Generic Fixture Rigging: Difference between revisions
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If working at height make sure you follow the correct procedure. | If working at height make sure you follow the correct procedure. | ||
===Raise Fixture=== | ===Raise Fixture=== | ||
The first step is to raise the fixture to the rigging point. If the fixture is light enough, and the rigging point is close to the ground, the fixture can simply be carried and placed on the bar by hand. If the rigging point is at height, or the fixture is too heavy to carry safely, | The first step is to raise the fixture to the rigging point. If the fixture is light enough, and the rigging point is close to the ground, then the fixture can simply be carried and placed on the bar by hand. If the rigging point is at height, or the fixture is too heavy to carry safely, use a rigging rope to raise the fixture. Make sure the rope used is a rigging rope, which is capable of supporting heavy fixtures and will not snap under the load. | ||
Loop the rope around the bar that the fixture is going to be rigged on, then connect one end to the fixture. The safest and easiest way to do this is to use a figure-8 knot around the yoke of the fixture. This is a strong knot used for climbing and rigging that can be untied quickly and easily once the fixture is secured on the rigging point. '''Ensure the knot and fixture are secure before lifting, if in doubt, ask a senior member of the crew''' | |||
The other end of the rope should also be at ground level, and | The other end of the rope should also be at ground level, and can then be used to raise the fixture to the rigging point. '''The fixture MUST be lifted by someone on the ground, NEVER by a person at height.''' | ||
===Attach Fixture=== | ===Attach Fixture=== | ||
Once the fixture is raised to the rigging point, it should be attached. If a G-clamp or space frame clamp is used, this | Once the fixture is raised to the rigging point, it should be attached. If a G-clamp or space frame clamp is used, hook this over the bar. '''Do not untie the rope yet!''' | ||
===Secure Fixture=== | ===Secure Fixture=== | ||
Secure the fixture to the rigging point by tightening the bolt of the clamp. This should be done by hand, as over-tightening can compromise the strength of the bar. The bolt should be tight enough that the fixture is held securely in position. | |||
Attach the safety chain by looping it around the bar and securing it to the fixture. While some fixtures have dedicated points for connecting the safety chain, for most it can be looped through the yoke of the fixture. The safety chain should NOT be connected to the clamp. | |||
'''ALL fixtures MUST have a correctly rigged safety chain. A falling fixture can lead to damage and serious injury!''' | '''ALL fixtures MUST have a correctly rigged safety chain. A falling fixture can lead to damage and serious injury!''' | ||
Revision as of 21:53, 8 June 2013
A generic fixture is a lighting fixture that does not have any additional functions. This distinguishes it from an intelligent, or moving light, which has additional functions such as movement and colour.
Generic fixtures are not connected to DMX directly, instead they are powered by a dimmer through 15 A cable with round-pin plugs. The dimmer is connected to DMX and controls the brightness of the fixture by varying the voltage/current of the supply.
Before Rigging
Before rigging the fixture, ensure the fixture and rigging point are prepared.
Check Rigging Point
Check the area you will be rigging the fixture in. Make sure there are no obstructions or hazards that could make rigging difficult or dangerous. If you are rigging the fixture close to other fixtures, be aware that these may be hot if they have been switched on recently. Take extra care when rigging lights near to intelligent fixtures, as these will move when in use so require additional clearance around the fixture.
Prepare Fixture
Ensure the fixture is ready to be rigged. Fit the appropriate size/type of clamp for the rigging point you will be using.
G clamps are the most commonly used within Venue 1, as they allow quick, easy and safe rigging onto all trussing and lighting bars, including the stage rig, octagon, and LX1/2/3 bars. There are a number of different lengths of G-clamps available, and the correct length for the rigging point/desired fixture position should be chosen.
If a fixture is going to be rigged on the space frame, it should be fitted with a smaller size of G-clamp, commonly referred to (within Ents) as a space-frame clamp. Only use these smaller clamps for rigging fixtures to the space frame, they cannot be used to rig fixtures onto trussing or lighting bars.
Whichever type of clamp is used, make sure it is fitted with a bolt allowing it to clamp onto the rigging point. A wingbolt should be used to allow the clamp to be easily tightened by hand.
Attach the clamp to the yoke of the fixture using a bolt. Use the correct size of bolt - one that slides easily through the hold in the clamp and yoke but does not give any play once tightened. Use a wingnut if possible, as this allows easy adjustment of the fixture when rigged. Note that the clamp should be attached as shown in the image, as this allows full rotation of the fixture when rigged. Finally, unscrew the clamp bolt slightly, so that the fixture can be easily hooked onto the rigging point when it is rigged.the clamp bolt should be unscrewed partially, so that it can be easily hooked onto the rigging point when rigging.
Ensure that that clamp is attached to the yoke correctly. Failure of the attachment when the fixture is rigged could result in damage and/or injury.
A safety chain appropriate to the fixture is also required. If the fixture is to be rigged at height, it's a good idea to attach the safety chain to the yoke to make life easier.
All rigged fixtures MUST be fitted with an appropriate safety chain. Failure to do so could result in damage and/or injury
Finally, it is easier to fit any gels/gobos/barndoors required to the fixture before it is rigged. Make sure these are secured and will not fall when the fixture is being rigged.
Test Fixture
It is a good idea to flash test the fixture on the ground before rigging, to ensure the fixture functions correctly. It is much easier to change a lamp on the ground than up a ladder!
Avoid Surprises
Make sure that anyone controlling the lights is aware that you're rigging, and they don't shine lights in your face while you're up a ladder. Ensure the UV cannons and strobes are switched off if you're working at height.
Rigging
Working at Height
If working at height make sure you follow the correct procedure.
Raise Fixture
The first step is to raise the fixture to the rigging point. If the fixture is light enough, and the rigging point is close to the ground, then the fixture can simply be carried and placed on the bar by hand. If the rigging point is at height, or the fixture is too heavy to carry safely, use a rigging rope to raise the fixture. Make sure the rope used is a rigging rope, which is capable of supporting heavy fixtures and will not snap under the load.
Loop the rope around the bar that the fixture is going to be rigged on, then connect one end to the fixture. The safest and easiest way to do this is to use a figure-8 knot around the yoke of the fixture. This is a strong knot used for climbing and rigging that can be untied quickly and easily once the fixture is secured on the rigging point. Ensure the knot and fixture are secure before lifting, if in doubt, ask a senior member of the crew
The other end of the rope should also be at ground level, and can then be used to raise the fixture to the rigging point. The fixture MUST be lifted by someone on the ground, NEVER by a person at height.
Attach Fixture
Once the fixture is raised to the rigging point, it should be attached. If a G-clamp or space frame clamp is used, hook this over the bar. Do not untie the rope yet!
Secure Fixture
Secure the fixture to the rigging point by tightening the bolt of the clamp. This should be done by hand, as over-tightening can compromise the strength of the bar. The bolt should be tight enough that the fixture is held securely in position.
Attach the safety chain by looping it around the bar and securing it to the fixture. While some fixtures have dedicated points for connecting the safety chain, for most it can be looped through the yoke of the fixture. The safety chain should NOT be connected to the clamp.
ALL fixtures MUST have a correctly rigged safety chain. A falling fixture can lead to damage and serious injury!
Ensure both the clamp and safety chain are fully secure before detaching the rope. If in doubt, check with a senior member of the crew before removing the rope.
Once the clamp and safety chain have been removed, the rope can then be detached from the fixture. The rope can be dropped back to the floor or used to rig more fixtures.
Power Fixture
The fixture can then be connected to the power supply.
Ensure that the socket you are connecting to is not switched on/powered/live. This can lead to electrocution or damage to the fixture!
Once the fixture is connected, it can be re-tested to ensure it functions correctly.
Focus Fixture
Once the fixture is rigged and connected, it can be focussed (pointed in the right direction).
This is done by loosening the relevant bolt(s) on the yoke or clamp and positioning the fixture. At this stage it may be useful to illuminate the fixture so it can be more accurately positioned. However, the fixture will become hot if it is illuminated for a period of time, so care should be taken. Gloves can also be worn, to help reduce the risk of burns from the fixture.
Any gels/gobos/barndoors can be fitted at this stage, if they were not fitted earlier. They can also be adjusted as desired.
Some fixture, such as fresnels and profiles, have adjustments such as focus and zoom on the fixture itself. These can also be adjusted as desired.
Once the fixture is in position, the bolts on the clamp and yoke should be tightened, to ensure the fixture doesn't move.
When focussing the fixture, ensure the power cable connection to the fixture is at the bottom of the fixture, as this reduces the heat the cable is exposed to and thus the risk of damage.
Once you've secured the fixture and are happy with its position/appearence, perform a final check of the clamp and safety chain. If the fixture is fully secure, you're done!
SAFETY GUIDELINES
- Always ensure you use the correct clamp for rigging point used.