Sweep along a curve. Can the skech profile dimension change as a function of the length of the sweep curve?? Like the diameter of a sktech circle, which become bigger and bigger as the squareroot of the length of the path?

Sweep along a curve. Can the skech profile dimension change as a function of the length of the sweep curve?? Like the diameter of a sktech circle, which become bigger and bigger as the squareroot of the length of the path?

Mogens,

Just how "curvy" is the curve you want to use for a path? Depending on how complex your profile and sweep path curve are, you may be able to use a guide curve (or curves) to drive the dimension of the profile. In this quick example the 0.5 radius circle is the profile sketch, and the end diameter is determined by the guide curve, the size of which is driven by an equation linked to the length of the sweep path.

If you're better at math than I am, you could use an Equation Driven Curve for the guide curve(s), and really change the profile size as it sweeps along. In these examples I replaced the 3 point arc guide curve with a freeform spline, if I knew any equations I could have put in an Equation Driven Curve instead. The sweep path could also be an Equation Driven Curve.

If you need the profile to change a lot, a loft might be more appropriate. Don't forget, you can use guide curves to refine the shape of a loft too.

If you can post more details, and/or an example of what sort of shape you're trying to get, someone can probably give you some more detailed advice.

Erik,

Hi Erik,

Thanks so much for your help. I am 90% home.... Only..:-(

if I try to have the lenght of the sweep curve in the sketch as one dimension, then I make your suggested equation to make the cirle diameter driven by this length of the sweep curve. But then I get only a constant diameter trough the whole sweep - the last value. How do I get the parameter through out the sweep, starting as zerro and ending as the length of the sweep curve. Thanks in advance.

Mogens,

You will need to use a loft, from a point to a circle. You can't just reduce a circle profile to zero diameter in SW. A mathematician might see a point and a zero diameter circle as the same thing, but SW doesn't. A circle has to have a diameter. even a really small one.

So if you need a point at one end you'll need to make a loft with a centerline.

Below: Sketch1 is the curve that is used for the center line, and to locate the end point. Sketch3 is just a sketch point, placed coincident to the end of the curve in Sketch1. Sketch2 is a circle, centered on the other end of the curve in Sketch1. I set the dia. of the circle equal to the length of the curve so it would be parametric. If you know the length of your curve, and you know it's not going to change, you could just put the dimension on the circle and not bother with the equation. You don't say if your curve is a simple arc like I'm using here, or something more complex. With the arc, as I have it set up here, you can't go much beyond 113° without having the loft turn in on itself and fail. The shape of your curve, and the end diameter will determine what you can get away with. Also note that the loft gets bigger uniformly as it follows the centerline. If you want a more complex transition from point to end diam. you will need to add guide curves, more profiles, play with the start and end constraints, or a combination of some, or all, of the above.

Again, if you can post an example of what you are trying to achieve it will be easier to help (click "use advanced editor" in the upper right corner of the reply dialog box to attach files). A picture is worth....

Hi Fons,

Another way to approach this problem is to create the sweep using an equation-driven curve. Check out the new "Stump the Chump" blog post with a video showing how to use an equation driven curve to control the diameter of the sweep profile.

Hi Mogens,

This is not possible, you'll need to raise an enhancement request for it.

You might consider using a loft with a centre-line guide curve to get the output you are after. But you'll still need to define the profiles at each end.