Explicit Vector Angle Constraint Issue

[Anonymous]

We have recently upgraded from Inventor 2018 to Inventor 2021. One of my constraints in my model is an Explicit Vector Angle Constraint. When the model is opened in 2018 and there is no issue and hasn't been for 4 years since I created it. However, when I open the same model in 2021 the angle is out by 180°!!

Can anyone tell me why is there a behavioural difference between 2018 and 2021 with regards how this constraint works? 

[SharkDesign]

No idea, unless explicit didn't exist in 2018.

Edit the constraint and use the third selection (the direction) to select the pivot, not the actual direction. 

It's a common mistake with this tool.

[johnsonshiue]

Hi! It sounds like a bug to me. If possible, please share the files (zipped) here or send them to me directly johnson.shiue@autodesk.com. I would like to understand why the angle flips 180 deg. It should stay the same.

Many thanks1

[Anonymous]

Thanks Johnsonshiue.

Attached is the file. I've also dropped in a singe PDF page showing the results of 2018 and the exact same model and process when opened in 2021.

1: Open "FAN_MODEL" assembly in 2018.

2: Change the "HANDING" from "L" to "R" and note the results.

Do the exact same when opened with 2021 (we skipped 2019 & 2020)

Thanks.

[johnsonshiue]

Hi! Many thanks for sharing the files! I tried the workflow on 2021.3 update and it worked fine. There could be a bug in earlier 2021 builds. Please make sure 2021.3 is installed followed by 2021.3.1 update.

Thanks again!

[Anonymous]

Thanks for looking.

There are several machines with this issue and all are running 2021.3.1.

Is there anything else that could have an influence on this constraint?

[Anonymous]

To add a little more to this is have tried the process on a machine that has 2018, 2019, 2020 and 2021. The issue happens 2019 onwards.