Tangent Arc. How do I switch arc direction?

[k6ls]

I cant figure this out, and I cant find anything addressing it.

When trying to draw a tangent arc, the arc goes in the opposite direction of what I want.
how do I force it in the other direction?

[TrippyLighting]

Maybe you can share more details e.g share your model or at least make a screenshot of the sketch.

[k6ls]

Thanks for taking time to respond.

I don't see how submitting a drawing will help answer the question/solve the problem.
you start drawing a tangent arc line, it wants to curve, but it goes in the direction opposite of what I want.

I gave up on trying in F360, so I just went to Draftsight, drew it exactly how I wanted, and with great ease, I might add,

and brought it back into F360 and extruded the part.  Voilà! a huge savings of time.

I don't want to be hating on F360, but there are a LOT of BASIC CAD operations that are near impossible / more complex then they need/should be.

but that is a whole other subject.

[Anonymous]

I cannot believe it's been two whole years and this issue is still not fixed. Currently running into the same issue you had back then.

[Reivaxy]

Here is a sketch illustrating this totally exasperating issue.

If there is a simple solution, it must be really hidden...

I want to make a tangent arc from point shown by arrow 1, to point shown by arrow 2

As soon as I start from arrow 1, the arc is tangent to the horizontal line. But I want it tangent to vertical line.

I want the arc to be "inner" rather than "outer", respectively to the top left corner of my sketch.

I've tried dragging the mouse up, I tried holding Shift, Ctrl, Alt, in all combinations.

The **** arc keeps not being where I want it.

I have tried removing the small horizontal line to the left of point 1.

Then the arc is tangent to vertical, BUT STARTING DOWN ! whatever the mouse direction.

I have tried starting from point 2 instead, with all the same combinations, it kept not being where I want it.

I can't believe there is not a way to draw it as I need it.

For people still interested in this subject, here is a work around but if it's the only way, F360 developers should really be taken care of in some creative way by a James Bond villain:

Draw the arc as it is shown in my screen capture

Draw a straight line between point 1 and 2

Use the Mirror action on the arc using the straight line as mirror line.

Remove original arc and mirror line.

Of course, if you need to change dimensions, you'll have to do it all over again...

[g-andresen]

Hi,

Try the 3 p arc and tangent constraints.

günther

[Reivaxy]

Thanks for the suggestion, but it then tries to fit the constraint and the third point, so it moves the rest of the schema.

May be adding extra contraints would solve this, but it's a workaround at best.

[LeonardoBN]

I wouldn't see this as adding extra constraints, but adding suitable constraints to your sketch. If you have unconstrained elements, you can have unexpected results when working on it.

[g-andresen]

Hi,

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@Reivaxy wrote:

... so it moves the rest of the schema.

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if it does so, the scheme is not constrained

günther

[Reivaxy]

True, but irrelevant to the original question.

I'm not asking for yet another workaroud, actually.

The tangent arc feature is flawed if you can't choose the direction of the arc a way or another.

[chrisplyler]

I wouldn't call it a "flaw" so much as just a limitation. Tangent arcs obviously just assume you want to continue in the direction defined by the thing you're attaching to, and they don't have a "flip direction" option. Guess it would be nice if they did, but they don't.

So the "work around" of just drawing an arc and THEN placing the tangent constraints works fine.

Having to constrain other sketch items to avoid unexpected behavior, however, is NOT a workaround. Fully constraining all sketch elements is a desired/intended workflow in Fusion, whether it's to save you getting wonky results when you try to place an arc or not.

[Reivaxy]

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@chrisplyler wrote:

Having to constrain other sketch items to avoid unexpected behavior, however, is NOT a workaround. 

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But I never said it was, please let's stay on the subject topic, or this will become one more useless thread from which people will only find answers to questions they never asked to begin with.

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@chrisplyler wrote:

I wouldn't call it a "flaw" so much as just a limitation. Tangent arcs obviously just assume you want to continue in the direction defined by the thing you're attaching to, and they don't have a "flip direction" option. Guess it would be nice if they did, but they don't.

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Well, I'm attaching it to a point on which two lines end and it won't let me choose the line it should be tangent to, so if the only thing it can do is "assume" which line, it will be wrong 50% of the time.

I'm fairly confident that in most designs, point having only one line attached are a minority, but I can't back this up, it's just a feeling.

Now when there is only one line, it keeps assuming the direction of the arc, with no possibility to pick the other choice.

These two assumptions combined, tangent line and direction, mean it will probably be right 25% of the time, and the feature can't be used for the remaining 75%

To me, a feature that gives an inadequate result 75% of the time is flawed.

I'm not trying to trash the software, you know, there is nothing wrong in admitting there are flaws, even bugs.

[chrisplyler]

You can choose which of the lines it decides to be tangent to by clicking on the common endpoint and then dragging your mouse out in the same direction as the desired line for a little bit before you start curving.

But of course you cannot flip the direction. That's the limitation.

[chrisplyler]

And you did so call constraining the rest of your sketch a workaround.

You said something suggested caused the rest of your sketch to move. It was pointed out that you should be constraining everything. You said it's extra steps and you weren't interested in another workaround anyway.

[chrisplyler]

I mean, I'm with you...having a 'flip direction' option for tangent arcs would be great. But let's be honest. Not a single other person has any problem with just drawing a 3pt arc as close to what is desired and then placing tangent constraints. And since I haven't pinned the tangent arc button to the toolbar, doing so doesn't really take me any longer than it would to open the create menu, hover over arc, then select the tangent one and sketch it, or to type s, t, then pick it from the list and sketch it.

It would be nice to have a flip direction option, but you've got a bit more concern about it than it's worth.

[OceanHydroAU]

At least for tangent arcs, the direction has to do with which end of the line you're drawing from - the arc always goes away from the line's end, so if you need the opposite direction, draw a parallel guide line extending out from the end of the line you're working with, and use that for the tangent arc.

[beechcraft12]

THIS is the best solution I have found for the OP's problem. I too don't want crazy work arounds. This solved my issue quickly! Do what he said. once you delete your reference line, you can move the end points of the proper arc to the rest of the sketch you may be trying to complete and the arc will remain in the correct orientation!

[patrickEEMNJ]

It's 2024 and there is still no flip.

[TheCADWhisperer]

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@patrickEEMNJ wrote:

It's 2024 ...

@patrickEEMNJ  

You can do this eight different ways in Autodesk Inventor Profession (years before Autodesk Fusion even existed).

[Reivaxy]

Oh I'm sure it likely can be done in any cad software BUT Fusion.

Which does not help much when using Fusion 🙂