Follow this tutorial and you will find out how to draw a clock that goes round and round to the infinite with the help of Adobe Illustrator's Art Brushes. You will also learn some tricks on how to make all the hours and the divisions to fit perfectly.
Start by opening a new web document then draw a 500 x 400 px Rectangle that will define your working space. Now take the Spiral Tool and draw the first spiral like the pink one in the image. While drawing the spiral press the Up Arrow key on the keyboard to create more segments. When you are done draw two more spirals or just scale the first one and make sure they are centered at the end.
To create the Spiral Art Brush first take the Star Tool and draw a small black triangle. Rotate it -90 degrees and using the Selection Tool (V) drag the right side to make it longer like below. Drag the obtained shape into the Brushes Panel and choose New Art Brush. Use it to stroke the first spiral made.
Next you need to divide the spirals and to do that first draw with the Pen Tool (P) a straight vertical path that will define the 12-6 direction through the middle of the clock. Take the Add Anchor Point Tool (Plus Symbol) and starting from the top click on each spiral to add a point where each spiral intersects this path. Zoom as much as needed and do this until you arrive at the other end of the spirals, all the way in the middle not only on the shown point in the image. When you are done take the Scissors Tool (C) and click on all these added points to cut and obtain the half segments.
Take the Type Tool (T) and type the hours from 6 to 12 first. The font I used is Algerian, 105 pt. Go to the Object menu and Expand then scale each hour like shown above each one. Now you need to place them at equal distance from each other and this is an important step otherwise the hours and the divisions won't fit. Take a look at the X and Y values in the Transform Panel. Keep the same Y value for all hours and at the X value starting from 6 keep adding 100 px for each hour according to the previous one. Repeat this step for the 12 to 6 hours.
Drag the 6 to12 and 12 to 6 hours into the Brushes Panel and choose New Art Brush. From now on I will refer to them as 6-12 Art Brush and 12-6 Art Brush. Stroke the first segment of the third spiral, the black one, using the 6-12 Art Brush and as you can see the straight path drawn at the step 3 doesn't go through the middle of 6 and 12 as it should. Here is the trick to fix that. Drag the art brush back into your working area from the Brushes Panel and there will be a rectangle in the group. Select it and drag the left side in the middle of 6 and the right side in the middle of 12 like you see in the image. Do the same for the 12-6 Art Brush then drag them both back into the Brushes Panel. Now stroke the segment using the new brush and this time it fits perfectly.
Double click on Stroke in the Appearance Panel to open the Stroke Options window. Here you can change the Size value if you think the hours are too big and if they are flipped or upside down check the Flip Along and Flip Across options. Also check Proportional. Continue to stroke the other segments all the way and use the 12 or 6 hours from the previous segment as reference to adjust the Size value as you go. After expanding you can delete the duplicated hours.
To create the Divisions Art Brush first draw a triangle shape and the four lines having a 1.5 pt black Stroke. Copy and Paste them five times and arrange them in a row then place one more triangle at the end. Scale each one of them from 100% up to 70% for the last triangle. Also use again the same method from the step 4 to make sure all the divisions are perfectly aligned and at equal distance. Keep the same Y value for each division and to the X value this time add only 10 px starting from the first triangle. This step will take some time but otherwise the divisions won't fit with the hours.
When you are done take the Delete Anchor Point Tool and delete the points from the left side of the first triangle and the points from the right side of the last triangle. This is another trick to know otherwise after you define the brush you will have to drag it back into your working area to move the sides of the rectangle in the middle of the first and the last triangle, like you did for the 6-12 and 12-6 Art Brushes at the step 5. Now you don't need to because you already obtained the halves.
Stroke the first segment of the blue spiral using this Divisions Art Brush defined earlier. I changed the Width value to 70% because I thought the divisions were too big but in your case it's up to you. Continue to stroke the rest of the segments and use the last half triangle from the previous segment as reference to scale the next segment as much as needed so they fit perfectly like shown in the close up. For example, in my case a 75% Width value was just right for the second segment then 80% for the third one, 85% for the fourth one and so on. As long as you zoom enough to see each pair of halves and you set the right Size value all the Divisions stroked segments will fit properly. You can also make further adjustments using the Direct Selection Tool (A) after expanding.
Next select the pink spiral, go to the Object menu and Expand Appearance. The colors used for the gradient are: blue (R=84,G=159,B=215), dark blue (R=0,G=86,B=120), orange (R=208,G=155,B=39), yellow (R=243,G=232,B=92), brown (R=122,G=117,B=99), green (R=98,G=138,B=102), again dark blue (R=0,G=86,B=120), again blue (R=84,G=159,B=215) and light blue (R=188,G=217,B=242). Set the angle value to 10 degrees. Copy and Paste in front this spiral shape, keep the same gradient just change the angle value to 90 degrees and set the Blending mode to Color Burn.
Let's add some shadows. Select the first group of hours (the 12 is missing because I said you need to delete the 12 and 6 hours that are duplicates) then go to Effect > Stylize > Drop Shadow and set the values like in the image. Do the same for the next four hour groups not for all of them because the rest of the hours are too small and there is no need.
Fill the 500x400 px rectangle in back from the beginning with a linear gradient called Purple, Yellow that you can find in the Swatch Libraries menu under Gradients > Color Combinations. Change the angle value to 180 degrees. Duplicate this rectangle, delete the fill and use it to mask the clock. To do that select all the clock shapes made so far and also the empty rectangle, that must be in front of them and go to Object > Clipping Mask > Make.
All that is left to do is to select the spiral shape in back (there are two) and go to Effect > Stylize > Outer Glow. Set the values like in the image and the color used is black (R=0,G=0,B=0).
Here is the final image of the infinite clock, play around with the settings to see what you can come up with. I hope you enjoyed this tutorial.