Welcome to the Onshape forum! Ask questions and join in the discussions about everything Onshape.

First time visiting? Here are some places to start:
1. Looking for a certain topic? Check out the categories filter or use Search (upper right).
2. Need support? Ask a question to our Community Support category.
3. Please submit support tickets for bugs but you can request improvements in the Product Feedback category.
4. Be respectful, on topic and if you see a problem, Flag it.

If you would like to contact our Community Manager personally, feel free to send a private message or an email.

Options

# How do I make a solid spiral on a cone with smooth transitions on top and bottom?

Member Posts: 3
Hello!

How do I make a solid spiral on a cone with smooth transitions on top and bottom?

I have made a solid cone with a helix on the surface and swept a triangle sketch along the helix to make the spiral, and also a solid 6mm cylinder in the middle of the cone, like a shaft. I would like to extend  the solid spiral into the shaft with a smooth transition. And the spiral should also end smoothly at the bottom. I have no idea how to do this... any suggestions?

Best regards
Kjell
Tagged:

• Options
Member Posts: 66 ✭✭
Depends exactly what you mean by "smooth transition".  For the bottom transition, if you just extrude the bottom of the object up and choose "intersect" it will chop off all the extra spiral stuff.  As far as continuing the spiral on the shaft, you'll just have to create a second helix on the surface of the shaft and monkey with the settings until the transition looks decent.

What exactly are you trying to model here?
• Options
Member, Developers Posts: 1,296 ✭✭✭✭✭
The general procedure for creating a spiral of any shape is to create a swept spiral surface using a simple line as a profile and a helix for the path. That surface can then be split using a second surface that has the desired overall shape - in your case, a cone. The edge of the resultant split surface is a helix laying on a cone. To generate a lead-in/out, just modify the cone surface to have the desired lead-in/out.

This isn't exactly what you're trying to do, but it might be useful.

• Options
Member Posts: 66 ✭✭
Depends exactly what you mean by "smooth transition".  For the bottom transition, if you just extrude the bottom of the object up and choose "intersect" it will chop off all the extra spiral stuff.  As far as continuing the spiral on the shaft, you'll just have to create a second helix on the surface of the shaft and monkey with the settings until the transition looks decent.

What exactly are you trying to model here?
• Options
Member, Developers Posts: 1,296 ✭✭✭✭✭
The general procedure for creating a spiral of any shape is to create a swept spiral surface using a simple line as a profile and a helix for the path. That surface can then be split using a second surface that has the desired overall shape - in your case, a cone. The edge of the resultant split surface is a helix laying on a cone. To generate a lead-in/out, just modify the cone surface to have the desired lead-in/out.

This isn't exactly what you're trying to do, but it might be useful.
• Options
Member Posts: 3
Thanks a lot! I finally made it Using both methods above. It could probably be solved in a better way but the part look almost as I imagined. Is it possible to make the part solid? Now I have surfaces that I thickened.
Here is the part now

• Options
Member, Developers Posts: 1,296 ✭✭✭✭✭
To make the part solid you just need to add material where it's currently missing. Perhaps revolving a triangle to create a cone base for the spiral?
• Options
Member Posts: 3

Thanks! That works great. I think I can fix the transition at the bottom someway.