Bearhawk Aircraft Bearhawk Tailwheels LLC Eric Newton's Builder Manuals Bearhawk Plans Bearhawk Store


No announcement yet.

Hanging QB ailerons and flaps

  • Filter
  • Time
  • Show
Clear All
new posts

  • Hanging QB ailerons and flaps

    I’m thinking the sequence goes something like this:

    install the bearings. (Done)
    Drill the 3/16 holes in the sheet metal hinges.
    Bolt the sheet metal hinges onto the bearings.
    Use the plywood template to get the control surface in position.
    Mark the location of the hinge mounting holes on the control surface spars by marking through the holes in the sheet metal hinges onto the spar.
    Drill holes in spars.
    Unbolt sheet metal hinges from bearings and bolt them permanently to the spars.
    Use similar technique for pushrod attachment
    store control surfaces until ready to add weights and covering.

    2 questions: do I have this about right? And, are there any good tricks to insure accuracy or provide greater confidence while drilling?

  • #2
    Sounds like the QB wings have the hinges already drilled or bolted to the rear spars?
    Scratch building Patrol #275
    Hood River, OR


    • #3
      No they are unattached and un-drilled. Mark called me this morning to walk me through the procedure. He said I was on the right track but suggested trial-fitting using small C clamps to hold the hinges to the spars and to the spherical bearings first. It’s so obvious, now! Then he walked me through the sequence of marking and drilling which is pretty simple.
      I should be able to proceed with confidence since I will have complete ability to adjust as much as I need to before drilling anything.

      correction: the part which attaches to the rear wing spar is mounted. You just have to check torque. The other half (which is in two pieces, is undrilled so you can get it exact. (or not).
      Last edited by Pbruce; 04-19-2020, 12:57 PM. Reason: Content corrected


      • #4
        Guys I’m still struggling with this. Clamping everything together first is proving to be more difficult than first envisioned. It seems like you have to manage all four corners of the flight control surface, the sheet metal hinge pieces, and the wooden template at the same time. All this while moving the control surface in, out, up, down, and through its range of angular motion. I’m feeling overwhelmed with this part of the process at the moment. I’m hoping others can relate and might be able to provide some tips to simplify the process. Thanks in advance


        • #5
          First of all you need to have everything securely lined up. I placed my wing on a table, on top of 5 2x4s. The 2x4's were located next to each hinge point but not directly under them. They have to be long enough to span from the front spar of the wing to the trailing edge of the flaps/ailerons. I used some small pieces of 1/2 plywood under the rear spar (on the 2x4s) to get the wing closer to level. I then placed the flap and aileron on the 2x4s and used the template to shim them into the correct position vertically. Required shims both at the spars and trailing edge of the control surfaces. Span wise alignment is very important. Each hinge needs to be offset in the pocket or you won't be able to insert the bolts in the bearings. Hopefully this ends up giving you even gaps at the aileron/wingtip, aileron/flap etc. Verify that the control surfaces are at the correct position chord wise and the trailing edges are even. At this point you can use small c-clamps to position the hinge pieces to the control surfaces so that the pre-drilled holes line up with the bearings. It might require aluminum shims under the hinge pieces to get correct alignment. I am fuzzy on the bearing set up on the B model, on the A model they move in and out of the support tube adding another layer of complexity. Double check everything before removing the control surface and drilling for the hinge bolts. Took me way too long to figure this all out and my hinges have some extra holes in them, I didn't think the wing manual was very helpful for this step. Hope this helps. Glad to hear that the factory is now doing this. I would post pictures if I could figure out how to get my camera to upload after windows 10 upgrade.


          • #6
            Have you closed your wing up yet?

            Warning, I have not yet seen anyone drill their hinges like I did. When I attempted to First drill them like you have described it didn't go well. The second attempt is heavily modified from the traditional may.

            So, Yes, I mis-drilled two of my hinges. I mean, I had the nut plates installed and everything before I was willing to admit to myself that it did not meet my standards. After talking with Bob about things, I followed his recommendation to get everything else done with the wings first (including the close up and the stiffener, aileron cove installed) before I drilled the hinges. Bob said one of my problems was I didn't have a stable platform to align the surfaces to the wings. Having it all closed up including the skin stiffeners and aileron coves installed provided a stiff workplace.

            During the first attempt I had difficulty getting wood template to match up to the wing, and I think I applied too much force trying to make it fit. There was variation in the fit between the template and wing airfoil. The variation would shift as I move the template around. It was not exact.

            I did not use a wood template on my second attempt. Rather, I fabricated two sets of templets using my wing form block using 1" angle aluminum. (The form block was left over from when I aborted scratch building) Each templet set is made up from an upper and a lower wing profile. (so I had four total pieces) Fabricating these to match the profile was not difficult and was accomplished by strategic and gentle flattening of one side of the angle to slightly deform/warp the angle to match the form wing rib form block.

            With the wing in my wing cradle and the control surface resting on the hinge pieces, I located and "clamped:" the control surface in place to the wing using the scissors shaped templates. This was done at two points on the wing. With the surfaces firmly clamped to the wing, clamping the hinge pieces to the control surface's spar was done.

            At the top of the photo below you will see string that ties the two pieces of the template together holding it snug to the wing. This string is a waxed nylon sinew I used for lashing a wood frame Kayak together like an Eskimo Kayak. The sinew has some stretch to it, and so I was able to get it to squeeze/clamp to the wing. The red line on the lower side of the template should line up with the rear spar
            Even after things were stabilized and riveted in place, there was slight variation between the template and the wing. One of the things that precipitated airfoil variation on my wing was the Aileron Cove. It curve was a little tight and the shape influenced the trailing edge of the skin slightly away from the truth airfoil shape. Its so far back in the turbulent airflow that it wont effect performance at all. But wasn't going to let it effect alignment of the control surface this time.

            Using this method gave me ability to see and judge the very best placement of the control surface. Whatever you do, make sure you can easily see things, tinker, move adjust, and mess around until you got it right. Don't guess. I got it centered up and I could see straight lines as best as I could down the gap between where the skin and the control surface approach each other. There is a lot going on, and to be able to see it all gave me a great deal of peace.
            Brooks Cone
            Southeast Michigan
            Patrol #303, Kit build


            • rodsmith
              rodsmith commented
              Editing a comment
              My wing template did not fit the wing profile the entire length but was tight to the skin around the nose and from the rear spar back. I was able to get good repeatability at each hinge location.

            • Bcone1381
              Bcone1381 commented
              Editing a comment
              FYI, my Kit did not have a wood wing profile template "tool" from the factory. I fabricate my wood profile tool, which risks the introduction of another possible error.

          • #7
            Thank you guys. Digesting...


            • #8
              We seem to be getting a handle on this. Thanks again for the help! We drilled the actual hinge points through the sheet steel hinges and bolted them onto the spherical bearings already attached to the rear spar with the welded metal metal dipod and tripod mounts. We had full freedom of left/right, and up/down, but not in/out as this was determined by the distance between the hinge point holes and the spar, which we had just drilled. The spars are straight, and the holes were measured very carefully from it, so we believe that all hinges will be exactly parallel to the spar.

              We might have sacrificed a 16th of an inch of in/out adjustment in order to provide the stability we needed for clamping the hinges onto the control surface spars, but now that it’s done, it seems we were right: we didn’t need it. It went a long way toward supporting the control surface as we measured and checked using the wooden template on the top of the wing and straight edges on the bottom. (Our template was a very close fit, incidentally). Then we clamped the hinges onto the aileron spar, marked the position of the hinge bases on them, and drilled through the hinges into the spar enough to make a good centre dimple. We removed the clamps and finished drilling the 3/16 mounting holes through the control surface spars. Voila! Ailerons have 30 degrees up travel available and more down. Even after covering, the required 20 degrees will be comfortably achievable with a bit of room to spare.

              Mark Goldberg called me as we were getting ready to drill. Unsolicited, he checks up upon my progress from time to time, lending both moral and technical support. His timing is implacably timely. Today he called to lend some timely advice about where the adjustment 2717BADE-04C3-4210-A2AD-C660A98A828D.jpeg74258AE6-760C-4011-9B30-20F6BBFD1C1B.jpeg tolerances are and to insure that my clearances were adequate. For example, the trailing edge of the control surfaces can be moved in or out slightly in order to make the entire trailing edge deadly straight. In fact it’s held on with very few pop rivets in order to facilitate adjustment prior to final riveting. Cool.
              Attached Files


              • rodsmith
                rodsmith commented
                Editing a comment
                Good job! Bet you are glad to have that behind you.

            • #9
              Yes. Only one wing done though so I still have to fly in a circle.
              Last edited by Pbruce; 04-18-2020, 08:18 PM. Reason: Spelling