topic Re: Fixing a point to a profile in Inventor Forum

Fixing a point to a profile

Vagulus — Wed, 07 Aug 2019 08:12:34 GMT

Assume I have an endless profile line, perhaps like an athletics track

If I insert a Point and make it coincident with the curved end of the track then try to push it onto the straight, it follows the circle. If I put it on the straight it ignores the circle altogether and stays parallel to the straight.

How do I make my point stay on the track?

Re: Fixing a point to a profile

JDMather — Wed, 07 Aug 2019 13:10:30 GMT

Curve driven pattern and hide the seed point.

Re: Fixing a point to a profile

johnsonshiue — Wed, 07 Aug 2019 20:29:38 GMT

Hi! Unfortunately, this particular type of sketch constraint does not exist. The coincident constraint is based on two pieces of sketch geometry. You cannot establish among a group of sketch geometry.

Could you elaborate what you try to achieve? Are you driving the point at assembly level? Or, it has to be within the part?

Many thanks!

Re: Fixing a point to a profile

JDMather — Wed, 07 Aug 2019 21:10:09 GMT

Re: Fixing a point to a profile

Vagulus — Thu, 08 Aug 2019 01:32:36 GMT

I am working on a schematic concept drawing to visualize moving parts without having to 3D model them. This requires one end of a line to follow a profile while the line itself is moved. I can do this with a circle - see attached - but I want to be able to do it with a more complex profile.

Re: Fixing a point to a profile

Vagulus — Thu, 08 Aug 2019 01:36:17 GMT

Hi JD

You wrote, "Curve driven pattern and hide the seed point."

Looking at your later post I an sure that your are absolutely correct (as usual) but I wish I could understand what you meant by what you wrote. Would you please explain your solution in greater detail.

Thanks

Re: Fixing a point to a profile

johnsonshiue — Thu, 08 Aug 2019 18:57:51 GMT

Hi! In a 2D sketch, the option will be limited. One thing to consider is to use a closed spline. Basically you create an oval shape spline. Then the coincident point can move on the spline.

Many thanks!

Re: Fixing a point to a profile

Vagulus — Thu, 08 Aug 2019 23:34:01 GMT

Thanks johnsonshiue

To do that you would need to positively locate all the points on the spline. Otherwise the spline starts to walk all over the place when you move your datum point 😝

I converted the spline to a block and positively located the block. Then it worked.