1. One cheap wall clock. £2.49 from tesco http://www.tesco.com/direct/tesco-value-wall-clock/212-0448.prd
3. Colour Printer.
Here I have already added the cut outline by applying a stroke to a circle selection.
Then I created some guides to find the absolute center and to have some sense of scale.
Once you found a good high-res picture of a hammer, scale it and place it where 12 would be.
Now we do some photoshop magic (it’s not magic, some people call it step repeat), press “Ctrl + Alt + T” to enter transform mode, now move the reference point (very important) to the absolute center of the document (you have guides, it should be easy).
Then we type in 30 in the rotation angle box and our hammers will be rotated around the clock face. Keep pressing down “Ctrl + Alt + Shift + T” to repeat-copy the transform and to complete your clock face.