City Theatrical Follow Spot Yoke
3
Preparing Your Lighting Fixture
If you are planning to use a 19º-50º or a 10º Source Four, you will need to remove the
shutters from the lighting fixture. This is not necessary, but may be desirable for a 5º Source
Four to prevent the shutter blades from accidentally being moved during operation. Remove
the shutters by removing the four machine screws which hold the two halves of the Source
Four barrel together and exposing the shutter, pressure plate, and shutter spring parts.
Remove the shutter blades, but reinstall the pressure plates and springs. Do not reinstall the
existing four machine screws into the barrel. Go on the next step:
Two Angle Brackets allow your Source Four to be installed in the Follow Spot Yoke. Replace
the four ETC machine screws with the enclosed #8-
32 x 1 ½” pan head Philips machine
screws into the Source Four’s existing #8-32 hex nuts.
Next, install the two Tee Slot Extrusions using the enclosed #8-
32 x 3/8” flat head Philips
machine screws (three screws per extrusion). For 19º-50º or 10º Source Four, install the Tee
Slot Extrusions with the excess track overhanging toward the rear of the lighting fixture. For
the 5º Source Four, the Tee Slot Extrusions overhang the Angle Brackets toward the front of
the lighting fixture. See diagrams below.
Angle Bracket
Tee Slot
Extrusion
#8-32 x 3/8 Flat Head
Machine Screws (three)
