Rubys Fort

Rubys Fort is a practical tolerance stack-up analysis tool designed for mechanical engineers, machinists, hardware designers, and makers. Build dimensional tolerance chains, calculate worst-case minimum, nominal, and maximum values in real time, and verify whether your results meet specified design limits. Everything works directly on your device, without requiring an account or cloud connection. Key Features Worst-Case Stack-Up Calculations: Combine additive and subtractive dimensions with absolute or percentage tolerances. Percentage tolerances are calculated using each component's nominal dimension, while calculations maintain full internal decimal precision before displaying rounded results. Target Range Validation: Define your desired minimum and maximum limits and instantly check whether the complete tolerance interval fits within your target. Get a clear PASS or FAIL result, including boundary values, remaining margins, and the exact amount of any undershoot or overshoot. Tolerance Contribution Analysis: Understand how individual dimensions contribute to the overall variation. Identify where tighter tolerances may improve your design and where adjustments could be considered without exceeding acceptable limits. Interactive Tolerance Chain Editor: Add, edit, and rearrange dimensional contributors using straightforward move-up and move-down controls. Follow your assembly through a visual tolerance strip that updates as you make changes. Assembly Library: Keep your engineering calculations organized by naming, describing, searching, sorting, duplicating, archiving, and deleting saved tolerance chains. Your entire assembly library remains stored locally on your device. Side-by-Side Design Comparison: Compare two assemblies using a consistent measurement unit. When units differ, explicitly convert between millimeters and inches to avoid unintended mixed-unit calculations. Local Revision Snapshots: Keep up to ten automatic snapshots of recent edits for each assembly. Review previous versions and recover from unwanted changes without depending on cloud-based revision history. Flexible Unit and Precision Settings: Choose the default measurement unit for new assemblies and customize the number of decimal places displayed. Your calculations retain full internal precision regardless of display settings. Designed for Practical Engineering Work Use Rubys Fort to evaluate machined housings, check bolted joints, review dimensional tolerances before releasing engineering drawings, or compare alternative design iterations during a design review. Its calculation tools help you understand tolerance limits, examine dimensional contributions, and make informed engineering decisions. Offline by Design, Private by Default Rubys Fort stores your assemblies, dimensional data, and settings in a local database on your device. It requires no account, sign-in, or cloud synchronization. The app requests no camera, gallery, location, or network permissions and works entirely offline. Open Rubys Fort and start analyzing dimensional tolerance chains in a focused workspace built for convenient, consistent, and organized engineering calculations.