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Leko rewire

Discussion in 'Lighting and Electrics' started by dickerst, Sep 6, 2004.

  1. dickerst

    dickerst Member

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    :?: I picked up some old Lekos (1960's vintage) that had the power cords cut off. I would like to rewire them but I think there is probably a lot heat generated in this area. (the original cables where asbestos wrapped). Does anyone have a idea what kind of cable I can use that will take the heat of 1000w halogen lamp?
  2. bdesmond

    bdesmond Active Member

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    Chicago, IL USA
    There have been several threads to this tune recently. The answer is that you need to have someone who knows how to do this do it for you. Even better, have them show you how to do it, and then supervise you doing the rewire on a couple more fixtures. Electricity kills you the first time. It's not all that difficult to get into such a predicament if something is not wired properly.

    Given the vintage of these fixtures, I would plan on replacing all the wiring and possibly the bulb holders as well. There are a multitude of things you need to be aware of when doing this, and attempting to explain the procedure online is not safe in my opinion. Talk to your local theatrical supply company and ask them to help with this.
  3. Radman

    Radman Well-Known Member

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    Franklin, TN
    Generally the wires on a leko are directly attached to the lamp base. Therefore, it is necesscary to replace the lamp base and then buy a new ground wire. The wires are either teflon or fiberglass, and can be purchased from a theater supplier. Get green for the ground. It is also important to get a fiberglass sleeve to surround the wires. This too can be purchased through a supplier.
  4. dickerst

    dickerst Member

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    Thanks for those who reponded, does anyone have the name of a good supplier that would have the parts and/or do the rewiring.
  5. Mayhem

    Mayhem Senior Team Emeritus Premium Member

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    Try a local theatre/production company in your location and see who they use/recommend.

    I agree with the previous post in getting someone qualified to do this and if possible, show you how to do it.

    Just one bit of advice if you are planning on stripping them down and giving them a good clean - do one at a time, so that you have a reference if you cannot remember what went where. Or take your time and either draw diagrams or take pictures to help.

    Nothing worse than ending up with spare parts once you have put it back together.
  6. ship

    ship Senior Team Emeritus Premium Member

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    What brand of Leko are they and where are you located anyway? (For a change this time I’m not opposed to someone working on their own gear thus this should be a interesting read.) You should be careful and unless you have good training with electrics, seek supervision in that area but given careful work, I don’t expect many people could do a better job with the fixtures than you.

    There has been other conversations on old gear on this website and on the old stagecraft website if working and the old conversations are transferred to the new website - it frequently goes down but such a search might be of use in advice and sources.

    Also given it's 1960's equipment, the wiring probably won't be coming with the replacement lamp base because it's probably a medium pre-focus type like you would find as a lamp base on a Fresnel, and not a medium bi-pin type. Otherwise like on my ?8x8 Century 1968's (something which rated at 2Kw cannot be replaced by modern gear for a good close but wide focus bright beam of directed light) it’s using a Mogul Bi-Post base (can about burn the costume off an actor at 3' away but oh’ how they glow from behind a scrim.) A Leko proper given it’s by Century or a Ellipsoidal Reflector Spotlight as it otherwise would be called if of another brand from the era can be a lot of different types of fixture. I most assume that the fixtures you talk of will have 6" lenses but 8" lenses were also common amongst details. I had the privilege of learning from and servicing some of someone’s gear that had road boxes upon road boxes worth of old Century, Altman, Kliegl and Major lights. At the time his finesse much less what I learned from him was good but even now I would consider hack and I would not trust him to do a good quality service to my lights any longer. This from a teacher that was about at the center of the lighting industry during the 60's. Beyond the Lekos, I even picked up some training with plano convex fixtures which are similar to Lekos, but somewhat of a Fresnel in design. Old gear is fun to work on and at times even to light with. Creates a effect and style of lighting that’s very hard to re-produce with modern gear. As if in photography, you just can’t reproduce the graininess and tint to the lighting with modern gear. Such effects do have their uses when part of a lighting concept. Much less the old gear when not right next to and competing with more modern and efficient gear still throws light on the subject in a very respectable way. In my opinion, everyone should learn from using such gear when possible at some point it will help the designer realize that all light does not have to have a blue white coloring to it’s color temperature to be useful much less the efficiency of the fixture can also at times add to the overall feel of the design.

    I don’t think the medium bi-pin lamp was invented yet in any case. Given it’s an incandescent fixture, the lamp base on a G-9.5 medium bi-pin common to more modern Lekos, will have been too small to support as large a bulb as will have been necessary for the wattage on a incandescent lamp. You might be able to get a medium pre-focus base with whip attached, believe Leviton makes some and it would still have the standard mounting locations as the old lamp bases in addition to screw contact bases having those same mounting holes, but it's most likely a screw connection to the whip already on the fixture especially if the fixture used to have asbestos whips attached to it on the older gear. Given it is a medium pre-focus (P-28s) lamp base in use, it’s probably going to be using a lamp with a lamp center length of 3.1/2" as opposed to the 2.3/16" standard to a Fresnel lamp. This type of incandescent lamp has been upgraded to a more efficient halogen type but if you are going authentic you might still be able to get some incandescent lamps for the fixture. Most efficient lamp in this case of wishing to use the fixture would than be the EGJ either by GE or Ushio based upon specifications. Given it’s output and color temperature are similar to a FEL used on more modern second generation Lekos for 1Kw, it’s actually a better lamp yet due to a longer expected lamp life. While you can modify this lighting fixture to use a more standard lamp and lamp base, it’s not highly recommended or probably worth it. The reflector is too inefficient to make much use of a more efficient filament or lamp. That said I have seen it done before to some degree of success given the more compact filament is also out of it’s center of useful focus by filament design. Effectively without modification to the base type you can probably expect that this fixture with this 1Kw lamp will have about or perhaps a little less output than a S-4 with 575w lamp. Not as high of a color temperature but as much light on stage. Such 1,000w lamps however might not be necessary, there are 500w and 750w lamps available also, and other than for long throws, I expect they would more normally be used.

    The lamp base might also be just fine. Will want to check the tension of the spring on them as well as for corrosion and arcing. Just because it's old does not mean that it won't be just fine with perhaps a bit of work if even not in perfectly fine condition. This style of lamp base is very rugged along with the entire fixture often. Given this type of lamp base also, you will need to have the hot wire going to the center contact meaning if your SF-2 or TGGT (a little less flexible but rated for a higher operating temperature) heat wires of 16AWG are both white as commonly found, you will need to mark one black with at least a stripe from a Sharpee. Depending upon where you shop, they might not always have black heat wire available nor if sufficiently marked will it be necessary to have both colors. This is if you don't use some three conductor heat wire on a cord such as Rockbestos or Tempflex. A little less used for a Leko but it would certainly work well and probably be more abrasion resistant than a standard fiberglass heat shield covering on the wire. Minimum temperature rating of what ever wire you get needs to be 200c for the heat wire to the lamp base

    You are also probably going to have to ground the fixture as such a concept was not much used back than. Not that difficult, you probably have a fairly large plate the lamp base mounts to which would have a lot of extra room that you can drill and tap for a ground screw. You can probably save money on this by just using type K or FEP wire. It’s much smaller in insulation and only rated for 150c in temperature but should work fine. I tend to use a slightly lower temperature heat wire on my grounds in that it is easier to notice a problem in them melting down at a point before the other conductors melt down this way. Also them in melting down won’t be as dangerous before it’s noticed, but will be a very good indicator of a problem when noticed. In any case, if I remember correctly SF-2 and FEP for the ground is commonly done in newer fixtures. Otherwise if using TGGT, I use green SF-2 for the ground for an overall rating of 250c for the conductors and 200c for the ground. TGGT also is not generally available in colors unless you custom order a spool of it than dip it. Possibly the same with getting a green SF-2 wire. Last spool I bought had to be dyed by the manufacturer. Theater dealers might stock this, don’t know I buy from the distributer. I don’t suspect that TGGT wire will be necessary for use in this fixture with a maximum wattage of 1Kw but it’s never going to melt down if used.

    Chances are also that if it does not have a strain relief on it 50/50 chance depending upon the brand and type, that you will have to drill out and install one. In that case you could go with a 1/2" NPT conduit type two screw strain relief any hardware store will stock - given there is room for it to fit, or better yet get from Altman one of their Leko 3/8" NPT two screw strain reliefs off a 360Q. In any case some fiberglass electrical tape around the fiberglass sleeving at the point of the strain relief will prevent it from cutting into the sleeving or the wire bending too sharply at this point otherwise cutting into it and damaging it.

    Other things to check and be careful about will be hair-line cracks in the castings, or snapped spot welds on the lens train and snapped yoke locks. Some small amounts of cracking on the pineapple part of the body can be fine when not structural, but you would want to watch out for anything near or on the yoke much less lens train. I dislike cast yokes, be especially careful of them.

    Also be very careful when removing the screws holding the thing together. Some prep with some Liquid Wrench a few minutes before you attempt to loosen many of them might be wise. It's very common even for stainless steel screws to break or corrode into place when they have been exposed to high temperatures and left in place a lot of years. Problems with dissimilar metals much less heat. Otherwise, get really good with a dremmel tool and screw extractor, if not abandon that hole and move it over especially where the lens train attaches as is commonly done.

    Another thing to work on no doubt will be the lenses. I would soak them in vineager or something similar a few days. Often there is a sort of grime on them which you can't really see or detect but will give off a sort of amber tint that hopefully this will remove if it's not part of the lens itself. Given also it's not using cheap lenses which will give off a green tint no matter what you do to them. The below similarities between brands will allow an easy replacement in this case. The lenses will be similar and easily replaced no matter the brand. Green lenses I expect are probably more of a 1970s problem I think but it’s a guess.

    On parts, Altman still makes them for their old 360 series - just bought some parts myself a few weeks ago, (have these "ancient" fixtures still sitting in line waiting for me to service but no time to work on them almost a year later) and their old radial 360 fixture is still on their website in exploded pictorial form including all part numbers - very useful if at least to find out what a specific part is called even if not the same brand. Chances are that if you need a part to a different brand, you can give them the brand of the fixture, hopefully the model number that the Photometrics Handbook by Mumm will hopefully have in it, than the Altman name and part numper to the similar part on their fixture and the place with the parts probably below will be able to figure out what you need.
    (Exploded pictorials being a very good and useful drafting assignment for anyone wishing for a challenge. Can be anything from a platform to your compass.)
    Altman will sell direct or just about any dealer can buy from them. It's going to be about the same price if not a little cheaper possibly thru the dealer. The website is very useful in giving general info about service of their fixtures and many of the older Lekos no matter what brand are very similar in parts thus if it seems very similar it just might be. Long story in the ties between Altman and Kliegl if either brand much less in general similarities amongst brands that is frequent.

    Othewise the Kliegl website will be useful if not for manuals at least as a resource on that brand and possibly other brands by now by way of the original catalogs and manuals on the website. It's not the actual company (out of business,) more a history of lighting website, but the contacts to the original family and lighting industry for old equipment are very good. The intent was for more than just that brand to be represented. The webmaster might also be a good resource on manuals and more info even if not listed.

    From what I hear Vara-Light/Dimatronics/Hub Electric 6207 Commercial Rd. Crystal Lake, Il. 60014. (815)455-4400 (no website known of) is still in business and at this point even owned by Altman though not much advertised by them. This would be a good source for parts in that over the years they have been known as a collecting house for discontinued lighting equipment and dimmer parts. Probably also have some service manuals and advice. You should also be able to get paint for any number of fixtures thru them.

    McMaster Carr will otherwise be a good source for the more general hardware and parts such as stainless steel screws and even graphite washers if used on the yoke mount.

    You might ask these above sources to recommend a service center local to you, or someone in your area known to have experience with wiring on older fixtures. Ten years ago, if you went to almost any theatrical supply in your area there would be a really good chance that they had a lot of experience with such equipment. Now, short of old man of the theater types who would be more in the front office than tinkering with gear anymore and select few that have experience working on them and are still working on equipment, the standard theater supply, much less even many college TD's won't really know that much about the little details making these things work as if new. For those that you did contact it would be a trip down memory lane. Hub would if they do so probably the only company specializing in such old equipment. In general however if they as a general service center know the 360Q fixture they can probably figure out something much older and hack together something that will work. It will probably just loose some of it's finesse in doing so as if new. General fixture service centers/theater lighting supply centers can probably do the job but the skilled labor having done so, much less the talent and new techniques might be less than worth what you pay to have it done.

    This caution I have is more in the little details such as the use of high temperature crimp terminals, stainless steel screws where zinc ones might be more commonly used without knowing any better, and details like that. You might also try some spray graphite on the lens train. Does wonders and it’s the little details that count.

    In other words, in working on a ETC S-4 or something modern, sure a theater supply will no doubt hopefully be able to service it very well - individual tech people really skilled at doing so dependant, but when it comes to older gear, there is getting to be less and less people with experience with such things working at such places. By my thinking, part of the pride that goes along with owning and using such fixtures is like with an old car, fixing them yourself and learning a lot about them in the process. You are going to have to maintain them anyway so some of what you learn will be useful.

    Some amount of hands on supervision will be necessary to ensure screw terminals are at the propre tension, crimp terminals are crimped with the proper Stakon tool and to the right tension, much less that they are perhaps wrapped in fiberglass tape to prevent fraying of the wire. That the wire is going to it's proper places, or that when yanking a lens retaining ring that you don't chip the lens, That when drilling into the casting you are using the proper bits and oils, or in cleaning the lamp base you treat it correctly afterwards much less don't scratch it up in using a steel or too abrasive a method. But in all old fixtures are good to learn with, and given similar details there often also won't be many service centers that would care enough to do so when not charging an arm and a leg for doing so. Figured out at one point for the amount of labor and materials it would take to pay me to service call a old fixture for a customer, you could about purchase a new one as a for instance.

    On old fixtures above are some notes to start with, I recommend that you have fun with them. Be careful but enjoy the pride in fixing and servicing the gear, than using them afterwards. That’s a good place for anyone to start just by pulling it apart, seeing how it works, than putting it back together again.

    Should it be of help the The Art of Stage Lighting, by Frederick Benthan; 1976 if I remember correctly is a very good book on the subject of parts making up and maintaining old gear given you can find a copy.

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