Surface modelling is a powerful way of using SolidWorks to create 3D models but it can be daunting for users who used to solid modelling.
As a stepping stone to full surface modelling there are two ‘pseudo-surfacing’ tools which are often overlooked. These are the Move Face and the Delete Face – both with quite self-explanatory names – and they are more like standalone features that can be very useful in all sorts of different situations.
The Delete Face Tool
As the name suggests, this tool deletes faces, but it also allows you to easily patch or fill faces.
The Delete Face tool can be found on the Surfaces tab (or Insert>Face>Delete) and after opening presents a fairly simple set of options.
First, the face to be deleted is selected, but we also have three different options – Delete, Delete and Patch or Delete and Fill.
Selecting Delete option simply removes the chosen face and leaves the body open. For example, if we have a solid cube and delete the top face we’re then left with an open surface body. Note that the previously solid body has turned into a surface body, because a collection of surfaces can’t be solid unless it is fully enclosed.
However, the real utility of this tool comes with the ability to patch or fill the deleted faces. For example, you may have been sent a part as shown below and been asked to remove or change the internal fillet.
Depending on how the part has been made this may be a trivial change, but if the fillet hasn’t been modelled in a certain way then adjusting or removing it may cause issues later in the model’s feature tree. You may have also been given a third-party file, like a STEP file, which doesn’t give you access to the model’s features. In these cases we can use the Delete Face tool.
By using the Delete and Patch option we can select the fillet faces and patch the remaining gap, resulting in a straight edge that can then be used to add a new, differently-sized fillet, or can be left as a straight edge.
When using Delete and Patch the adjoining surfaces are extended to a form straight edge.
The Delete and Fill is slightly different in that it replaces the multiple fillet faces with one single surface. Selecting the Tangent Fill option ensures that this new face joins the surrounding faces in a suitable way.
The Delete Face tool can also be useful removing holes and openings. For example, in a normal SolidWorks model the hole feature below could easily be deleted or suppressed, but if the model is an imported third-party file then you might not be able to directly edit those features. Or, in other cases perhaps feature elsewhere in the model depends on the hole, so we don’t want get rid of the feature itself, we just want to fill the hole.
In many cases you could fill this hole manually using features like Extruded Boss/Base and Up To Surface end conditions but actually it’s easier – especially when working with curved faces – to use Delete Face.
Simply select Delete and Patch, then select the inner face of the hole. This will delete the selected face and patch the two remaining large faces as shown below.
Some further examples of the Delete and Fill and Delete and Patch options are shown below.
It should be noted that the automatic patching or filling doesn’t always work. When working with complex geometry patches may fail, or result in undesirable strange-shaped surfaces. In those cases it’s best to use the basic Delete option and then manually create a patch using a feature like a Boundary Surface.
The Move Face Tool
The Move Face tool is quite a similar tool that can also be used in all types of modelling. This tool allows you to move, offset or rotate faces easily. For example, you may have a STEP file – similar to the bracket below – which has no editable SolidWorks features and so isn’t very easy to make changes that otherwise would be pretty simple.
The Move Face isn’t on the Surfaces toolbar but rather can be found under the Insert > Face > Move
After opening the tool we’re presented with a selection box here and three options –Offset, Translate (move), or Rotate.
When Offsetting faces are moved inwards or outwards by a set amount. This can be used to make the entire part larger or smaller, or simply to move specific faces.
Offset is also useful for adjusting hole sizes. The inner faces of holes are selected and the Offset amount is set, making them larger or smaller.
The next option is Translate and this allows you to move faces in a specified direction. Select a face, then move it in the X, Y or Z direction, by adjusting the values in the property manager or by dragging the orange arrows in the graphics area.
As well as X and Y and Z directions, specific directions can also be used by selecting edges or axes.
Finally, faces can also be rotated. The direction of rotation, and the origin point of the rotation can be adjusted in the property manager, or the rotation arrows in the graphics area can be used. When a face is selected, the rotation point will be in the centre of that face by default.
You can also choose an edge or an axis to rotate around, then set a specified angular rotation.
Design Intent
When using these two useful tools, especially Move Face be aware of your design intent. If your part is mated in an assembly, for example, and then the Move Face command used on one of the mated faces, then the mate in your assembly will use the new position of the face, not the original position.
Any features that reference the moved faces will also be affected. So, for example – if a hole is 80mm from this face and the face is moved, then the hole will remain 80mm from the new position but will have changed its relative position.
Delete Face & Move Face Top Tips
- The Delete face and Move Face tools are quite simple tools but can be extremely useful.
- Delete and Patch extends the surfaces to give a straight join
- Delete and Fill replaces the previous surfaces will one single, new surface
- Move Face is especially useful when working with imported parts that have no feature tree
- It can be used to remove holes and openings, adjust fillets and much more
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About the Author: This is a guest post by Johno Ellison, a design engineer with over fifteen years or experience, who specializes in SolidWorks 3D CAD modeling. Johno is the author of the following online SolidWorks courses:
Master SolidWorks 2021 – 3D CAD using real-world examples
Master SolidWorks 2019 – 3D CAD using real-world examples
Master SolidWorks 2018 – 3D CAD using real-world examples
Check out his latest SOLIDWORKS course – SolidWorks SURFACING Fundamentals, rated 4.7 stars on Udemy!
