All About Part Workbench - Advanced Level

This article will take you through the advanced level operations in Part Design Workbench in CATIA. Before you dive into the topic, let’s get an overview of Part Workbench.

What is Part Design Workbench in CATIA?

The OpenCASCADE Technology (OCCT) kernel, a professional-grade CAD system with potent 3D geometry creation and manipulation, provides the foundation for FreeCAD's solid modelling capabilities. The OCCT libraries are layered on top of the Workbench Part.svg layer of Part Workbench. The user has access to the geometric primitives and functions of the OCCT. Every workbench's 2D and 3D drawing functionalities are essentially built on the capabilities offered by the Part Workbench (Workbench Draft.svg Draft, Workbench Sketcher.svg Sketcher, Workbench PartDesign.svg PartDesign, etc.). Therefore, it is believed that the most important aspect of FreeCAD's modelling capabilities is the Part Design Workbench in CATIA.

What Happens At The Advanced-Level Of The Part Design Workbench?

1. REMASTERING METHOD - PART 

Since we discussed nonparametric bodies, measuring between, measuring items and removing face options, it is important that we also need to know about Remastering Procedures. Remastering is a technique used to create proper parametric bodies from non-parametric bodies. The remastering can be divided into two, based on the procedures we follow to create a parametric body, i.e. surface and part remastering. Remastering is a topic that comes under reverse engineering topics.  Here, we are discussing part remastering.  Also, remember that the explanation below is a simple example to make you understand what is meant by remastering and its basic procedures. Advanced remastering procedures will be covered in separate articles. 

Situations where remastering is performed.

If we need to develop/modify a new design from our parent/old design. Also, we only have the dump/non-parametric version of our old design. In this situation, we must create the parametric version of the old (same design) using remastering. So after getting a fully dimensioned parametric body of the old design, later, we can use the model and edit the values accordingly based on the new changes and requirements. Remastering must only be performed if we do not have a parametric version of the old design.

Example

Let's take the same model that we previously worked on.

So let's imagine that we only have this model available and that too in a non-parametric/dump form. So we use a remastering process to recreate this same model into a parametric body with all the dimensions and operations available.

Now for recreating this model first, we need to make sure we need to modify the dump body into its simpler form. For that, let’s temporarily remove the fillet for now. For removing the fillet, we have already learned two different tools in the previous session. 

So let's see if we can remove the fillet using deactivate mode.

When we search for deactivation, that option is not available for the dump body. So now we only have one option, i.e., remove face option.

Inorder to perform easy remastering, its will be better if we temporarily remove the entire fillet face option for now.

Lets rename the body “non_parametric_body” and insert a new body and rename it as parametric_working_model.

So now we will work on the newly inserted body.

First, let's take the top plane and create a new sketch. Let's project the dump body into this new sketch using the project 3d element. Before going with these steps, I need to discuss an important rule of remastering. The newly created parametric body should not be related to the non-parametric/dump body. So while projecting the model using the project 3d element, we need to ensure that we are isolating it properly using Create Datum and then project it. For more details, refer “ADDING AND AVOIDING RELATION WHILE USING PROJECT 3D ELEMENT” topic explained in the previous session of the sketcher workbench.

By doing this we are completely removing the relation between the sketch and the dump body.

Since we broke the relation, now we want to constrain it properly from the origin(horizontal/vertical).

By doing this we now know the length and breadth of our model. Let's exit the sketch and move on to the pad operation.

Again we are not aware of the height of the body in mm because it's a dump body. But we previously learned that with the measure between and measure item option from the pad, we can easily find the height of a dump body.

Let's define the body Parametric_working_model.

By doing that we can put our new parametric model inside the body parametrci_working_model.

First, select the pad operation and then select the new sketch.

Right-click on the length and go with the measure between options.

Now select the two opposite faces to measure the height of the body.

Uncheck the keep measure and click ok.

Click ok to pad definition as well.

Just for understanding purposes, let's change the colour of the dump body. For that right click and select the properties. From there select the graphic and choose a suitable colour.

Let's hide the parametric_working_model for now. Also, let's remove the remove face option by deleting removeface.1 from the tree.

Now, let's unhide the working model and we may notice that we need to add the fillet onto the top edge.

Let's hide the working model again and measure the fillet value using the measure item option by clicking any one of the fillet faces.

Now we know that the fillet value is 15mm. Cancel the option and add the fillet over the new working model edge with a value of 15mm.

Now we have our final result.

By this, we made our new parametric body an exact copy of the dump body.

Sometimes we are not sure how closely we have achieved our final result using the remastering technique. For that, there is a separate tool called deviation Analysis.