Inventor tips and tricks: #3 dimensions and tolerances
Published Wed 3 Feb 2010
Steve Bedder shares his tips on dimensions and tolerances
1) Giving parametric dimensions more clarity
1a) When entering dimensions into the Edit Dimension dialogue box, if you just enter a numerical value - e.g. 80mm - Inventor will create a parametric value and list it in the parameters dialogue.
1b) However, when you are adding your numerical values it is a good idea to also enter a name for your dimension to identify what the dimension is for e.g. height, width, length etc. You don’t need to pre-define the parameter name, you can do this dynamically when creating/editing a dimension.
1c) The end result is a parameters dialogue that is understandable with a list of dimensions that mean something rather than just d1, d2, d3 etc
2) Applying tolerances
2a) You can also use the Edit Dimension dialogue to apply any tolerances, limits and fits to the parametric dimension. Just click on the black arrow at the end of the input box and use the fly-out menu to select Tolerance. The Tolerance option will allow you to add intelligent model tolerances to the dimensions for:
- Symmetric
- Deviation
- Limits-Stacked
- Limits-Linear
- MAX
- MIN
- Limits/Fits-Stacked
- Limits/Fits-Linear
- Limits/Fits-Size Limits
- Limits/Fits-Tolerance
Using the Limits/Fits option will allow you to select from a list of Hole and/or Shaft to set the tolerance value for hole dimensions when using Limits and Fits tolerance.
2b) If you apply a tolerance to a parametric dimension, you can then have Inventor automatically re-model your part to show it at it the evaluated size in the upper tolerance, lower tolerance, median tolerance and nominal tolerance. These are represented by the four buttons in the Tolerance dialogue.
