how to model continuous belt path

[potrero]

I am attempting to create a model of a simple "racetrack" oval belt path (two straight lines, two equivalent arc sections).

Is it possible to create a continuous curve, which can then be used to constrain to?

For instance, if I then made another sketch, and constrained a point to the path, I could drag it all the way around the path.

I've tried using the "use edge" command to copy a loop into a second sketch, after first creating the path out of straight lines and arcs, but it doesn't result in a continuous loop.

If someone has an idea of how to accomplish this, I'd appreciate it. Thanks.

Other keywords: spline, join

 

[vlad1979]

I think you are talking about sweep. Or you could use var sec sweep for more control.

 

[potrero]

I'm trying to accomplish a continuous oval loop in a sketch, not a surface (as I think the sweep or vss would be).

Is that possible?

 

[vlad1979]

first create a sketch:


View attachment 4242


View attachment 4243


then create a sweep or var sec sweep, both have an option to make surface or solid, the example is with sweep because it's a bit simple to explain (but you can explore then the var sec sweep option)


insert / sweep / protrusion (you can see you have an option for surface in that menu, same for var sec sweep).


Go with select traj, then curve chain, click on the previously created sketch, doesn't matter where, then click on select all, then done / done, it will automatically swith to a sketch mode for you to sketch the section of the belt.


and it will look like this:


View attachment 4244


View attachment 4245

 

[gkbeer]

I am attempting to create a model of a simple "racetrack" oval belt path (two straight lines, two equivalent arc sections).



Is it possible to create a continuous curve, which can then be used to constrain to?



For instance, if I then made another sketch, and constrained a point to the path, I could drag it all the way around the path.



I've tried using the "use edge" command to copy a loop into a second sketch, after first creating the path out of straight lines and arcs, but it doesn't result in a continuous loop.



If someone has an idea of how to accomplish this, I'd appreciate it. Thanks.



Other keywords: spline, join

You want something called a composite curve. First you create the simple sketch consisting of arcs and lines. After that is finished select one segment of the resulting curve and type ctrl-c ctrl-v. This will start the creation of a composite curve. In the model tree it will show with the name of copy #. In the dashboard select the references button and click on details. With the chain dialog you can add additional curve segments. Those segments can be from the same sketched curve or any feature, sketch, solid edge... as long as they are contiguous.

When complete, the composite curve can be selected as the reference for a point and the dimension of the point can be driven from one end of the composite curve to the other. You can even pattern the point along the entire composite curve. It can also be used to drive sweeps, or whatever else a curve is needed for.

Composite curves need not be planar.