I keep getting email asking for help with antenna construction, probably from this newsgroup. One of the most common questions is "how accurate do I have to cut the parts?" Let's grind the numbers.
The wavelength of 2.4GHz is: 3*10^8 meters/sec / 2.4*10^9 Hz = 0.125 meters
At this frequency, the length distance per MHz is: 0.125 meters / 2.4*10^9 Hz = 52*10^-6 meters/MHz
Assuming we aim for center frequency, the 2.4GHz band is about
+/-40MHz wide: +/-40 * 52*10^-6 = +/-2.1 mmTherefore, if you want to stay within the band limits, the cut accuracy has to be well below plus or minus 2.1 mm of design dimension. My guess is within 0.5mm will work well.
Lose the rulers and tape measures and get out the calipers.