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G. W. Craig "Baby" PC

Discussion in 'Lighting and Electrics' started by gafftapegreenia, Dec 14, 2007.

  1. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    I've had this fixture on my hands for a few months, but its been at home while I've been at college. Well, here at pics at last! It's a rather nicely designed unit. 5 inch, unscathed, PC lens. Nicely placed light baffels, sturdy construction, spring loaded rear door, and very little rust for its age. It even still has the screw to retain the color frame. Just alot of dust from the shop it had been sitting in for who knows how long. Also pleasing are the "curves" of the hood, which probably took more to machine than a "box spot". The back plate says "G. W. CRAIG - BABY - DETROIT - MICH".
    I want to make this light shine again. The 5" lens is intact, but it needs a lamp base. The previous one was a ceramic medium "household" screw base. Coming from the bottom of the lamp base was a threaded stud that went through the sled and then out the bottom. On this was a wing-nut that could be loosened to change the focus. Sadly, the base is no longer in my possession, I didn't want to deal with the asbestos.
    It also needs a yoke, but I think that should be easy enough to fabricate.
     
    Last edited: Mar 2, 2008
  2. Logos

    Logos Well-Known Member

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    Love it. Keep us posted on the project won't you.
     
  3. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    I most certainly will. I need to first figure out a lamp base solution.
     
  4. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    Use this, or that. Or just stick any old FEL in there--I'm sure ship won't mind.:twisted:
     
    Last edited: Dec 15, 2007
  5. Van

    Van CBMod CB Mods Premium Member

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    QUESTION:

    When you say "PC" lens do you mean Plano Convex or something else? If it's a "Baby" I would think it should have something similar to a Fresnel lens in it or at least a Plano Convex with a pebbled flat side. My experience with Baby's is only in the cinema world, where Baby usually refers to any Fresnel under 8" but not to Inkies. Baby is often used in connection with other names to denote size, ie: "Go Grab that Baby Soft Light, and bounce it off the soffit for some fill, Then go to Craft services and get me some M&M's and a Pepsi".
     
  6. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    It is a Plano-Convex. The longer hood, lack of reflector, older "pre fresnel" styling all would suggest that this was intended to be a plano-convex. In my readings of older lighting texts, they often refer to 5" plano convex spots as "Baby" spots.

    Here's information from Theodore Fuchs, "Stage Lighting" (Many thanks to ship for this incredible tome)

    "Thus there is the standard large spotlight, employing either a 1000, 1500 or 2000 watt spotlight lamp, the standard small spotlight, employing either a 500 or 1000 watt spotlight lamp, and the baby spotlight, employing either a 100, 250 or 400 watt spotlight lamp" (Fuchs 184)

    "The size of the lens with which each of the principal sizes of spotlights is usually equipped for general stage usage is as follows: standard {the "small spotlights" of the previous citation} spotlights, 5" or 6" in diameter, 10" focal length; baby spotlights, 4.5" or 5" diameter, 7" focal length; and smaller sizes, such as the footlight baby spotlight, 3.5" or 4.5" diameter, 7" focal length" (Fuchs 185)

    Being as this book was written before the Fresnel came into use as a stage instrument, it is safe to assume that Fuchs' usage of the word "spotlight" can easily be understood to mean "plano-convex".

    It seems that there were four classifiable sizes of PC spots.

    There were the Large PC's, using 6" and 8" lenses, with wattage's from 1000 - 2000 watts.

    There were the Small PC's, using 5" and 6" lenses, with wattages from 500 - 1000 watts.

    There were the Baby PC's, using 4.5" and 5" lenses, with wattages from 100 - 400 watts.

    And there were also the Footlight Baby Spots, using 3.5" and 4.5" lenses. Based upon descriptions and examples given in the text, the "Footlight Baby Spot" would be the "full name" of that which we commonly refer as a "Box Spot". Often these Box Spots would have a removable lens, allowing them to be used as small floods.

    So, based upon this info, my PC is indeed a "Baby" spot, at least in theatrical terms. It seems the correct wattage would have been up to a 400 watt G lamp. I would theorize that, over the years, as more varied and complex types of lighting instruments were developed, the usage of the terms "Large, Small" and especially "Baby" shifted in use from referring directly to the PC spot to being universal terms to all lighting instruments.
     
    Last edited: Dec 15, 2007
  7. Les

    Les Well-Known Member

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    Can ya just put a prefocus fresnel base in there?
     
  8. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    I think so, but it would require some modification. The original used a ceramic medium screw base that had a threaded bolt attached to the bottom, that then come through the sled and out of the bottom of the light. Thus, when one loosened the wing nut on the bottom to change focus, they were literally moving the lamp base by means of the bolt, instead of a lamp base attached to a carriage that is then attached to some sort of focus mechanism. To modify it shouldn't be too hard, I'd just probably offend some of the purists out there. (Ship help)
     
  9. ship

    ship Senior Team Emeritus Premium Member

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    Interesting name, not in Fuchs’ appendix so the fixture probably dates after say 1929. Different design than any similar Major, Chicago Stage Lighting, Kliegl or Century fixtures I have seen or have of a similar type.

    Interesting rear latch, what keeps the lamp changing cover closed, is that a spring keeping the door closed? I don’t see a hole for a missing latch on the top otherwise.. Very interesting basic shape and by far different hole/vent pattern than I have ever seen before (not very efficient where they are located - heat rises.) Single wide wiring hole in the rear of the fixture, normally there is two holes for running the wires in parallel - wonder if this was a very early grounded fixture at one point? Gel frame retainer knobs or as we see a screw for it... that’s also a new one for me in seeing it, normally there is spring clips in use if anything and the gel frame retainer if not one piece with the front assembly is cast aluminum brackets not using standoffs for a (?aluminum) retaining front bar. This much less, normally the top is vented not spaced back from the front gel frame assembly to let the hot air out. Very unique way of doing the top of the fixture. Again, never seen anything like this fixture before in shape.

    Very interesting, seems like a kind of American DJ clone of other known brands of similar fixture but very unique in having its own worth. I note a hex screw on it’s rusted solid yoke screw (assuming it has factory paint on it), but round head screws in general use to hold the frame together. Best very rough guess, I would say 1940's for a date - this especially if the nuts inside these round head screws are also hex.

    More details will be helpful in further photo info about the very unusual fixture you have. Inside photo, lamp base assembly, focus adjustment knob will be very useful. Does it have a mirror inside it, and given rear hatch, how is the lamp base mounted? If no mirror, does it have any posts / holes / mounting assemblies to the slide base / lamp base assembly that might mount some auxiliary parts not provided? (Note past photos of some of the gear I have worked on in all this style fixture being similar in some ways but unique in far others.)

    The designation of “Baby” on it means this spotlight was designed for a 100w, 250w, or 400w spotlight lamp which would mean a medium screw (E-26) base - possibly a rectangular porcelain Bryant style of one as a theory, and the 400G/FL primary lamp designed for the fixture is still made, also that would make sense with the 5" lens - this is the equivalent of a 3.5Q6 back than (though due to its size in having used Major or were they Kliegl 4.1/2 PC’s that were much shorter [forget which though probably the latter] it could be more like a 3.5Q8 in beam spread), just a lot more size to the fixture than I have seen with that lens size. Hard to get a scale without a ruler or dimensions. Otherwise lamp wise in doing a quick search, I’m noting a 250w halogen lamp that might have a decent filament sufficient, a few 25 and 40w G-16.1/2 lamps that would readily work, a 170w lamp, 150w and a few more misc. lamps with 3" or shorter LCL’s which would be important to match or be shorter than in jacking up the lamp base slightly so as to compensate for the fixture’s bench focus LCL. (Lamp Center Length - length in this case from bottom of the screw base to center of the filament.)

    What would be really cool would be to put a color changing LED lamp into the fixture such as a Osram/Sylvania Mosaic LED S14 (S14/30LED/RGB) 064135 720949 I play tested recently and it would work well for such a fixture. In theory (if it’s LCL is the 2.1/2" of a normal S-14 lamp), this lamp type would need you to lift the lamp base up by ½" - meaning a drilled for lamp base mounting screws plate put between lamp base and sliding base assembly, & longer screws installed now to mount the lamp base. That would be cool - a color changing LED lamp inside an antique fixture. Output would not be much, but it would make it a very nice prop light that doesn’t draw much current and has exponential life. Such a modification to the lamp base - jacking it up ½" by way of spacer plate also would not change the worth of the fixture as original in all other ways.

    Save the original hardware though later in discussion saving and totally origonal verses using newer replacements but saving verses upgrades is debatable for resale value. Resale value so far without seeing the bottom, it’s knob and inside and lamp base assembly, I would put this unique fixture in value as at $250.00 -if it has focus screw and lamp base assembly due to its being new to me as a brand thus theoretically rare, and it’s unique features. Doing modifications to it could effect price downward or keep it the same. In the end, it is your fixture and one that will please you no matter how it should effect worth. Low balling be it rusting thru, missing parts or totally screwing up by doing a bad job of “fixing” it would be $45 to $25.00. Large range in price dependant upon condition and what’s reasonably well done to it or not and if not what should have been done.

    Theoretically you could also leave the lens dirty, though it looks like the rest of the fixture and it’s yoke bolts especially needs a bit of work before the rust and corrosion eats away too much at it. Separate post as to what might or might not be needed to the extent I have taken past fixtures of my own in bringing them back to factory spec condition (with or without wiring them for use) or in leaving them antique condition but preventing further rust and corrosion.

    Fuchs “Stage Lighting” on p.185 notes this should have a 7" focal length lens, though there is a chart on the next page that ranges from 5.1/2" to 12" focal length. (Elsewhere on the forum somewhere I posted the way to measure the lens so as to determine the exact focal length.)

    In the end, beyond re-wiring, than a strain relief that is debatable in how you do it, depends upon how period piece verses factory spec you want to go with the fixture. In my opinion, antique lights that continue to deteriorate are less valuable than those that are factory spec - this even if they are re-painted and or rust transformed so as to stabilize the fixture. Re-wiring of course is a must and acceptable, as with adding a place to ground it if not already there. Adding a yoke would also be fine, figure on one that allows for a +/- 45 degree angle from the rear of the fixture. This in noting that the yoke bolt is far off center... must be compensating for the lens weight or something.

    Nice fixture, really cool to see something I have never seen before. I want it... Would love to see what makes this one tick. This much less, were I still in college my next term paper as with Major and Chicago Stage Lighting fixtures would be for a research project on the history of G.W. Craig as a brand and any relation to E.G. Craig? This would especially be important. That would be a great research project, much less one important to share with the community. Could check my books on E.G. Craig if of help if he had any relations in the Colonies.
     
  10. ship

    ship Senior Team Emeritus Premium Member

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    You could modify the fixture to take a "Normal" Fresnel lamp into it - though the fixture is not rated for that wattage, it could easily take a higher wattage lamp given its heavy duty construction. Still why? We are talking most likely about a fixture that does not even have a reflector - didn't use one due to the inefficiencies of the lamp and lens. Nope, designed for the exact same lamp as would still be in use for a 10" scoop and a lamp type that still goes out on specialty custom lighting used on rock shows even today. Very ancient lamp, the 400G/FL is possibly the oldest stage and studio lamp un-modified still in use. Respect that, no need to change it as you are not going to get a more efficient lighting fixture. Besides, change the lamp base, you now have to measure the seat height of the filament within this new lamp base type than re-calculate it verses what it would have been in that new seat height of the filament being the same higher or lower than where it should sit in projecting thru the lens. Bad image/light if not centered on the lens. Can be done, a lot more work than necessary at this point or is recommended.

    Besides, just think, at the point this fixture was developed, the Fresnel was not even invented/developed for stage use yet. Is that cool or what? Beyond this, I have changed some 4.1/2" PC ?Major fixtures that even had reflectors on them into Fresnel in the past. It is a waste of time for the most part, the slot at the bottom of the fixture was not designed to allow the proper other than at best spot proximity of lamp to lens so as to make a good soft Fresnel beam of light.
     
  11. ship

    ship Senior Team Emeritus Premium Member

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    Further info on pricing/worth if of help - my opinion at least in setting up some sort of base for the fixture.
    Say $300 to $350.00 for this fixture, if a bit less rust shown under it’s top hood and about it. This due to the rareness of the fixture brand and style. This given yoke, original clamp and debatably Mazda lamp - though if working Mazda lamp it could drive the price up more. Wiring on the fixture is acceptable to be missing and better off gone. In addition to that, I would want to see a reflector on this style of fixture, one that is in decent condition and all lamp base assembly, focus knob etc. in good condition.
    $250.00 would be for one without a reflector but with yoke, lamp base assembly in good condition and focus knob. The clamp would be bonus to offset the rust some. Serviceable condition would mean better condition than what is in the photo.
    $150.00 I would expect for one with a little less rust under the hood and yoke bolts, - assuming hex screws on the yoke are origional, but having in as is condition all the rest of the lamp base and focus knob assembly plus yoke. A question at that point of fixture conditon.
    At best $65.00 to $75.00 assuming it has the lamp base and focus knob but no yoke and is in the condition seen otherwise & is missing the yoke.
    $45.00 assuming what is in the photo - condition, missing the lamp base, focus knob and yoke but otherwise is all original in parts.
    $25.00 if the hex screw on the yoke is not origional, missing yoke, lamp base, focus knob and due to its general conditon which re-finishing won’t help persay, only stabilize.

    Hope it helps as a base pricing or worth given this is a rare fixture but seemingly is missing parts.

    Lamp base should have been as you described - should have cut the asbestos where it hit the porcelain as opposed to throwing out the lamp base.. If the style I am thinking about, they don’t make that style any longer but you could replace it with a different similar and just as old style - given some work to ensure its seat height is the same. The yoke, a bit less important and easy to make. Wing nut for the bottom can be replaced - they still make that same or a similar cast style wing nut assuming that is what is original to the fixture and was not a replacement due to a lost one over the years. Can be made to shine again but its value is in the lower end of the spectrum and only worth what it is by it’s rare brand.

    Different set of posts perhaps in how to fix it so it works and prevent it from deteriorating further.
     
  12. ship

    ship Senior Team Emeritus Premium Member

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    If of further help, my 6" Chicago Stage Lighting fixture with its original yoke measures 17.1/4" long not including its gel frame clips or rear handle your fixture does not have. The yoke given this, measures with it’s 45 degree bent corners, 15" long and 9" wide inside. Your fixture with the 5" lens should be scaled down from there if not further in yoke leg length.

    The lamp base given you have seen it should be easy to describe be it rectangular, square or round. Many of the old lamp base styles are still available unless as described and in some photos I believe of my PC fixtures, the rectangular style still available. Leviton still has available a few types that were in use for fixtures since the 1920's. Than again, as posted about my PC fixtures in the past, it could be something really unique and special that could have been in this fixture. Than it would be a shame to be missing but could be reverse engineered for a different medium screw lamp base. Tricky but you just have to find the center of the lens in relation to the lamp base platform, than given a 3" LCL of your lamp find a lamp base type that either matches that with the lamp installed or once jacked up will again bench focus correctly.

    However given your photos show only the light shielding slide plates I fear this lamp base platform is missing from your fixture. That would be a problem in making it work properly. Possibly given what is shown it is similar to what is used on a Fresnel - sort of a bent U-shaped platform that is atop the plates - the wear of the fixture in sliding over the years will help otherwise. Otherwise a thick possibly aluminum or copper stepped platform that slid. Age of the fixture would be a determinant of what was used back than on this fixture.

    Doubting it had a reflector but it is possible, especially if there were some sort of knob system that allowed the reflector to be removed from the rear in access to the lamp replacement. Another factor in not just age of fixture but also quality of fixture given age. Hex verses square nuts inside the fixture - behind those slotted round head screws holding the frame together would tell a lot about the age of this fixture thus other details to consider in making it right.

    I noted the wing nut to the lamp base slide, missing but seen. McMaster Carr www.mcmaster.com if you type in wing nut shows a lot of shapes to wing nut so as to replace that exact wing nut and that is the easy part. Possibly after that it used a slab base weld nut attached to the lamp base assembly but up for debate in style. Hard to make guesses after that. Really a shame the lamp base is missing and possibly that of the lamp base assembly.

    In the future, save the lamp base and various other parts even if trash. Spray some WD-40 into a ZipLock bag and put the parts into it you won’t be using. Cut the asbestos at the lamp base or where its insulation was stripped off, and save that part. Save everything in general by way of sealing them up with some oil if necessary when in question of what one can replace or not. That missing lamp base and especially missing mounting assembly I theorize drove this fixtures worth down quite a bit given its unique nature. Were it a Altman 360... not as big a deal, here it’s like re-inventing the wheel if you want to get it back up and running.

    Post back what you remember in what is missing if not sketch out and post what you can about what was there. That all would help in finding original replacement parts and or calculating what would replace what is needed. Sure you can make it work... make it work well, if not make it work in at this point as close to original condition as possible is another potential question. It ain’t a S-4 Leko, instead it will have its own style.

    On the cord strain relief / wire in bushing, that can be replaced by a two screw strain relief without a problem. Today’s ethics say you provide a fixture strain relief of the cable beyond just a at best UL knot to the wires. Save the bushing that was on the fixture in the WD-40 coated plastic bag and replace with dependant upon size and ½" or 3/4" NPT two screw strain relief. Believe this hole will properly fit one of these two sizes. At that point use say a #0 sleeved fiberglass cover and some #16ga SF-2 wire to feed the lamp base. TBA the lamp base type. High temp. ring terminals to the lamp base, some fiberglass electrical tape, ceramic fiber cushioning for the lamp base and fiberglass electrical tape to the barrel part of the crimps. Silicone coated bronze lock washers on the lamp base terminals if removable etc. amongst other details - lots of other details. Ground the slide - that is okay to drill a hole for.

    At lest once determined what lamp base to use you get one, you won’t have to re-surface a used one. That is always challenging, but a shame the lamp base no longer exists.

    On lamping or use, I wouldn’t plan to use it any longer for theatrical uses. Fixture is tired, let it retire if not just leave it un-wired or modified for current usage. Note my idea of turning it into a LED prop fixture. Were it two fixtures, potentially you could make some special use of them when called for in a design, but one fixture would be very hard to make use of by way of design instead of intent. Form follows function = not the reverse. As a 25w or even color changing LED fixture it would be really cool as antique - preserved and there is lots of rust reformer spray paint out there, in working and being a cool prop, without attempting to make it into a fully factory spec lighting fixture.

    Factory spec also means something. Take apart every screw, tap every hole, replace every screw that is deteriorated with a similar one etc. Or just replace what is necessary such as the yoke screws, oil up the thing, rust reform and leave in place the fixture attaching screws once oiled and rust reformed. Overall paint, if aluminum, corrosion should be removed and if the base color of it was natural, leave it alone, if painted aluminum than your choice to paint it. How much paint is also a question.

    In areas not easy to chip the flaking paint off if any, rust reformer or at least spray paint if not high temp. spray paint will prevent the rust from getting worse in varying degrees. On more noticed surface panels, dependant upon rust and intent to keep origional, rust reformer, some sanding the edges, if not up to sand blasting than a new coat of paint might be called for or appropriate. Very hard question to determine the extent of need. This much less in value, some would like to see totally original, others would accept cared for condition on such a fixture.

    Personally, were I buying such a fixture, I would want it as I see it in the photos. From there I would do my own work on the fixture in preserving it. For me, someone else doing the work to it would decrease its value to me in me at least thinking I could do a better job and or enjoy the item more were I servicing it. Given this however, if a fixture for you on the other hand, it should perhaps be you that services and saves it no matter end result of value. Make the fixture what you need it and wish it to be.

    Hope it helps, love old fixtures as one can probably see. I also have serviced a few of them over the years and it's always a challenge not just to do but how much to do to them by balance of what is origional and what is current factory spec. Often that very much is dependant upon what you start with, but otherwise it also depends upon how much you don't touch in trying to do good. At times even if a surface layer of rust under the paint, it is a good question of if you should remove the paint so it cannot rust, coat so it cannot get worse or leave it alone in being origional.
     
  13. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    So, first things first. I'm not looking to do a complete factory restore, nor do I want it to rust away on my hands. I want to do a job of preservation. I would like to restore this to use a standard G lamp. I just want that golden glow from a historically accurate source.

    That said, all bolts and screws look original by means of having the same krinkle-black finish. All are rounded head and flat-headed screwdriver.
    The nuts are all hex, old and showing minor rust. The screws the hold on the color frame holders also have hex nuts.

    The lamp base was round. It was truly the most simple of setups. The lamp base sat on the metal sled-the circle caused by the dust is still visible. The metal sled then sat on the bottom of the fixture, again the dust indicator is visible. No risers or even washers. No holes on the sled other than for the focus bolt. The top part of the lamp base which I was able to keep is 1 and 1/8" high.

    no reflector. No mounting holes for a reflector. No focus knobs for a reflector. The only screws are those that hold the unit together. No ground or indication of one.
    The only hole in the bottom is for the focus bolt.

    The lens is interesting. Faintly marked are the words "SUN-RAY FRANCE".

    Frnt and back faces are cast aluminum painted black.

    Dimensions:
    Length: 10" to top of vent.
    Height: 7.5"
    Width: (at widest) 5 and 7/8"
    Focus Slot Length: 4 and 1/4"
    Length from Front to Yoke Bolt: 4"
    Length From Yoke Bolt to Rear: 6"

    Sled Dimensions:
    Length: 7.5"
    Width: 2.5"
    Focus Slot Length: 2 and 1/4"
    Bolt Diameter: 1/4"

    Lamp Base:
    Diameter: 2 and 1/4"
    Lamp Base Height:????

    Distance from bottom of fixture to center of lens:
    4"

    Pics:
     
    Last edited: Mar 2, 2008
  14. ship

    ship Senior Team Emeritus Premium Member

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    so what is black/white with the screw fittings in both sets of photos is what remains of the top of the lamp base. Intersting, not a style I have seen before. Doesn't match up with any of these styles that are still sold by brand or fairly standard style. Add to that you have like a 3/8" hole in your bottom slide plate and somehow it mounted to a lamp base mounting plate or the lamp base itself.

    I suspect that it is most like lamp base #4 left to right however. Would have to do a leviton parts search for the exact part number but it is a common type and the one I would recommend. Have to verify seat height with the 400G/FL lamp in seeing at that point how much to jack it up if necessary.

    Interesting wear pattern in the slide plate - the round lamp base wear in it as if a lamp base attached directly to it. Still short of mounting features to that plate, and a way to attach the focus bolt/knob to that plate - and normally it would be a U or C shape plate kind of like a sled, or a solid piece of aluminumm with focus bolt in front of the lamp base, it is hard to say what is what. This other than perhaps it's a different brand but simlar to part #4 in my photo I expect in use.

    What is shown of what is left of your lamp base is something I have never seen before but seemingly not unique in how it works.

    really interesting wear pattern to the slide or sled as it were with the round wear pattern. Not sure in photo if sled shaped C channel or flat plate. Still short of any holes to mount the lamp base or holes from the sled plate, I think perhaps this had a sled plate - possibly even a round one though I don't see a way of anti-rotation for it. Difficult missing assembly this is. Seen round assemblies but they do mount to something so as to prevent rotation.

    Is it possible that you do remember a wing nut of a sort but also a shaft of a sort the wing nut attached to, with a knob attached to it? Perhaps a sort of dual knob - though the wear pattern on the plates don't show evidence of it. One wing nut below to adjust the slide, another knob it rotated on to adjust up and down of the lamp?

    What size was this wing nut, are the photos off in size of hole, like a 8-32 wing nut or more something like 3/8" wing nut? Could be the photo is misleading, what is the dia. of that hole in the smaller of the slide plates?
     

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    Last edited: Dec 18, 2007
  15. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    Ah I need to clarify. The smaller slide plate fits inside the C channels of the larger slide plate. The smaller slide plate has a hole that is 1/4". So all slide holes are 1/4". I swear when I got it, inside was a ceramic lamp base with a bolt attached to the bottom. The bolt went through both slide plates, through the bottom, through a washer and then had a wing nut on it. No knobs that I ever saw. If they were there they were gone long after I got it. So seemingly no way to prevent rotation. I'm telling ya ship, the thing was baffling. The lamp base was mounted on the sled by the same bolt that was used to change focus. No separate bolts. No wear to seemingly indicate one. Have you ever seen a ceramic lamp base with large bolt on the bottom of it? And again that circle on the slide plate is how I found it. The round ceramic base was sitting directly on the sled.

    And the lamp base was nothing like your pictures. Crap.
     
    Last edited: Dec 18, 2007
  16. ship

    ship Senior Team Emeritus Premium Member

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    So the 1/4" bolt was centerd on the lamp base in holding it to the slide plate. Single bolt nothing to prevent the lamp from spinning theoretically unless some sort of carriage bolt that will have had a square hole not a round one in the slide plate. Just cannot see this bolt on center - that is where the hot lead spring contact is on the lamp base. Given it was a one piece porcelain bottom, cannot imagine it.

    Granted by the wear pattern, it was assumed one slide sleeved into another.

    The porcelain sat right atop the steel plate without an asbestos pad correct? The bottom porcelain section had the screw terminals of which the other part of it covered up sort of like my lamp base #4 correct?

    I would still say that #4 is going to be the closest you can get to what you had, and what's left of it will screw into it.

    Measure what's the light spot in the steel, what is it's dia?

    I'll check some old catalogs to see if anything can be come up with as what was used.

    It was not similar to a table lamp lamp socket correct? That's the only thing simlar to what you describe that I can imagine yet it would stick up too far. Must be similar but with a flat low base that's tapped on one side and lamp socket on the other. Still nothing to keep it from spinning.

    Normally in a similar situation I will have thought the first lamp base in use or #4 both using two screws. One with the knob attached, the other terminating just inside the slide - the slide was often extended to compensate for the second screw without extra travel. That or the slide such as on a Fresnel is jacked up some but there is a second screw.

    Hmm interesting, Ill look into some catalogs over the next few days and post if I find anything.
     
  17. gafftapegreenia

    gafftapegreenia CBMod CB Mods

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    I think you've got it pictured pretty well ship. It was a "two-piece" very similar to #4. There were the two screw terminals inside the base. The main difference was in height, it was about 2" to 2.5" tall all assembled. The bottom half was about the same height as the piece I saved. The bottom of the lamp base was flat. And, based upon wear pattern and memory, the bolt was indeed in the center of the bottom of the base. Perhaps this is why it was taller than your #4, to allow for the bolt and the center contact for the lamp. Don't remember if it has a square portion, the hole is round and there is no wear indicating a square portion. As for an asbestos washer, I do not recall one, but there may have been.
     
  18. ship

    ship Senior Team Emeritus Premium Member

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    got some initial pictures for you though I don't think any are the one you are looking for.

    First is out of Fuchs and possibly the one that's second in the second row - it seems to have a screw at its base but also seems one piece and square.

    Other photos are from a 1902 Sears catalog, imagine the primary one with its key for the socket switch removed.

    Neither are most likely it but its worth a shot. I'll check some lamp catalogs at work tomorrow while not doing inventory on my lamps - brain will need a break at some point anyway.
     

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  19. ship

    ship Senior Team Emeritus Premium Member

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    Did a lot of searching thru the net, and various normal and OEM catalogs from a number of brands of lamp bases today. (I'm only missing a few brands who make lamp bases at this point - that's a catalog type I try hard to get while in long term search of the elusive E-17 Intermediate screw lamp base of a specific type.) Lots of possibilities of stuff that could do potentially but nothing that stood out as what will have been used as described.

    (Amazing how crappy the photos are in one catalog can be, yet a different catalog of the same brand often has a different photo that is much more useful. Parts without photos or specs etc. to them. Websites are also often useless on a hit or miss basis.) Still there are a few possibilities I saw that would work.

    If you get a chance measure the shadow ring on the light baffle slide plate for what the lamp base dia was, and the height from that plate to the center of the lens. Also, I take it for granted it was a female wing nut not a male wing bolt? This would help to refine your choices some.

    Given it is unlikely there will be a replacement lamp base on the market, its time to start figuring out what would work.

    Figure for the anti-spinning part of it, preliminary theory would be to add a bit of fish paper (or similar material) between bolt and lamp base terminals of one of a few forms of lamp base. The fish paper - an insulator and pressed hard cardboard like material takes temperature well and would if cut to the width of the light baffle plates at the bottom prevent the lamp base from spinning. Most lamp base choices would be some form of lampholder with side wire slots for the wiring to get out but a bracket below the to mount to a normal table lamp pipe bracket or even a ground screw. Tap the extrusion, bracket or hickey for 1/4-20 if possible amongst other ways to prevent the bolt from spinning, put the fish paper between bolt attached to lower bracket and upper lamp base and its screw terminals and you are all set to have this sliding lamp base with center mounted wing screw. The fish paper will also help in further blocking light and or as a heat sink some.

    Basic concept wise. A few styles of lampholder to choose from after that.
    Got a few choices of lamp base but would need to limit that down some by seat height needs of the lamp base.
     

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