Atlantic Illumination Entertainment Lighting

AIEL Shop Tips

ELLIPSOIDAL OVERHAUL

(Image Left: Ellipsoidal Stage Light)

The ellipsoidal or profile spot is a favoured light
of the theater. It produces a soft-edged
or sharp beam via plano-convex or
step lenses that is able to be shaped
using internal shutters. Patterns (gobos)
are able to be projected with this fixture. Typical
wattages are 300 to 1000, but can go outside of this.

    The instructions provided in this guide will take
you through a complete refurbishment of a typical,
non-LED ellipsoidal. Should only part of what is given
be required, simply go directly to the pertinent section(s).
Realise that you may have to modify these instructions in order
to fully suit the makes and models of the fixtures in your inventory.



INFORMATION BELOW MAY
NOT BE REPRODUCED
WITHOUT PERMISSION
FROM THE AUTHOR ©

Be aware neither Atlantic Illumination, nor its owner
and employees will be responsible for any problems
encountered as a result of following or not following
the procedures here. This is only a guideline. You
must decide the suitability of the steps given, and
be responsible for the results of your own work.


  Topics

PRELIMINARY


Disassembly


Inspection


Reconditioning


Washing


Electrical


Painting


Reassembly


  Electrical Testing


Alignment

Final Procedure



 

  Preliminary

Because the ellipsoidal has more parts, its complexity is greater
than that of a PAR or fresnel. Its precise optics and beam quality
demand a more critical calibration. As such, these fixtures exhibit
the worst impairment of ability when they go out of alignment or
their components deteriorate. Due to all of this, ellipsoidals will
suffer most from lack of upkeep, meaning their maintenance
is the most involved of the basic stage lighting fixtures.

There are a great number of variations in ellipsoidal
design. This instructional will lean toward the basic
styles, so you may have to modify what you read
so as to match your make and model of fixture.

    This article assumes that the fixture is to be completely overhauled. As mentioned though, your requirements may entail only part of what is detailed here, so simply review the relevant section(s). Regardless, before starting, read through everything that follows so you'll know all of what is expected, and will realise what tools and supplies will be required. Make notes or drawings as to what parts are associated with a given procedure -- there are many of them, so have lots of containers and a large muffin pan to hold the components from each step of disassembly.

    Even more so than with fresnel and PAR lights, an assembled fixture should be available as a reference during the overhaul process should you not be familiar with the particular model on which you are working.

    You may also find that some steps are better done out of order for your particular light or way of doing things.

Before you begin with the procedures, determine
which of the items below to make available:

  • Replacement Parts
  • Alignment Cradle
  • Alignment Screen
  • Test Dimmer
  • Multimeter
  • Newspapers
  • Heat Shrink
  • Heat Gun
  • Small Parts Bottles
  • Parts Containers
  • Large Muffin Pan


  • Bench Vice
  • Bench Brush
  • Small Anvil
  • Screw Drivers
  • Nut Drivers
  • Diagonal Cutters
  • Locking Pliers
  • Wrenches
  • Knife
  • Fine-Toothed Flat File
  • Narrow, Metal Paint Scraper

  • Rubber Mallet
  • Steel Hammer with
    a Flat Face
  • Electric Drill
    or Bench Buffer
  • Drill Bits
  • Rotary Mini-Tool
    (Optional)
  • Variety of Wire Brush
    Attachments (Brass)
  • Plastic Soap Pads
  • Steel Soap Pads
  • Scrub Brush
  • Tooth Brush
  • Dish Detergent
  • Cut-Off Garden Hose
  • Emery Cloth
  • Sanding Sponge
  • Fine Steel Wool
  • Spray Paint
    (Heat Resistant for Metal)
  • Paint Solvent

  • Masking Tape
  • Cardboard Mask
  • Rayon or Cotton Batting
  • Glass Cleaner
  • Methanol Alcohol
  • Distilled Water
  • Soft, Lint-Free Tissues
  • Penetrating Oil
  • Lubricating Oil
  • Oil Station Bin
  • Silicone Lubricant
    (Industrial Grade)

  • Crimp Tool
    and Connectors
  • High-Heat Wire Nuts
  • Paper Towels
  • Cloth Towels
  • Rags
  • Permanent Marker
  • Electrical Tape
    (White and Black)

    Set up a work space with proper lighting and the tools required. See our Work Area Setup series of articles to help with this. Have the numbered containers and muffin pan available for placing the parts from each phase of the disassembly. This will be of benefit when it comes time to put the unit back together. Lay clean newspapers on the bench to protect both it and the fixture, and to contrast with small parts that might get dropped during the procedures that follow.


    Now begin the overhaul itself:  

(Image Left: Screwdriver)   DISASSEMBLY

A reminder that if you are new to this to keep track of the
disassembly by making notes. Use the numbered containers
or muffin pan to hold the parts removed during each step,
and have an assembled fixture available for reference.
Now do the following:

  1. Initial:  Work with a room-temperature fixture and be sure that the shutters are pushed inside to lessen the likelihood of them getting bent.

       First, take off the yoke. With some models, the removal of internal nuts may be required to get it off. Some techs wait to do the above until after the next two steps. If you wish to delay, ensure during movement that the still-attached yoke and clamp do not damage anything on the bench. It's easy for an unsecured yoke to swing unexpectedly and hit something, or to jam a finger between it and the bench or the fixture itself. Now remove any clamp or stand adaptor, and place it aside.

  2. Lens System:  If your model does not have an internal track/holder for the lens(es), remove the focus hardware and slide the lens tube out of the body. Take the lens(es) from the tube either by removing a retainer ring or clips, rubber saddles, and any spacers. Place the lens(es) in your safe place as discussed in the Work Space Design article and set aside the tube and spacers. Place hardware into a numbered container. If the lenses are internal, you will have to wait to remove them during the body disassembly stage. If the front accessories holder is removable, take it off now.

  3. Lamp House:  Remove the lamp cap and electrics. This is typically done by undoing one or more retainer screws or knobs and removing the assembly. For some models, there may be an access door for lamp replacement, but its mount and electrics often won't be able to be removed until the body is taken apart.

       Take out the lamp but don't worry about touching the bulb. You will be cleaning it before re-insertion during the reassembly stage near the end. Put it in your safe place. Set the cap aside with socket and line cord intact for the time being. You will not be dissembling this now but will do it during the electrical procedure. Keep any associated light shields or hardware with it.

  4. Yoke:  Now, if not already done, detach the yoke and clamp or stand adaptor, and place them aside. Retain the date tag (if there is one) and place it with the lamp so it can be reattached or recreated upon reassembly.

  5. Shutter Module:  This is typically a self-contained unit, but its components can also be mounted within a section of the body; if so, these may not get removed until the next step.

       If the module is separate, remove it and begin to dismantle. Closely note the order and orientation of the separator plates and any hardware. Some ellipsoidals have spring-tensioned shutters and it's easy to lose this hardware during disassembly because there can be a lot of it, so be vigilant here. Pay attention to the order of this tensioning hardware and put all into a small container of its own.

       Some modules have shutters that cannot be removed until their knobs are taken off. If these are riveted, drill them out in order to remove. Otherwise, take the knobs off by unscrewing their hardware. Place all shutter assembly components into their own container, and small hardware into a capped container such as a pill bottle.

  6. Body:  If your model has a hinged reflector housing, remove it now and disassemble its internal components. If not, remove the remaining internal brackets and mounts. In order to do this, you may have to take apart this section of the body, or remove access panels. The shutter components may be taken out now if you have not already done so.

       Continue until the remainder of the fixture is apart, stressing the importance of noting the order and orientation of all parts and hardware. Remove remaining electrical components and strain reliefs if they were not part of the cap. You should now have an empty body shell in two or more main sections.
 

(Image Left: Detective with Magnifying Glass) INSPECTION

  1. Body:  Look to see if there are dents or bent parts. Repair as necessary. To pound out dents, use a wooden form and rubber mallet to lessen metal damage as compared to a direct blow from a steel hammer.

        Inspect the threaded mounts for the yoke; they should not be worn or damaged. If so, then it means a trip to the machine shop to have them re-threaded, unless you own a tap & die set. Note that some models use a "grab plate" locking mechanism, so the yoke mounts are free to pivot, thus stripped threads associated with the locking mechanism are less of a problem.

  2. Yoke:  Look at the yoke. Note any burrs that should be filed off, and if straightening will be needed. The latter can be done using a vice to squeeze ripples flat, and as a clamp to permit reshaping by hand.

  3. Reflector:  Have a look at the reflector. If it's badly tarnished and can't be improved as described in the "Washing" section, it will have to be replaced or sent to a metal refinisher.

  4. Shutter Plates:  These should be flat and have a smooth finish. Some bends can be straightned as will be discussed, but the worst will have to be replaced.

  5. Electrics:  These will be inspected during the "Electrical" procedure.
 

(Image Left: Shop Tools within Oval Borders) RECONDITIONING

  1. Initial Restoration:  If the fixture is very dirty, you may wish to remove loose dirt with a bench brush, then skip ahead to the "Washing" topic. Return here while it is drying to study the next procedures.

  2. Main Component Buffing:  For flaking paint and/or a severely corroded body and/or yoke, employ a narrow paint scraper to remove the worst of it, then use a bench-mounted buffer with a brass wire brush to redress the finish. (A brass brush is preferred over steel so as to lessen the chance of gouging.)

       Should no bench buffer be available, use an electric drill with a lockable trigger, and attach a suitably-sized wire brush accessory. Clamp the drill into a vise so that the brush sticks out well into the open. You will find that clamping the drill and moving the parts against the rotating brush works better than clamping the parts. It saves having to clamp and unclamp each part, and having to put the drill down to do this clamping operation every time. Work gloves are recommended, as are hearing protection, and goggles or a face shield.

       Begin to buff the bad areas. Do not press too hard because the wire bristles can score the metal. Use the side of the bristles for finer work with less chance of marring the finish. Use the scraper to dislodge flaking paint, then buff the area underneath.

  3. General Body Buffing:  Begin with any painted areas so as to prepare the finish for its repainting. You need not take off all the old paint -- only that which is loose. Of course, rust should be removed, too. The main goal is to remove grime, surface rust, and any patina that has accumulated while the unit was in service. Continue until all parts are corrosion and tarnish free. Dust off the components with a bench brush. Set aside prepared items for washing.

  4. Hardware Refurbishing:  Replace any severely rusted parts that cannot be restored. Clean and buff the remaining metal hardware including the pipe clamp or stand adaptor back to being shiny. Take them apart to do this. Use a pair of pliers, preferably a locking type, to hold smaller items. This will give you more control, and it will also distance your skin from the rotating brush.

       Be cautious not to distort these smaller parts by over-tightening the plier locking mechanism. If locking pliers are unavailable, use snub-nose pliers and grip them tightly as you manipulate the item being buffed. Too loose a grip will see parts go flying due to the speed and torque of the rotating brush.

  5. Hardware Protection and Lubrication:  After buffing, protect metal hardware with a thin coating of light machine oil, but use a medium oil for threaded parts.

       Keep oil from soaking into your work bench. A greasy bench is not a good environment for lighting fixtures because oil will work its way into areas where it is not wanted. As such, it is suggested to buy a medium-sized plastic bin such as a dish pan to employ as an oil station. To soak up excess lubricant, cover the bottom with one thickness of an old towel. Cut large towels to fit. Oil all metal components in the pan, turning them to assure full coverage. Leave parts there until needed for reassembly, being sure to keep the parts clustered into the same groups as were in the individual containers. If the bin is too small to do this, then only buff and oil each group of parts just before reassembly.

  6. Shutter and Plate Work:  Straighten the shutters on an anvil or a flat, hard surface such as found on some bench vices. Use a broad-head, metal hammer to do so. Due to the nature of the stainless steel used, you likely will not get shutter plates to be absolutely flat. Replace those that are severely rippled because they will bind or jam during adjustment.

       Now buff until very shiny, being cautious not to score them. Use the side of the brass wire bristles so as to not have this happen. Finish with fine steel wool to achieve as smooth a surface as possible. Do the same for the separator plates. Set all aside for reassembly.

  7. Lens Tube:  Buff painted parts to remove loose paint and corrosion. For tube sections that are unpainted, polish with a fine sanding sponge and complete with steel wool to achieve a silky-smooth finish.

  8. Remaining Items:  Clean and recondition hardware and items not already done, such as the lamp cap. If it requires painting, first review the electrical section regarding disassembly. As always, replace any severely rusted parts if they can't be restored. Put rejuvinated hardware that won't be painted into the oil bin and coat with a light, protective oil.

For parts that do not have dust or built-up grime and so
don't need washing, you might now wish to skip to the
"Painting" procedures so that these first items will be
drying while you continue with the steps below.

 

(Image Left: Hand Washing an Object) WASHING

  1. Main Parts:  Place non-oiled items such as the yoke and body sections into a plastic set tub, or use rubber mats to protect an enamel one. Scrub items one at a time using hot water and dish soap. Use a tooth brush to get into narrow areas. Dislodge remaining rust with a soapy scouring pad. For stubborn rust, use a sanding sponge or emery cloth with water. Rinse well. (A cut-off, one-metre length of garden hose is good for this because the end can be squeezed to increase water pressure.) Dry with an old towel. Don't use a new one as some rust will likely come off. Hang the unit up to air dry inaccessible areas.

  2. Metal Reflectors:  Place the reflector into the sink. Hose off the main dirt first. Use a plastic soap pad to clean the back of the reflector as a scratch test. Move the pad with a motion that follows the reflector's shape. If it polishes with no scratches, do the same to the front. If scratches appear from the test, you will have to decide if it is better to have a tarnished reflector versus a shiny, scratched one. I vote for the latter if it reflects more light without too much scatter, rather than leaving it tarnished. If the pad is not suitable, substitute a clean, soft cloth or sponge with lots of dish soap. Rinse and dry.

       If severely tarnished to the point that it may not be usable, you can attempt to polish it with actual steel wool soap pads, or with automotive rubbing compound. The worst ones will have to be taken to a professional metal refinisher or be replaced.

  3. Glass Components:  Handle non-coated glass lenses and reflectors by their edges. Feel for rough sections that might cause cuts so you'll be cautious around them while cleaning. Blow off loose dust using a can of compressed gas or a large air bulb as used by photographers. With a clean towel in the sink on which to rest glass components for protection, rinse under warm water until no grit is left. You may apply moderate pressure from the hose. Rinse the towel from time to time to keep it grit free. Be careful that your slippery hands don't drop the item. Glass components are expensive, so it is best to only have one at a time in the sink to preclude breakage. Have a thick, clean towel on the counter beside the sink to hold washed items while they air dry.

       To remove film build-up, do the above and then mix a squirt of dish detergent and warm water in a container. With soapy hands, gently wash each wetted component in a motion that follows its contour. Feel for grit that might scratch, and for rough edges that might cause cuts to your hands. Don't rub areas with grit; hose them off as soon as you feel it, then continue the hand washing with soapy water. Step lenses often have black-painted risers. Be careful not to remove this coating.

       If the grime is particularly stuck, full-strength alcohol can be employed if there is no coating. (See the "Coated Optics" warning, below.) When finished, rinse and air dry. If you find some streaks are left, you might repeat the process, but use distilled water as a final rinse. Once completed, place glass reflectors into your safe place with soft cloths or paper towels protecting them.

       WARNING! Some glass reflectors and lenses have coatings that increase their efficiency. These can be dulled or destroyed if glass cleaner or undiluted alcohol are used on them. Use only soap and warm water, or 10% alcohol and warm water, for cleaning.

       Even though many glass components can handle glass cleaner and full-strength alcohol, as a caution, use only soap and warm water, or the 10% alcohol solution even if the manufacturer of the fixture states otherwise. It's possible that someone could have replaced a lens or reflector with one which coating cannot handle certain cleaners. If you suspect this, follow the coated-optics cleaning instructions father back.

       Whatever the material, when finished cleaning, rinse and air dry. Place the lenses back into your safe place with cloths or paper towels protecting them.

While components are drying, you may move on to
restoring the electrical parts you removed earlier.


 

(Image Left: U-Ground Plug)
     ELECTRICAL

  1. Lamp Cap:  Inspect the socket assembly and electrics. If there are no problems and the cap is not to be painted, move on to look at the line cord.

       Otherwise, prepare to remove the socket and inspect the contact screws. Note the alignment screw positions; count the number of visible threads and make a note so that during reassembly you can thread each screw back to this same point. These will become the starting points for the alignment procedure later on.

       Clean off any corrosion associated with the socket. If it remains severely discoloured, you should replace it. (Discoloured sockets can contribute to reduced lamp life.) During replacement, consider renewing the insulator wafer (if one is required) as located under the socket. It should not be damaged, split, or missing.

       Clean off the socket mount and inspect for damage. Repair as necessary. If it's rusted, it will have to be scraped, buffed, washed, and possibly painted with a heat-resistant finish. (Follow the steps under "Painting", farther on.)

  2. Line Cord and Covering:  If the line cord is melted, frayed, or brittle, it will require replacement. Some cords may be covered with a fibreglass sheath. Replace or repair as necessary. If the damage to this is external to the fixture body, you may use electrical tape or heat shrink. If it's internal, cut off the bad part and slide a good section inside. (Tape or heat shrink may not last in there if the temperature becomes too high.) If the amount to be cut off will be excessive, make up the shortfall with an appropriate length of sheathing coupled via heat shrink or electrical tape. If using tape, wind at a 45-degree angle while pulling the tape taut. Reverse direction and wind back over the first layer, again at a 45-degree angle.

  3. Connector:  Inspect, and replace if cracked, has heat damage to the plastic or rubber, or has badly discoloured pins that cannot be restored. Otherwise, open the body to see if the wiring is tightly connected and that there are no errant copper strands. When it comes time to reassemble, make sure that the strain relief grips both the cable's insulation and any outer sheathing. Buff the blades back to shiny.

  4. Asbestos:  Should the fixture be an old one with asbestos wiring, it is generally best to replace with a new line cord. Asbestos conducts electricity when wet and is hazardous to breathe if it is shedding. Put the removed wiring into a plastic grocery bag and send to your local Hazardous Waste Facility. Some later fixtures used a better-quality asbestos covering that does not shed; if the fixture will be used indoors in a permanent installation, and if the asbestos has not been compromised, you may reuse it unless local electrical codes forbid it. More electrical work will be discussed in the "Reassembly" phase, farther on.
 

(Image Left: Spray Can) PAINTING

    Paint Choices:  If there are parts that are rusted or discoloured (other than electrical or the reflector), painting will be required. The usual colour would be flat black. This is recommended for all interior body surfaces in order to minimize unwanted reflections. The paint chosen should be able to handle directly radiated heat. Barbeque paint is a good choice. Buy a test can first! Some barbeque paints have a flat black cap, but actually dry with some degree of shine.

    For the exterior, you may want a different colour. This might be to dress up the light, to better identify your lights from those belonging to others, or to give your show a uniqueness if you like to have visible fixtures. Even so, endeavour to stay with a darker colour to minimize external reflections. A satin (semi-gloss) finish is recommended regardless of the colour chosen.

Now gather your paint materials as given
in the preliminary list near the start
of this article and do the following:


  1. Preparation:  Mask any things not to be painted such as electrical stickers, screw threads, or lens barrels that must slide without guide tracks. To facilitate tape removal, leave a tab by folding a small bit of the sticky side back on to itself.

  2. Lamp Cap:  If the lamp cap is to be painted, it is best to fully remove its socket, wiring, and hardware. If this can't be done, or you don't want to do this, mask all parts not needing paint. Be aware that this can be tedious given the number of parts involved and how close together they are. Pay particular attention to the socket by wrapping it and covering over the opening. You may wish to insert rayon batting into the socket to shield the threads and button.

  3. Painting Procedure:  Put the items onto newspaper in your booth or ventilated area, as discussed in the Work Space Setup. Follow the instructions on the can regarding optimal temperature and for re-coating. Shake the can well and begin to make a base coat in even strokes. Stop the spray at the end of each pass and then restart as the stroke returns. Blend each line of paint with the previous in a manner that does not leave gaps of excessively thin coats or ones that are too thick. Keep the overall coating thin. Allow it to dry, then do a second coat, and a third one if necessary.

       Since fresh paint can still be soft underneath, leave items to dry over night so that the paint will cure. Repeat the process for the yoke and other parts requiring paint.

       After the base coats have dried, if the exterior is to be a different colour, coat it using the technique above. Keep overspray out of the interior. Partly to segregate the outside paint from the interior, but also to limit stray light reflections, it is suggested that the front of the accessory holder and its inside runners be left flat black. This is easily accomplished by leaving the fixture in a nose-down position for all of the exterior paint work. Of course, if the holder has been removed, it makes it much easier to paint whatever colour you want without employing masking techniques.

       If the nose-down fixture position is not to your liking, a hand-held cardboard mask may be used to keep spray from where you don't want it. Even so, you might still have to touch up the inside after the exterior has been completed. Allow the final coat to dry over night to achieve a harder, more robust surface.

  4. After Each Painting Session:  When completed painting for the day, blow out the paint can nozzle by turning it upside down and spraying until only propellant comes out. To lessen waste, I always do this onto one of the lights just as I am in the process of finishing a coat. When the can is empty, keep the nozzle in case future ones get clogged, and send the can itself to Hazardous Waste.
 

(Image Left: Screwdriver)   REASSEMBLY

  1. Cautious Handling:  There should now be a number of sections and parts that are clean, non-damaged and possibly repainted. Being careful of your new paint work, start to reassemble the fixture in reverse order, beginning with any internal sections. Regarding paint which is dry, but fresh, it may take a day or so for it to harden completely, hence the caution when handling.

  2. Shutter Module:  Pay particular attention when assembling the shutter module. Its components must be put together in exactly the right sequence and orientation. It is easy to mis-order the components, especially any spring hardware. Shutter blades must line up properly with their slot openings to the exterior, so their stacking order must be correct. Start all screws before final tightening so as to allow for slight adjustments. Restore the shutter module to the body.

  3. Reflector Assembly:  Mount the reflector and any aperture components. Be sure orientation is correct. As above, start all screws before final tightening.

  4. Lens Assembly:  Gently use a soft cloth to remove any finger prints or smudges from lenses that happened after the washing process, or repeat the cleaning process and use distilled water as a final rinse. Remember to keep glass cleaner and alcohol away unless you are absolutely sure the lens has no optical-enhancement coating. Restore the lens(es) to the tube or internal track/holder using any required separator elements and rubber saddles. Note that in some models, the separators must be oriented to allow the operation of focusing devices or the insertion of retainer knobs.

        Confirm that each lens is loose! Do not place retainer clips or rings hard against them. They must have room to expand during operation. Place the lens tube into the fixture. Silicone the tube where it contacts its guide tracks or the fixture itself. Be careful not to transfer silicone to unwanted surfaces.

       Mount the outer lens tube with any extension. Be sure they are correctly oriented in the vertical and horizontal axes so that the accessory holder's opening will be up, and that any slots for knobs are in the correct positions. Attach the accessories holder, if not already captive to the outer lens tube. Attach the holder's spring retainer if there is one.

  5. Restoring the Electrics:  Do any remaining line cord and socket work not done before. This might include buffing and oiling the plug blades, taping or heat-shrinking the cord and/or sheathing, and replacing electrical terminals.

       If the lamp cap was taken apart, put it back together by starting with the strain relief unless it's the "crimp" type. These black plastic reliefs can be mounted near the end of the procedure. Connect the line cord to the socket. Be sure to observe electrical polarity when rewiring: In Canada, the hot (black) lead goes from the center contact of the socket, down the line cord and onward to the brass screw of the plug. The neutral (white) lead is connected to the silver screws, the ground lead to the ground post on the body of the fixture and then to the connector's green screw.

       Symmetrical sockets, such as the G9.5 (Medium Two Pin), do not observe polarity. The hot and neutral leads may go to either terminal, but should still go to the correct terminals in the connector. Poke the line cord with any sheathing through the strain relief in the cap and attach the socket to its mounting plate. This in turn is attached to the cap via its alignment screws. Reference your note regarding the number of screw threads that are to be visible.

       Install or tighten the strain relief and pull sheathing slack toward the plug end of the line cord. Restore the plug to the cord, being sure to observe electrical polarity. Pull excess sheathing into the plug's strain relief, trimming if necessary. Tighten the strain relief. When the light is fully assembled, the sheathing should run from the socket assembly (allowing for the splay of individual leads), along the line cord and into the plug's strain relief at the other end. Silicone the socket's contacts.

       If the socket assembly is internal to your model, replace the strain relief on the body, then install the mounts of the assembly. Attach the line cord to the socket with any sheathing and poke it out through the strain relief. Mount the socket and restore the line cord as above. Silicone the socket's contacts.

       After doing the procedures in the "Electrical Tests" section, set all aside until the remaining assembly work is completed.

  6. Additional Lubrication:  Lubricate any hardware threads that have not yet been done with a long-lasting, medium oil, and use silicone spray for any lens guides, for or parts that slide past one another such as shutters. Keep oil and silicone off any parts not intended. This is especially true for the lenses, reflector, and lamp. Separate these different lubricant types so that one type does not land on a part where another is being used. One may compromise the operation of other.

       A reminder to keep lubricants from landing onto your bench. An oil/silicone soaked bench is not a good environment for lighting fixtures because they will work their way into areas where not wanted. Replace bench-top newspapers often.

  7. Final Assembly:  Restore any remaining parts to their proper location and orientation, lubricating as necessary. If the lens tube is not yet installed, do this now. You may elect to leave the yoke and pipe clamp off until after the alignment is done.
 

(Image Left: Multimeter)   ELECTRICAL TESTING

  1. Continuity Test:  Use the `ohms' setting of your multimeter to confirm a continuous electrical path from plug to socket. Check the neutral path, as well. `Zero' ohms should be the reading. Diagnose and fix any problems.

  2. Shorts Test:  Test for shorts between hot and neutral, and from each conductor to the metal housing of the cap. If the meter reads anything but "infinity", there are problems. Diagnose and fix before moving on.

  3. Lamp Test:  You may choose at this point to install the lamp as an additional test, but can wait if you must return to previous sections to do more work. Do a lamp continuity test if you choose to install it. If all is well, move on to the alignment.
 

(Image Left: Chart with Arrows)   ALIGNMENT

    This is best done with a stand or cradle which will support the ellipsoidal with its shutters open. It may be made of wood or metal but should have the supporting parts lined with cloth, rubber, or carpet to prevent scratching the fixture body. Alternatively, one can use a pipe on to which to clamp the light. Also, a screen or flat white wall is best for proper alignment. A bonus is if the screen or wall can have a center dot and concentric circles at half-metre intervals.


  1. Install the Lamp:  If not already done, apply silicone to the socket's contacts. This will facilitate later lamp removal in that it will prevent the lamp from seizing in the socket. Unless using a new lamp, do a continuity test on the old one. If it's working, wipe the bulb with soft tissue dipped in methanol alcohol to remove dirt and finger oils. Insert a working lamp into its socket. Close the lamp access door or restore the cap to the lamphouse.

  2. Support the Fixture:  Begin by setting the light in the alignment cradle so that it is level and the center of the lens aligns to the screen's center point. Plug the fixture into a dimmer and reduce light output to the lowest setting that still produces a bright circle. Lowering the voltage is done to lessen the chance of lamp burnout during possible rough movement as its alignment is adjusted.

  3. Focus:  Moving the lens tube, sharpen the edge of the image. For variable-focus (zoom) fixtures, set the image diameter to a middle size, or if the fixture's location and use are known, to a size that suits. This will matter less with top quality units as they exhibit the same characteristics regardless of zoom setting. However, some cheaper units may vary, hence this suggestion.

  4. Adjustments:  Exact alignment procedures cannot be given because they differ from manufacturer to manufacturer and sometimes from model to model. However, via either set bolts or a single-control alignment adjuster, move the lamp in and out of the reflector to achieve the brightest circle on the screen. Some models will require that you reopen an access door or remove a hatch cover in order to make this adjustment.

       You may do a preliminary test on some models by not securing the lamp and electrical assembly in its housing. Instead, carefully move it by hand in and out of the lamphouse while tilting it back & forth and up & down. When you see the desired brightness and degree of evenness on your alignment screen, note the position and angle of the assembly in your hand. This will give you a rough idea of where the alignment mechanism must be set.

       The hand method is less likely to be needed in modern fixtures, but for older ones, especially those with three-bolt alignment setups, it can speed the procedure. Reseat the assembly and adjust it to that point; test by moving it around by hand until it's the way you want, and continue with adjustments to achieve the correct point.

  5. Setting the Field:  Now do a fine adjustment to achieve a flat or peak field, and if peak field is chosen, where that peak occurs. This means the fixture will either produce an even (flat) illumination within its circle of light, or it will have a hot spot (peak) somewhere. An off-center peak spot is achieved by sideways or up & down movement of the alignment adjuster(s). You will see the bright area move around within the circle. For theater stage washes, this hot spot occurs in the center. For key light purposes, it often is near the top of the beam to throw more light onto a person's head area or face. If unsure, go with a flat field.

  6. Verifying Your Work:  Observe your final alignment with the dimmer at the full-rated voltage of the fixture's lamp. Although not necessary, one could use the `AC Volts' setting of the meter to ensure this voltage is accurate. Operate the zoom optics through their full range to see if the flat or peak field characteristics change. Re-adjust alignment until you are satisfied it will work for your purposes.

       Once done, fully secure the assembly in the lamphouse. Close any access door or replace/secure access panels and you are done.
 

(Image Left: Roll of Tape and a Marker) FINAL PROCEDURE

  1. Date Tagging:  This is an important step because the tag will give an indication of lamp service life. If the time period is less than expected, there may be a problem with the fixture, its location, or its input voltage.

       Make a date tag by using white electrical tape which will be placed onto the inside of the yoke. Make the date tag twice the required length so that at the next lamp replacement, there will be room to write the new date. This way, the date tag only need be replaced every second burnout.

       If a new lamp is installed, mark the current year (four digits) and month (two digits or three letters) on the tape. Should the old lamp be used and its installation date is unknown, write the current year and month along with `P.I.S.' This stands for "Previously in Service". Otherwise, copy the date from the old tag, or reuse the old tag if its condition is good.

       Stick the tag to the inside of the yoke on one of its vertical surfaces -- usually the one opposite the tilt-lock knob. Be consistent so that you and your crew will know exactly where to look. Don't use the underside of the top of the yoke because heat here will be greater than along the sides when the fixture is hung in its typical orientation.

You should now have a refurbished
fixture that is ready to return
to your lighting inventory



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