How to Edit Your Onshape Parts Associatively With VisualCAMc

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If you’re new to VisualCAMc, MecSoft’s Full-Cloud based Production CAM solution for Onshape, then you may not fully understand yet how your VisualCAMc toolpaths are associatively linked to your Onshape part model. In this blog we’ll discuss the model associativity in more detail.  We’ll also take you through the steps needed to update your machining operations automatically after making edits to your Onshape part.

The Need for Associativity

Consider this very typical scenario when you are working with Onshape and VisualCAMc.

You load an Onshape Part Document into VisualCAMc and create machining operations.
Subsequently, you modify the Onshape Part Document due to a design change.
You then go to the VisualCAMc app to update your toolpaths.
In this scenario, you want to update the machining operations and toolpaths easily without having to start over. VisualCAMc handles this in the following ways:

Global Associativity

When VisualCAMc is invoked, it detects any changes that were made to the Onshape parent part. If changes are detected, VisualCAMc automatically replaces the older version with the modified version. In addition, all machining operations will be displayed in red text in the operation tree to indicate that they need regeneration.

Object Associativity

Onshape geometry objects such as edges and sketches can be utilized in creating one or more machining operations in VisualCAMc. For instance, in the case of a 2½ Axis Pocketing operation, a group of edges is selected to create the pocketing toolpath. When edits are made in Onshape, it is quite possible that the sketch defining the pocket was modified. VisualCAMc handles this case in a couple of different ways:

  1. A Non-Destructive Edit:  If the object ID in Onshape is still the same, even though the underlying geometry has changed, VisualCAMc will continue to use this object but will recognize the new geometry. Using the 2½ Axis Pocketing operation example, if the dimensions for the length and/or width of the pocket have changed, VisualCAMc will propagate these changes to the pocketing toolpath automatically. Onshape dimensional edits fall into this category. The machining operation will be displayed in red text in the operation tree to indicate that it needs regeneration.  
  2. A Destructive Edit: If the object ID in Onshape is changed, VisualCAMc will lose the association with the object and the regions will have to be re-selected before the machining operation can be regenerated. We call this a destructive edit. Using the 2½ Axis Pocketing operation example, here is a list of possible destructive edits:
  • The geometry feature is changed (a square pocket is now circular).
  • Additional geometry is introduced (a rectangular pocket now has fillets).
  • A new feature is added (a slot cuts through the pocket).
  • A sketch or feature is suppressed (the pocket is now removed). 

Here again, the machining operation will be displayed in red text in the operation tree to indicate that it needs regeneration.

Sample Exercise

Here are the basic steps needed to update the machining operations in VisualCAMc once part geometry changes have been made after machining operations are created. In the example below, changes made in Onshape are automatically propagated to the VisualCAMc toolpaths.

1. Load a Part from Onshape into VisualCAMc and create your toolpaths. The sample part below has three toolpaths created (2-1/2 Axis Facing2-1/2 Axis Profiling and Hole Drilling).



Original Onshape Part



VisualCAMc Part w/Facing Toolpath



VisualCAMc Part w/Profiling Toolpath



Hole Drilling

2. Select the Part Studio tab to display your Onshape part.


3. Right-click on an Onshape sketch and select Edit.


4. Now select Top from the Onshape View Cube to see the sketch more clearly.


The View Cube


5. Edit a few sketch dimensions and then pick the check-mark to accept the sketch. We edited the coordinate location of all of the holes as well as the outer perimeter dimensions.


Current Onshape Sketch

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Modified Onshape Sketch

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Select the checkmark icon in the sketch editor to accept and close the sketch.

6. The Part will rebuild. Now select the Isometric View icon from the Onshape View bar to display the Isometric view.




Isometric View

7. Now select the VisualCAMc tab and you will be informed that the part was reloaded due to geometry changes. The updated part geometry is loaded and displayed automatically.


8. You will notice that all of your machining operations are flagged in red text to let you know that they need to be regenerated.

9. Since the geometry changes modified the length and width of the part, let’s update our Part Bounds Stock. Double left-click on the Stock icon in the Machining Job tree to display the Part Bounds Stock dialog. From this dialog, pick the Calculate Geometry button and then pick the Save button. The new stock size will display on the part.

Part Bounds Stock dialog


New Part Bounds Stock Displayed

10. Because our Stock dimensions have changed, we want to redefine Work Zero now defaults o where we had it set in Step 1 when we started (Highest Z, South West corner of the stock model). Double-click on the Work Zero icon in the Machining Job to display the dialog.

11. From the Work Zero dialog, select Set to Stock Box, Highest Z and the South West and then pick Save. This place the Work Zero where we had it before.


Work Zero is Updated

12. Because only non-destructive edits were made to the Onshape part, we can now proceed directly to regenerating our toolpath operations. Just right-click on the Machining Job and select Regenerate. All of our toolpaths are recalculated from the updated part.










13. Selecting each operation from the Machining Job tree will display the updated toolpath based on the dimensional changes we made to the Onshape Part model.

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Revised Onshape Part

2-½ Axis Facing Updated

2-½ Axis Profiling Updated

Drilling Toolpath Updated


14.  Now we will select Save from the VisualCAMc main toolbar to save our CAM Data to the Onshape part document. You must Save your document to save your toolpaths.

Try It Yourself

If you want to learn more about the VisualCAMc Full-Cloud based Milling plugin for Onshape, check out MecSoft’s Products Page, Tech Blog and YouTube Channel for what’s new, specifications, videos, tutorials and more. To join the free VisualCAMc Beta program, go to the Onshape App store and add VisualCAMc to your Onshape account. Enjoy!

Try VisualCAMc For Onshape

This powerful cloud-based CAM tool works directly inside your Onshape Documents.

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Don LaCourse

Don LaCourse

Don LaCourse is an Application Engineer with MecSoft Corporation. Don brings over 20 years of experience in CAD/CAM operations in both automotive and mold design applications. Don also has extensive experience in documenting CAD/CAM products and is actively involved with writing the on-line help as well as creating training tutorials for MecSoft's products.
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