Best or common practice - sketch as master reference for multiple components

[Anonymous]

Hi,

What are the best practices in Fusion 360 concerning a reference sketch?

As an example lets take simple object consisting of to components - box and lid. See attached f3d.

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I want them as components not objects, because goals are
A) They share same "global" shape/dimensions
B) Each should have it's own history
C) Quicker updates (master sketch updates propagates to all components that refer to  it, say i want to change width of box or some radius), much faster than if I were to redraw sketch in each component and then manage global state using parameters.
D) Lid can be reused with different height box and vice versa.

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Right now I see no issues with reference sketch, but maybe i am missing something down the road in Fusion workflow?

1)
In top project component i created a sketch with box outlines.
2)
Created new component for box
Created a sketch within it
Via project tool scraped master sketch in the component sketch
Created offset constraint for walls
Press pulled (projection lines)  (i know that i could actually extrude it upwards which is more logical and later down the road throw the lid in top of the box via joint, this is just an example)
3)
Created new component for lid
Created a sketch within it
Via project tool scraped master sketch in the component sketch
Press pulled (projection lines)

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A, B and C goals seem to work.
D kind of. After exporting separately component Lid.f3d it works as the base sketch for it which originally had projection to master sketch consists now just of lines (there are no missing references or whatever). ALL constraints (line segment joints, dimensions, name it) though are lost, to make it well behaved I have to redo all dimensions, doable but meh.

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Should a reference sketch be used or avoided in A-C goals?
Is project tool right way to go to bring in master sketch into component?
What about D goal?

Thanks in advance!

P.S. Pardon, this is repost because the original (link) posted few hours ago seems broken, reports "-1 answers" and can be seen only by me, I hope the original suddenly just does not pop up in forum making visible duplicate. Already wrote email to support.

[TrippyLighting]

Please refer to Fusion 360's R.U.L.E #1.

In short, your workflow works with a skeleton sketch that is created before you create any components thus it resides in the top level sketch folder..

As soon as you want to start building geometry off of that sketch, create a component and make sure it's activated.

[Anonymous]

Thanks!

I learned rule no 1 from Lars Christensen introduction videos about how things work/differ in Fusion 360.

In short, your workflow works with a skeleton sketch that is created before you create any components thus it resides in the top level sketch folder. As soon as you want to start building geometry off of that sketch, create a component and make sure it's activated.

Indeed this is what I did. master level sketch first. Components then.

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However I don't think that order is that important though.

New blank file.

Immediately adding new component and activating it.

Doing some dummy rect sketch on XY plane within component & press pulling a body from it.

Selecting back master comp. Adding new sketch in XY plane. Adding circle. Dragging this sketch before any actions of the subcomponent in the masters timeline.

Activating again subcomponent and opening it's XY sketch. I can project circle from master sketch. Do something with it, say offset bigger circle and press pull a hole in my subcomponent box.

Thus imho actually one can just start making subcomponents and proceed. If time comes when it is seen - well this stuff should be shared with a master reference - just creating it in master level and sending back in time does the job. Or am i missing something?

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From the rules you linked 1st exception suggests that the answer to if this is a common practice is yes.

Still, is project tool right thing to choose?

And what about D case, where component is separately exported to be reused in some other design - all reference dimensions and constraints break and has to be recreated. Is this just the way it is or is there a smarter way to export component that has references to master sketch?

P.S. A good candidate for rule #2 is grounding objects as soon as possible. 🙂

[TrippyLighting]

Lars Christensen learned that Rule from me or in particular this forum where I first posted it. Unless he also participated in the Autodesk University class where I taught it 😉

It is likely the most referred to tip on this forum.

Projecting "stuff" is not wrong, but unnecessary in this case.

The Master sketch should include all the common features/dimensions you want represented in both components.

Sketches, features, etc that are unique to each component are then added to each individual component.

[Anonymous]

In reference to https://forums.autodesk.com/t5/design-validate-document/best-or-common-practice-sketch-as-master-ref... duplicate

@Mike.Grau answer

Should a reference sketch be used or avoided in A-C goals? Yes, should be used
Is project tool right way to go to bring in master sketch into component? Yes, it is

What about D goal? Yes, it can be reused

I think you got a great workflow. What will help is creating groups for your time line features and name them properly
The "ground" function should not be used initially for all components, better to ground a reference part and use joints for everything else.
You may also want to turn on "Component color" and use "Selection Sets"
I hope this helps.

Thanks,

Mike Grau

Technical Support Specialist

[daniel_lyall]

That may be so but if you move that sketch when it's not in a component, bad things can and will happen if you are not aware of what can go wrong.

If you wont to reuse that sketch somewhere else and it has dependencies they will get lost like parameters the sketch will come in dead even if you pulled it out of a component.

I do master sketches all the time if it's an important reuse object to play safe I always go by RULE 1.

If it's a dead model it does not matter one bit how you do it.

A simple way to see this is draw a square with 2 user parameters one for length and one for width, copy that sketch and paste it into a new model open the edit parameters dialog and watch the sketch collapse.

Now do the same thing but with a sketch in a component then copy that component out and past new into a new model, that sketch and user parameters are still there and it's a living sketch.

So if it's a do onces and use once whatever goes, if it's a living model RULE 1.

For an example of a living model I have done with a master sketch https://forums.autodesk.com/t5/design-validate-document/sensible-way-to-do-mortises-for-hinges-on-ja...

To draw a simple box with a lid what can be changed at will you only need 3 rectangles and an offset plane plus 4 extrudes it can all be in one component with the lid as a sub component.