Manufacturing
This page is primarily for Structural's usage. It's to help new members know what training they need to do to be able to manufacture, along with a list of purposefully-manufactured (not member-training pieces to prove their readiness) parts.
The CTS-SAT-1 frame primarily uses 316 Stainless Steel Socket Head Fasteners (M2.5 x 0.45) 6 - 12mm in length.\ M2 316 Stainless Steel Countersunk Philips fasteners are used for mounting the deployment switches.\ M3 316 Stainless Steel threaded Rod is used for securing the PC104 Main Stack as 3.2mm is the default PCB hole size.\ Aluminum spacers go in between the PCBs.\ Aluminum Standoffs are used to secure the PiCam.
Selection considerations: In our research of the fasteners other cubesats have used 18-8(AKA 304) Stainless Steel Socket Head or Flat Head (Countersunk) are the most common. M2.5 seems to be the most standard size. Torx or Hex drivers. Torx is preferred as it strips less easily but there are less sizes/types of fasteners available that use Torx.
Coated Fasteners such as galvanized steel are not generally allowed in the design specs.
We choose to use 316 instead of 18-8 because it is less magnetic than 18-8 with similar/better mechanical properties and minimal cost difference.
We used hex head drives as Torx was not available in 316 for the sizes we needed.
We went with socket heads primarily to simplify manufacturing by avoiding countersinking which also wasn't possible in some locations due to the thickness of the sheet metal we were using. Button head fasteners would also be acceptable but they are harder to handle during assembly.
Stainless Steel Helicoil inserts may be be used to increase thread strength and reduce the chances of aluminum threads becoming deformed from repeated use.
Before diving into the manufacturing phase, it is critical to engage with the design prime of the satellite frame early in the project. This collaboration will:
- Determine Material Selection: Ensure the chosen material aligns with the launch provider's specifications and operational needs.
- Validate Manufacturability: Confirm that the designed parts can be produced using your team's available machinery. If the available machines cannot handle the requirements, outsourcing to a vendor may be necessary. However, it's important to note that outsourcing can significantly increase manufacturing costs, particularly for parts with tight tolerances that require CNC machining operations.
By addressing these considerations early, we can ensure a more efficient and cost-effective design-to-manufacturing transition. When designing a satellite frame, it's crucial to note that the materials available for manufacturing are often specified by the launch provider. Common materials include Al6061, Al5052, Al7075, and others.
When choosing material for a satellite frame, there are multiple factors you might want to consider such as:
- strength-to-weight ratio: minimizing the overall weight of the satellite while achieving great structural integrity
- Fatigue Resistance: withstanding repeated loading during the launch environment without experiencing any material failure
- Stiffness: preventing buckling under stressful loads and resisting deformation
- Thermal conductivity: dissipating heat generated by electronic components to avoid overheating
- Corrosion Resistance: protecting against environmental factors and increasing surface hardness
- Anodizability: having a great ability to create oxide layers on the surface based on its chemical and physical properties (anodizing will be discussed in more detail later in of this section)
- Outgassing: not contributing excess outgassing to avoid contamination of sensitive electrical components
- Fastener Compatibility: having high thread retention for small tapped holes
- Machinability: being easy to machine with minimal tool wear
CTS-SAT1 frame is manufactured by using Al 5052 (two side panels) and Al 7075 (others). Specifically, because of the small holes tapped to M2.5 and 4-40, Al 7075 is a better choice than Al 6061. Al7050 has higher tensile strength and hardness compared to Al6061. This makes it less chance of stripping when tightening those small screws. This is especially important when there is a higher likelihood of disassembling and reassembling the parts.
First things, please note choosing the right thickness material will save time and cost in manufacturing. Even if you are a student and have free access to machine shop/material, your time is also considered as money.
Based on the design of your satellite, go to the McMaster website to determine the size/thickness of materials commonly used in the industry. For example, if the designed part has a thickness of 15mm, you can choose 5/8” (15.88mm) or 3/4” (19.05mm) material. Unfortunately, a lot of satellite organizations use metric dimensions while many materials in Canada use imperial units. Please use table 1 as a reference when you check the material thickness in McMaster. It shows in both inch and mm units.
It depends on your design to choose between 5/8” (15.88mm) or 3/4” (19.05mm) material. Let's say your stock is already in the exact size of your designed part and you do not care about the surface finish of the part, you might want to select 5/8” material. However, if your stock is oversized and the surface finish needs to be flush since it mates with other parts, you might want to choose 3/4" material. The reason is you need some extra material thickness to clump material on a machine device.
Exact Size Stock (5/8" material):
- Use this if the stock dimensions already match your design requirements.
- It minimizes waste and reduces machining time and costs.
- Best for situations where the surface finish and precision are not critical factors. Oversized Stock or Critical Surface Finish (3/4" material):
- Allows for extra material to securely clamp onto machining fixtures without compromising the final part dimensions.
- Ensures a smooth, flush surface finish when the part must mate precisely with other components.
- Offers room for fine-tuning and error correction during machining.
In short, when surface finish and precision are essential, it's worth the extra material and machining effort to start with 3/4". Conversely, for simplicity and cost-efficiency, 5/8" is ideal when precision clamping and finish aren't priorities.
You might be also wondering why we do not choose 11/16” thickness material. If you go to the McMaster website and search for 11/16” thickness material, McMaster-Carr offers very few options for 11/16" material. This makes it challenging to find a specific material type, size, or finish for your needs. Custom or less common thicknesses like 11/16" often require special orders, which can increase cost and lead time. Sticking with standard sizes helps avoid these delays and reduces expenses. Materials in 5/8" and 3/4" thicknesses are far more common and widely available. This means you have a greater variety of materials (e.g., aluminum alloys, steels, plastics) and dimensions to choose from. Student shops and general-purpose machine shops are more likely to stock standard thicknesses like 5/8" and 3/4" due to their widespread use and accessibility. By keeping material availability in mind, especially for student or budget-constrained projects, you streamline the process and ensure compatibility with standard shop resources. It’s always a good idea to design around what’s easily attainable unless there's a compelling reason to deviate.
Please note that the width and height of the material are other important factors. However, those are much easier to control even if you have oversized stock. If the stock's width and height are oversized, they can be easily trimmed down using tools like a bandsaw or waterjet cutter, which are standard equipment in most student shops. Waterjets, for example, can cut through a variety of materials and thicknesses with high precision, making them ideal for initial stock preparation. However, waterjet can only control the height and width of the material and cannot control the material thickness. Reducing width and height with these methods is typically faster and less expensive than working with a non-standard thickness, which might require extensive machining or special ordering.
Table 1: Material Thickness Reference (Al6061, McMaster)
| McMaster Link | Thickness (Inch) | Thickness (mm) |
|---|---|---|
| 0.016" | 0.016 | 0.4064 |
| 0.025" | 0.025 | 0.635 |
| 0.032" | 0.032 | 0.8128 |
| 0.04" | 0.04 | 1.016 |
| 0.05" | 0.05 | 1.27 |
| 1/16" | 1/16 | 1.5875 |
| 0.063" | 0.063 | 1.6002 |
| 0.08" | 0.08 | 2.032 |
| 0.09" | 0.09 | 2.286 |
| 3/32" | 3/32 | 2.38125 |
| 0.1" | 0.1 | 2.54 |
| 1/8" | 1/8 | 3.175 |
| 0.16" | 0.16 | 4.064 |
| 3/16" | 3/16 | 4.7625 |
| 0.19" | 0.19 | 4.826 |
| 1/4" | 1/4 | 6.35 |
| 5/16" | 5/16 | 7.9375 |
| 3/8" | 3/8 | 9.525 |
| 7/16" | 7/16 | 11.1125 |
| 1/2" | 1/2 | 12.7 |
| 9/16" | 9/16 | 14.2875 |
| 5/8" | 5/8 | 15.875 |
| 11/16" | 11/16 | 17.4625 |
| 3/4" | 3/4 | 19.05 |
| 13/16" | 13/16 | 20.6375 |
| 7/8" | 7/8 | 22.225 |
| 15/16" | 15/16 | 23.8125 |
| 1" | 1 | 25.4 |
| 1 1/8" | 1 1/8 | 28.575 |
| 1 1/4" | 1 1/4 | 31.75 |
| 1 3/8" | 1 3/8 | 34.925 |
| 1 1/2" | 1 1/2 | 38.1 |
| 1 5/8" | 1 5/8 | 41.275 |
| 1 3/4" | 1 3/4 | 44.45 |
| 2" | 2 | 50.8 |
| 2 1/4" | 2 1/4 | 57.15 |
| 2 1/2" | 2 1/2 | 63.5 |
| 2 3/4" | 2 3/4 | 69.85 |
| 3" | 3 | 76.2 |
| 3 1/4" | 3 1/4 | 82.55 |
| 3 1/2" | 3 1/2 | 88.9 |
| 4" | 4 | 101.6 |
| 5" | 5 | 127 |
| 6" | 6 | 152.4 |
| 2 mm | ||
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| 25 mm |
Please check this document in CalgaryToSpace Google Drive for the training you need to complete at the University of Calgary in order to gain access to manufacturing equipment: "Manufactuing Tips for CalgaryToSpace Memebrs"
This is a list of things that have been manufactured. It is arranged by chronological completion date, with incomplete components being given a status. It also shows who manufactured the component.
- Machine Used: Waterjet, Manual Mill
- Material: Aluminum 6061
- Drawing & CAD (Internal Only):
This frame was designed and manufactured to prepare for our first vibration test at the David Florida Laboratory (DFL) in Ottawa, ON. DFL was operated by the Canadian Space Agency (CSA) and was a key facility for spacecraft assembly and testing. This marked our very first opportunity to be involved in the manufacturing process and participate in a vibration test.
- Machined Used: Waterjet, CNC (TM-2P &, Hass Automation)
- Material: Aluminum 6061
- Coating: Type II, MIL-A-8625
- Drawing & CAD (Internal Only):
- CNC Program (MasterCam, Internal Only):
This testing P-POD was manufactured to test the fit of our designed satellite and function as a fixture during the vibration test conducted in Calgary, AB, in September 2024. This opportunity allowed us to enhance our manufacturing skills and prepare for the production of our flight frame.
