topic Re: Clear explicit instructions on using the angular constraint? in Inventor Forum

Clear explicit instructions on using the angular constraint?

SharkDesign — Wed, 20 Sep 2017 09:54:21 GMT

I often struggle to get the result I really want from an angular constraint.

Is there a video somewhere that clearly describes how to use this feature because it has got to the point where I'm just thinking I must be using it wrong rather than it being a software issue?

I've just tried using the explicit reference vector and it made absolutely no difference where I clicked the reference, face or edge, in any direction, I still got the same result.

Re: Clear explicit instructions on using the angular constraint?

Anonymous — Wed, 20 Sep 2017 13:11:14 GMT

That's something I'd like to see too. There are three different ways of defining angles. What would so useful would be clear examples, saying, in this kind of situation you should use 'type 1' constraint method, in this kind of situation you use 'type 2' constraints, and so on. I have looked many times in the past, but never found clear examples.

Re: Clear explicit instructions on using the angular constraint?

Curtis_W — Wed, 20 Sep 2017 14:55:47 GMT

Hi jameswillo,

This is what I had on hand from a previous discussion. It's in no way comprehensive, but has helped a few people realize that flipping the explicit reference vector direction was the part they were overlooking. It might not apply for your situation though.

Keep in mind that if you are selecting edges for the first two selections, the direction for those selections come into play as well, and so selecting a a different edge (often and edge on the other side of the feature) is sometimes the key.

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

Re: Clear explicit instructions on using the angular constraint?

Curtis_W — Wed, 20 Sep 2017 15:03:47 GMT

@Anonymous wrote:

What would so useful would be clear examples, saying, in this kind of situation you should use 'type 1' constraint method, in this kind of situation you use 'type 2' constraints, and so on.

Hi moto748,

In my opinion (others might disagree), we can forget the other 2 methods and just use the explicit reference vector method. I view those other methods as "legacy" methods, and choose not to use them, since they are sometime/often likely to flip rotation direction when components are in motion.

The explicit reference vector method can flip also, when geometry is updated/rebuilt (rather than just set in motion), and so often when automating something using the APi /ilogic, we will want to use work axes rather than model geometry, in order to ensure a stable and predictable result.

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

Re: Clear explicit instructions on using the angular constraint?

SharkDesign — Wed, 20 Sep 2017 15:06:40 GMT

Yeah I found your video when I was searching but there was no audio so I didn't completely understand what was going on.

Re: Clear explicit instructions on using the angular constraint?

Curtis_W — Wed, 20 Sep 2017 15:19:39 GMT

@SharkDesign wrote:

...but there was no audio so I didn't completely understand what was going on.

I can add some polka music if that would help.

Re: Clear explicit instructions on using the angular constraint?

johnsonshiue — Wed, 20 Sep 2017 19:26:17 GMT

Hi James,

Explicit Angular Constraint is a powerful tool but it is a bit confusing regardless. The right-hand rule might help better understand how it behaves. Basically, an angular constraint is like doing the cross product.

1) Open your right hand and have the thumb pointed up.

2) The four fingers are pointing to the first angular reference.

3) Bend the four fingers and that will be the second angular reference.

4) The thumb basically points to the third reference, the rotating plane direction.

This is how you predict the result. You want to select a face or an axis pointing to the rotating direction. Assembly constraints usually have multiple solutions. This 3rd reference helps keep components consistently in one direction without flipping. Please feel free to post an example if you need more clarification.

Many thanks!