All the Features you need, built for Tolerance Stack-Up Analysis and Optimization
The RD8 Tolerance Stack-Up and Optimization Software helps you to do tolerance stack-up analysis on the fly during the product development process.

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Step 1: Import.
Stay in sync with the latest CAD.
".STEP" File Import
To get started - import a ".STEP" file.
The system recognizes all meta data from your .STEP file; dimensions, tolerances, GD&T annotations, part names, part colors, sub-assemlies, ...

Iteration Feature
Keep your work up-to-date anytime.
The "iteration feature" allows you to import a new .STEP file and keep track of design history.
The system then automatic recognizes parts and changes in the design. The user will only need to approve/adjust changes where the model looks different from the previous iteration - making it easy to reuse and refine the design during the development process.
See the example in the adjacent YouTube video.
Start without a ".STEP" File
If the user don't have a .STEP file yet - and start from a blank piece of paper - the user can create a project without a .STEP file.
This allows project teams to:
- Draft critical tolerance stacks
- Plan a shared vision of a product architecture
- Plan an exact constrained system design

Step 2: Setup Your Project
Lay the foundation with the right inputs.
World's First Path Finder
Automatic stack-up detection
Get instant help to set-up tricky tolerance stacks and check if tolerance stacks are ambigious (to avoid overconstraints).
Define a 'Point of Interest' and let the system identify possible tolerance paths. See the video to see an example.
Functional Requirements
Set functional requirement:
Target, LSL (Lower Specification Limit), USL (Upper Specification Limit), Sigma Level.
Read projected DPMO and yield in a simple interface.

Product Architecture Module
Setup a product archtecture from scratch or inherit the architecture from the .STEP file.
From an initial import-setting "interface definition" - the system identifies all interfaces between parts.
The architecture feature let's the user(s) arrange and re-arrange parts in assemblies and sub-assemblies to make tolerance analysis easy and simple.

Interface Map
The interface map feature aids the users by a graphical overview of the product architeture.
The system automatically generates the map. A mapping of part or sub-assemblies and their interfaces.
This feature is helpful to:
- layout product architecture
- divide work-tasks or areas of responsibility
- spot complexity (if the map looks like spaghetti you are most likely overcomplicating things and makes it imposible to make any valid tolernance analysis)

Quick Setup
From the "Path Finder" feature - automatically setup a given tolerance stack. Based in the identified path the system automatically sets up initial parameters for the stack to get the user off to a quick start.

Pre-CAD Stack-Up Analysis
The system offer the ability to manually setup stacks - handy pre-CAD - to estimate performance of critical features before development.
Assign nominal values, tolerances, distributions, Cp, Cc and/or Cpk values.

2D and 3D Stacks
Handle 2D and 3D stacks.
The system allows you to setup multi-dimensional stacks. In combination with the iteration feature the analysis can be refined during the development process.

Non-linear Stacks
Set-up non-linear stacks. Calculate forces, pressure, your commute-time-to-work, only your imagination sets the limit - as long as you can provide a mathematical expression.
The system works with all standard math-operators such as cos, sin, cosh, sinh, Pi, etc.

Apply GD&T Modifiers
Refine tolerance stacks with GD&T modifiers such as Symmetry, Straightness, Total Runout, Circular Runout, Profile of a Surface, Profile of a Line, Position, Perpendicularity, Parallelism, Flatness, Cylindricity, Concentricity, Circularity, or Angularity.

Sketch Canvas
Draft tolerance stacks and allocate estimated tolerances based on sketches or illustrations.
Annotate on sketches to draft and communicate design intents.
Keep the design history. After sketching - link the paramenters to the CAD model.

Tolerance Lookup
The system allows you to look-up and assign tolerance on the fly based on the ISO 286 IT grade standard.
The user can either input a tolerance and then calculate the corresponding IT Grade or input a tolerance grade and then calculate the related tolerance.

Embedded 3D Viewer and 2D Canvas / Infinity Canvas
Take screenshots from the embedded 3D viewer directly into the 2D Documentation Canvas. No app-switching.
Easy annotation of stacks by:
- Point of Interest annotation
- Leader lines
- Arrows
Semi automatic link of annotation to parameters and parts.
The canvas is an "infinity canvas" and can be used to add notes, screenshots, stickers to support the development and thought process.

Step 3: Analyze Tolerance Stacks.
Let the system handle the heavy lifting.
Spot and fix problems before they escalate.
Simulating Success or Failure
Easy switch between different evaluation methods:
Analyze the Stack
Read DPMO- and yield projections.
Identify impactful parameters - often a source for optimization.

Parameter Studies
Analyze sensitivity and impact of parameters.

Step A: Overview
Approve design with confidence.
Deliver clear 2D drawings.
The Great Overview
Tolerance Stack-up Overview
Linked Calculations Sheets
The "What if" feature.
Preview Impact of Parameter Changes
Easily preview the impact of publishing your parameter changes
"What if" this parameter changes? Instantly check the impact on other calculations.
E.g. handy in case if a part is out of specification. Check the impact in seconds.
Parameter List: The Foundation for the 2D Drawing
The systems parameter module makes it easy to filter out all relevant elements that should be transferred to the final 2D drawing.
The parameter module summarizes parameters from all tolerance stacks into a single list.
With respect to axiomatic design - the parameter list also reveals information regarding how many times/places an element is used which can be an indicator for how many couplings that exist in a design.

Time-Machine
Create iterations along the early to the late development phase. Track development over time and document decisions.
Step B: Collaborate.
Make Tolerance Stack-Up Analysis and Optimization a Part of the Product Development Process.
Live Collaboration
Collaborate real-time with colleagues 'google docs style'.
Cloud based system: no check-in or check-out.
Manage and control access/viewer rights.
PDF Export
Document your efforts with a few clicks by export a PDF-document.

Step C: Optimize.
Make life easy.
The secret sauce.
Simplify tolerance stacks by optimized interface design.
X-ray Interfaces and Identify Overconstraints
Our technology is built on world-leading interface engine.
Here you see an illustration of two parts - a grey and a purple.
Our 'X-ray' mode lets you inspect functional surfaces between the parts.
In this case almost all functional surfaces are highlighted in orange - indicating overconstraints. This results in unnecessary complexity for tolerancing.
Optimization Checker
Contrary to the other example with an overconstrained design - here's an example with no overconstraints.
The 'X-ray' and constraint evaluation engine determine that there are no overcontraints and that the part is ideally constrained - indicated by green functional surfaces. The parts are exact constrained and hereby easy to tolerance.
How-to create a Tolerance Stack-up Calculation in 2 min.
Easy Setup in minutes
Automatic stack-up detection
Get instant help to setup tricky tolerance stack-ups and check if chains are unambigious.
2D Canvas and Annotation
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