aevyrie / tolstack

1D tolerance analysis for mechanical engineers

Overview

TolStack is an open source tolerance analysis application for building and analyzing 1D geometric tolerance models. The goal of this tool is to help make tolerance analysis fast, intuitive, and explorable. Built with Rust using iced.

Read the TolStack user guide

Roadmap

Disclaimer

🚧 This application is in development, untested, unstable, and not ready for general use. 🚧

This software should only be used by engineers who are able to independently verify the correctness of its output. The software is provided as is, without warranty of any kind. The intent of this software is to aid in the exploration of tolerance analyses, not to replace existing methods of analysis or verification.

Features

• Build one-dimensional tolerance stackups in a visual editor
• Evaluate and tune your tolerances with:
  • Monte Carlo analysis
  • RSS analysis
• Export results to CSV

Screenshot

Build Instructions

1. Install Rust via Rustup.
2. Clone the repository with git clone https://github.com/aevyrie/tolstack.git
3. From the tolstack directory, run cargo run --release to build and launch the application with compiler optimizations.

Hardware and Software Requirements

• Note: make sure your graphics drivers are up to date!
• Linux/Windows: You will need a modern graphics card that supports Vulkan
  • Integrated graphics (Intel HDxxx) requires vulkan support, check here
• MacOS: the backend uses Metal, check here for requirements

License

This project is licensed under the MIT license.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in tolstack by you, shall be licensed as MIT, without any additional terms or conditions.

tolstack's Issues

Mismatch between MC and RSS analysis

Mean and tolerance do not match between the two analysis methods.

Means do not match due to bounding - the MC analysis can discard any out of spec samples. If the BoundingParam is set to KeepAll, the RSS and MC means match.

MC analysis currently does not report tolerance positive and negative, only the symmetric tolerance is specified. Taking the average of RSS results seems to show they (almost) match. #12 should be resolved before continuing this investigation.

Worst case floats incorrect.

Calculation is incorrect.

Autosave overwrites data after new file

When opening a file then immediately hitting new, blank data will be written to the old location, losing data. Implement a last-saved tracker and get rid of the async timer that causes delayed saves.

Add buttons to reorder stack entries

Add up/down arrows to reorder tolerances in the stack.

Add warning that RSS is only valid for normal distributions

If any tolerance has a non-normal distribution, highlight the RSS results, and warn that they are only valid for normal distributions.

Validate and document correctness

Develop validation test to pass input and compare against known correct output.

Also need to document this validation.

Good reference: https://www.smlease.com/entries/tolerance/tolerance-stackup-analysis/

Add RSS Analysis

Provide RSS analysis in addition to the MC sim

Report interference rate for floats

Report the rate that a pin and hole results in interference.

Display part distributions graphically

Especially useful for non-normal distributions. Show how the distribution falls relative to the bounds.

Allow user to specify Cpk instead of sigma

Add dropdown so user can specify either CpK or sigma level for the part.

Autosave Toggle

Field tabbing

Need to be able to tab between fields in tolerance entry forms.

Add "100%" inspect toggle on parts for MC

Allow user to see the effects of 100% inspecting a part.

Simplify input validation

Simulation params have strict text validation on the input fields. This results in non-intuitive behavior, especially when the number is at it's minimum, and backspace just moves the cursor backward without deleting.

Enhanced CSV Export

• "Report" style output with rows/cols to show the tolerance stack input
• Results summary
• Use formulas to show work for RSS and worst case. (excel evaluates "=SUM(1,2)" in a CSV!)

Add New button

Add a menu button to create a new blank document

Change data export to TEMP directory

Use std::env::temp_dir

Undo/Redo

New tolerance default behavior

When a tolerance is added as an 'incomplete' entry, the implication is that the user did something wrong or off the happy path. There should either be a way to add the dim/tol values up front as its added, or open the entry dialog by default

I think the best path here is to add the tolerance in the editing state to start.

Stack Diagram

• Visual representation of the tolerance stack

Hide cmd window during execution

cmd window runs in the background

Timestamp csv exports

CSV exports do not include a timestamp, so opening successive CSVs from the application does not open the file if already open in Excel, as it does not allow multiple files with the same name in session.

Allow multiple Stacks per project

Projects can contain multiple tolerance stacks. Allow stack duplication, moving, renaming, deletion. Similar to tabs, but in a vertical scroll entry list.

Appearance/Accessibility

• Zoom multiplier (apply to all values by storing in stylesheet?)
• Dark/light mode

Assert when calculating with empty stack

Hitting "Run Simulation" with an empty tolerance stack results in an assert, and some unpredictable behavior.

Editing new project name should replace text

Trying to input a project name, I clicked the field expecting the 'New Project' text to be a placeholder and began typing

If a project name is new and unedited, any time it's edited, the placeholder text should be replaced. Currently, the text is not replaced and new text is inserted alongside the "New Project" text.

Add button for tolerance creation

Currently relies on keyboard to add. Should add a button for mouse user parity.

Add save button to project title editing field

Right now saving the field requires hitting Enter. Not obvious that this is needed, should also add a button in edit mode.

Change auto save/load behavior

• Don't open file by default
• Don't autosave to disk until saved once with a specified file name
• Open Save As menu if Save button is hit in an unsaved project

Autosave only works for every other operation

Disable debug messages on release builds

Remove the println() spam "MESSAGE RECEIVED"

Show positive and negative tolerance for MC analysis

MC analysis only shows the symmetric result, should report pos/neg for non-symmetrical results.

Documentation

Need to add

• Algorithm details
• List of assumptions

Simulation Output Graphics

Suggestions for output graphics:

Non-normal tolerance distributions

Allow non-normal distributions, such as flat, or skewed. Skewed distributions could be defined by mean/median/std dev.

Encapsulate structs and improve interfaces

Remove pub struct field access and replace with getters. For example, accessing the DimTol of a hole or pin, it isn't clear if the dim is diametric or radial. Replace the struct field with a float::hole_dia() or something.

Add button to open up help page

Compute RSS automatically

Compute RSS, worst case, and nominal any time a value is changed.

Asymmetric MC results incorrect

Ex, a linear tolerance with dim 10 +5/-1 will have a MC result with an equal positive and negative tolerance. The total tolerance appears to be correct, e.g. 48 total in this case, however the output is incorrect.

Unequal Float Variance

Floats seem to result in unequal variance results. This should not be the case.

Warning prompts

Show warning prompts when opening or creating a new file with unsaved changes. Use msgbox ?

Use uniform distribution for floats

Floats currently use a normal distribution. This should be flat.

User specified assembly tolerance limits

Allow users to specify the USL and LSL for the assembly. Report amount of predicted assemblies outside these limits.

Disable 100% inspection by default for MC

Monte Carlo should not default to 100% inspection (discarding parts that are OOS).

Add unit selection (mm/in) per tolerance

Allow input to be in inches and mm. The application will automatically convert to the output type, also user specified.

Fix results getting cropped

Results area is cropped when resizing vertically.

Report tolerance contribution

Show the % contribution of each tolerance to the overall tolerance stack.