I've got a spline that I constructe

[Timelord]

I've got a spline that I constructed with a 3D sketch. It is a sine wave wrapped around the inside of a cylinder. It is for a cam slot. The spline is not closed. How do I make it a closed loop? I tried editing the sketch and making the start and end point coinsident, but it won't let me. The spline property manager has no tools to close the curve. It must be a closed loop to sweep a sketch around, because I do not have the start point on the sketch's plane.

TIA,

Timelord

 

[sirmick]

Why not create a new plane parallel to an end of the cylinder and coincident with a sketch point. Then create your cut profile on that new plane.

 

[JNR]

Isn't there an option to make a spline a closed loop at the time you create it? Just seems to be something floating in my memory about that. It means you would have to recreate the spline, but try and see. I'm sure I have been able to make closed splines

3/4 of all the Spam produced goes to Hawaii - shame that's not true of SPAM also.......

 

[SBaugh]

You might be thinking of "Fit spline" but you have too already have a closed spline. This Fit Spline is greatly used for making Cam mates when the part is in the assembly.

Regards,

Scott Baugh, CSWP
3DVision Technologies

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376
When in doubt, always check the help

 

[TheTick]

I took some time to browse the API looking for a back-door solution to this. It looks like the the open-end condition of a spline is hard-coded from creation and can not be changed.

There may be a workaround. Roll back your model and make a composite curve from your spline. Change the references downstream so that they use the composite curve instead of the spline. Make a new spline (either in the original sketch or in a new sketch) and change the composite curve to use the new spline.

This is probably not simpler than recreating the spline, but it may serve your needs.

All this machinery making modern music can still be open-hearted.

 

[Timelord]

The Tick is right, the only way I got it to close was to redo the spline from the start and make it closed while creating it. As for your method to correct it; How do you make a composite curve? What is a composite curve? This is something new to me.

Timelord

 

[TheTick]

"Insert --> Curve --> Composite" to access the composite curve tool. Composite curve is a way to make a single 2D or 3D curve feature out of multiple sketches and other curve entities. It can be useful for making guide curves for sweeps in 3D out of 2D sketches.

All this machinery making modern music can still be open-hearted.

 

[SBaugh]

A composite curve is great to use when making springs. Lets say you make the helix portion of the spring. Now you want to add 2 straight lines off each end of the helix. You make the 2 sketches for both ends. But now you have 3 separate sketches and when you do a sweep you can only have 1 path in one sketch. Well you can convert those 3 sketches into one composite curve and now when you do you sweep you can use that 1 composite curve as your path.

Regards,

Scott Baugh, CSWP
3DVision Technologies

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376
When in doubt, always check the help

 

[JNR]

Note a subtly in what Scott said about CAM mates. If you want a cam mate, you have to have a single surface. If you use a composite curve that was generated from more than one curve a surface created from it is STILL to all intents and purposes mathematically separate surfaces. I had to do one once and ended up manually fitting a spline onto the separate curves. This is tedious, since you have to space your control points according to curvature and rate of change of curvature. However, depending on what you need, the new physical dynamics stuff can be of some help since it uses collision detection between objects.

3/4 of all the Spam produced goes to Hawaii - shame that's not true of SPAM also.......

 

[Timelord]

Thanks for the explaination. I've never used a composite curve, it was new to me. Never to old to learn something new.

Timelord