What doesn’t the FIX constraint do for a spine?

[laroot]

If I dimension a spline’s first and last points and then apply the FIX constraint to the spline, then what does the sketch lack that a fully constrained sketch would provide?

I can fully constrain even a fairly complex sketch made up of standard geometric elements.  But fully constraining a fixed point spline by hand quickly becomes burdensome when there are more than 3 points.  Is there a constraint or function to constrain a spline?

If not, is FIX a work around to prevent me from accidentally altering the spline in subsequent edits?

If I cannot/will-not fully constrain a spline, is it worthwhile to fully dimension the remaining elements

Very respectfully,
Larry

[TheCADWhisperer]

If you don't need to adjust the nodes or handles - you can use Fix.

Just select the spline. (Not the individual nodes.)

You can always toggle the Fix later if needed.

[g-andresen]

Hi,

When specifying splines, note that Control Point splines get by with 2 dimensions (vert/hor) per control point.
Fit Point splines, on the other hand, have 4 dimensions per point, 2 of which are necessary to define the tangent handles.

günther

[shahriarsifat1802164]

Hi, basically spline gives an approximation of your desired sketch.

[shahriarsifat1802164]

I am going to make a screencast regarding this. Hope it will help.
Thank you.

[shahriarsifat1802164]

Here is it.

[shahriarsifat1802164]

Make a spline fully constrained | Fusion 360 | Autodesk Knowledge Network

[laroot]

Guys,

Thank you for your comments and the screencast. 

I apologize for not being clear:  I can and have fully constrained a spline.   It' just that doing so becomes a bother as the number of a spline's fixed points increases. 

My current project is modeling a carved panel from an 18th century chest -- the Design model is a graphic made up of 37 arcs and 7 fixed point splines.  That section is then copied, rotated, and pasted to create a half model in which the laid out cavities get milled.  That half model is then mirrored to create the full panel.

In Sketchup, I can put dimensions in multiple layers to keep them manageable.  I haven't found a way to do that in Fusion 360.  As a result, even without trying to fully constrain the splines, there are a lot of closely spaced dimensions called out.  (I can uncheck dimensions to visibly remove them from the sketch, but it still strikes me as a mess.)

So I am trying to compare the benefits of (1) constraining nothing or only a few points, (2) fully constraining the arcs but simply FIXing the splines, and (3) fully constraining everything. 

     What benefits do I get as I fully constrain more of the model? 

     Is it worth doing for a 2D project?

Very respectfully,
Larry

[TheCADWhisperer]

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