if I did. Also, keep in mind that the stuff above is very general concepts. Engineers consider many more factors in greater detail when actually designing an airplane.
     
    Luke D.
     
     
     
    • 0


  8. EDMO added a post in a topic For Sale: Avid Flyer fiberglass floats   

    Jim, and Trackwelder,
           Sorry I cant get to the photo and parts search right now - Minor disaster started yesterday with upstairs toilet leaking and it looks like a major teardown of the bathroom floor to replace it and all the tiles that have cracked.   I will get back to you when I can.
    EDMO
    • 0


  9. EDMO added a post in a topic Cant open Avid Manual series...Can Someone give strut attach measurements?   

    Thanks Wild Bill and Luke,  I don't know who or why the Kitfox struts are farther out on the wing than Avid's 80 inches - Guess it is because the wing is longer - But then, why was it changed from 86 5/8 to 96 3/4 on the Kitfox 4 when the wing stayed the same?
    Wish we had Dean Wilson here to talk to about it.
    EdMO
    • 0


  10. saskavid added a topic in Avidfoxflyers General Hangar   

    rotax radiator flush
    just wondering if anyone has used those prestone flush and cleaner products containing sodium citrate  on their rotax engine and if it is safe to do so? Don't know what rotax recomends just know I'm running a bit warmer than I should be for a given air temp and a bit of a gummed up cooling system is the only culprit left.
    • 4 replies
    • 1,026 views


  11. EDMO added a post in a topic FAA Registration   

    Since there is no TCDS on experimentals - How would the FAA know if the prop had been changed?  Check the logbooks and get the copies they have to make sure.
    EDMO
    • 0


  12. C5Engineer added a post in a topic Avid B model to MK4 Elevator upgrade   

    Yes a great flight! Sorry I was at the hangar on my phone and excited. So today I went out and started by washing the plane it was covered in hangar dust pretty bad. I then put in some fresh fuel, vacuumed the metal shavings off the floor, and replaced all my panel mounts which was a PIA to get to the nuts on the left side where all the instruments are. Some 6" harbor freight needle nose  and a telescoping magnet saved the day.
     
    I set the trim tab just slight nose up for takeoff and broke ground and stayed about 20 ft over our 4700ft runway and made sure everything felt right and then climbed to pattern altitude. On downwind I did some pitch changes and it felt great so I left the pattern and went to 2000 and did some testing. The trim tab has plenty of authority! The pitch felt way more solid . It was slightly heavier but not enough to really be noticeable. I did about 10 stalls power on and off and the difference is amazing. It will make a noticeable shutter and break now where before it just got mushy and started descending. I put in 10 gallons of fresh fuel today so I had 21 gallons on board and it was 94 degrees and it was stalling NOTICEABLY slower than before.
     
    On approach with the power at idle before if I let go of the stick I was a straight up lawn dart it wanted to head to the earth NOW. Today with just a quick blip of the switch I was able to fly a hands off approach no problem.
     
    I did 3 stop and goes and was able to lift the tail and sit still while holding the brakes. Before even at full power the tail wouldn't budge. Overall I am VERY pleased with this modification. Time to get my TK1 Racing gear on so I can utilize the slower approach capability. I hit tail first on every landing today and wasn't even feeling like I was getting very slow. I think there is a lot more potential there with a higher AOA.
    • 0


  13. 1avidflyer added a post in a topic FAA Registration   

    Another angle that could come back to bite you with an inflight prop is this.  Changing the prop is considered a major change and as such the FAA is supposed to be notified of that change.  If that notification has occurred, then they have paperwork showing that the plane at one time had an inflight prop.  You can get a copy of all the paper work they have on that plane, they will send it to you for about 10  cents a page (real cheap).  Something to think about......  Jim Chuk 
    • 0


  14. Av8r3400 added a post in a topic Avid B model to MK4 Elevator upgrade   

    I assume a successful test flight!  Congrats!
    • 0


  15. Luked added a post in a topic Avid B model to MK4 Elevator upgrade   

    Very cool!! Can you tell us more?
    • 0


  16. Luked added a post in a topic Can't find fuselage structural diagram   

    Thanks for the pictures Larry. That helps a ton. It will be a little while before I get to the struts, but I'll be coming back to this thread when I do.
     
    Ed, I would have just used the stock Avid struts if I was going to go with the standard length Avid wings. The KF wings are longer though, and the struts attach farther out. This changes the angle, of the struts, so the forces should change. It also makes the struts longer, so they will buckle more easily in compression (negative Gs). That's my thinking anyway. If 1" x .049" tubing worked for the IV-1200, then I would think it would be adequate for my plane.
     
    The lower attachment pictures are very interesting. I remember my engineering instructor saying that connections (vs. the members themselves) are usually where people run into problems.
    • 0


  17. C5Engineer added a post in a topic Avid B model to MK4 Elevator upgrade   

    BEST MOD EVER!
    • 0


  18. Av8r3400 added a post in a topic FAA Registration   

    Placarded as electrically ground adjustable.
     

    • 0


  19. akflyer added a post in a topic FAA Registration   

    By the regs, if it's ever had an ifa prop it will never again be sport pilot legal.... burn any log book that shows an ifa installed and make new books if you want it legal as light sport.


    • 0


  20. Av8r3400 added a post in a topic Can't find fuselage structural diagram   

    Dave's use of .065" wall tube was probably WAY overkill...
    • 0


  21. Av8r3400 added a post in a topic FAA Registration   

    E-LSA is not something that you can register as.  The only way to do it now is to build a kit that is produced as an S-LSA (Factory produced), you must build exactly as the factory does (panel, engine, all equipment - no deviations).   This provision must be supported by the factory.  Vans does it with the RV12.  I don't know if Kitfox does.  Avid is gone, you they are SOL.
     
    E-LSA allows for the builder to construct less than the 51% mandated for experimental amateur built.  Therefore you can not have the builders certificate, you can only get the repairman's license after you take the 16 hour class.
    • 0


  22. EDMO added a post in a topic Can't find fuselage structural diagram   

    Thanks Larry,
          That is just what I wanted to see.   I think most of us forget that the 7/8 struts were tested to 15 G's - So our 1" struts may be a little overkill - but it makes us feel better since Kitfox used 1" on the later models.
    EDMO
    • 0


  23. Av8r3400 added a post in a topic Can't find fuselage structural diagram   

    I took some lift strut shots of Dave's plane this afternoon.  
     
    Including one of the lower strut attachment.  
     
     



    • 0


  24. EDMO added a post in a topic FAA Registration   

    Thanks for the info ChrisB - I didn't know that another owner of an ELSA could get the repairman certificate for that plane.
    The original builder of an EAB can get the repairmans certificate without going to school.   Maintenance and repairs can be made by anyone and entered into the logbook.  If you don't have the repairman certificate, you need an A&P to do the annual condition inspection and sign it off.
    Paul, the IFA prop is not legal on Sport Pilot Certificate - only fixed pitch or ground adjustable are legal.
    EDMO
    • 0


  25. allonsye added a post in a topic FAA Registration   

    Making the aircraft attractive to a non-A&P prospective buyer was the main reason I thought it worth switching to ELSA.  But as Ed pointed out, is it really worth the hassle. And besides last owner installed IF adj prop. That would have to be eliminated before the DAR inspection. 
    • 0