1. Overview
Click Open Builder in Tab A to open the visual tool for creating and editing a structure before analysis. It can be used instead of manually filling the Excel structure data template. It creates the same Excel workbook format used by the main StructureTool2D workflow.
The Builder opens from Tab A. The Builder Instructions button is on the first Builder toolbar row and opens this guide. The x button at the top right closes the Builder view.
The canvas shows an Active Tool badge near the upper right. The bottom status bar gives brief instructions for the selected tool. Toolbar buttons and File Actions buttons include hover tooltips.
The Builder can create and edit:
- Structure type: Frame, Beam, or Truss.
- Nodes and members.
- Member material, E, A, and I values assigned when members are created.
- Supports: Fixed, Pin, Roller-X, and Roller-Y.
- Member-end hinges.
- Nodal loads and member loads.
- Dimension lines between nodes or solid member-load points.
- Display colors, manual label positions, node-label style, node-marker visibility, and grid/axes visibility.
- Canvas range, grid spacing, zoom, and centering.
2. Recommended workflow
- Click Open Builder in Tab A.
- Select the Structure Type: Frame, Beam, or Truss.
- Select the Units option.
- Set the canvas limits and grid spacing.
- Choose the default material, then enter E, A, and I before creating members.
- Use Node mode to place nodes.
- Use Member mode to connect nodes. The first clicked node becomes the member start node.
- Add supports, hinges, nodal loads, and member loads.
- Add dimension lines if you want visual dimensions on the Builder drawing.
- Use display controls for labels, node visibility, grid/axes visibility, and colors.
- Use Save & Load Structure to export the workbook and load it into Tab A.
- Use Tab B-C for stiffness analysis or Slope-Deflection, or use Tab D-E for ULM/FM workflows.
3. Builder settings
Model Setup
| Setting | Description |
|---|---|
| Structure Type | Choose Frame, Beam, or Truss. This value is written to the exported workbook and is detected by the main interface. |
| Units | Choose the unit set used for coordinates, loads, material properties, and member properties. |
Canvas Settings
X min, X max, Y min, and Y max control the visible canvas range. X grid and Y grid control snapping. When you click or drag a node, the coordinates snap to the nearest grid point. The Grid/Axes display button hides or shows gridlines and axes without changing the snap spacing.
Default Member Properties
The default material, E, A, and I are assigned to new members when they are created. Existing members keep their stored properties unless edited or recreated.
Model Summary
The summary panel shows counts for nodes, members, hinged member ends, supports, loads, and dimensions. Use it as a quick check before exporting.
File Actions
| Button | Use |
|---|---|
| Import Data File | Loads an existing StructureTool2D workbook into the Builder for editing. |
| Save & Load Structure | Exports the current Builder model to Excel and loads it into the main app. |
| Save Image | Saves a PNG of the Builder drawing using the current display state. |
| Reset Builder | Clears the current Builder model and restores default Builder settings. |
4. Unit behavior
The unit selection controls the labels and values written into the workbook. Keep one consistent unit system for the full model.
Switching units after building a model
Changing units after a model is built changes the active unit setting for new input. It does not automatically convert all existing numerical values. Review coordinates, loads, E, A, and I if you change units after creating objects.
5. Toolbar commands
The top toolbar is grouped by task. The first row contains Create, Setup, Loads, Annotate, Edit, and Builder Instructions. The second row contains View, Display, and Color controls.
Create
| Tool | Use |
|---|---|
| Node | Click the canvas to add a node at the nearest grid point. Click and drag an existing node to move it. |
| Member | Click the start node, then click the end node to create a member. |
Setup
| Tool | Use |
|---|---|
| Support | Assign or edit a support restraint at a node. |
| Hinge | Add or edit a member-end hinge at a selected member end. |
Loads
| Tool | Use |
|---|---|
| Nodal Load | Add a force or moment directly at a node. |
| Member Load | Add a point load, distributed load, or member moment to a member. |
Annotate
| Tool | Use |
|---|---|
| Dimension | Add a visual dimension between two nodes or solid member-load points. |
Edit
| Tool | Use |
|---|---|
| Select / Move | Select and move editable items. |
| Delete | Delete selected items. |
| Undo | Undo the last supported Builder edit. |
| Redo | Redo the last undone Builder edit. |
View
| Tool | Use |
|---|---|
| Move Structure | Move the full model on the canvas. |
| Zoom In | Zoom into the canvas. |
| Zoom Out | Zoom out from the canvas. |
| Center | Center the model in the visible canvas. |
Display
| Tool | Use |
|---|---|
| Font - | Decrease Builder label font size. |
| Font + | Increase Builder label font size. |
| Nodes: A, B, C / Nodes: 1, 2, 3 | Switch node labels between letters and numbers. |
| Nodes: On / Nodes: Off | Show or hide node markers. |
| Grid/Axes: On / Grid/Axes: Off | Show or hide both gridlines and axes. Snapping still follows the X grid and Y grid values. |
Color
The color control applies display colors to supported selected items. Colors are saved for Builder display and image export. They do not change structural analysis properties.
6. Geometry
Adding nodes
Select Node and click the canvas. Nodes snap to the active grid spacing.
Moving nodes
In Node mode or Select / Move mode, click and drag an existing node. Connected members, loads, supports, and dimensions update with the node.
Adding members
Select Member, click the start node, then click the end node. The member stores start and end node order, which affects local member directions and report labels.
7. Supports and hinges
Support types
| Support | Typical restraint meaning |
|---|---|
| Fixed | Restrains horizontal translation, vertical translation, and rotation where applicable. |
| Pin | Restrains horizontal and vertical translation. |
| Roller-X | Provides a horizontal reaction restraint. |
| Roller-Y | Provides a vertical reaction restraint. |
Support rotation controls the drawn support orientation. Available rotations are -90°, 0°, 90°, and 180°. The 270° option is not shown because it is equivalent to -90°. Old imported files containing 270° are still handled safely by mapping 270° to -90°.
Beam fixed supports are oriented automatically based on the member side when possible.
Member-end hinges
Select Hinge, then choose the member end where the hinge should be placed. Hinges affect analysis data and are written to the workbook.
8. Loads
Nodal loads
Select Nodal Load, click a node, then enter the force or moment information. Nodal loads are written to the workbook and are shown in the structure preview and applicable reports.
Member loads
Select Member Load, select a member, then define the load type and parameters. The Builder supports common member load inputs used by the analysis workflow.
Editing loads
Use Select / Move or the relevant load tool to choose an existing load and edit its values. Review load direction, magnitude, and location before using Save & Load Structure.
9. Dimensions, labels, colors
Dimensions
Dimension lines are visual annotations. They help document the model geometry but do not affect analysis data.
Labels
The Builder supports number or letter node labels, manual label positions, and adjustable font size. These settings improve drawing readability.
Colors
Color settings are display aids for Builder drawings and image exports. They do not change material, section, load, or support data.
10. File actions, export, and images
Import Data File
Use this to load an existing StructureTool2D Excel workbook into the Builder. The Builder reads supported geometry, support, load, hinge, material, and display data.
Save & Load Structure
This is the main Builder export action. It creates the output workbook and loads it into the main app so you can proceed with Tab B-C or Tab D-E.
Save Image
Saves a PNG of the Builder canvas. The saved image follows the current display state, including node visibility, grid/axes visibility, label style, colors, zoom, and canvas position.
Reset Builder
Clears the model and restores Builder defaults. Use this when starting a new model.
11. Excel file conventions
- The Builder writes the standard StructureTool2D workbook format.
- The workbook is the source for Tab A, Tab B-C, and Tab D-E analysis operations.
- Analysis uses the structural model data, not visual-only Builder annotations.
- Use clear node and member layout before saving.
- Review units, material properties, supports, hinges, and loads before analysis.
12. Checks before analysis
- Confirm the correct Structure Type: Frame, Beam, or Truss.
- Confirm units and all numerical input values.
- Check node coordinates and member connectivity.
- Check supports and support orientations.
- Check hinge locations.
- Check nodal loads and member loads.
- Use Save Image if you want a record of the Builder model display.
- Use Save & Load Structure, then confirm the preview in Tab A before running analysis.