Introduction to tolerance stack calculations

What is it?

This course introduces the method for tolerance stack calculations.

• A systematic method for analysing the effect of tolerances across a component or assembly
• Calculation can be carried out with spreadsheet software or pocket calculators
• Tolerance stacks allow you to ‘tune’ a design by adjusting dimensions and tolerances to meet a specific objective.

The tolerance stack method is suitable for analysing ‘one-dimensional’ tolerance stacks, e.g. the build-up of tolerance in a single direction. Two-dimensional tolerance stacks can sometimes be tackled using this approach, but this requires that the vectors be resolved into two components, which are analysed using two different stacks, and the results combined afterwards. Three dimensional tolerance analysis really requires the use of specialist software (and specialist operators) and is beyond the scope of this method.

The 1-D stack method is widely used, as it can be used to tackle many of the critical tolerance build-ups in components and assemblies. This is an essential tool for the well-equipped engineer.

Duration

1 day

Who is it for?

Designers and mechanical engineers.

Delegates need a thorough understanding of engineering drawing, geometrical tolerancing and the Maximum Material Requirement.  This course is normally run as a follow-on to the three day Geometrical Tolerancing (Level 1) course.

What does it cover?

• The tolerance stack concept.
• How to set up a tolerance stack calculation (objectives, conditions, the vector loop and the stack table).
• How to set up a stack for components with limit (+/-) tolerances.
• How to set up a stack for components with geometrical tolerances.
• How to take account of bonus tolerances.
• How to take account of datum shift.
• How to set up tolerance stacks for assemblies.