Derived dimensions

[deant.mobile]

I understand how to make a dimension in a sketch a function of another dimension in that sketch.

Is it possible to make a dimension a function of a dimension in a different sketch (In the same component or a different one).

As a concrete example, if you have a pulley defined in one component, can you dimension a shaft in a different component that has a diameter that is a function (bore size of the pulley minus a clearance value).  I know that I could project the profile into the drawing and make the diameter a function of that projection, but my understanding is that the projection is static (not linked to the size of the original).  

Or is there a more elegant solution to this problem that I am not aware of?

[TrippyLighting · Accepted solution]

Yes, you can do that. 

1. You can define a user parameter and assign that to both dimensions.

2. When applying the dimension in the one sketch it usually tells you the name of the dimension e.g. "d34". You can use that as a variable name when dimensioning the other sketch.

[deant.mobile]

Marvelous.  Thanks for your help.

[Anonymous]

How are you able to set the dimension of one sketch as a function of another dimension? I.e. How do you make the diameter of a small circle dependent on the diameter of a larger circle?

[laughingcreek]

Here's one approach.  When your prompted to enter the value for a dim, click on any other dim and it will copy the parameter name there for you.  See screen cast.  Alternately, use the user parameters.

[lichtzeichenanlage]

@laughingcreek: Didn't know that this exists. But it looks like, this way is a bit buggy. Check this out.

[lichtzeichenanlage]

@laughingcreek: Looks like this way of linking dimensions has a bug. Check this thread.

[TrippyLighting]

What the guy observed has been reported a long, long time ago and is less a bug (programming mistake) that a result of the functionality,pity not being fully thought through.

[lichtzeichenanlage]

@TrippyLighting: Thanks for your feedback. I'm to new to this stuff to know the history. Is there a bug tracking tool, where people could look up existing bugs? And regarding to bug vs not thougth fully through. Specifications could have bugs, too 😉

[laughingcreek]

No bug tracking tool.  That's been talked about some too.  Would save a lot of people a lot of frustration, but would also reveal just how buggy this thing is, and how long they persist.   

[laughingcreek]

You can still just manually type in the parameter names of the dims if you need to reference more than one.  You have to remember to first hover over each dim you want to ref, and get the parameter name, then type them by hand when entering the value for the dim.

[laughingcreek]

And so the cycle of learning how fusion is suppose to work, and then learning the work around for the bit that doesn't, continues.

[TrippyLighting]

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@laughingcreek wrote:

And so the cycle of learning how fusion is suppose to work, and then learning the work around for the bit that doesn't, continues.

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Yep! Spot on!