Derived part sketch not working as expected

[dutt.thakar]

Hello,

One of our users have created a skeletal part where he has created some sketches and then he derived the part and there is a sketch named as "Tailing_lug_sketch" in skeleton, this sketch can not be added in with Edit derived. There is already a sketch with the same name exist there which is being shown as children of derived part, but does not behave correctly.

This is happening in Inventor 2022, Build : 350, Release : 2022.3

When I right click the sketch and click on "relationships" it shows derived part as children, which is strange. See below image. The sketch also shows shared icon.

I was trying to reproduce the issue with by trying different methods but could not. Also I did rename the sketch in the main part where I am deriving, but is is not helping,

I can not delete this sketch also (see below snap)

Some body has did something which has caused this issue. I am not able to delete the sketch from a derived part, the geometry is different in derived part. I have not seen something like this before.

I have attached both the parts here for anyone who has time to see and check what is wrong here.

I would appreciate the help.

[blandb · Accepted solution]

When turning on the sketch in .30 ipt of the tailing lug with the shared symbol, it is shared due to being used in the revolution and the extrusion. Main thing I noticed is the fact the the sketch is purple and not yellow, meaning it is stagnant geometry.

If I go and remove the revolution and extrusion the sketch is no longer shared but still purple:

Now, if I edit the derived part, I can include the sketch again and all is yellow (associated again):

as a check, I will change the length of the plate and it updates:

adding the extrusion will make the sketch shared again and all updates accordingly:

[dutt.thakar]

@blandb Thanks, I did not think about deleting features and try.

I really appreciate your help.

[dutt.thakar]

@blandb 

I still have a question how someone was able to remove the existing geometry from sketch, that lifting lug derived geometry. I understand the new geometry can be created, but is it possible that when you derive a sketch you can still remove the existing geometry?

[johnsonshiue]

Hi! When a sketch is derived to another part, the derived sketch in the new part is still editable. You may add new or edit geometry. But, you cannot edit the derived sketch geometry itself, except when the derive link is broken.

Please share an example if it exhibits otherwise behaviors. It could be a bug.

Many thanks!

[dutt.thakar]

@johnsonshiue 

I do not know but, may be copy design from Vault has done something (referencing may be) , but the actual geometry from derived part is not there any more, The link was not broken. If you download the parts, I have attached in my original question, and if you see the sketch in skeleton and in the derived part you will not see the original geometry of the lug, but you will see the manually created geometry (which is possible ) but I do not know how the original geometry was gone. If I understand correctly, the original geometry can not be deleted. Something has caused this but I do not know what.

I also tried deleting the feature and adding the sketch again the from the derived part, which is actually replacing the manually created geometry which makes sense because the sketch name is same. if the sketch is created manually with same name for an example, how can it be act as a child of derived part, that is another thing I was wondering.

[johnsonshiue]

Hi Dutt,

There is some sort of corruption for sure in the parts. Open the derived part and edit the Derive feature. The sketch is not included in the Derive feature, which means there isn't any association between the derived sketch and the source sketch.

As a result, any change to the source sketch is no longer propagated to the derived sketch. If you can find out how to reproduce the behavior from scratch, it will be very helpful to finding a fix. In the meantime, the Derive feature may need to be deleted (as well as the features consuming the sketch). Then derive the part again.

Another approach is to keep the Derive feature as is. Then simply derive the same part again to include the sketch.

Many thanks!