how to make a line tangent to spline

[Anonymous]

I cannot make a line tangent to a spline.  Is there a workaround?

Attached is a simple example of a fully constrained spline I need to make tangent to a vertical line.

Thanks.

[scottnorrie]

I'm evaluating a transition from SW to Fusion. I've put some time into this and so far finding the Fusion UX good. However, I didn't expect this sketching limitation to trip me up on my first test part.

In SW, I use the tangent to spline constraint so often it is almost indispensable (both in modelling and drawings for section thickness measurements). A good example is a relatively simple single body fin component. In SW, section foil thickness can be adjusted/measured using a horizontal/vertical constrained line that is tangent to the foil spline (similar to original post). The 2018 Fusion work-around provided doesn't work because this involves modifying the spline (+ geometry) when adding a fit spline point. This technique is also unavailable for projected / intersected / section drawings (which is where it often needs to be used frequently and quickly I multiple sections). Seems there's also no way to measure foil section thickness in a Fusion 2D drawing because there's no points / lines referencing the thickest part of the foil (spline) section to dimension with.

@jeff_strater - Understood that not every suggested improvement can be prioritised, but are you able to share if this is under consideration / in development? This would help to evaluable the suitability of Fusion for these types of parts & workflow.

Thanks!

[HughesTooling]

Edit Deleted. 

[lqg5960]

No, as I said, I know about that setting; that would also be an issue if it weren't there. What's missing is the ability to invert the scroll/panning direction.

[lqg5960]

And it continues to not be funny now.....

[Art5]

Agreed. As others have stated, I have need for this functionality almost daily. Very disappointing to see that this has been an issue for years that many have brought up and it still hasn't been addressed.

[VeloDsn]

I need this all the time. probably my top frustration with fusion right now is the lack of this capability.

Seems like a pretty basic capability that doesn't request a huge investment.

[diegopaivaQJDA7]

The "create a plane along path" solution only works if you are working on a more "freehand" style like the video posted in this topic, 'cause Fusion 360 don't have the option "to the object" when we create a plane along path... I hope the team make this uptade ASAP

[ericjm297ML]

But this changes the shape of the curve?

You are making the curve tangent not picking a tangent angle.

You can see the shape change in the video.

Or am I missing something?

As this was many years ago has this problem been fixed?

I am still looking.

[bwalker145]

I think I've found a solution that can create a true tangent line between two splines.

Obviously going to be some limitations, and it's a little finicky, but has worked well on the few examples I've tried.

I built a separate component to use as an alignment plate, and constrained it to the spline component via "Tangent Relationship" under Assemble (constrain each face on the alignment plate separately to each spline). Project the components onto a sketch, and constrain a point at the line intersections to define the locations of tangency.

[Edit: Revised method. Breaking projection link not necessary, just add a point with a coincidence constraint between the two lines to find the intersection, and then the new sketch remains parametric.]

[pickinben]

7 years later.....  this is a little tough and exactly the thing that makes the life of the sales people more difficult.  I understand that most users of Fusion are making prismatic parts, but this would really go a long way if it were addressed.

[VeloDsn]

Still waiting for this to happen. I also wonder why this request is marked as 'solved' when it clear has not been. The linked solution is to add a fit point to the spline and then use the handle for the constraint. This could work if you never make a change to the spline but any movement of the underlying geometry would result in a change the spline

[neil.mendoza]

The hacky workarounds I normally use don't work for my current project so thought I'd check back in to this thread and see if it was fixed yet. Guess not 😭 We should all submit this as a feature request. https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/How-to-submit-a-pr...

[Art5]

There is already a feature request for this from over 2 years ago; doesn't seem to be much of a priority: 

https://forums.autodesk.com/t5/fusion-support-forum/feature-request-constrain-sketch-lines-tangent-t...

I started another thread for this particular issue, and there has been one work around posted to that thread that has been working for me:

https://forums.autodesk.com/t5/fusion-design-validate-document/is-there-a-way-to-make-a-line-tangent...

[matt_bolty]

It's not a workaround. On Solidwroks, I can find both the chord and maximum thickness of an airfoil with tangent line properties which makes things much more efficient to constrain. On Autodesk fusion it's infuriatingly impossible. Seems an incredibly poor oversight tbh. 

[matt_bolty]

Appreciate the reply Jeff! I would say that for airfoils, this missing feature is essential! And it might be that you don't get so many tickets because people from very early on gave up and had to do clunky workarounds or just eyeball it. It doesn't strike me as a particularly complicated thing to fix although I may be mistaken. 

[MichaelT_123]

Hi Fellows,

“How to make a line tangent to a spline” still attracts a lot of interest … I will also add mine!

I will divulge some secret thoughts about … but in a separate post … as there will be some bonus!

The Post:

https://forums.autodesk.com/t5/fusion-design-validate-document/curve-double-tangent-orientedminimumb...

Regards

MichaelT

[matt_bolty]

Could you explain it with clearer steps perchance?

[matt_bolty]

Is one of the secret thoughts that they haven't solved such a simple issue in 7 years because they want to make money hahah