Make Line Tangent To Included 3D Geometry Curve

[MaxHugen]

Is there a way to make a line in a sketch Tangent to a curve in Included 3D Geometry?

[Anonymous]

It should be as simple as setting a Tangent constraint on both the projected geometry and sketch line. Must be the lines not the end dots. The sketch lines end dot will need a Coincident to the referenced arc.

The sketch plane is on the top of the body.
https://autode.sk/2S28Py0

[davebYYPCU]

Projections are splines, tangent to spline / ellipse curves are limited to end points.

You will have to split face so that the spline end point arrives at that tangent point, then it is easy.

Might help....

[MaxHugen]

I think I started off then wrong way. I'm making the "pod", which is a sort of strong-back between the forward and aft beams in the centre of the boat. This is an old pic of one being molded in two halves, looking from aft and upside down:

I've split the faces of the aft beam to Loft the aft flange that connects to the beam, and used Offset and Patches to create a solid body:

From there, I'll continue forward, and cut &/or join the resulting bodies to each other.  As I have zero details of how the forward end of this pod connects to the forward beam, I'll have to get imaginative.

[davebYYPCU]

You get all you need from that mould.  Right up the front, is a formed flat cuff, for the underside of the front beam.  Runs straight back from its trailing edge to top of spar at the rear beam.  Front profile is nearly flat triangle, rear profile an ellipse at the spar position chord line, with vertical extensions.  (Draw the 3 straight rails first, fit the profiles to them).  The very front of the pod reaches the cross member inside the back of the peak jib booms.  Lofting to the back of your green cuff, will provide the intersecting curves for you.

Might help... 

[Anonymous]

Didn't notice it was a Spline.. That takes Calculus 😱

Just for fun I came up with a way to approximate the tangent point, if you know the starting point and general area it is tangent to then it looks pretty close to perfect. Generates a profile at least. and the smaller the construction line geometry (especially horizontal & vertical lines) the more accurate it is.

Move the "Tangent calculation" Sketches far left point about to watch it all work

--
Secant lines was my inspiration, but I'm a long ways off understanding more on how to implement this into Fusion
https://www.youtube.com/watch?v=O_cwTAfjgAQ

[davebYYPCU]

Your file has an error, the tangent line should not be coincident here.

For splines there is an easier Approximation workaround smaller the circle the better.  Connect to the Centre point and secant line parallel to it.  Can slide the circle anywhere.

Might help.....

[Anonymous]

This was the first time I attempted anything like that 😊 Knew it wasn't ideal, hadn't consider a circle/secant. All that's needed is that mid point between the secant.
That approximation is probably just fine in a real world application. Right? Although you have to be careful to guess the Tangent of the line by eye. I was probably attempting to reduce the DoF to prevent errrors

[MaxHugen]

I'm having endless issues with "Compute Fails. Revise dimensions...".

I Split the forward beam, where the pod would intersect, plus a face where the pod topside should be. Also split the faces on the Aft Beam Flange body.  This was to limit the amount of sketch lines as you recommended.

Should then have been able to draw the Line for the top of the Pod from the Flange to the Forward Beam, but get the error every time I try to connect the second point of the Line.

I've also created the 3D sketch again from scratch, but same result.  Can't figure out what I'm doing wrong, any suggestions pls?

Oh great, I can no longer attach the file, it exceeds the limit of 71Mb. And Zip hardly reduces the file size.  😞

[davebYYPCU]

 Although you have to be careful to guess the Tangent of the line by eye.

No guessing in CAD, these two are parallel.

Might help....

[MaxHugen]

I've made some progress with the pod, after a fair bit of trial and error.  🙂

[Anonymous]

You can Create/share the link to the file from the File/Project browser window in Fusion. e.g https://a360.co/3u1u7Jh and can allow people to download it that way.