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Model B aileron question

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  • Model B aileron question

    I’m getting ready to move on from the rib-forming phase to the assembling-stuff phase, and am planning to tackle the ailerons first (smallest spar and fewest parts to redo if I screw up). I’ve been looking over my plans and reading through Eric Newton’s manual (and searched this forum), but have three aileron questions:

    1. I still need to drill the balance tube holes in the aileron nose ribs. I’m presuming I should do it for all ribs, even though the tube is only in the center section between the hinges. I figure this will allow me to install it after aileron assembly, and also means I can get a long drill bit in there if I need to drill out any lead to balance. Any problems with this logic?

    2. Speaking of the balance tube, I’m presuming I can use any aluminum alloy/temper since it is not called out in the plans? I’m planning on getting 2024T3 because, well, why not? The plans just say 3/4” OD and 0.035” wall thickness. I’m not planning to install the tubes until after I cover (years from now), but will probably get the tube so I can dry fit to check tolerances, etc.

    3. I can’t find the sheet thickness on the plans for the inboard aileron skin gusset. I may just be missing it, but I don’t see it. It’s the one with the pen pointing to it in the attached picture. Eric’s manual says it’s 0.032” because it’s where the actuation arm goes, but that was a model A. Can anyone confirm/deny that this is 0.032?

    Attached Files
    4-Place Model 'B' Serial 1529B (with many years to go...)

  • #2
    My balance tube holes in my B model aileron were 7/8" OD. I bought AL tube from McMaster. My weight came out almost perfect @ 5lbs 2.3oz with #9 lead bird shot. Part # 1658T16
    Rob Caldwell
    Davidson, North Carolina
    EAA Chapter 309
    BH Model B Quick Build Kit Serial # 11B-24B / 25B
    Build Log:
    YouTube Channel:


    • nborer
      nborer commented
      Editing a comment
      Thanks Rob! Yes, I shouldn’t post right before bed, the plans clearly say 7/8” OD, not 3/4” OD as I originally posted.

  • #3
    1) The factory ailerons have all the ribs drilled. It allows the builder to slide the tube into the aileron with it attached to the wing. Balance the aileron after the aileron is assembled and have a way to install and remove the tube. The factory method is the only way I know how you could do it.

    3) I would call Bob. This is a screen shot of the PATROL plans. Seems to me like its possible that Information is missing.

    Screen Shot 2020-10-17 at 7.55.19 AM.png
    Brooks Cone
    Southeast Michigan
    Patrol #303, Kit build


    • nborer
      nborer commented
      Editing a comment
      Thanks Brooks! I’ll add this to my growing list of Bob questions. I try to build up a queue before making a call.

  • #4
    While I’m putting together my next order, I’ll add one more question...

    4. Any reason to NOT have the vendor roll the sheet I’m planning to use for the aileron spar webs? It saves a bundle on shipping. I know I’ll need to inspect for scratches and dings, but I’ve had pretty good luck with my ACS orders thus far. I’ve been using 4x4 sheets for my ribs (easier to store and handle), so this will be the first 4x8 set of sheets I order (including some 0.025” for the trailing edge material and for the two tip ribs). I’ve noticed that the 4x4 sheets seemed to lose any residual “curl” pretty quickly...

    As always, thanks for your thoughts!
    4-Place Model 'B' Serial 1529B (with many years to go...)


    • #5
      Yes, order them rolled.