Aileron Design

Task Description

Based upon current CAD of the wings and research completed, design ailerons for our wings to allow for the correct flight controls. Refer to Wings for the design decisions made for the wings. The CAD can be found in PDM at Fixed Wing → Fixed Wing Design → Wings.

Additionally, refer to Aileron Sizing for a starting point. A lot of the research and calculations were based on Sizing Control Surfaces which can also be used for reference. The fixed wing calculator has lots of working info as well.

I suggest brainstorming a few ideas and asking for feedback as there are many factors at play. This task may require more research into aileron shapes. Some thought into linkage/servo connection would also be good.

Constraints

Relevant Contacts

Assignees

Task Progression/Updates

Author: @ person updating Date: 2024/09/25

Design Progression #1

Initial Ideas:

• The initial idea is to take the existing rib and create a cut, splitting it into two parts.

  • The more extensive section of the rib towards the leading edge will form the profile for the main wing.

  • The smaller section of the rib towards the trailing edge will form the rib of the aileron flap.

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• The aileron and the rest of the wing will be covered in the same singular piece of fabric.

  • The fabric will cover gaps between the aileron and wing. This is thought to improve aerodynamics.

• The aileron will be attached to the wing by a hinge at the top edge of the rib.

  • Top placement reduces adverse yaw.

  • The servo will control the aileron movement using a horn and torque rod.

Progress:

Initial Ideas

• The idea was to overlap the aileron cutout with the total aerofoil and connect them with a spar or pin.

  • Concern → weakness of a balsa joint with a metal pin passed through

• Idea 1: use a sheet metal plate on either side of the balsa rib to reinforce the joint → whether we want to use

  • Concerns →

    • Lack of vertical constraint and twisting resistance with the balsa for the rest of the rib that is not covered by the sheet metal.

    • Use an aileron leading edge spacer across the entire design → weight concern

• The result was to instead use frame to strengthen the ribs and constrain them from movement as shown in Design #1:

Design #1: Embedded mounts with Sheet Metal Rib Frames

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Dimensions:

• Aileron Cord:

  • In line with the suggestions for the cord length

    • Total cord length: 230mm

    • Aileron Cord: 57.5mm → 25% of the cord (upper end of 15-25%)

• Aileron Span

  • Total semi span: 750mm

  • Aileron span: 250mm

  • Aileron Span Ratio: 33.3% → 35% of the cord (below lower end by 2%) → concern of increasing since the design needs the ribs to line up.

  • Concern → syncing up with the existing rib spacing and the wing's trailing edge with a potential cutout and wall to mount the wing hinge

Current Mass

• Mass: 22.53 grams

  • → excludes integration mechanism and corresponding changes.

Suggestions for Servo Horn Mount:

• Place holder depending on the servo used:

Author: @Nathaniel Li Updating Date: Oct 1, 2024

Aileron Sync

• Confirm using the updated ribs

• CAD the overlap design

• Required materials → Manufacturing

  • Try everything to be a 3D print

• Make a weight comparison

• TBD servo placement (need to get from Smile?)

Author: @Sam Wong @Keegan Jeewan Updating Date: Oct 6, 2024

Overlap Design Updates

• full wing with overlap aileron fully modeled

• mass of entire wing = 237.16 g

• mass of aileron = 20.57 g

Author: @Agapa Goombs Updating Date: Oct 8, 2024

Hinge Design Updates:

Important Notes:

• Due to the weight associated with adding a structure for mounting the flat face of Design 1, the decision was made to instead use the existing aileron-side hinge alongside a pivot spar.

• Alongside this, the number of hinge points was reduced from 4 → 2 to simplify the mounting of the aileron's end plates.

  • Finally, the general modifications to the main wing were standardized between the Overlap and Hinge Design to minimize the time for integration.

    • Also exteds to the spacers used between Ribs

Dimensions

• Aileron Span: 254.9mm

• Aileron Cord: 57.0598mm

Weight:

• Aileron: 26.94 g

• Wing with Aileron: 243.47 g

Mass Summary

Author: @Nathaniel Li Updating Date: Oct 10, 2024

CAD Review 1:

• Looks great, both designs are really cool and we will definitely want to save both designs in case we want to implement them in the future

• For now, the overlap design is preferred as its simpler and easier to manufacture → weight is also a big benefit

• Some changes that need to be made:

  • The aileron itself will need to wrapped in MonoKote so the design will need to be adjusted to allow for that

    • As it is right now, we would have to wrap each individual section from one rib to another

    • One method I thought of: Make the aileron one entire piece and connect it to the wing at only the left and right most ribs using the (ie. disconnect from the end of each “main” rib, look at image below)

    • Putting some extra work into making the manufacturing of the ailerons as easy as possible will be helpful later on

  • Servo placement and linkage that connects to the to the horn

    • The mount for the servo would most likely be 3d printed for weight savings

    • Most likely placed on the spar but I’ll let you decide on exactly how/where

Author: @Sam Wong Updating Date: Oct 30, 2024

• updated the overlap design so that the aileron only attaches on the sides

• this design iteration will allow the wing and the aileron to be properly wrapped in the MonoKote