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Revolved....Loft?
Aaron_Gottuso
Member Posts: 2 ✭
Good afternoon OnShape Community!
I am trying to gradually connect (revolved loft?) the two orange-highlighted profiles in the below screenshot.
The first profile (Sketch 3) is actually shown as an orange dotted line. If I could loft from a flat line that would be great, but I actually made it a very very low triangle, with a height of .001, so that the number of vertices in each profile would match.
So far, I have not been able to successfully get the loft to complete. I only want this lofted section for the 90 degree part of this arc, and then on the other side of the large triangular profile, I will loft back down to "flat".
Am I missing a much easier way of doing this?
I am trying to gradually connect (revolved loft?) the two orange-highlighted profiles in the below screenshot.
The first profile (Sketch 3) is actually shown as an orange dotted line. If I could loft from a flat line that would be great, but I actually made it a very very low triangle, with a height of .001, so that the number of vertices in each profile would match.
So far, I have not been able to successfully get the loft to complete. I only want this lofted section for the 90 degree part of this arc, and then on the other side of the large triangular profile, I will loft back down to "flat".
Am I missing a much easier way of doing this?
0
Best Answer
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james_dalessandro195 Member, Onshape Employees Posts: 7Hi Aaron! While it seems like the solution is to loft to a line, you can actually achieve the same thing by lofting to a point.
See in my screenshot I have the triangular profile, an arc that is a quarter of the circle edge, a quarter turn helix, and a point. Loft the triangle to the point, and use the helix and the arc as guide curves. This should get you what you're looking for.5
Answers
Some CAD systems allow you to vary a parameter over the course of a sweep or extrude using some kind of Law function, and that would be the ideal way of handling something like this. Given that Onshape doesn't currently have any such thing, I think this is one valid solution.
If it were me, though, I'd probably use a surface loft instead of a solid loft, thus saving me the trouble of creating the bottom guide curve and allowing me to go all the way around. I'd then use replace face to bring the flat top face up to the surface.
See in my screenshot I have the triangular profile, an arc that is a quarter of the circle edge, a quarter turn helix, and a point. Loft the triangle to the point, and use the helix and the arc as guide curves. This should get you what you're looking for.
I was able to successfully create the loft with your help.
Now a question that is more about helixes, If I wanted the highest point of that helix spiral to be half as high (or an arbitrary height that doesn't correspond to the top face of the main body) what is the easiest way to achieve that? I could create a reference plane with a construction circle...at the height that I want, but is there a quicker way? Actually, would that even work? It wouldn't be a cylindrical "face".