Recently someone asked about information on Assembly constraints.  I realized I didn’t have much info here, so I thought about what I’d mention first.  I decided on the Insert Assembly Constraint.


This is just down to earth Inventor work; Motion and Transition constrains are much ‘cooler’ to discuss.  However the fundamental features in Inventor are where the rubber hits the road; stability, organization, and ease of manipulation are the keys to success.

Insert Constraints are my favorite because:

  • Super easy to set and visualize
  • Serve the function of 2 constraints in 1
  • Use the offset to evacuate entire subassemblies to make some modifications easier

2 in 1

The Insert Constraint is most commonly thought of for fasteners.  A fastener needs to align to a bore, and mate up to what it is fastening.  The Insert Constraint does just that.  Mechanically, it uses an axis-to-axis constraint for longitudal alignment, and a point-to-point constraint to set the offset; (forgive the references to Simulation Joint terminology, but it works).

In order to achieve the same result using other constraints, we would need 2 Mate Constraints, one along the axis of the fastener-bore, and another plane or line at the head/receiving material location.

Easy to Set and Visualize

Inventor bypasses a few tedious steps of identifying axis mates.  Just 2 picks and you‘re done. The Insert Constraint prompts the user to identify the circular mating edge of the first object to be joined, and then the concentric circular edge of the receiving object.  This can be said as the bottom edge of a fastener countersink, to the bottom of the fastener hole’s countersink.


Inventor then calculates an axis from each radius point, perpendicular to the circular edge selected to form the coaxial constraint.  Then the radius points are constrained together to establish the Offset along the axis.

Use Offset to easily manipulate objects

Unlike numerous mate constraints used to fix an object, The Offset of an Insert constraint only moves along its own Insert Axis.  Using this as a tool to extract objects for various reasons is easy to understand and visualize.


In this example I used a screw, but imagine an entire bearing/seal/shaft combination.  Just offset the subassembly out and you can simultaneously inspect the bore and components in instances where slice views, View Representations, and transparencies will be too cumbersome or time consuming to create.


If You do a great deal of this kind of manipulation in an Assembly, save the Offset instructions to a Position Representation.  That will keep this kind of operation organized and easy to use.

I hope this conveys the usefulness of Insert Constraints a bit clearer.  Keep checking back and I’ll post some more constraint topics.