A new gobo-holder spring has been implemented in the MAC 500 that makes it easier to change rotating gobos. The new spring has a bend on one end that allows the user to remove the spring with small pointed (needlenose) pliers. Once the spring is removed, it is easy to remove the gobo holder from the wheel and replace the gobo. Another advantage is that, with the holder removed from the wheel, it is easy to apply a drop of high-temperature silicone glue between the gobo and the holder to prevent the gobo from spinning.

For upgrading existing fixtures, the new spring may be ordered as P/N 17760040; five springs are required per fixture. Extra gobo holders may be ordered as P/N 17320090.

Tip: The old springs can be removed without removing the module with a pair of snap-ring pliers. Tilt the lens down (by hand with the power off) to prevent the springs from falling into the head.

The new procedure for changing gobos is as follows (the old method may still be used as well):

  1. Remove the top head cover.
  2. Turn the gobo wheel until the easiest access to the desired gobo position is obtained. Turn the color wheel until the open position is over the gobo position.
  3. Turn the gobo holder until you can see the tab on the holder retaining spring.
  4. Grip the tab on the retaining spring with a pair of small nose pliers. Place your index finger over the spring to prevent it from falling into the fixture. Open the spring and remove it from the gobo holder.
  5. Remove the gobo holder from the bearing by pulling it forwards towards the lens.
  6. Push the gobo and gobo retaining spring out of the holder.
  7. Insert the new gobo. Insert the gobo retaining spring. The bend in the spring faces out, away from the gobo. Push the gobo and spring all the way down into the gobo holder.
  8. Replace the gobo holder in the bearing. Do not force the holder into the bearing: it will go in easily if it is installed straight.
  9. With the pliers, grip the retaining ring by the tab. Place your thumb on the back of the gobo holder to press it all the way down in the bearing and use your index finger to hold the other end of the spring on the holder. Open the spring and place it in the groove.
  10. Replace the head cover.