Sweep inside a triangle

[tripleSheva]

I've Googled long and wide, watched videos, but still can't figure this out. I have a triangle of "absolute size" that I want to trace a profile along its inner perimeter. When I use the Sweep command, if the profile is located inside the perimeter I get the following:

If I move the profile so that it is touching the perimeter from the outside, it works as expected, and I get a nice looking profiled triangle:

However, this makes the overall size of the profiled triangle larger than it should be, as it's adding the width of the profile to the body.

The triangle's size (from shortest "base" to opposite point) is meant to be controlled by a user parameter, so that I can create N triangles of varying sizes, with the same profile and "thickness", which is why the profile must be on the inside of the perimeter.

I've even tried coming up with a way to have the profile on the outside, and use a formula to size the triangle based on the profile's width (E.g.: triangleSize - profileWidth * 2), but that screams wrong to me. Can anyone help me?

And while I'm at it, is there no easy way to snap things to one another" I get that F360 is "parametric", but editing the sketch just to add a guide line/point that I can then use to snap to the triangle's outline is stupid and cumbersome. I miss SketchUp's inference system so much!

This is the profile itself, BTW:

[g-andresen]

Hi,

works for me

günther

[davebYYPCU]

Only difference, I have Origin, midpoint of bottom item, breaks reliably, for outside path.

Op first question - how to stop that, he was getting same result.

I think he wants Origin on common cutter point.

Waiting for how he wants N number of triangles, because he has not got one (1) working yet.

Might help

[tripleSheva]

@g-andresen Looks like you simply moved the triangle, instead of the profile. This doesn't feel right, as it moved the entire assembly off from the document's origin point, as @davebYYPCU pointed out.

I'm trying to find a way to coincide the profile to a the corner of the triangle, but it's proving too difficult, so I'm going to resort to using a formula to size the triangle based on the profile's width. It's ugly in my mind, but reading @davebYYPCU's comments, it seems like the only viable solution.

[tripleSheva]

I managed to rearrange the sketches, reconfigure the sweep and splits, and got the triangle to respond to parameter changes. I managed to create the formula to compensate for the profile's dimension. However, it doesn't seem to update when I change the parameter. It does work, though, if I edit the sketch and double-click the formula and re-submit/confirm it with Enter/Return; or if I use the Utility > Compute All action.

Shouldn't the Automatic Update checkbox on the Parameters window do that for me automatically?

Here's what the updated sketch looks like now:

[davebYYPCU]

My next stage of the process.

I can't break it yet, 3 parameters to play with.

Creating N frames from one Sweep is a bit above my paygrade, but I will keep trying.

As for your frame profile.

Can I suggest, you construct the outside Path, and offset it 19.456 inside.  Use the inside path for the Sweep and the Outside path being the source, has the dimensioning you want.  I have not done that in this file but would not be hard to set up.

Might help....

[tripleSheva]

Thanks Dave! I think I got an elegant solution without additional sketches. Just need to figure out why I have to manually recompute after updating the parameter, and if there's a way to avoid that. 🙂

[davebYYPCU]

Not sure I am keeping up, 

Sketches have no history, I think is the problem.

Manipulating the sketch with parameter changes, works, so not sure why a manual recompute is even required.  I am thinking a not so recent upgrade "we have improved compute speeds" removed this automatic recompute to save time.  I did find Sketch > Offset does not retain a formula, just a value, so the parameter has to be edited.

Parameter Auto update is working my end, and it just takes the edited value and updates the model without waiting for the dialogue box to be closed.

As I see it, overall height is the driver, the visible opening is just a driven readout.  Could be wrong.

Might help...

[tripleSheva]

Hey Dave. Check out the updated version attached. It'll help you understand better, I hope. The issue is not with the lack of history for sketches (that exists in the Edit history, to some extent). The issue is that once the parameter is updated, the values inside the sketch do not get re-computed automatically.

It could be because of the Fusion 360 changelog that you were referring to. Is there a way to tag them on a thread? (So that I don't have to start a new one via email/support.)

[davebYYPCU]

Your formula locks up the frame sketch, probably due to the use of driven values, supposed to work but is new functionality, it locks the Parametrics in this case.  I don't think you need it either but still not worked out the design intent.

Now you early in the peace mentioned N frames automatically, in that case I would put the 3 fillets in the profile sketch, to save finding 9 edges for each frame as you did them.  Do not trim this outside vertex.

[tripleSheva]

Oh, I didn't think about simply constraining the entire triangle to the parameter! That works much better than a formula that's dependent on two other properties. Thanks!

You mentioned doing the fillet inside the sketches, which I understood is not a good idea in general. If I only intend on having a few (under 10) triangles, should I still fillet inside the sketches? In a way, it kind of makes sense, as I might want to have different fillets for each body, but I'm ok with manually selecting 9 lines, if it means better performance, or considered "best practice".

Lastly, you said not to trim the outer vertices, if I have fillet in the sketch. Can you share why? I assume I'll have to hide them how in the body's geometry in order to see the rounded edges?...

[davebYYPCU]

Whether you add a fillet to the sketch, or later as a modelling feature, comes down to personal preference.  For me it would be a PITA, doing it after the sweep, in my multi file it’s 27 edges. And 90 for your 10 frames, the way you did it.

Fillet in sketches make the sketches harder to fully constrain, much easier if you don’t trim.

the vertex in the pic is the one you projected to the path, so you can’t trim and keep the parametrics working. Prevents the Manage lost Projection dialogue, that would have no solution.

Edit the sweep select the majority profile, and the fillets are done for you, 

if not in the sketches then I would fillet before the split bodies to reduce to 3 selections.  KISS.

Fillets in sketches are not prohibited.

So about the 10 frames, are you doing a configuration for different sizes or were you off to 10 different Sweeps?  My multi file was 3 frames and adjustable equal spacing by parameter.

Now you should be seeing the power of Fusion, and how Timeline ordering of the features makes life easier.

Didn’t know about the diffuser, could be added to the profile sketch, to save extra work.  Another KISS situation.

Might help….

[tripleSheva]

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Whether you add a fillet to the sketch, or later as a modelling feature, comes down to personal preference.  For me it would be a PITA, doing it after the sweep, in my multi file it’s 27 edges. And 90 for your 10 frames, the way you did it.

For me as well, but watching some videos led me to understand that it's better not to fillet inside a sketch.

the vertex in the pic is the one you projected to the path, so you can’t trim and keep the parametrics working. Prevents the Manage lost Projection dialogue, that would have no solution.

I filleted the profiles now (both channel and diffuser) and the sweep worked fine, without keeping the vertices. My sweeps are done before the split, so it's already keeping it stupid. 😉

I'm keeping the diffuser separate from the profile because they are independent from one and another. And also, the channel sketch is already quite busy with all the lines and constraints, that it's easier to keep the diffuser in a separate sketch.

So about the 10 frames, are you doing a configuration for different sizes or were you off to 10 different Sweeps?  My multi file was 3 frames and adjustable equal spacing by parameter.

I'm not actually sure about the final number of triangles. I just know it won't be more than 10. That's what I was referring to in my previous response.