Martin MAC III AirFX User Manual page 26

Followspot handles use and construction
The MAC III AirFX's rear head cover is a magnesium alloy casting. Magnesium alloy is prone to galvanic
corrosion when steel screws are fastened into it and has a relatively low resistance to mechanical wear on
threads. Self-tapping screws fastened into magnesium alloy should be left there permanently.
If you are going to switch between using the MAC III AirFX as a manually-controlled followspot and as a
DMX-controlled moving head from time to time, you will need to install and remove followspot handles. In
this case, we recommend that you fabricate two intermediate mounting brackets in a suitable material for
repeated installation and removal of screws, fasten the brackets permanently to the rear head cover, and
use these brackets as mounting points for the followspot handles.
If followspot handles are going to be installed permanently, there is no need for intermediate brackets.
The design of the brackets and followspot handles is left up to the user to match user requirements, but the
following points must be noted:
• Intermediate mounting brackets must be as light as possible in order to minimize the effect of their extra
weight on the balance of the head. It may be best to make them in aluminium.
• Four holes (arrowed in Figure 15) are
provided in the fixture's rear head cover
for fastening followspot handle
mounting brackets. Use regular M6
machine screws for attachment but
ensure that screws are the correct
length: the portion of the screw that
goes into the rear head cover must have
a length of between 12 mm (0.47 in.)
and 15 mm (0.6 in.).
• The rear head cover becomes very hot.
Ensure that handles are insulated well
enough to avoid discomfort or burn
injuries for the followspot operator.
• A handle must only be fitted after
followspot mode is enabled and tilt is
performed manually. Always remove
any handle that is fitted before
disengaging followspot mode.
Besides being constructed so that they
will not foul the yoke at any point in the tilt
range, mounting brackets must match the
dimensions shown in Figure 15.
Dimensions in Figure 15 are shown in
millimeters:
• 216.8 mm = 8.53 in.
• 230.7 mm = 9.08 in.
• 78.9 mm = 3.11 in.
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Figure 15: Dimensions for followspot handles
MAC III AirFX user manual