Design
Pros
Cons
https://www.apogeerockets.com/Peak-of-Flight/Newsletter599
Airbrakes Engineering Notebook
10/8/2023 Getting Started
Requirements of a solution:
Ideas
Design | Pros | Cons |
| Compact, Easier to integrateSimpleLess mass than hinge deploy | Potentially less surface area than hinged deploys | |
| More potential surface area than slide deploys | Would require significant force to open against the airflowComplex mechanismPotentially more mass than slide deploysWould require significant structural alteration to the outside of the rocket |
| Compact, easy to integrateSimpleLess mass than hinge deploy | Potentially less SA than hinge deploys |
| Not fighting drag, drag assists deploymentIncreased surface area compared to slide deploys | Could accidentally deploy, depending on implementationComplex mechanismPotentially more mass than slide deploysLots of alteration to outside of rocket |
Calculations:
Speed of the rocket: 1300 ft/s
Force on 14 in2 of air brakes: 866 N
10/15/2023
Goals
Servo motor SG90 Datasheet: http://www.ee.ic.ac.uk/pcheung/teaching/DE1_EE/stores/sg90_datasheet.pdf
Torque of servo: 2.170 lb in
10/22/23
Drawings and CAD
Slight change in design of current model to expand surface area
Now 2 levels of brakes that leave the rocket in 4 total leaves
Cad drawings started on the leafs, the connector and the base plate
Plan to complete CAD drawings and 3D print before next meeting
11/5/2023
Larger holes on connectors (3/32) - amber
Countersink under the leaves (3/16) - nicole
Change the leaf shape and add area (.625”), remove space between the inner part of the leaf and servo mount - pari
Decrease shaft cross section size (tolerance) - alex
Locknuts
Remove gap between leaves and the servo mount on the side, remove lip on servo mount - enrique
11/16/2023
5.49 in^2 (each leaf)
7.44 in^2 (each leaf)
11/19
Adding a top base plate (which are the rails)
Add something plastic for the leaves to sit on to reduce friction
Make leaves longer/arms shorter
Change the shaft to an octagon/hexagon
Edit base plate to accommodate one set of leaves instead of 2
1.75 in^3 →volume of leaf
11/30
Changing entire design basically
CAD all parts from scratch
PUT EVERYTHING IN “NEW AIRBRAKES” FOLDER
12/03
Final area of leaves: 3.5 in x 1.57 in
5.49 in^2 each leaf
21.9 in^2 total
Spacers + tray that leaves slide in
PLA (3d print)
Servo
HS-1005SGT Servo
Frame, leaves, servo mount, everything else
Aluminum (machine)
6061
Cost breakdown:
https://www.mcmaster.com/products/hex-shafts/material~aluminum-2/
Dimensions:
Materials:
1/8/2024
KERF List
Servo Mount: make screw holes larger - done
Aluminum Spacer: make screw holes larger - Done - 🦑
Leaves: make leaves vertically thinner (extruded part does not have to be vertically thinner) - Done, all screw-holes (larger) - Done, reduce width of leaf and extruded part - Done, bearing hole (larger) - Done - 🦑
Cylinder - Outside Casing: make screw holes larger - Done - 🦑
Frame: all screw-holes (larger), bearing hole (larger) - done
Hex Connector Middle: make hex bigger
Tray: reduce the wall thickness, reduce the width, reduce the height, bearing hole (larger) - done
The servo doesn't need to be as strong for the sustainer
Make a second airbrake with a new servo mount