Inside Tube Dialog

The Edit Inside Tube Dialog in SpaceCAD 7 allows users to configure inside tubes, which are commonly used for housing engines, engine mounts, and other internal elements. These inside tubes can act as multipliers for sub-elements, making them useful for rocket designs with clustered engines or other replicated components. The dialog provides options for adjusting the tube’s dimensions, material, and placement within the rocket, as well as controlling how many sub-elements are included inside the tube.

Key Fields and Features:

1. Inside Tube Name

• Editable field to specify the name of the inside tube.
• Example: “Engine Mount Tube.”

2. 2D Color

• Allows users to assign a custom color to the inside tube for easy identification in the 2D design view.
• Example: The inside tube is assigned a Custom Maroon color.

3. Load from Database

• Users can select a predefined inside tube from the SpaceCAD database. This feature simplifies setup by providing industry-standard parts with predefined dimensions and material properties.

Material and Structural Properties:

4. Material

• Defines the material used for the inside tube, such as paper, plastic, or fiberglass.
• Change Button: Opens the material selection dialog, allowing users to choose from various materials based on the tube’s structural requirements.
• Example: Paper is used for lightweight rocket designs, while heavier materials like fiberglass might be used for high-powered rockets.

5. Fix Weight and Fixed CG

• Fix Weight at: Allows users to override the calculated weight and set a fixed weight for the inside tube.
• Fixed CG Position at: Lets users manually set the center of gravity (CG) position for the inside tube, which can be useful for balancing the rocket.

6. Dimensions

• Length: Sets the length of the inside tube, which impacts how much space is available for housing engines or other sub-elements.
• Outside Diameter: The outer diameter of the inside tube. This value must fit within the rocket’s main body tube or other structural elements.
• Wall Thickness: Defines the thickness of the tube walls. Thicker walls provide more strength but increase weight.
• Example: A standard engine mount tube may have a length of 69.8 mm and an outside diameter of 18.7 mm.

Sub-Element Management:

7. Count (Sub-elements)

• The count field specifies how many sub-elements are housed within the inside tube. This is especially important for engines, where the inside tube can act as a multiplier.
• Example: If the count is set to 3, the inside tube will contain three engines or other sub-elements, enabling clustered engine configurations.

8. Circular Position within Rocket Body

• Start Angle: Defines the angular position where the first sub-element starts inside the tube (in degrees). This is useful when placing engines in a circular arrangement.
• Distance to Centerline: Specifies the distance of the sub-elements from the rocket’s centerline.
• Example: In a clustered engine setup, the engines may be spaced evenly around the centerline, with the start angle and distance controlling their positioning.

Internal Element Positioning

The inside tube, like other internal elements, can be positioned relative to the rocket’s main structure in four ways:

• Absolute Position: The exact distance from the reference point is set and remains fixed.
• Relative to Top of Owner: Adjusts the position of the inside tube relative to the top of the owning element (e.g., body tube).
• Relative to Middle of Owner: Positions the inside tube relative to the middle of the owning element.
• Relative to Back of Owner: Ensures the inside tube remains at the back of the owning element, even if the element (e.g., body tube) is resized.

These positioning methods ensure that the inside tube is correctly aligned within the rocket, regardless of any design adjustments made to the rocket’s main body.

9. Distance from Owner’s Top

• Sets the distance between the top of the inside tube and the top of the owning element.
• Example: The inside tube is positioned 133.3 mm from the top of the body tube.

10. Preview Button

• Provides a real-time preview of the inside tube and its sub-elements, allowing users to visualize the placement before finalizing the configuration.

Example Workflow:

1. Configuring an Engine Mount with Multiple Engines:

   • Open the Edit Inside Tube Dialog and set the name to “Engine Mount Tube.”
   • Set the count to 3 to allow three engines to be housed within the tube.
   • Adjust the start angle and distance to centerline to space the engines evenly around the centerline of the rocket.
   • Ensure the inside tube is positioned relative to the back of the owner to keep it aligned at the rear of the rocket’s body tube.

2. Changing the Material of an Inside Tube:

   • Open the Edit Inside Tube Dialog and click Change under Material to select a different material.
   • Switch from paper to fiberglass for added strength, especially if using high-power engines.
   • Preview the changes to see how the material and positioning affect the rocket’s overall design before clicking OK to apply.