topic Re: dynamic simulation automatic constraint conversion not working properly in Inventor Forum

dynamic simulation automatic constraint conversion not working properly

aworst — Thu, 22 Dec 2022 13:24:23 GMT

How can I get a revolution joint?

I have used the "Automatically Convert Constraints to Standard Joints" in an assembly dynamic simulation before and got it to work but had to start from scratch basically since I lost all of my parameters. I had an aligned constraint and a mate constraint that is perpendicular to the axis of the aligned constraint. This gives 1 degree of freedom which is rotation. I thought this would convert to a revolution joint but just binds the parts together such that both are grounded because one is grounded. If I remove the mate constraint, it becomes a cylindrical joint.

I made up a simple model to show what I am talking about.

Alternately is there a way to make manual joints without having to establish the coordinate systems - as in the parts stay where they are?

Re: dynamic simulation automatic constraint conversion not working properly

JDMather — Thu, 22 Dec 2022 15:40:54 GMT

I am not at my Inventor machine at the moment so this is going to be a guess.

Sometimes Inventor tries to help you, but gets it wrong.

For example - let’s say you are assembling a wheel/tire assembly with a lug nut fastener.

The fastener still has a rotational degree of freedom, but you don’t really want to turn or the wheel could come loose. That is the logic behind Inventor placing in Grounded folder.

To fix the Joint issue, right click on the component in the Grounded folder and select Retain Degrees of Freedom.

Re: dynamic simulation automatic constraint conversion not working properly

aworst — Thu, 22 Dec 2022 15:55:13 GMT

Thanks! That works. Maybe that is how I did it.