Feature Request: Constrain sketch lines tangent to splines, mid-spline

[zkamen]

When sketching, there is no ability to constrain a line as Tangent to a spline, somewhere in the middle of the spline. They can be constrained tangent at the end of the spline, but not anywhere else. 

This would be extremely helpful when projecting lines off previously built bodies or sketches, and wanting to create a tangent line (or then perpendicular line to that tangent line).

Thanks

[Art5]

Seconded. I have use for this on a regular basis.

[davebYYPCU]

There are many workarounds, making this a low priority.

Did you search the forum for those?

Might help….

[Art5]

I have looked through those, but as you stated, these are 'workarounds' for a function that every other CAD system I've used just does. Additionally, many of those workarounds don't actually work the way I need them to. If I've projected a spline from a part into a sketch, I routinely need to place a lines in that sketch and then constrain them to be tangent to the projected spline. I looked through the forums with search terms 'tangent to spline' and couldn't find any posts that showed how to do this easily and effectively. If I've missed something, I'd be most appreciative if you could direct me to the thread you're thinking of!

[Art5]

Bump due to lack of response and/or viable solution. Encountering this problem again today.

[davebYYPCU]

With picture file or movie of the actual problem - intended outcome, will be able to suggest which workaround might suit.

Might help….

[Art5]

Just to be clear, you're asking me for a picture/video of fusion's inability to constrain sketch features tangent to a spline?

I'm not sure how a picture/video of this will bring any more clarity to the issue than the description of the problem, but if you really think it will help you to visually see that fusion will not constrain a sketch line tangent to a spline, I'll post a visual aid for you.

[davebYYPCU]

I am sorry to offend.  

This problem is not limited to a line and it’s perpendicular cousin. 

Draw a construction circle - centre point on an appropriate position on the spline. Trim one side off.

draw the perpendicular line from midpoint of arc to centre point.  (Smaller the circle, more accurate you will be.)

Might help….

[Art5]

Thanks for your reply.

The workaround you described won't work for me, but perhaps it will work for the OP. 

No offense taken, I just wasn't clear on how the image would help. I understand now. I've attached an image of what I need to do regularly for clarity.

 

[TrippyLighting]

While I definitely would support tangency to a spline as a feature, I am not sure why such a design (your screenshot) would require any spline(s)

[davebYYPCU]

won't work for me,

Joking?

Might help....

[Art5]

I don't understand what you mean when you say the design doesn't require splines. The splines you see in the design are projected from a body, provided by the customer. I cannot adjust these to make them arcs, they have the remain the exact same as the part.

[Art5]

Based on your description of your procedure, what you described "centre point on an appropriate position" is not actually 'tangent' to the spline, no?

If I knew the exact position to place the center point, I would have no need for the tangent to spline feature. 

[TrippyLighting]

---

@Art5 wrote:

Based on your description of your procedure, what you described "centre point on an appropriate position" is not actually 'tangent' to the spline, no?

---

Correct!

[davebYYPCU]

During the construction of the workaround nobody knows the actual position of the result.

You had the line in the approx location as required is all I am saying, (which line on which spline) then you constrain it.

The arc/s move as you place the constraints.

Good enough for govt work.

Smallest possible arc is most accurate, never said it was exact.

However, the resulting line is coincident to two splines.  Tangent?

Trippy did a movie with a lot more construction for the exact method, using Plane on Path, and offset surfaces iirc.

.

[Art5]

"Good enough for govt work."

Perhaps for what you do this is an acceptable solution, but in my case tolerances are pretty tight, .001" sometimes. 

Close enough isn't close enough, I need it to be right. Again, this is something that every other CAD system I've used just does, and I have no clue why it wasn't implemented when the tangent constraint was created. Seems like a major oversight. 

Once again, I have need for this today, thus the reason for revisiting this thread.

[davebYYPCU]

What part of 

Trippy did a movie with a lot more construction for the exact method

did you miss?

[TrippyLighting]

---

@davebYYPCU wrote:

What part of 

Trippy did a movie with a lot more construction for the exact method

did you miss?

---

I started working with Fusion 10 years ago. In that time it should have been possible to implement tangency to splines.

I find any argument to the contrary entirely indefensible at this point!

[Art5]

Pretty certain I've watched the screencast in question, and as far as I can tell it still has the same issue that I'm pushing, which is that I have to GUESS where I THINK the tangency point MIGHT be, which again, is NOT a solution. In fact, picking an arbitrary point that's supposedly 'close enough' completely defeats the purpose of what everyone in this thread is asking for. It needs to be right, not close enough. If you aren't going to help, perhaps you should quit wasting people's time by posting irrelevant replies.

[Art5]

I couldn't agree more. There are multiple threads asking for this basic feature.