# Problem with drawing ellipse

I need to draw a 45° ellipse, the X (outside) being 2". There will be an inside ellipse, and it will be .075" thick. In short, a ring. Following SketchUp’s instructions, I drew the circle, then used the scale tool, but I only get a handle on the lower left. and no indication of the angle. Where am I going wrong and how can I fix this?

4 Likes

Having watched mihal.s’ solution it trigerred a deep memory back to my engineering drawing lessons at school circa 1970 when we were forced to draw ellipses according to a vertical scale which is here;

5°= 10% vertical scale.
10° = 18% vertical scale.
15° = 26% vertical scale.
20° = 34% vertical scale.
30° = 50% vertical scale.
Isometric ellipse (35 degree 16 minutes) = 57.4% vertical scale.
40° = 63% vertical scale.
45° = 70% vertical scale.
50° = 76% vertical scale.
55° = 79% vertical scale.
60° = 83% vertical scale.
65° = 88% vertical scale.
70° = 94% vertical scale.
80° = 97% vertical scale.
90° = the perfect circle.
Note: Other ellipses can be created by extrapolating the above table.

So I tried it in Make 2017:
From a perfect circle>select it> select scale tool>select centre grab point>hold cmd(mac) and type decimal scale in measurements. Result ellipses very quickly that are accurate enough for my needs without the need for an extension.

Not saying this is the way to go but the old grey matter kicked in and I had to give it a go.

4 Likes

I knew that once, too. Notsure I’ve ever needed to model an ellipse defined that way but a good thing to try to remember for the future.

1 Like

Yet another item from my drafting museum:

8 Likes

Speaking of the drafting museum, I have one of those green plastic templates. Great for drawing an ellipse on paper or plastic, but cutting it on plastic with any reasonable accuracy is another story. The ring is going to be 3D printed and used on a scale model of a sign on a building, so a better degree of accuracy is needed.

Fine, but I’m not getting the six handles on the drawing, just one. Any idea where I’m going wrong?

Sounds like you are using the wrong tool, can you give us a screenshot of what you see.

Here’s another option.

I’ve changed the gif as the original method I showed is prone it inaccuracies.

3 Likes

What version of SketchUp are you using? Your profile says 2015 Free (web) which can’t be right.

Are you using the Scale tool or some other tool?

Interesting use of Sandbox Tools to get an orthographic projection.

1 Like

BTW, mathematically, parallel offset of an ellipse, isn’t an ellipse. If it’s just a little bit offset, it’s visually close, but push it to an extreme and you get an American football.

Hover your mouse over the icons and read the name of the tools. Or you can hit S on keyboard

If you say you have a single handle point, you’re probably using another tool (that’s what Box already told you).