"mate" constraint turns into the "flush" constraint when selecting faces of parts which are facing the same direction

[ErikStoeken]

Hello,

I used to use inventor 2022, now I went over to inventor 2025.

I am pretty sure Autodesk made a change with constraints in assemblies where the "mate" constraint turns into the "flush" constraint when selecting faces of parts which are facing the same direction, even though the "mate" constraint is selected.

I dont know when autodesk made this change, since I didnt use inventor 2023 and 2024, but is there a way to turn that change off in the settings somewhere?

-Erik

[YannickEnrico]

You're right. That's incredibly frustrating. And selecting flush, and then choosing two opposing faces, keeps the setting.

That makes no sense Autodesk.

It was added in 2025. I'm on 2024, and I'm not in a rush to update seeing this implementation.

[CGBenner]

@ErikStoeken @YannickEnrico 

Welcome Erik!  Let me tag @johnsonshiue here.  Maybe he can explain this, or offer some insight.

[johnsonshiue]

Hi! This behavior was implemented in 2020 or 2019 based on an idea on the Ideas forum. It has been a while. Basically, the Constraint command takes the current orientation of the selected geometry to determine it is closer to Mate or Flush. Then switch the type accordingly.

Many thanks!

[YannickEnrico]

Hi @johnsonshiue 

I am confused. I've worked in IV2019-2021 + 2023-2024 and just installed IV2025 on my machine. This is the first time I experience this behaviour, and I find it atrocious.

I'll attach a recording of the behaviour in my IV2024 installation.

[brstleon]

Thank you for your reply,

Me and my colleagues have been using Inventor 2022 for multiple years and this behavior feels new to us.

Either way, this behavior of the constrain switching to flush when you clearly have mate selected is very frustrating. I don't see the logic behind this behavior since you select "mate" to make a mate constraint, and not to make a flush constraint. 

It would be a very nice QoL feature to have a setting added which simply just makes sure that when you click "mate" it makes a mate constraint and not a flush constraint. If I want a flush constraint, I simply select "flush".

Again, I appreciate the reply.

- Erik

[YannickEnrico]

And here is a recording from IV2025.

If I select flush before selecting anything, it'll respect the flush, but even if I actively press on mate before selecting anything, it doesn't respect that.

It's a poor and inconsistent implementation of the submitted idea.

[YannickEnrico]

Also, you may find yourself in a situation where your parts are in an orientation where you need the constraint that isn't the closest, and the software "intelligently" switching every time will cause some serious frustration because of "dumb work" where you have to change the constraint options *every* time because the software thinks it's the right option.

[johnsonshiue]

Hi Folks,

I am sorry I was mistaken. This behavior (predictive Mate or Flush) was indeed first introduced in 2019 but because of negative feedback, it was reverted during one of the updates. But for whatever reason, the behavior is back in 2025 surprisingly. I need to work with the project team to understand it better.

Many thanks!

[kacper.suchomski · Accepted solution]

Hi

Install update 2025.0.1

https://help.autodesk.com/view/INVNTOR/2025/ENU/?guid=Inventor_ReleaseNotes_updates_2025_0_1_fixed_b...