Perpendicular-to-tangent constraint?

[JetForMe]

Is there an easy way to constrain a line to be perpendicular to a curve at a point? I found a cumbersome way, with two lines, two points, two coincident constraints, and a perpendicular constraint, but that's very cluttered. I need to make a number of such lines, and don't know of a simpler way.

[TheCADWhisperer]

@JetForMe 

There might be.

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

(If your actual file is proprietary - simply make up a dummy file that exhibits the same behavior.)

[jhackney1972]

Take a look at the video.  You will end up with multiple sketches but the method is easy.

[davebYYPCU]

... a line to be perpendicular to a curve at a point? 

Sure, draw a line from curve to it's centre point. (Radius line)

There are a few workarounds for Splines, but more context is needed for which one to use.

Might help.

`

[TrippyLighting]

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@JetForMe wrote:

Is there an easy way to constrain a line to be perpendicular to a curve at a point? 

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Arcs show with a center point, and you can make a line perpendicular to an arc by using the coincident constraint between the line and the center point of the arc.  

It's perhaps not as intuitive as a perpendicularity constraint, but it works the same effect.

Unfortunately, tangency, or perpendicularity to a spline curve, still requires workarounds. 

[MichaelT_123]

Hi Mr JetForMe,

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The theme "Tangency and Perpendicularity to Spline at Point" ... is popular on this Forum, like 'Dark Side of the Moon' by Pink Floyd. It is timeless.

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This is the excerpt from:

https://forums.autodesk.com/t5/fusion-design-validate-document/tangency-and-perpendicularity-to-spli...

There are some more or less viable approaches to the conundrum posted already.

Please find another one below. I am not sure whether it has worked in previous Fusion sketch machinery, but it seems quite a natural, friendly solution now, but ONLY for 2D spline/sketch. For the 3D scenario, “a planeOnPath” is a viable solution.

What to do:

• Draw a spline
• For the existing one, insert a fit point where you want your line segment to be perpendicular
• In the sketch trigger spline’s tangential handlers
• Apply a perpendicular constraint to the line and the handler at the fit point of interest
• That’s ALL

How to test:

• Drag the fit point
• Drag and end of  a tangential handler (changes its angle in 2D)
• Drag the line itself (by position and/or angle)
• That’s ALL … I can think of!

The simple test file is attached.

 

Have  Tangential_or/and_Prependicular 2026

MichaelT