topic variable angle constant gap maintained in Inventor Forum

variable angle constant gap maintained

NachoShaw — Thu, 15 Oct 2020 16:21:53 GMT

Hey

I dont have my geometry hat on today and cant seem work this out properly. I have to maintain a 1/4in gap between a vertical side member and a variable angle top rail. The top rail must always have a 90 deg cut.

So,

If the top rail is horizontal, there should be a 1/4in gap between the top rail face and the side face

if the top rail is angled upward, there should be 1/4in gap between the top corner of the top rail and the side face

If the top rail is angled downward, there should be 1/4in gap between the bottom corner of the top rail and the side face

the problem i am getting is that the sketch lines will auto constrain when they reach a certain point.

anyone have any good ideas on how to set this out so that i can maintain the gap?

Re: variable angle constant gap maintained

JDMather — Thu, 15 Oct 2020 16:27:31 GMT

What version of Inventor are you using?

Can you Attach an example file?

Re: variable angle constant gap maintained

johnsonshiue — Thu, 15 Oct 2020 20:44:34 GMT

Hi! This could be related to Constraint Inferencing. Go to Tools -> App Options -> Sketch -> Constraint options -> uncheck "Persist constraints." Or, you can uncheck some related constraint types to avoid unwanted inferencing.

Many thanks!

Re: variable angle constant gap maintained

NachoShaw — Mon, 26 Oct 2020 15:47:18 GMT

Hey

Changing the setting gave me all sorts of random results, one being rectangles were no longer perp constrained...

I thought i had a solution but using a circle as a tangent constraint like this

but in code it would still somehow constrain itself depending on the angle of the top rail. In the end i went with a sketch driven distance that is approximate. Not the ideal solution but its close enough..

Thanks

Re: variable angle constant gap maintained

johnsonshiue — Mon, 26 Oct 2020 21:45:14 GMT

Hi! The behavior is indeed a bit complicated. You may want to uncheck "Coincident" constraint in Tools -> App Options -> Sketch -> Constraint Settings -> Inference -> Selection for Constraint Inference. Does it work better?

Many thanks!