Hole

A revolved volume removing material from a solid.

It’s form follows three main profiles;

  • a parallel, flat bottomed volume (default)
  • a custom profile driven by a sketch
  • a ‘standard’ hole whose profile is specified by a standards agency such as ISO

The Hole feature commonly starts from a;

  • planer surface
  • datum plane
  • cylindrical surface
  • conical surface

If a hole needs to start from a complex curved surface or enter a planar surface at an angle then an appropriately positioned Datum Plane should be used as the Placement surface

A hole can also be referenced to a Datum Point on a surface and it’s axis will be normal to the surface at that point

 


 

Why not extrude or revolve?

You could use either of these functions to produce the same geometry but for a simple parallel, flat bottomed volume the whole feature is much quicker and simpler.  For a standard ISO hole the dimensions are built in.

 

Fundamental references

Primary reference – this is not always the placement surface.  This is the most significant reference in placing the hole.  It could be a planar, cylindrical or conical surface, or it could be an axis or a point.  Depending on what you choose will dictate what other references are required.

Offset References – defining the position of the axis on the placement surface – access via right click menu or Placement drop down.  Different types of positioning references will be required according to what type of placement reference you have chosen.  Planar surfaces and datum planes are common picks for this references

 

Positioning strategies

Linear – dimension from x and y references – these must be perpendicular to the primary reference.  Select a surface/plane as placement reference

Coaxial – the hole axis is aligned with an existing axis.  Ctrl pick the axis and a surface/plane in placement box.

Radial/Diameter – the hole axis is placed at a radius/diameter from a reference axis.  It also needs an angular dimension ‘around’ the axis from a chosen plane which is parallel to the hole axis.  Select a surface/plane as placement reference, change Type to Radial/Diameter, axis and perpendicular angle surface/plane as Offset references.

 

Combinations

Planar placement reference – positional references could be linear, coaxial, or radial/diameter.

Cylindrical placement reference – this will require a linear reference to place the hole along the cylinder and a plane parallel to the cylinder axis to give an angular reference.

Conical – this requires the same references as a cylindrically placed hole.  The linear reference will translate the the distance along the angular surface.

Point – if a point is chosen as the primary reference then the hole axis will be normal to the surface the point resides on.