1. Hold the perimeter of the nozzle with fingers and turn the nozzle counterclockwise to increase the arc.


2. To decrease the arc, hold the perimeter of the nozzle with fingers and turn the nozzle clockwise.
   

Note: The arc can also be increased or decreased by using a flat-bladed screwdriver.

Radius Adjustment

1. Hold the nozzle arc stationary with fingers, or with the two pins on the side of the Hunter wrench between any of the nozzle spokes.


2. Adjust the radius with a flat-bladed screwdriver by turning the center screw clockwise to reduce the radius.

Note: The radius should not be reduced more than 25%. The sprinkler is preset at the factory for maximum radius.

 

Adjustable heads are preset to approximately 180°. Sprinklers may be adjusted with water on or off. It is recommended that initial adjustments be made before installation.

1. Using the palm of your hand, rotate the nozzle turret counterclockwise to the left stop to complete any interrupted rotation cycle
   


2. Rotate the nozzle turret clockwise to the right stop. This is the fixed side of the arc. The nozzle turret must be held in this position for arc adjustments. The right stop does not change.

1. Insert the steel hex end of the Hunter wrench into the radius adjustment screw.


2. Turn the screw clockwise (into the stream of water) to decrease the radius, or counterclockwise to increase the radius. Radius can be reduced up to 25%.

Caution: Turning the adjustment screw clockwise more than five full turns may result in a lost radius adjustment screw.

 

1. Insert the plastic key end of the Hunter wrench into the lifting socket of the sprinkler and turn 90°. Pull the riser up to gain access to the nozzle socket.


2. Using the steel hex key of the Hunter wrench, turn the radius adjustment screw counterclockwise to be sure it is not blocking the nozzle socket opening. If a nozzle is already installed, it can be removed by backing out the adjustment screw and turning on the water, or by pulling outward on the nozzle “ears” with a pair of needle-nosed pliers.


3. Slip the desired nozzle into the nozzle socket. Note that the socket is angled up 25°. The “ears” should be adjusted so that the nozzle range screw threads directly down between them. Then tighten the nozzle range screw. The raised bump with an arrow on the rubber cover will always indicate the location of the nozzle and direction of water flow when the sprinkler is retracted.

Aligning the Right (Fixed) Side of Arc

If the right side of the arc is not properly aligned, the results may be a wet walkway or a dry turf area. The right side arc can easily be realigned. One way to realign the right stop is to turn the whole sprinkler body assembly and the fitting below it, left or right to the desired position. This may require temporary removal of the soil around the sprinkler to allow you to grip the sprinkler housing. Another way to reset the right arc is to unscrew the body cap counterclockwise and remove the internal assembly from the body. Once removed, rotate the nozzle turret to the right stop, screw the internal assembly back into the body with the nozzle aligned to the right side of the area you want irrigated (Fig. 9). At this point you have realigned the right arc stop, and you can adjust the left arc to an appropriate setting.

Note: It is not necessary to dig up and remove the whole sprinkler to realign the right arc.

Note: The G Type rotary sprinklers adjust the same way a PGP does. See the PGP Installation and Adjustment Instructions above.

SOURCE: HUNTER IRRIGATION

The R-50 is an internal impact sprinkler. This means that there are two small stainless steel balls that act as the drive mechanism.

Arc Adjustment for R-50

To increase the arc - Keep in mind that the sprinkler is preset to approximately 180°. Pull up on the stem, slide the vandal collar out of its groove. Push down on the nozzle slightly, and rotate the nozzle to the right (clockwise). The arc will be increased by the amount the nozzle is turned. For example, if the arc was previously set for 180°, and it was turned 90° while the nozzle was pushed down, the sprinkler will now have an arc of 270°. Be sure to replace the vandal collar when finished.

To decrease the arc - Pull up on the stem, slide the vandal collar out of its groove. Push down on the nozzle slightly, and rotate the nozzle to the left (counter-clockwise). The arc will now be decreased by the amount it is turned. Be
sure to replace the vandal collar when finished.

To change the arc to a full circle - Remove the internal assembly from its case.

Slide the vandal collar out of its groove, and rotate the nozzle to the right (clockwise) until a strong resistance is felt. It will feel as though it is locked in place. Return the vandal collar to its groove. Rotate the nozzle to the right (clockwise), there should be no resistance felt in the 360° turn.