Mechanical tolerance analysis
Serious tolerance analysis for hobbyists and independent builders. Start with a simple stack today, then grow into richer projects without buying an enterprise system or creating an account.
Deterministic envelope under the entered model and limits.
Statistical comparison with assumptions kept in view.
Export the inputs, outputs, unit basis, and product notice.
Guided project workflow
Choose the job, document where every tolerance came from, check the outcome, and preserve the assumptions with the project.
Small tools / fast answers
Three transparent helpers for common desk checks. They run locally and are intended for preliminary work.
Make the workspace yours
Theme names are descriptive and intentionally generic. Stackwise is not affiliated with the companies or design systems that may have inspired them.
A workspace that grows with you
Stackwise is being designed for home shops, hobbyists, students age 13 and older, and independent builders who want deeper personal analysis without enterprise pricing or complexity.
Mixed units, worst-case and RSS comparison, contribution ranking, requirements, exports, and a documented validation trail.
Asymmetric limits, probability distributions, process shifts, Monte Carlo simulation, correlation, nonlinear equations, yield, and sensitivity analysis.
Purpose-built bolt patterns, fastener clearance, datum schemes, position, profile, material-condition modifiers, and assembly-focused reports.
Saved projects, scenario history, reusable templates, personal review reports, measured-data import, and privacy controls.
Live analysis / 1D linear stack
Monte Carlo / Advanced simulation
Worst-case remains the deterministic boundary. Simulation adds a separate statistical view using the distributions, shifts, and relationships you define below, including nonlinear geometry, estimated yield, and simulated capability.
Start with the defaults: normal distributions, no correlation, and 10,000 trials. Expand the advanced controls only when your process model needs them.
Output = x1 − x2 + x3
Design Advisor / Decision workspace
Find the tolerance worth changing, allocate a realistic budget, and compare the model with measurements from actual parts.
Current model · WC ±0.1700 mm · RSS ±0.1136 mm
SOLIDWORKS + CAD Bridge
Export an assembly dimension table from SOLIDWORKS, import it here, then highlight only the components that affect the fit. Stackwise checks the selected chain before adding it to the calculator.
Create a self-contained HTML summary that can be printed to PDF and includes the inputs, requirements, results, and review notice.
Beginner’s guide / 5 minute read
A manufactured part is almost never exactly its drawing value. Stackwise follows the chain of allowed variation through an assembly and shows how much the final gap, length, or clearance can change.
Add every length that affects the final measurement. Use + adds when traveling across that dimension moves the result forward. Use − subtracts when it moves back toward the starting datum.
Nominal is the answer when every part is made at its stated drawing size. It is the center of this analysis—not a promise that a real assembly will measure exactly that value.
10.00 − 5.00 + 1.50 = 6.50 mmWorst case assumes every dimension reaches its allowed limit in the combination that hurts the result most. Stackwise adds the tolerance magnitudes, then applies that total above and below nominal.
±(0.10 + 0.05 + 0.02) = ±0.17 mmPossible range: 6.33 to 6.67 mmRSS produces a narrower statistical comparison because it does not assume every contributor reaches its extreme at once. It is appropriate only when the variations are independent and the entered values have a defensible statistical meaning. Ordinary drawing limits are not automatically standard deviations.
√(0.10² + 0.05² + 0.02²) = 0.1136 mmEnter the allowed minimum and maximum for the final assembly measurement. A pass means the entire worst-case range fits inside those limits. In the example, 6.33–6.67 mm fits inside the required 6.20–6.80 mm, so the design passes.
Result glossary
The deterministic calculator supports signed one-dimensional chains with symmetric ± tolerances. The separate simulation workspace adds asymmetric limits, correlation, process shifts, common probability distributions, and user-defined nonlinear equations. Stackwise does not yet solve full 3D GD&T datum mobility, bonus tolerance, form, orientation, contact, or assembly kinematics. Treat every result as an engineering analysis aid and require qualified review before manufacturing or safety-critical use.
Method note / Read before use
Worst-case adds all symmetric tolerance magnitudes. RSS uses the square root of their squared sum and is shown only as a comparative estimate. Drawing limits are not automatically standard deviations.