How to make a helix throughout a shape?

Matias_HOJ

Hi,

So I recently got back to Onshape, and I have been messing around with the Helix function. But I keep running into problems..

I want to be able to make my Helix from one shape to another. See example here:
https://cad.onshape.com/documents/2eae5b4cb4d22a888521b13d/w/3797173ca787aeecbd147251/e/a048472f26adb8dc10d7e055

But I can't seem to choose both faces in the Helix feature.nor do i have the possibility to choose the conical shape in my Helix feature?

What you guys reckon I could do to overcome my challange?

Evan_Reese

If I understand your goal, here's one way. It's unfortunately not as straightforward as just using the helix feature. Since you can't make a helix on anything but a cylinder or cone, I lofted the helix to the center axis of the part and used split to find the intersection. The composite curve and delete part features are just for general tidiness.
https://cad.onshape.com/documents/d139c65008d88f93cc5e26a2/w/63e2edce50ac82da874ac67f/e/c821aa7825af7aed7595fb1a

Eric_Wong

The helix just makes a curve on a cylindrical face, it's the sweep that generates the geometry you see in the example you linked. What are you trying to select in your helix feature?

Matias_HOJ

Hi @Eric_WongI'm trying to create a helix from the cylinder to the top of the revolve. But it won't let me select both faces in the Helix feature.

Evan_Reese

If I understand your goal, here's one way. It's unfortunately not as straightforward as just using the helix feature. Since you can't make a helix on anything but a cylinder or cone, I lofted the helix to the center axis of the part and used split to find the intersection. The composite curve and delete part features are just for general tidiness.
https://cad.onshape.com/documents/d139c65008d88f93cc5e26a2/w/63e2edce50ac82da874ac67f/e/c821aa7825af7aed7595fb1a

Matias_HOJ

@Evan_Reese, exactly like that! Thank you for taking the time to explain this on an educational level.

Evan_Reese

Glad to hear it. Now that I think about it, it might be a little bit faster rebuild time by sweeping a line to make the surface instead of lofting, but the principle is the same.