Martin MAC III Profile User Manual page 25

Followspot handles safety precautions
Warning! It is the user's responsibility to ensure that the followspot handles and any mounting
brackets are safe and that the fixture is kept in followspot mode at all times while handles are
installed to avoid collision between the followspot handles and the yoke.
Warning! Intermediate brackets for permanent mounting on the back of the MAC III Profile head
must be constructed so that they will not touch the yoke at any point in the head's tilt range!
Warning! Screws used to fasten any item to the rear of the head may only be fastened into the holes
(arrowed in Figure 13) provided in the rear head cover. Do not attempt to fasten any item to the rear
of the head by any other method. Screws must not protrude more than 15 mm (0.6 inches) into the
rear head cover, or there is a danger that they may damage insulation inside the head and create a
risk of serious or lethal electric shock for the operator.
Warning! Followspot handles must be insulated so that it is impossible for the operator to suffer
discomfort or a burn injury.
Followspot handles use and construction
The MAC III Profile'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 Profile 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 13) are provided in the MAC III Profile rear head cover for fastening
followspot handle mounting brackets.
• On most MAC III Profile fixtures manufactured before August 2009, the four holes are drilled but not
threaded. In this case, use M6 thread-forming screws (DIN 7500) to fasten mounting brackets. Torx head
screws are recommended because considerable force will be required to tighten the screws into the rear
cover.
• On some of the first MAC III Profile fixtures manufactured, the four holes are threaded. In this case,
regular M6 machine screws can be used for attachment.
• Whatever type of screw used, 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 13.
Dimensions in Figure 13 are shown in millimeters:
• 216.8 mm = 8.53 in.
• 230.7 mm = 9.08 in.
• 78.9 mm = 3.11 in.
Figure 13: Dimensions for handle
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