How can I extrude a plane along this circle?

I've followed various array and extrusion tutorials but can't work this out. The Cowling needs to have a certain depth as I want to 3D print it. If I start with a Bezier curve, I can't seem to make it rotate via extruding. If I start with a circle and extrude outwards and scale it, it gets thinner and thinner each time I scale. At one point I used a UV Sphere and tried to distort it. I'm really scratching my head on this.

so im trying John Easton's method and it works!. it took me a few times to understand what he said but when i did it exactly as he wrote, it works great!!!. thank you so much!

• What exactly do you want to model? Could you edit and clarify specifically - what form are you talking about? Add a picture of it. Modelling questions get answered extremely quickly here. It's just a matter of communicating clearly what you need. As far it's unclear, what you want. Commented May 25 at 11:18
• Is it this part? Commented May 25 at 11:22
• hi there Martynas. i uploaded an image of the starting position shwoing the circle i planned to extrude along, plus the plane profile i wanted to extrude, a picture of the original aircraft cowl so it can be seen as it was in real life, and an image of the current model shwoing the unshaped cowl on the front to show the position. i thought that that was enough?. can you please recommend what else i might need to explain it? cheers and thank you for helping me. Commented May 25 at 23:55

3 Answers

Start with a Cylinder. RX > 90 to turn it on its side and Ctrl-A > Rotation to apply the rotation. In Edit mode, I to inset the end face to the size needed for the propellor shaft then X > Face to delete the face. Alt-Click the outer edge of the cylinder and Ctrl-B to bevel it, scrolling the mouse wheel to increase the number of cuts as required. Then in Front view, go into X-Ray mode with Alt-Z and in Vertex mode, box-select the bottom half of the cylinder and X to delete the Vertices. Then back in Object mode, add a Solidify Modifier, setting the thickness as required and Apply the modifier by hovering over its property panel and hitting Ctrl-A. Shade Smooth (by Angle if using the latest Blender version or Auto Smooth if earlier). Job done!

• i think this might be the solution im after. ill try to follow. thank you. Commented May 25 at 23:49
• hi John, this worked a treat!!!.. i updated my original message as i couldnt see a way to add images to your reply here directly. Commented May 26 at 0:59
• Good! I think all three answers are valid although you might need extra work to modify the others to get the results you need. Please click the check mark beside my answer if you consider it's the best one for your needs. Thanks. Commented May 26 at 8:06

maybe I don't really understand your question, but I will try my best! if you want to make the cowling like in the front, then take the circle, extrude to x or y axis(So it creates a tube) and then make a loop cut(Control+R i think) in the middle of the tube(but you can also move the loop cut a little closer to the edges). Then select the edges from the extruded part, scale down, select the edges from the loop cut, Control+B to bevel and mousewheel to add more segments to the bevel. Now, you can select the bottom half, delete the faces and there you have it.

BTW: You can use the "solidify" Modifier to add depth. I forgot to add this to the picture, but i hope you will come along with it

• this method results in a zero thickness plane doesnt it? i tried this and th thickness by scaling the cirlce as i extruded it longitudinally ended up being zero. i need to maintain the thickness as its a 3d print. Commented May 25 at 23:48
• See the text below his answer saying that he hadn't added a solidify modifier. Commented May 26 at 8:09
• @JohnEason thanks for the reminder for the OP
– 2sa2
Commented May 26 at 11:21

Press Ctrl+C to set the 3D Cursor at World Origin. Set the Transform Pivot Point to 3D Cursor. Prepare the profile of curve you want at a certain radius from the World Origin.

Select the Spin Tool and spin on the axis of choice. Here it should be Y-Axis. make sure Angle is set at 360 and adjust number of Steps.

Optionally extrude backwards on the Y-Axis to give it some length and add a Subdivision Modifier and a Solidify Modifier.

• Well those answers should give him a few options! :^)) Commented May 25 at 16:40
• not sure about this one as the SSS rounds the rear of the cowl. the rear needs to be flush with the fuselage. i might be missing soehting as im still learning. Commented May 25 at 23:50
• im still a bit confused as its not a line i want to extrude/rotate, its a plane. its a plane because it needs to be a certain thickness as the part will be 3 d printed. i tried for ages to get the spin technique to work but will try again using your advice. thankyou. Commented May 25 at 23:51
• @JohnEason yes more possibilities more learning opportunities 😁 Commented May 26 at 8:25