Task Description
eBig Project | Project | Project Manager |
|---|---|---|
Post-comp fixed wing | Wing Design |
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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
Constraints | Written By | Append Date |
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1 aileron per wing |
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Adheres to sizing found in Aileron Sizing |
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https://hitecrcd.com/products/servos/analog/sport-2/hs-311/product Will be using this aileron |
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Relevant Contacts
Subteam | Contact | Contact Description |
|---|---|---|
Subteam collaborating with | @ of contact | what is the contact responsible for? |
Assignees
Assignee | Asana Task | Date |
|---|---|---|
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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.
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.
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full wing with overlap aileron fully modeled
mass of entire wing = 237.16 g
mass of aileron = 20.57 g
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Author: Agapa Goombs Updating Date:
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 simplfy simplify the mountinng mounting of the aileron's end plates of the aileron.
Finally, the general modifications to the main wing was were standardized between the the Overlap and Hinge Design to minimize the time for integration.
Also exteds to the spacers used between Ribs
The Hinge Aileron Design is shown below:
Dimensions
Aileron Span: 254.9mm
Aileron Cord: 57.0598mm
Weight:
Aileron: 26.94 gramsg
Wing with Aileron: 243.47 grams243.47 g
Mass Summary
Design #1 | Mass of Aileron (g) | Mass of Aileron-Wing Assembly (g) |
|---|---|---|
Overlap Design | 20.57 | 237.16 |
Hinge Design | 26.94 | 243.47 |
Author: Nathaniel Li Updating Date:
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:
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
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