An orphan quilt block of just about any style would work, although a Dresden Plate block is a natural choice.
The clock above by Gale, found on Quilting Board, was made with a scrapbooking frame, although any deep frame should work (to allow room for the clock parts).
Making a clock from a quilt block is a simple process. Quilt your chosen block, affix it to a very stiff piece of cardboard and insert it into a deep frame – or stretch it over a canvas stretcher and forget the frame – and install the clock parts.
Julie at Distant Pickles shows how to make a clock using an already stretched canvas for mounting (canvas on stretcher bars, like these).
Notice how you’ll need to have a lot of extra fabric to wrap around the stretcher. If you’re making a Dresden Plate block, put it in the center of a piece of fabric that is larger than you think you’ll need. You can always trim off excess.
Be sure to choose a stretcher that is deep enough for the clock parts. You don’t want them to stick out from the back!
This Year’s Dozen also provides a nice tutorial. Just substitute a canvas on stretchers, or something similar, for the base she found at a thrift store.
We like this style of Dresden Plate for a clock, with one petal for each hour.
Here are some helpful links to get you started: