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composite curve(2?)

composite curve(2?)

composite curve(2?)

(OP)
Hi all, sorry if this gets posted twice.
I have an outward tapered helix joining to a straight helix joined to another outward tapered helix. I can sweep cut a profile for each helix to make the continuous cut. If I wanted to form a composite curve of the three individual helixes, how can I define where one helix starts and the next to begin. It would be easy if the number of sweep revs was a known, however the transitions are of discrete lengths and will change according to the configuration. Does the composite curve function require any more system resource than the individual helix?

RE: composite curve(2?)

You can put the start angle in the helix diameter sketch.  Use construction lines to connect to the endpoint of one helix before starting another.  Attach reference dimensions to the construction lines to show angle relative to 0°, and use an equation to make the start angle of the next helix the same as the reference dimension.

I have two torsion spring models that use this technique.  One is in Hinge.zip, one is named TorsionSpringByTheTick.  See models at <http://www.esoxrepublic.com/models/>

batHonesty may be the best policy, but insanity is a better defense.bat
http://www.EsoxRepublic.com-SolidWorks API VB programming help

RE: composite curve(2?)

(OP)
Thanks Tick
Do you know if composite curve is more taxing on the system than multiple helixes?

RE: composite curve(2?)

Composite curve is only a method of associating multiple edges and curves into a single feature.  Very light, almost "weightless".  Helixes themselves are "low tax", as well.  What gets taxing is helical surfaces.  You will probably have a more robust feature if you combine all three helices into one curve.

Generally, I prefer 3D sketches and "convert entities" to composite curves for combining helixes.  Easier to edit and manage.  You will notice I use a 3D sketch "copy" of the helix in each of my springs.  This is because once you use a helix in a feature, you can't select its endpoints for other features.

RE: composite curve(2?)

I believe using a 3D sketch also lets you blend the curves using fillets.

RE: composite curve(2?)

You could also blend the curves in a 3D sketch using a spline.  This would allow you to control tangency matching(C1) and possible even curvature matching (C2) depending on how you did it.  More flexible than using fillets, although a little more controls needed to get it to behave well.

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