How do I make custom-sized dowels?

Where can I get properly sized dowels? When I buy ³⁄₄ " dowels, they always seem to be slightly undersized.
—Mike Chester, Champlin, Minn.

Look no further than your router table, Mike. Start with your choice of dry, straight-grained stock to avoid the curling you often see in store-bought dowels. Joint and plane a blank down to the dowel's diameter—in your case ³⁄₄ × ³⁄₄ " square—then cut it about 3" longer than the dowel you will need.

Install a round-over bit with a radius half that of your dowel blank—³⁄₈ " for your ³⁄₄ " dowel stock. Set the fence flush to the bit's bearing. Then, set the bit height to make an even roundover in your stock. Make a test roundover on a cutoff to verify your setup.

Mark start and stop lines on all four faces of the blank about 1" from each end. By routing between these marks, you keep the ends square to act as guides. After each pass rotate the blank 90° for the next pass. Finally cut off the square ends and cut the dowel to length on your bandsaw.