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Thread: Lowrider LSA

  1. #1641
    Lowrider
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    Sky,

    I can easily bend the edges of 0.050 CM is that adequate or do I need to weld a 90 degree flange on the edge to provide some serious stiffening? I can do zerks to do a better job of lubing. I also thought about a 0.015 teflon liner between the tube and bolt. I think I have some somewhere left over from a boat repair issue awhile back...it's slick as greased owl snot.

    Don,

    I understand the concept but I need to think about this some. I have an overbuilt wing for the LSA weight limit so I'm reluctant to add more complexity and weight to the plane. How much lift vs drag gain is there with the droops? It would seem my 8' flaps should provide all that's needed even if I go to floats...but then who knows until you try it. My '48 170 has the little mini flaps and they do very little on that wing. Using the Riblett wing and flaps I think there is a balance there between cruise and slow flight...we'll see when I get it done. Gotta do some research on droops...what's the real gain????
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

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  2. #1642
    skywagon8a's Avatar
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    Quote Originally Posted by don d View Post
    If you can get the bell crank mount or the mount where the push-pull tubes are secured to move along with the flaps then you can get drooping ailerons. A lot tougher to do with cable type controls than with push pull rods. if there is a Murphy rebel around take a look at the way they did their flap an aileron drive.
    I like this idea.
    N1PA

  3. #1643

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    Low,

    Do a Google search on drooping ailerons and you will find all sorts of stuff from this site. My experience is with Cessna Rstol and yes it reduces stall speed/landing speed.

    Build aileron control attachment so you can easel change from 0 droop to 10/15 on the ground. Then have flap setting the same. Just a thought.

  4. #1644
    Lowrider
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    OK, don't cost nuffin to look....
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    There are no new ways to crash an airplane no matter how hard you may try!

  5. #1645

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    Lowrider,

    I'm mimicking the original Piper flap bell crank with .100 4130. It will have a flange welded around the perimeter, and a stiffener running from the pivot to the inside of the dog leg. I plan to drill some holes similar to the aileron horn to waste some time lightening it. It should be comparable in weight to the original. If I get it hacked together this week, I'll put it up. Seems like Javron makes a pretty simple one out of steel, maybe Bill Rusk has a picture of his.

    Thanks,

    Jim

  6. #1646
    Lowrider
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    Thanks Jim! I cobbled up a triangle shape with flanges bent all around. I primed it and I'll get a picture in the morning after bacon and pancakes.

    Sky/Don,

    OK, I'm still thinking but have come up with an idea. How about the bell crank mounted just as it is with a sliding tube that the brace can move thru to adjust the angle of the droop? Along with that what if I put a jack screw on top operated by an electric motor with limit switch at the two ends of travel. It could be controlled with a two way switch on the stick or throttle. That way it could be run from zero to say 30 degrees droop depending upon conditions and desire. I guess a "flap position indicator" could be used to keep track of the droop.

    Still thinking....
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

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  7. #1647
    skywagon8a's Avatar
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    Quote Originally Posted by Lowrider View Post
    Sky,

    I can easily bend the edges of 0.050 CM is that adequate or do I need to weld a 90 degree flange on the edge to provide some serious stiffening? I can do zerks to do a better job of lubing. I also thought about a 0.015 teflon liner between the tube and bolt. I think I have some somewhere left over from a boat repair issue awhile back...it's slick as greased owl snot.
    Heat the edges and bend a radius. A 1/8"-3/16" flange should be sufficient. The teflon should work providing you do get a good fit without slop. I would hate for that bolt to get a little rust on it getting stuck in the pivot tube. That would cause you more grief.
    Quote Originally Posted by don d View Post
    Low,
    Build aileron control attachment so you can easel change from 0 droop to 10/15 on the ground. Then have flap setting the same. Just a thought.
    Make the drooping function so that it can be operated independently of the flaps. If the ailerons are drooped in a strong crosswind your control will be compromised. Also if the ailerons are drooped during landing you will require more up elevator to hold the tail down since the aileron droop moves the center of lift on the wing aft.

    ps, I'm a big fan of drooping ailerons with the wind on the nose. They do make a considerable reduction in % of stall speeds and angle of climb improvement.

    pps, The aileron droop on my 185 is placarded to use for take off only.
    Last edited by skywagon8a; 02-22-2016 at 06:35 AM.
    N1PA

  8. #1648
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    I'm on the ragged edge of being convinced that drooping is worthwhile.

    Dave Calkins talked me into the full length ailerons and he is a big supporter of drooping 10 or more years back. He seems to have left the site since I haven't seen much of him lately.

    Having many others use and love the droop and since I'm at a point in construction where it would be fairly easy to incorporate it into my ailerons I guess I should proceed. 2 or more questions persist:

    1. It seems that the ailerons MUST act together being deployed or retracted to avoid an imbalance in lift/control. How to do that? My answer would be an electric motor driving a screw on the bell crank support to move the ailerons up or down. One switch to control motors in each wing in unison.

    2. What is the control loss with the ailerons in the down position...say 30 degrees? Normal down deflection is 18 degrees and up is 23* so we get 48* on the down alileron and I guess effectivly only 7* up. Or am I missing something here? I guess the down aileron side will lift the wing anyway but it seems the control is not the same as ailerons that are in the up position. If you have a gust against the down aileron do we end up with an over control situation and roll the plane more than intended?

    More questions to come I'm sure.
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  9. #1649
    skywagon8a's Avatar
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    1. If they do not act together, they are just ailerons.

    2. Total droop wants to be in the 12-15 degree range. That will give you 30-33* max down with full aileron throw and 8-11* up when drooped. 8-11 up is not much at low speeds particularly when the boundary layer starts to separate moving the air away from the aileron.

    Remember that it is the up aileron which does the most work when rolling the airplane by dumping lift on that wing. The down aileron provides some lift while increasing the angle of attack and drag of the outboard portion of that wing, thus increasing stall speed of that section of wing. A down force counteracting the minimal opposing force of the opposite aileron.
    N1PA

  10. #1650
    Lowrider
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    Sounds to me like you could teach ground school!!

    How's the motor idea sound?
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    There are no new ways to crash an airplane no matter how hard you may try!

  11. #1651
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    Better? 0.050 bent and welded in the corners.

    Click image for larger version. 

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    Strong like bull!!
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  12. #1652
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    The British and the Pietenpol guys just use sheet steel and hammer or bend it into a dimensional shape and weld the edges together and weld in bushing. Lite, cheap, simple and strong.





    Control horn



    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  13. #1653
    skywagon8a's Avatar
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    Quote Originally Posted by Lowrider View Post
    Sounds to me like you could teach ground school!!

    How's the motor idea sound?
    One motor driving both sides. Two will be greater possibility for trouble. You don't want just one drooping. Mine has a 172 flap drive motor mounted in the left wing connected by cables to the right wing.

    Quote Originally Posted by Lowrider View Post
    Better? 0.050 bent and welded in the corners.

    Click image for larger version. 

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    Strong like bull!!
    Is the upper left edge bent as well? Cut a big lightning hole in the middle. Either triangular with big radius corners or a big circle. All of the strength is around the outer edges. The middle of the plate is just dead weight.
    N1PA

  14. #1654
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    Sky,

    Bent and welded all the way around. A lightening hole is needed...WILCO.

    I was thinking 2, one to drive each side. You're right about 2X the chance of failure but running wire is a lot easier and better I think than cable. How does your cable drive the other side...by wheel, chain and sprocket or what?

    Glenn,

    That really nice work. Is that yours? Is it a Pietenpol?
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    There are no new ways to crash an airplane no matter how hard you may try!

  15. #1655
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    Quote Originally Posted by Lowrider View Post
    Sky,

    Bent and welded all the way around. A lightening hole is needed...WILCO.

    I was thinking 2, one to drive each side. You're right about 2X the chance of failure but running wire is a lot easier and better I think than cable. How does your cable drive the other side...by wheel, chain and sprocket or what?

    Glenn,

    That really nice work. Is that yours? Is it a Pietenpol?
    3 of us met on Monday nights for about 10 years and built 80% of a Pietenpol. Then Ed who's shop we were using bought a Staggerwing project and the Piet went up in the rafters. One member has died and Ed got the Piet down last winter and finshed it by himself. The horn in that picture I posted is not ours but we built everyone on our Piet, landing gear, motor mounts, lift struts......
    Ed got it flying this fall and has about 30 hrs on it.





    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  16. #1656
    Larry G's Avatar
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    Quote Originally Posted by Jim A. View Post
    Lowrider,

    I'm mimicking the original Piper flap bell crank with .100 4130. It will have a flange welded around the perimeter, and a stiffener running from the pivot to the inside of the dog leg. I plan to drill some holes similar to the aileron horn to waste some time lightening it. It should be comparable in weight to the original. If I get it hacked together this week, I'll put it up. Seems like Javron makes a pretty simple one out of steel, maybe Bill Rusk has a picture of his.

    Thanks,

    Jim
    Is this what you where thinking of Jim
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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  17. #1657
    Lowrider
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    Glenn,

    That's gotta be lot of fun to fly! I take the doors off my Challenger in warm weather and it's almost like flying a helicopter with that "open air" flight feeling. Lets see...3 people once a week for ten years got to 80%...how much beer was involved or is this an Irish coffee crowd?

    Larry,

    Something like that would certainly work. I did some searching around and found there must be a trillion ways to make bell cranks out of every material you can think of. Thanks for the idea!
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  18. #1658
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    Sky,

    12-15* and not 30* makes it a lot easier...not sure where I got the 30*...maybe from some 2002 posts from the AK crowd. Full deflection up and down is only 3" on the bell crank so to get 15* down won't take much linear movement at all.

    I pulled out the motor that several folks have used for the elevator trim screw and it looks like it would work just fine to get the droop. I believe it uses an 8 or 13 pitch screw so not many revolutions are needed to get the appropriate droop. It is a geared motor so it doesn't pull much power and should be OK with my battery plan since my guess is a couple times per flight would be all that's necessary.

    Wish I could find some pictures to show how others have built their system.
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  19. #1659
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    Sky, et al,

    Forgot to mention this but the Riblett wing calls for a stall fence at the juncture of the flaps and aileron. Also, what I've read seems to agree that VG's are an important part of the droopers. Any issue with either of these?
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  20. #1660
    skywagon8a's Avatar
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    Quote Originally Posted by Lowrider View Post
    .. How does your cable drive the other side...by wheel, chain and sprocket or what?
    The 172 flap drive system is connected to a drive wheel which has 2 cables passing through the fuselage to the other wing to another drive wheel. Each drive wheel pushes and pulls push rods which connect to a complicated aileron bellcrank which moves the position of the aileron push rod. You could connect the two wings with one of your push/pull controls.

    Quote Originally Posted by Lowrider View Post
    Sky, et al,

    Forgot to mention this but the Riblett wing calls for a stall fence at the juncture of the flaps and aileron. Also, what I've read seems to agree that VG's are an important part of the droopers. Any issue with either of these?
    Your Lowrider Speedbird is one of a kind. You have no idea whether it will need or have the advantage of the installation of any fence or VGs. Leave them off until you determine that you actually NEED them. These items are installed as "fixes" after flight testing is begun. After you get flying, talk to me.

    What airplane which has droopers needs the VGs? And where are the VGs located for what purpose? My 185 runs out of rudder control before needing any more mods to the drooping system.
    N1PA

  21. #1661
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    Sky,

    I'm opposed to complexity if it's not necessary...less to build, less to fix and less to fail.

    I'm still thinking electric motor is the simplest yet reliable way to move the droop. I'll certainly think the push/pull rod out and maybe there is a easy way to apply it to this requirement. Or, how about a power window motor on each side? Thinking...I understand the possibility of one motor failure and the other side retracting on a good motor and asymetrical lift issues. Not sure what the real effect of a 15* droop on one side and not the other...will the other control surfaces overcome the problem? Do you end up with an uncontrollable situation?

    When I was doing some research on drooping most of the planes that were involved were Super Cubs with maybe a PA12 or two thrown in there. Some were using VG's and some did not. When a slat was on board they used them just behind there to help hold the air flow down on the ailerons at high AOA. I'm not sure there was popular consent that they were needed/worked however. I'm no where near ready to install the VG's or stall fence so there's time.
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  22. #1662
    skywagon8a's Avatar
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    IF, there is an electrical failure so that one aileron is drooped and the other is not, the control stick will be over to one side enough so that the ailerons are equal in deflection. They will both be down an equal amount. You will then be restricted in moving the ailerons in one direction and basically unlimited in the other. In a cross wind landing situation this could be an issue.

    Since you are using a push/pull control to move the ailerons, you will need something to fix the end of the housing in order to get the proper motion. IF you mounted this fixed end on a small movable arm (bellcrank) with a separate push/pull control back to the cockpit to manually move it, you would have a simple droop system. Just thinking this through as I type, Hmm rather simple. You could even devise a control which is adjacent to the flap handle which you could grab or not as you wish when the flaps are operated. Sort of like a motorcycle clutch handle mounted on the flap handle with a catch to hold it. Hmmmm this is simpler than I thought.
    N1PA

  23. #1663
    Lowrider
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    I got the motorcycle clutch part and that had merit too, but I need to get the sliding aileron bell crank out of my mind. I've been thinking the bell crank would slide to the rear from a neutral position to allow the droop to take place. That's why I was thinking a motor operated screw would be the simply way to do it.

    So, you're talking about a "second" bell crank in each wing to mount the aileron bell crank on and connect together via a push/pull rod, then have another running to the cabin where it would provide droop to both ailerons at the same time...right?

    I haven't set up the aileron to measure 15* and determine how much the bell crank needs to move to the rear to get that much deflection but I'm guessing +/- an inch. Using your idea, I could still use the sliding bell crank operated by a lever in each wing driven by a push pull/rod between the wings to get the same movement and run another rod to the cabin.

    The reason I wanted to use a slide fore and aft is to keep the bell crank in straight line with the attachment point on the aileron, although, using a rod end that can swivel on another bell crank could work as well.

    Off to do some thinking and measuring.
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  24. #1664
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    As best I can tell using my little protractor, a level and holding the aileron by myself at the same time it takes 7/8" of movement of the bell crank from neutral to 15* droop...18* being the max down according to the plans. Does anyone see a reason why I can't go to 25* down on the aileron so when it is in 15* droop I would still have 10* of movement to give more aileron authority in the drooped position??

    What if...I mounted the primary bell crank on a piece of 3/4" tube (lubed of course) that would slide on the 5/8" supporting tube and milled out a 7/8" long notch in each side of the 3/4" tube and then welded in a pin in the 5/8" that would allow the 3/4" tube to slide fore and aft which would allow 15* droop?

    The 3/4" tube would then be controlled by a push/pull rod ending in the cockpit, maybe on the the flap handle or adjacent to the throttle which is on the left side. The other (right) aileron would be slaved to the primary (in this case the left) aileron by another push/pull rod giving it the same droop. Full forward of the bell crank would be neutral aileron and any amount from 0* to 15* droop could be selected and a friction knob at the lever would hold that amount of droop. Or maybe set notches would be better.

    While I was figuring the amount of movement it popped into my little mind that I could also add some "up aileron" as well as the droop if it served any purpose.

    Thoughts please!!
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  25. #1665
    skywagon8a's Avatar
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    Quote Originally Posted by Lowrider View Post
    So, you're talking about a "second" bell crank in each wing to mount the aileron bell crank on and connect together via a push/pull rod, then have another running to the cabin where it would provide droop to both ailerons at the same time...right?
    Before I say much more I need to see more. Do you have a picture of how your push rods connect to the ailerons in the wing? How is the end of the push/pull control fixed to the wing? That is where I'm thinking of placing the bellcrank.
    N1PA

  26. #1666
    Lowrider
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    I'm off this morning to look at some property but I started a sliding type movement last night so I'll put that together and shoot some pictures for analysis. I upgraded the tube size to 3/4" and 7/8" to make it more resistant to bending since there will be two operations taking place on the support tube. The push/pull will be in line with the tube now and not diagonal to it for the droop actions. Pics to follow.
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  27. #1667
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    Still not finished but should give an idea of what I'm doing. 10x32 screw is just in there to show how the pin will hold the sliding tube in proper alignment. Someone misplaced my 0.250" mill so I just cut the notch with a hand grinder. Notch will be re-enforced on sides and ends to only allow the 1.00" movement of the tube to give roughly 15* droop.

    #14 shows droop with slide to the rear and #15 is retracted to normal aileron operation.

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    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  28. #1668
    skywagon8a's Avatar
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    Where does this mechanism mount? In the fuselage or the wing? How is the telescoping tube controlled? Where does that plate attach? Is that push rod connected to the aileron or to the control stick? It looks heavy and complicated.

    I thought that you said that the push control was to connect to the aileron directly?
    N1PA

  29. #1669
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    It mounts between the front and rear wing spars in line with the aileron control rod which is on the short end of the triangle. It's less than an pound more than the original aileron drive...a 9" piece of 7/8 tube and 18" of 3/4 tube instead of 5/8". The additional push/pull rod will add weight as will the cabin control...the cost of drooping ailerons.

    I don't have the whole thing competed which I'll try to get done today. That will make it easier to envision than thru words.
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  30. #1670
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    Still not done but here's a couple shots. The first one show the ailerons in droop position and the the other in retracted normal positon.

    Click image for larger version. 

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    The rod on the left controls the droop and the one in the center attached to the bell crank does the aileron. I gave the droop a 1.0" travel and as best I can calculate it'll result in about 16* total droop. With the sliding bell crank you get an infinite amount of travel in droop and the other aileron control will be attached at the same spot as the rod in the picture, hopefully giving an equal about of droop to both ailerons. No way to know until I get the other wing done but it looks promising. The other control is a mirror of this one.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

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    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

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  31. #1671
    skywagon8a's Avatar
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    I see where you are going. I think that you can eliminate most all of those parts. I wish that I could draw you a picture. Consider this: Mount a straight movable arm on the rear of the rear spar, parallel to the spar, which is pivoted on one end hinged to the spar. At or near the other end mount the fixed end of your push control with the movable arm connected to the aileron for the aileron control. Then run the droop push control so that the fixed end is mounted forward of the rear spar. The movable end then is connected to the straight arm next to the other cable's fixed end. The distance between where the two are attached to the straight arm will determine how far the droop moves. The droop push control will then move the fixed end of the aileron control the droop amount.

    An access hole near the center of the spar web will not likely become a structural problem. If there is a concern then place a reinforcement plate on the web.

    Do I make sense?
    N1PA

  32. #1672
    Lowrider
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    Sky,

    Of course you make sense! I spent an hour trying to draw that picture in my mind and thus far have failed. I think you are using the rear spar as the anchor point for everything...I just can't picture exactly what you propose.

    Mean while, I've finished the parts for both wings and I'm ready to install them in the wing as shown above. Maybe my pea brain is contaminated by the way I designed it but I'm trying to figure out a way to use your ideas and save some weight. These added parts to make the ailerons droop weigh 7 oz per side so I was close with a guess at a pound. I feel comfortable with the extra bracing in the wing and the span between the front and rear wing spars even though it does add weight.

    I gotta tell you the way it works now that I have everything together is good and the sliding bell crank works well with the other wing pieces attached. Of course I can't tell how it will work with 60 kts of air moving over the surfaces. Maybe the best answer at least at first is to follow your lead with the placard for "take-off only". I've made so many changes in this craft that it's best to experience them individually when possible.

    I discussed this yesterday with a 40K hour ag pilot who said he'd changed so many things in airplanes over the years that he couldn't remember them all but there's nothing wrong with trying new stuff just do it slowly. He said there is a 150 hp C-150 tail dragger with drooping ailerons somewhere but he didn't know how they were done.

    I'll think some more about what you described, maybe it'll make more sense in the AM...Thanks for the thoughts!!
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  33. #1673
    skywagon8a's Avatar
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    .................................................. .................................................. ..........[]..........[]
    .................................................. .....................................Aileron control....[]..........[]
    .................................................. .................................................. ..........[]..........[] Droop control
    .................................................. .................................................. ..........[]..........[]
    .................................................. .................................................. ..........[]..........[]
    XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Spar
    .................................[........].................................................. .................[]..........[]
    .......Fixed to spar pivot [...0xx]xxxxxxxxxxxxxx movable arm xxxxxxxxxxx[x]xxxxx[0]
    .................................[........].................................................. .................[]
    ..................................----- .................................................. ...................[]
    .................................................. .................................................. ...........[]
    .................................................. ........................../---------------------Aileron ---------------\


    Lets see if this helps. Ignore all of the dots they were the only way I could make the drawing work. The Red is the picture.

    The housing of the droop control is fixed forward of the spar.
    The housing of the aileron control is fixed to the movable arm here x. The amount of travel of this point is the amount of droop. Depending on the amount of travel this x probably should be able to pivot to prevent binding. For you to determine.
    The 0 is the pivot bolt for the arm and where the center end of the droop control attaches to the other end.
    Place fixed or adjustable stops at the movable end of the arm. One for droop up stop and the other for droop down stop.
    The arm can be either aluminum or steel with a bent up or down flange for stiffness to prevent twisting. The highest loads will be between the two push control attach points to the arm. Less towards the pivot end.


    You can safely place the aileron travel stops at the stick end of the system ignoring any travel stops at the ailerons. Just be sure to install gust locks on the surfaces if you leave the plane outside where the wind can blow from behind.

    Depending on the amount of room available, this whole assembly could be placed forward of the spar with the same results if necessary.
    Last edited by skywagon8a; 02-27-2016 at 07:30 AM.
    N1PA

  34. #1674
    Lowrider
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    OK, the control lines are the push/pull rods. How much stand-off would be needed forward of the rear spar...maybe 4"? How long would the movable arm need to be to get 1" droop movement? The entire mechanism is bolted to the rear spar and the rod from the arm to the aileron (I'll call it the control rod) goes to the attach point on the aileron.

    I know the wing skin which will be 0.020 2024 will help stiffen the top and bottom of the rear spar and should reduce (stop) twisting potential but that worries me some. I think there is a lot of pressure/force from air flow on 18" x 8'-0" ailerons and adding in the droop which would probably be for much longer periods and throw in some gusts I end up with a lot of stress on the rear wing spar.

    I like the CM tube with attach points on the front and rear wing spars that currently supports the aileron/droop stuff...it's VERY strong. I have a tendency to overbuild but it costs weight.

    Let me do some layout on the wing with what I think you have drawn and think about it some. Thanks for the "drawing"...as they say, pictures are worth many words.
    Last edited by Lowrider; 02-27-2016 at 10:20 AM.
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  35. #1675
    Lowrider
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    Sky,

    I took the short piece that bolts to rear spar (without the support that bolts to the front wing spar) and connected both push/pull rods and the aileron control rod. The good news, everything works as it is supposed to, the bad news is the rear spar moves much more than I'm comfortable with. The angle of droop came out at 20* and varied 2* - 3* plus and minus as the aileron was moved up and down with the control rod from what would be the cabin. Using the normal aileron rod and that control which would be the control stick functions and I got just about the same movement of the rear spar as the aileron was raised and lowered.

    I put the front support in place and bolted it to the front wing spar and the flexing of the rear spar stopped when the aileron was raised or lowered and drooped. I still have droop at 20* which can be adjusted back to 15* with no problem. Bottom line, it needs the front support in place to relieve the stress from the rear spar.

    The pieces I used were probably heavier than the ones that would make up your design but I don't think that difference in weight would make a difference in how much the spar flexed. The wing skin would certainly make a difference. The movement and I guess added leverage of the aileron is what causes the flex in the spar. I think the front spar support is very necessary to stop the flex and while your idea would work it wouldn't be my choice for this application. I also added a "lock out" bolt to stop the droop and can easily be removed to make that feature function. I need to do initial flight testing without the droop active and add it in when I'm comfortable with the handling characteristics of the plane overall.

    Thanks for your thoughts and design and maybe it would be applicable to another plane like the cub wing or similar.
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  36. #1676
    skywagon8a's Avatar
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    The torque loads in the spar generated by aileron deflection indicate that you do need a rib or other such device in the location of the aileron push controls which transmits these loads to the front spar. Your sliding tube arrangement could bind when these loads are applied to it. In my opinion you still need a strong rib between the spars in this location to prevent any twisting possibilities.

    My droop design is only intended for a system which uses push/pull controls such as yours. It would require further thoughts for another type of system.
    N1PA

  37. #1677
    Lowrider
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    Sky,

    The tube that runs between the spars provides solid support to the aileron control and droop movements. There is a rib maybe 6" away but without the skin it does not do a credible job of supporting. The slide moves smoothly now and should work even better once I lube it. It is the load of the aileron in the air flow over and under the wing that worries me since it has leverage on the spars.

    The sliding part is stable since the push/pull rod is in line with it's normal movement back and forth for an inch. I made the sliding part longer and larger in tube diameter than it needs to be so it would reduce the possibility of flexing that might cause binding. Dirt, dust and other things that might get in there could cause some issues with the droop system but the actual aileron control on the bell crank should not be a problem and it's also going to be greased thru the zerk. The under side of the wing will have an access panel so it will be easy to access as needed for cleaning, lube or whatever. I made the whole thing so it can be taken apart and cleaned or maintained.

    I think it will work and thanks to you and Don for sorta talking me into the mod...can't wait to try it!!
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  38. #1678
    Lowrider
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    I'm setting up my trailing edges on the aileron and flap and both are perfectly straight length wise which is pretty easy to set up with an 8' straight edge. The aileron is straight to +/-1/4" in 8' or so vertically and I think that will be taken care of when the fabric goes on if I use the straight edge to keep it as straight as possible during shrinking of the fabric.

    The flap on the other hand has about a 3/4" droop on the ends when the center where the control rod activates the flap is held in line with the aileron. I'm thinking that the fabric will also straighten the flap during shrinking as long as I use the straight edge to keep it in the proper alignment.

    Is this problem common and will the fabric do the trick to hold the alum frame in line??
    Somewhere along the way I have lost the ability to act politically correct. If you should find it, please feel free to keep it.

    There are no new ways to crash an airplane no matter how hard you may try!

  39. #1679

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    Just curious: how do you plan to inspect the tele-flex cables for wear?
    One of the failure modes is jammed solid; not what I would want on a primary control.

  40. #1680
    marcusofcotton's Avatar
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    Quote Originally Posted by Lowrider View Post
    I'm setting up my trailing edges on the aileron and flap and both are perfectly straight length wise which is pretty easy to set up with an 8' straight edge. The aileron is straight to +/-1/4" in 8' or so vertically and I think that will be taken care of when the fabric goes on if I use the straight edge to keep it as straight as possible during shrinking of the fabric.

    The flap on the other hand has about a 3/4" droop on the ends when the center where the control rod activates the flap is held in line with the aileron. I'm thinking that the fabric will also straighten the flap during shrinking as long as I use the straight edge to keep it in the proper alignment.

    Is this problem common and will the fabric do the trick to hold the alum frame in line??
    Low, this does not sound good. I've been concerned about flutter with the many points of movement/flex in your aileron control design. Now with this description, I'm getting more worried.
    Practicing open cockpit extremism

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