Isometric laying cylinder Illustrator

Question

Okay this may be a bit OCD.

How do you make a perfect isometric cylinder like this?

Connecting the two circles has always been eyeballing for me. How do you make it perfect?

Answer 1

One option is to use Illustrator's 3D Extrude & Bevel. Start with a flat circle and go to Effect → 3D → Extrude & Bevel...

There are isometric presets already available.

Another option is to use an isometric grid. There is a nice tutorial on creating an isometric grid in Illustrator here: How to Create an Isometric Grid in Less than 2 Minutes!.

1. Use the Rectangular Grid Tool to create a uniform grid.
2. Object → Transform → Scale, check Non-Uniform and set Vertical scale to 86,602%
3. Object → Transform → Shear at 30 degrees
4. Object → Transform → Rotate at -30 degrees
5. View → Guides → Make Guides

Answer 2

I draw stuff like that all the time. Usually I use the Common Tangents script by Hiroyuki Sato. It works quite well and helps you in any other find the tangent situation too. I find the script indispensable.