How do I make a cylinder with different diameters?

[Anonymous]

I need to make a cylinder with different top and bottom diameters. My usual method of making a cylinder is to sketch it and extrude it, but I can't find a way to modify one of the top diameters. 

Thanks

[taylor.stein]

Hey there - great question!

There are many ways to do this, but here are the easiest two:

• Take advantage of the Loft command! The loft command is built exactly for this: creating a transitional shape. Create the first sketch with the first diameter as you normally would. Next, create an Offset Plane (Construct --> Offset Plane) off of the original sketch plane. Then, create a sketch on this new construction plane, and sketch the second circle directly above the first one. To ensure this, you can project (Sketch --> Project/Intersect --> Project) the first circle into the second sketch for reference. Lastly, start the Loft command (Create --> Loft), and select the two circular profiles.
• If you don't have a particular second diameter in mind (or if you don't want to do trigonometry), you can add a taper angle to the extrusion of the first circle. In the Extrusion dialog window, there is a section for the degree of taper angle.

Let me know if you have any questions!

Taylor

Fusion 360 Evangelist

@taylor_stein

[Anonymous · Accepted solution]

Hi,

If you know the top and bottom diameter, you can make a sketch of half the side profile of your cylinder and use the Revolve command, like so:

Keep in mind that your top and bottom dimensions in the sketch are the radii of the cylinder (well, truncated cone, technically) and not the diameters. 

Hope that helps!

Niels

[Anonymous]

Ah yes, loft might be easier in some cases, especially if you can building this cylinder onto something existing as it lets you place the first diameter nice and accurately on the part and then you have someting to offset the plane from. Like you say, there are a multitude of ways to achieve this. Perhaps why its not aways immediately obvious what the best approach is.

[Anonymous]

Taylor and Ndenekamp,

Thank both of you. The revolve tool looks like it will integrate with my workflow better than the loft tool and allow me to avoid calculating the angles, so I will try that first.

Thanks again. 

[Anonymous]

Thanks, although just to be clear; in case of the loft there is no need to calculate the angles either. you basically create a separate sketch for both start and end diameter on two parallel planes by using the Offset Plane command. Then create a Loft between these two sketch profiles:

Cheers,

Niels

[Anonymous]

So I'm just getting into using fusion 360 to make tools for my business but this is kind of what like the first tool I need to build. Is it possible to modify the curve of the walls of the cylinder?

 I need the walls to be a parabolic curve but end and start at specific diameters. 

[davebYYPCU]

In your case, you have to use the Loft command, with section profiles, and a few Rails, to manage the curved walls.

Unless you can get what you need with the Revole Command, as shown above, outside line becomes a suitable curve.

Browny

[Anonymous]

now the next question is .. how to pattern the surface?

[davebYYPCU]

Sounds like a totally different question, I suggest you create a new topic with a few more contextual details, an old solved topic will not bring you any answers.

[Anonymous]

"use the Loft command, with section profiles, and a few Rails, to manage the curved walls."

I tried this, but do not get a regular surface. For example using a single rail, the bottom side of the rotational figure is pulled in. Using two rails (top & bottom) the front and backside are "flattish". Am I doing something wrong?

[g-andresen]

Hi,

1. please start a new topic

2. share  your design and describe your particular situation

File > export > save as f3d locally  > attach it to the next post.

günther

[TheCADWhisperer]

---

@Anonymous wrote:

now the next question is .. how to pattern the surface?

---

Which surface do you want to pattern?

What type of pattern?

Can you post link to image of something similar that exists in the real world?

More information is needed.

[Anonymous]

Ok, let me rephrase my question/remark.

From my beginners perspective the methode referred to does not work. It does not result in a rotation symmetrical cylinder. (At least not symmetrical for any angle, at best only for specific angles)

Unless I am doing something wrong of course - which is quite possible at my "novice" level.

Hence I though it more appropriate to question/remark in this thread.

[TheCADWhisperer]

---

@Anonymous wrote:

It does not result in a rotation symmetrical cylinder. 

---

Do you want a cylinder, or do you want a cone?

What is your true Design Intent?

(Any pictures to illustrate your intent?)

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

[rushabhthakkar_910]

yes, i too think a new topic should be created...... 🙂

[suquet_paul]

Loft is exactly what I was looking for. That did it. However, it creates what seems to be an empty body. I can't seem to find a way to "fill" it. It'll end up being a 3D printed part so I need it to be filled. I found I could "thicken" it, but it would still leave an empty cylinder in the middle. 

[Warmingup1953]

It is best to start a new thread. Your needs are quite different from those canvassed here. Can you do that?

[suquet_paul]

Thought there'd be a simple "yeah, click on the Fill function under tools > blah > blah" but I guess there's no such thing huh.

I posted a new question here:

https://forums.autodesk.com/t5/fusion-design-validate-document/how-do-i-make-a-cylinder-with-differe...

Thank you guys and the community.