User Parameter Scale Break

[hernandez.frank]

Hi, 

I am encountering what seems to be a bug.

The steps to reproduce are as follows:

1. Create a user parameter called ScaleFactor (used to scale all dimensions in a sketch), default value of 1.
2. Create fully constrained sketch where each dimension is a base value multiplied by ScaleFactor
3. Attempt to change the ScaleFactor (Depending on the sketch it might fail to scale up, but some others fail to scale down with "failed to solve" the dimensions.) 
4. See attached cast. 

Expected behavior: Sketch scales without losing dimension or error. 

Minimal Fusion 360 file presenting the issue: https://a360.co/3cfmY0V

Screencast URL: https://autode.sk/32LePOE

Does anyone know what could be causing this? 

Thanks,

Fusion 360 Version:  2.0.8950

OS: Windows 7

[davebYYPCU]

I can repeat the error, but only with very large changes to the parameter, small increments do behave as expected.

(100, 90 ,80, 60, all ok....)

one for AD to check, @jeff_strater  

Might help....

[hernandez.frank]

Thanks for the reply @davebYYPCU . You are right, I have noticed that sometimes if I step by small increments I do not see the issue. However "small" seems to also be relative as sometimes increasing by 1 at a time will work while others the same increment amount it will give the same issue.  

Thanks again,

[jeff_strater · Accepted solution]

@hernandez.frank and @davebYYPCU - thanks for pinging me on this.  Thanks for narrowing down the problem so efficiently - it is always easier to work with a smaller model.

Yes, we have seen instances of this before, where large dimension changes will fail, but getting to the same values in small increments will succeed.  In this case, I was only able to reproduce the failure on the way down (from, say, 100 to 1), but scaling up always worked for me in the limited testing I did.  I created bug FUS-72636 to track this problem.

[hernandez.frank]

Hi @jeff_strater ,

Glad I could help. 

Thank you for looking into it and opening a ticket to track it.