Engine Dialog

The Edit Engine Dialog in SpaceCAD 7 allows users to select and configure rocket engines. The engine is a key element that powers the rocket, and this dialog provides options for selecting the engine type, setting the delay time, adding additional mount weight, and positioning the engine within the rocket. If the engine is a sub-element of an “inside tube,” which multiplies the number of engines or other sub-elements, the dialog will notify users about any duplications.

Key Fields and Features:

Engine Name

• Non-editable field that displays the selected engine’s name.
• Example: “Estes A8-3”.

2D Color

• Allows users to assign a custom color to the engine for better visual identification in the design interface.
• Example: The engine is assigned a Red color.

Duplication Info

• A info message appears if the engine is duplicated, particularly when engines are children of inside tubes.
• Inside Tubes: These tubes act as multipliers for their sub-elements (such as engines), and the count in the inside tube configuration determines how many engines or sub-elements are added.
• Example: The message “Engine is duplicated in collection of 1 elements” means this engine is replicated within an inside tube, where multiple engines are configured.

Engine Selection

• Select Button: Opens the engine database, where users can choose from various engines based on manufacturer, thrust, and size.
• Users can select engines that are compatible with their rocket’s motor mount and performance requirements.

Delay

• Specifies the ejection delay in seconds. The ejection delay determines when the recovery system will deploy after engine burnout.
• Example: A 3-second delay is typical for an Estes A8-3 motor.

Additional Mount Weight

• Allows users to add extra weight to the engine mount, useful for balancing or fine-tuning the rocket’s center of gravity (CG).
• Example: 0.0 g indicates no additional mount weight is applied.

Internal Element Positioning

Engines, like other internal elements, can be positioned relative to the rocket’s other elements in four ways:

• Absolute Position: Sets the exact distance from the reference point.
• Relative to Top of Owner: Adjusts the position relative to the top of the rocket element (such as the body tube) that houses the engine.
• Relative to Middle of Owner: Positions the engine relative to the middle of the owner element.
• Relative to Back of Owner: Keeps the engine positioned at the rear of the owning element, ensuring proper alignment even if the element (e.g., body tube) is resized.

This flexibility in positioning ensures the engine stays correctly placed in the design, especially in setups that involve resizing or reconfiguring the rocket’s body tube.

Relative Position

• Specifies the exact distance from the top of the owning element to the engine.
• Example: The engine is positioned 5.0 mm from the bottom of the body tube.

Preview Button

• Provides a real-time preview of the engine and its position within the rocket design, allowing users to make visual adjustments before finalizing the configuration.

Inside Tube Context (Multiplier for Sub-Elements)

Engines can also be part of an inside tube, which acts as a multiplier for the number of engines or sub-elements. The inside tube has a count field, determining how many sub-elements (e.g., engines) are replicated within the tube. This is useful for designs with multiple engines, such as clustered motor configurations.

• Count: Defines how many engines or sub-elements are added to the rocket.
• Duplication Warning: When multiple engines are configured within an inside tube, the duplication warning helps users keep track of the multiplied engines.

Example Workflow:

1. Configuring a Single Engine for a Small Rocket:

   • Open the Edit Engine Dialog and select the Estes A8-3 motor using the Select button.
   • Set the delay to 3 seconds, appropriate for small, low-power rockets.
   • Ensure the engine is positioned relative to the back of the owner (e.g., the body tube) to maintain correct alignment.
   • Click Preview to check the engine placement before applying the settings with OK.

2. Configuring Multiple Engines with an Inside Tube:

   • In the Edit Inside Tube dialog, set the count to 3, meaning 3 engines will be added inside the motor mount tube.
   • When configuring each engine using the Edit Engine Dialog, the duplication warning will notify users that multiple engines are applied.
   • Adjust the delay and position of each engine if necessary, then click OK to finalize.