Is there a way to create linear spirals?

http://en.wikipedia.org/wiki/Image:Archimedean_spiral.svg#file

This method may give a little more control. Here I started with a series of concentric circles, and created a brush which represents only one revolution, which rises the same distance that the rings increase in diameter.

When the concentric rings are stroked with the art brush they combine to create a spiraling effect.

I've found the art brush to work pretty well too. You would think that there would be an easier way to accomplish something so seemingly simple.

I was actually playing with the 3D version when I saw your post come up. I had already done the pattern brush version, but hadn't made an image yet.

The 3d version is a lot of fun to play with in alternate views.

Thanks for the sketches, Jean.

I was too busy preparing stollens which will then be scorched as always.

;-)

BTW, you can get a better center on the spiral above, I just didn't monkey with it much.

Theoretically, you should get a more controllable spiral by mapping the same art, via a symbol, to a cone created by revolving an angled line, then viewing it from above.

But again, Illustrator 3D leaves a lot to be desired



Apparently Illustrator outlines the strokes of the climbing angled lines, and trashes the accuracy of the original linework in the mapping process.

Hmm... I was wondering when someone would bring that up.

- Draw a horizontal stroked line, 200 mm wide for example

- Select the line and Copy Move, Vertical Movement: 5 mm, for example

- Hit Command+D as often as you like, for example 8 times

- Direct select all anchor points at the right ends of the lines

- Hit Enter and set vertical movement to 5 mm

- Select all and create an Art brush out of the selection

- Draw a stroked circle, 60 mm diameter, for example

- Apply the Art brush

This is, of course, no Archimedes spiral, no it's the so-called Circular Probert Spiral. It was originally discussed in the Illustrator Windows forum some years ago.

The Spiral tool was introduced in Illustrator 6.0, and in those days I think the tool had the capability of making Archimedes spirals.

Here's an image used in the AI 6 User Guide:

http://www.newmango.com/test/spiral.png

The description says "Hold down the Control key to increase or decrease the amount by which each wind of the spiral decreases relative to the previous wind."

In recent versions, that value is a percentage, and I'm thinking that in 6.0 it may have been an absolute value. And Adobe has since disallowed the Control key, so now it does nothing. You can enter the decay rate in the Spiral options dialog, but it has to have a value of 5% or greater.

http://www.pixentral.com/show.php?picture=1cXMXReDQoa9AsM5CHmdEMfzUfIO

Here's a shot of another "faux-spiral" done with the "compasses" method. It's easy to construct and completely accurate (see how the stroke widths kiss exactly). Like I said, not a true spiral but good enough for most people and much smoother than anything that Twirl and Twist can do.