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  1. akflyer


    do NOT have the cabane vee like that where it gives a straight pull through.. Do a search for gear on here and see the number of reasons why. 

    Please learn from everyone else's mistakes and do not do the same just for ease of fabrication unless you want the gear and fuse buckled and your plane wrecked.

    :BC:

     

    2 people like this
  2. akflyer


    damnit.. that little smack down should not have bent the gear... Chalk up another one to the shitty design of the spring gear not allowing enough travel before it all goes metal to metal.  I truly hope after all the preaching that has been done on here and the relatively easy fixes that have been posted (I fixed my problem in less than a day) that we don't have to ready any more of these stories of birds being bent by a very well known and documented problem. 

    Sucks that it happened to ya but glad you walked away from it and the bird will live to fly another day!

    :BC:

     

  3. FredStork


    So how do they say this... If it ain't broke, don't fix it...?

    Not all planes are alike. The Avid Flyer takes a lot of footwork and some getting used to but it has a very sane behaviour. While no one will say it is the easiest plane to fly with clean turns there are no real traps to fall into. 
    But it takes a little time to fully appreciate (well, that was actually very fast) and master (takes a little longer).

    Get some airtime before deciding what to change, if not you might not improve your plane but degrade it. By degrading I could mean just that (depending of what you used to fly before...) or change characteristics of the plane that you with more experience would have appreciated (or no longer noticed).

    I changed to the the F7A bell cranks, they have a positive impact but do not transform the plane (it still need an active pilot - luckily as that is one thing I like about it...). With just the F7A mod you do not have to disconnect anything when folding the wings.

    Regards

    Fred  

    3 people like this
  4. saskavid


    Ya know just to see if it could maybe be done I went to work and designed a mixer for my avid that should produce like 2.7 to 1 differential and still allow the wings to fold without disconnecting the controls.... Everything works.... on paper. Just a matter of getting ambition up and building the components and seeing it if actually works on a physical plane. And that is the reality. Don't have the time and ambition to tackle it. Would take a lot of time or money or both probably. Just not in the mindset to do it. Then there is also the question of how much up travel on the alerion is structurally acceptable. My plane fly's without it. for now.

    1 person likes this
  5. akflyer


    More down than up deflection.. Well known well documented issue.  The F7a arms help to fix this.  You have to get into the designers head to really understand why it is why it is.  Folding wings by just pulling 2 pins and folding them back.  The only way to get them to work was wit the mixer system set the way it is.  its called design trade off.  give a little hear for the better of the overall design goal.  Others have changed the arms in the mixer even more so that just the swap to the F7a arms and you have to pull the bolts on the flaperon linkage horn and manually roll the flaperons up then fold the wings.  it doesn't do the magic all by itself.

    Can there de refinements to the design.  Yes for sure.  Is it worth it for minimal gains?? that's a question only you can answer for yourself.  Several people have spent a ton of money trying to turn an avid or a kitfox into a supercub, its not going to happen.  Gas through the tanks is the single biggest performance enhancement you can do.  I see guys with 200K + planes that can't fly them even close to the planes potential.  I personally would not start mucking with anything on the plane other than get the roll out of it by adjusting the rod end and getting your CG back to about 16" with some weight on the tailwheel and just fly the crap out of the plane till it becomes a part of you, then you can start making little tweaks here and there if you want to. 

    Again, Just my opinion.  Put that with 5 bucks and you may be able to get a cup of coffee these days.

    :BC:

     

  6. birddog486


    To make a long story short, after a recent diagnosis of Rheumatoid Arthritis, being 6' 2" tall and having joint pain issues in the knees I'm considering selling my 2014 Avid model C approx. 60hrs. with raised skylight and turtledeck. 912ULS(350ish hrs.) extended aerobatic speed wing.

    The plane is setup as a Tri gear now but I have the complete setup for tail dragger including a set of main gear and matco 6" tailwheel. The conversion to tail dragger was complete and approved by the local FSDO after I completed phase 1 and is noted in the logbook, including W&B.

    The Kit was purchased new from Avid by my father in DEC. of 1990 and stored after a couple years. I started construction in 2011 and first flight around June of 2014

    IVO medium 3 blade prop

    Dynon D60 glass panel

    GTR 225 comm

    Garmin GTX 327 transponder

    PS engineering intercom

    GRT 4000 engine monitor 

    ACK E-04 ELT

    AeroLED landing light and Nav/Strobes

    I know the value will be nowhere near whats been invested but I'm looking for opinions on how to value this.

    Travis

     

     

    Avid Pics 006 [800x600].JPG

  7. Avid Randy


    I know in the past there have been several discussions on flap handles becoming loose.  I found this while installing mine and thought I would just throw it out there.  Probably would be more for the ones that bought used already assembled Avids since they would have no idea how or how well the builder assembled the bird. 

    The kit provides you with the F-54 friction washer that goes between the frame and the handle and it has a 1/4" hole in the center from the factory.  In the first photo you will notice the side by side photo of the washer and where it is to be installed.  The center hole is 1/4" but where it is to be installed over the shoulder of the 1/4" bolt hole is 3/8".  So the washer needs to be drilled to 3/8" so that it will fit over the shoulder and sit tight against frame and the handle when installed.  If not like the second photo the only friction that you are getting is against that little shoulder around the bolt hole and that will wear very quickly and become loose for sure if installed that way.  The manual does not reference this in any way so some may have installed as is.  I don't know if anyone has installed this way or not but just thought I would show what I found while installing mine.  The third photo shows washer installed after being drilled and this would allow the friction to be spread across the whole washer from frame to the flap handle.  Maybe this will help someone some day.  Cheers Randy  (I guess the photos got backwards but I'm sure you can figure it out)

    Flap Washer Installed resized.jpg

    Flap Washer Top View resized.jpg

    Flap Washer Side by Side resized.jpg

    1 person likes this
  8. Avid Randy


    Finally FREE!!!  Not without a lot of aggravation though!  I first started by shortening the connecting link to get control sticks to be parallel with each other and low and behold now the controls bind side to side!  Had not been prior to shortening!  I was flipping MAD after all of this!  Well shortening the link (which needed to be done) now created sharper angles when moving side to side and the same thing that was happening at the bellcrank now was happening at control stick.  The rod bearing shoulders were binding against the lower part of the pivot sockets.  At this point I was ready to throw the whole mechanism in the trash and call for a new one!  I finally grinded of the corners of the shoulders that were binding on all rod end bearings, added a washer between u-joint and bellcrank to allow it to move more freely, grinded off the top of the bellcrank pivot point and placed two washers underneath to raise it an 1/8" or so.  This helped all together to finally have FREE controls!!!  Thanks for all your input!!

    Yeah.....that lasted real long!  Then I installed the elevator control rod and it is so stiff that truly I think I could possibly break the control column if I would attempt to mess around with it that way.  Has anyone had a very stiff elevator control rod?  The bushings were drilled out to 9/16" as directed.  Would it be OK to drill out the first 2 or so bushings to 5/8" to help reduce the friction through the bushings?  That's my only thought of correcting it at this point.  I just don't know how critical it is to have the rod tight in the bushings.  Just seems to be more of a guide than anything else.  Again just figured I would see what you guys think before I may do something that would not be wise or maybe you have a better idea/way.

    Rod End Bearing resized.jpg

  9. nlappos


    ....My question is this.  If I backed off the pitch to 15 to achieve the 5300 static / 5800 in flight how would that improve takeoff performance since its not pulling as hard with the 17.5 pitch. 

    Let's look at the propeller as a wing, and recognize that the wing makes lift (thrust) by a combination of angle of attack (pitch) and airspeed (RPM). f the two, the airspeed is more influential, since the lift equation used the velocity squared.

    At 5500 rpm the prop blade tip is moving at 740 feet per second (with a 2.43 reduction box), at 5800 rpm it is at 780 ft/sec. The difference i thrust is about 11%, assuming the engine was producing the same power. But with the engine producing 4 HP more power at 5800, that would make the prop thrust about 15% higher at 5800.

    2 people like this
  10. zadwit


    Also blade angle, measured at some blade station with a  protractor or digital protractor just tells you the angle between the hub flat face and the  tip of the blade... 

    IT IS NOT GEOMETRIC pitch.. .there are formulas to figure this out but it looks to me that most are 38 to 40 inch pitch in the end... this means if turned in a solid with no air slippage, you would travel that far in one revolution as if you were in a solid....of course there is air slippage but the faster you go generally the less it is...

    Most of these 503-582 rotax engines with 68" diameter props run 11 degrees blade angle at the prop tip + or - a few degrees, but like C5 says, 1 degree can = 300 rpm change on some engines....

     

  11. zadwit


    Its a complex problem.. the faster you turn the blade, the more "air drag" each blade has. For a slow plane, a longer blade, with pitch flattened enough to get RPM in the max torque band would likely make best thrust for takeoff.... as shorter blade would need more pitch to keep the rpm in check but might yeild faster cruise at the expense of not as good take off perfrom....and each brand prop is a little different as well... seems most the big aircraft prop manufacturers re going to a semitar tapererd blade design and that makes sense, ,higher aspect ratio = more effecient wing(or blade). so ask around  what the other guys are doing , what prop do they have, how many blades, what engine, do they have big tires installed(these slow the plane down).

    Ive talked to guys who flew thousands of hours in 503s and they say keep the rpm at 6000 cruise, egts around 1000-1100 and that seems to give best performance for fuel used.....I also know using 5500 rpm will use less fuel but  alot less power... so there are lots of variables.... fixed pitch prop is a compromise....

    Leni has an in flight adjustable prop and these are ok but you better get a good understanding of them because I think you could get in trouble with too coarse a pitch or maybe too flat a pitch. IT would take a little work to set it all up, ask leni about it....aka..AK flyer

  12. Yamma-Fox


    We all have had our ass handed to us out there buddy...  Hell I, as a new TW student, ground looped twice in one day!  (No better way to learn than THAT!!)

    Thanks for posting.  This is a great reminder for everybody to review and think through.

  13. Turbo


    The Junkers- style flaperons have the advantages of the CP peak reduction of a slotted flap if rigged correctly, and of not inheriting the wing's tired boundary layer, but at our scale tend to develop their own wimpy laminar boundary layers, which limits their max CL,  and contribution to roll authority.  It may be possible to trick them into early transition to the much more robust turbulent boundary layer with an appropriate level of surface roughness, which is likely quite fine.  Teensy VGs could also be effective in this, but it's relatively easy to overkill the problem and make things worse.  In any case, there's only so much even a slotted flap ( in our case as an aileron) can do.  Having studied the kinematics of the mixer mechanism, I was somewhat unimpressed to see greater down deflection than up deflection as flaps are lowered.  I think there is a cure, with a different mixer geometry.  Leni says they overpower the elevator at the higher deflections anyway, so maybe it's a moot point.  Maybe they are just the ticket at 15 degs as-is.  I need more experience flying the bird.

  14. zadwit


    I had the carbs apart and they are clean, including the idle jets.  The floats had sunk, so I had to buy new ones.  Gotta look to see what size those idle jets are, though.  Joey flies out of somehere near Fairfield, which has to be less than 100 ft elevation, so maybe the #50 idle jets is a good call right out of the box.  I too will be flying out of fields at less than 1000 ft elevation.  Totally agree re static idle rpm vs on final - part of why I had a tough time getting the bird down.  Trees at approach end of runway & short strip - bad combo for green TW pilot in unfamiliar bird.  Smooth at 1400 static is my new goal!  Next time The Dalles with 5000 ft, 100 ft wide tarmac!  Just loved putting around the verdant Hood River valley & hills, though.  This is why airplanes have such magic.

     

    Aircraft spruce has the jets , about $60 a piece!!!! but they make it run better....

  15. zadwit


    I saw a kitfox model 2 wrecked on takeoff because the guy tried full flap takeoff (no wind) but one wing went down and when he fed in aileron the flaperone on the low wing went further down and stalled the wing which hit the ground, dug in and flipped the plane.. major damage and all in about 100 ft ground roll.

    In hte KF manual they say to rig the flaperone for 23 degrees down, no more.. I did and  you have very little aileron control.. I would not use them at all in the wind, you are asking for it... the advantage is you have aileron control in the stall...

    Install a set of the cheap (100) stol speed VGs from aircraft spruce.. I put a set on my Ridge runner and stall went from 35 mph to 26mph... 

    location is critical but most say 2" aft of the WLE, any farther back and they dont help,  IT was 28 (f) and 2500 msl) when I flew this, gross wt=660 #, that plane is light single seat...

     

     

     

  16. zadwit


    IF you install the smaller idle jets, then install the clutch, you will first notice the idle speed is too high and even if you back the idle speed nut(the big one) all the way out it still  might be too high....IF that happens, you might have to take a dremmel tool and cut the groove a little higher , the one the idle speed screwpresses on the slide...

    I like the clutch,it is easier on the engine.... cant hand prop but if you have a good battery and starter not a problem.....

  17. zadwit


    Because of the mass airflow thru a two stroke engine, it is real hard if not impossible to get it to idle much below 2200-2300 mainly because of the prop load, the turngind of the gearbox and prop... I have a clutch on one of my engines and it will idle down below 2000 maybe as low at 1400 just like a snow machine engine sounds...

    Im sure you read the pros and cons of clutch... one thing the guys didnt mention, is the C and E gearbox havbe a rubber dampner in the gearbox adn it "steals" power...

     

    I easily got 100 rpm more on takeoff with my clutch......I flew in the morning with the standard setup, then install the clutch and flew the same day a few hours later and saw 100 more rpm on takeoff and climbout...its because you dont waste power compressing and expanding that rubber coupler....it is mainly installed for low speed to protect the gears from chatter...