Current Offset from Parent Assembly Origin

[M.Hawryluk]

Hi,

One of users from our sister company reported strange issue regarding Current Offset from Parent Assembly Origin in Inventor 2018.

The workflow was as follows:

1. Component was imported from SolidWorks to Inventor 2015 some months ago.
2. The component was all the time grounded at the origin and Current Offset from Parent Assembly Origin values were zero.
3. The problem (corrupted drawing with skewed geometry) appeared after recent software upgrade from Inventor 2015 to Inventor 2018.

Has anyone encountered similar problem?

[johnsonshiue]

Hi! This wacky behavior is due to exposing numerical noise in display precision. It has zero impact to the validity and integrity of the data. It is a known issue in some cases. We are working on a solution to avoid showing the noise.

Many thanks!

[M.Hawryluk]

Hi,

The thing is, that we figured this out (angles) because we have problem with corrupted drawing.
I understand this may not be the reason for skewed geometry but still it looks suspicious because:

There is one affected component used in "Assembly 1" (shown in my previous post; grounded at origin).
This "Assembly 1" is grounded at origin in "Assembly 2".

In "Assembly 2" we have much higher values of the Offset (iProperties of Assembly 1 which is here component of Assembly 2):

Screenshot from "Assembly 2" drawing:


Do you have any idea how to fix it, so the lines between "Assembly1" and other components of "Assembly2" are parallel?

Best Regards,

Michal

[johnsonshiue]

Hi Michal,

Then I suspect there could be geometric issue with the parts. Did you measure the angle between the face and one of the origin plane in the assembly? Is it indeed parallel? Could you share an example exhibiting the behavior?

Many thanks!

[catot · Accepted solution]

Hi Michal, long time no see!

I've encountered something similar in 2016 (which I'm currently using). If I remember correctly, I've seen issues like these when moving parts between various assembly levels in the model tree/browser. (Moving a part from the top assembly, to an sub-assembly in the browser).

That might not be the case here, but worth mentioning.

Anyway, I normally fix it by making the part/assembly not Grounded, then applying flush Constraints between the problematic part/assembly origin planes and the main assembly origin planes. Finally I Ground that part/assembly again, and delete those 3 Constraints.

It also seems that you can save a few clicks by trying the command "Ground and Root Component" found on the Assemble-tab, in the Productivity section. I've not used it much, so I don't know if it behaves predictably.

Regards,

Cato

[M.Hawryluk]

Hi!

I'm sorry for late reply but the responsible user who reported the problem was on holiday.

@johnsonshiue
Geometry was checked and it is fine.  Unfortunately I cannot send files out of the company.

@catot
Great to see you here! Solution accepted.
After un-grounding and re-constraining to origin the drawing is fine again.
There are still values like 0.000002 deg in the "Current Offset from Parent Assembly Origin" but as this is a display issue only, the problem is fully solved. Thanks!