Constrain Components so that they remain associated with each other if a parameter is revised

[chris_heath01]

I have a number of components that I would like to remain associated with each other is I modify a parameter - like the length of one component - I have tried applying rigid joints by two methods but each time I change the length the parts become disassociated  - see movies.   Also is there a method of applying an offset to a rigid joint please .

Thanks. 

Chris

[TheCADWhisperer]

@chris_heath01 

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[chris_heath01]

Please find attached - I have moved along a bit but the same requirement applies  

many thanks for look at this for me

Kind regards

Chris

[TrippyLighting]

Your assembly does not include any assembly joints, which is required for a proper assembly.

Using the position capture feature to permanently position components is not a good solution.

[chris_heath01]

I believe it does contained assembled joints - the videos show the symbol for rigid joints has been applied - I did not use capture position.

[chris_heath01]

The .f3z file I posted does not contain the joints because I moved the component manually - but I presume that if I did apply a rigid joint then changed a length parameter then the same issue would arise.

Also - is there a way to apply an offset to a rigid joint please?

Regards

Chris

[TrippyLighting]

The design you posted does not contain a single joint but 6 position capture features.

In the video at you apply an as-built rigid joint to lock the components in the place, but you located the components using those position capture features. That workflow is not recommended!

The as-built  joints are very useful on a top-down design, where all components are designed in place.

However, your design is a bottom-up design.

[chris_heath01]

I have used capture position, However I have experimented and added rigid joints - then applied an updated parameter to increase the length - I would have assumed that the joints would remain, however in the video attached the length is increased but the component it is attached to remains the same.

So are you saying I should never use capture position as this causes issues?

[TrippyLighting · Accepted solution]

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@chris_heath01 wrote:

So are you saying I should never use capture position as this causes issues?

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Correct! It has its use, but not for component assembly.

[chris_heath01]

Okay thanks for the information - Can't see what use capture position is for then - it gets "offered" for lots of things.  Will ignore it in future.    

kind regards

Chris

[jeff_strater · Accepted solution]

I would like to clarify this a bit:  Instead of saying:  "never use Capture Position", I would say:  "understand what Capture Position is useful for, and use it in those cases".  But, @TrippyLighting 's point is valid:  Do not use Move Component + Capture Position to put components in place relative to each other.  Use Joint instead.

Another thing to be very aware of:  As-Built Joints (and Rigid Group, which is a type of As-Built Joint) are very convenient, but, they do not have any geometry references, so in your case, where you want the assembly to react to geometry changes, As-Built will not work well.  Use Joint, and select the geometry on the component you want to constrain.

Back to Capture Position:  It is useful to do "position-based modeling".  For instance, to create a cutout for a foldable handle when that is in the closed position.  Constrain the components using Joints, then use Drive Joint to position the handle in the closed position, use Capture Position to, well, capture that position, then use Combine to remove material to make a pocket for the handle.  The reason why Capture Position is prompted is for any operation (such as Combine) where the position of a component could be interesting to that operation.

Hope this helps to clear some of the fog away

[chris_heath01]

Hi Jeff

Thanks for the information - a lesson learnt - the hard way - always the best way

Kind regards

Chris