Constraints between sketch and 3d objects

[Anonymous]

I created a paramteric sketch of a board game and want to move this into 3D.Therfore I extruded my sketch plane into a 3d body and now I want to create hollows at some of the points defined in the sketch. I used the sphere tool to create a sphere above one point in the sketch and subtracted the resulting sphere from the board body. Until now everything looks good.

However, when I change my paramters, the sketch changes accordingly but the position of the hollow does not reflect these changes. There is no constraint which  pins the hollow to the point in the sketch. How can I state this constraint? Or is there a better method?

In a second step I would also need to repeat this first hollow along a path (some lines) defined in the sketch. I hope to use the pattern on path tool (somehow this isn't working as expected) for that. The path depends also on the paramters and therfore I have to manage it, that the pattern updates together with the path. How can I achieve this?

I am sorry for the bad description, but I am completley new to CAD modeling and don't know the correct words.

Any help is appreciated!

[Anonymous]

I forgot to add a link: 

... (somehow this isn't working as expected) ...

[jeff_strater · Accepted solution]

thanks for the post @Anonymous.  Yeah, this is a known limitation with the sphere primitive.  Today, none of the primitives create associative relationships to their inputs, unfortunately.

So, the workaround is to use the Revolve feature and a sketch with a semi-circle.

Here is a screencast showing how:

Hope this helps you,

Jeff Strater (Fusion development)

[Anonymous]

Thanks for this tip @jeff_strater. It seemed to work, but I noticed a strange behaviour when changing parameters back and forth. What am I missing?

[jeff_strater]

sorry, @Anonymous, but that link does not resolve for me anymore.  I remember seeing the original post, but now I cannot find it.  Can you re-post or explain here? 

Thanks,

Jeff

[Anonymous]

http://forums.autodesk.com/t5/design-validate-document/strange-behaviour-when-changing-parameters-ba...

[jeff_strater]

great!  Thanks.  I'll reply there.

Jeff