NX Replacement Assistant

Working With Revisions of Non-NX Parts and Translated Files

Note: Download the part file and  follow along with the blog! Replacement Assistant Part File

If you deal with customer data from a non-NX part (Inventor, Solidworks, Catia etc.) you know that they are easily opened in NX.  The problems come in when they send you a new revision or change of their part.  There is no associativity between the original geometry and the new file so anything you have added will lose its parent uid (Unique ID) when you open the new revision of the part.

Dimension you added will turn into retained dimensions and manufacturing data will be out of date.  Your goal is to transfer as much associated data as is possible so that you are not starting over.  To do that, you need to use the Replacement Assistant.

There is a necessary step involved in the way you will work on the original Rev-A file.  You will need to create an associative copy of the model before you begin your work.

If you are working in master model mode where your manufacturing template is referencing the engineered part, and have used a Linked Body, you can apply this technique.

If you are doing your programming or drafting in the engineering part, you can still use this re-parent technique.  The difference would be that you would need to have an associated Extracted Body instead of a Linked body in a template (master model).

  1. When you are given a new revision, you may want to do a Model Compare to see what has changed. Modeling Analysis tabModel Compare

In this image the part on the left is Rev-A and the part on the right is Rev-B.  I have set the changed faces to “Yellow” (see next image)

2. Add Rev-B as a component and put it on a layer different than the Rev-A part. Turn on the layers that have both revisions. (see next image)

In my example shown above, the linked body of Rev-A color has been changed to green. 

3. Edit the linked body whose parent is the Rev-A part.

4. Deselect the linked body from Rev-A and select the Rev-B component as the replacement.

Now the Replacement assistant option will become available in the Geometry Link Dialog

5. Select the Replacement assistant. NX will now present side-by-side views of the Linked body and the Rev-B part.

6. In the “Settings” section of the dialog, you may like to enable the “Synchronize Views” toggle. This means that when you rotate or zoom, both views will be modified by the same amount.

7. At the top of the dialog, change the Matching Algorithm = Geometric. Then, “Find Geometric Matches” (see next image).

Once executed, at the lower RH corner of your screen, the system displays an Alert of how many matching faces that were found.  Also, in the dialog, Correspondences section, it displays a list of the matched faces and you can highlight a match and see in the graphics window where it is.

8. To see what is not yet matched, in the Match Specific Objects section, enable the Emphasize Unmatched Objects toggle. This will indicate which faces remain to be matched. The matched objects are displayed in the “Dim Color” of your choosing (see next image).

This Dim color (for me it is dark gray) is indicating the faces that were found to be a match.  Faces and edges that are a different color (green or light grey) still need to be matched.

If the dim color faces are correct, you need to accept them.

In the Matched objects section of the dialog, the Correspondences in the list window have little lightning bolts in front of them.  They are tentative matches until you accept them.  Highlight the top node in the Correspondences section and then select the check mark on the right margin to accept a matches in the list.

The lightning bolts should have all changed to “Checkmarks” in the list.

9. Continue to match up faces. Based on the accepted matches, the system may be able to do additional matching.  At the top of the dialog change the Matching Algorithm = Infer from Accepted. Then Find New Matches again.

In this example, several more matches were found.  Review them and if they look correct, accept them.  Remember that if it appears in the dim color (dark gray) they have been matched (see next image).

From here, you can begin manually matching up the faces.  The green faces on the Rev-A part can be matched up to the faces on the Rev-B part.  After that, there will still be some new faces on the Rev-B part that will have to be added to the operations that cut those faces.

10. Change the Matching Algorithm = Geometric. Then highlight the “Select Objects” line in the Matched Objects section.  You will now begin selecting a face in the Rev-A part and the matching face in the Rev-B

When you have selected a pair of faces, click MB2 (middle mouse) to pick the next pair of matches (see next image).

After matching the existing faces, there will be some faces that are new and they will need to be looked at in the manufacturing module.  For now, you still have some unmatched Edges.  The system should be able to find them using the “Infer from Accepted” option.

11. You need to accept the matches by selecting the top node in the Correspondences window and then the Checkmark to accept them.

12. At the top of the dialog change the Matching Algorithm = Infer from Accepted. Then Find New Matches again.

13. Accept the new matches and review the parts to make certain there is nothing else that can be matched. If there are no additional matches to be made, choose OK and OK to accept the Linked Body editing process.

You are now ready to repair any problems with the geometry that was associated to the faces and edges.  In this case, we need to look at the manufacturing operations.

14. Change to the Manufacturing Application (if necessary) and open the Operation Navigator, Program Order view to see the operations.

As expected, all of the operations are out of date and need to be regenerated.

15. Highlight the 1234 parent object. On the home tab, choose Generate Tool Path. When updated, you can perform a Verify Tool Path, 3D Dynamic.  Carefully look for any uncut areas to see if the operations need to be edited to include new geometry.

In this example, all of the operations updated correctly and the new radii were automatically added to the operations.

With a little practice, the Replacement Assistant can really speed up your processes when you need to incorporate a new non-NX revision into your existing model.


For more information on how to work with revisions of non-NX parts and translated files!


Post by Al Kraus

One Comment "NX Replacement Assistant"

  1. Good morning Al
    So, I’ve been working with NX for about 9 years. Unfortunately, I never really had a mentor to teach me the right way of linking models to use on cam from revision changes. I came across an expert on Catia that all he does he exports his cat settings with model, tool path operations and he’s able to put a similar part and regenerate just like above. I’ve been wondering how the heck he programs so fast! lol. I guess my question is, do you guys have some type of small training for part.files just like above. Just to make sure I got it right.

    also, any training on how to program faster? by that I mean some type of advanced programming? NX has so much to offer it’s just not as easy to figure things out on your own. I guess a good example would be creating macros and journals to start creating shortcuts. I’m literally working with a Catia Guru and man I tell you he’s good! lol

    one more question
    what syntax is better for NX. I know that you’re able to select a syntax for NX for the macros and journals.

    Thank you for this great tip above.

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