Technote: Inventor Sketch Datum Point.
This is one of those instances where you do something on a regular basis and don’t really appreciate the significance of the process. What I am referring to is when you create a sketch Plane using the option “Parallel to Plane Through Point”.
It transpires that this selected point becomes the datum for the particular sketch created on this plane. For this example, for a P-39 wing rib, we have selected a point for the Plane location along the wing leading edge as shown.
The Bell P-39 and similarly for the P-51 Mustang the wing ordinates are set out from the leading edge of the wing so it makes sense that the rib sketch is setup with a suitable datum point. You can tell the location of the temporary datum in the sketch applied to this plane by the position of the main axis.
This is the really interesting part, when you now import a set of points from the Ordinate spreadsheets it will recognize this sketch datum and import the points relative to this point irrespective of the model origin.
This is very useful particularly for these aircraft projects as we tend to use a lot of ordinate data for the outline geometry.
Another Quick Tip:
To automatically apply a tangent constraint to a sketch line just select and drag the line from an existing line and the tangent constraint will be applied.