Push the wind vane onto the shaft on the bottom side of the sensor package until it goes no further, as shown on the left side in Figure 3. Next, tighten the set screw with a Philips screwdriver (size PH2), as shown on the right side, until the wind vane cannot be removed from the axle. Make sure the wind vane can rotate freely. The wind vane’s movement has a small amount of friction, which is helpful in providing steady wind direction measurements.
Bought Ecowitt wind cups to replace damaged Ambient Weather WS-0900-IP wind cups. They fit perfectly and we’re very easy to install.