Mole Light Conversion Project

[ship]

Following will be a series of photos on 11 Studio Grade Fresnel lighting fixtures I spent about two weeks in servicing and modifying for a tour. Four 10Kw, Four 5Kw, one 2Kw from Mole Richardson, and two Strand Bambino at 5Kw. They all needed to become normal 20 amp stage pin powered 2Kw lighting fixtures for a more set decoration prop use than for their normal light output. As opposed to someone else’s tour that did a similar concept on prop large Fresnels with a PAR can I think shoved inside, these fixtures would work as designed only with a smaller lamp.

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5K and 10K Fresnels on arrival (top) and on the work bench (bottom) :: Click on each for to enlarge

The concept of converting them to a lower wattage lamp was simple enough given the same lamp base type used in a 2Kw CYX lamp as that of the larger 5Kw DPY and 10Kw DTY cousins. Just a question of in the case of 10Kw Fresnels jacking that lamp base up by 5" so the filament is re-centered in the fixture. In the case of the 5Kw fixtures, by an inch and a half. Simple enough given one just needed a short metal platform mounted under the lamp base and the other needed a piece that would mount into the existing rail mounted lamp base frame with a platform on it’s top for an alternate lamp base. The theory of doing this but not needing to modify much else so they could go back to their original design after the tour was over was another selling point for other than just sticking a PAR can in them. The concept was about the only simple thing as it turned out.

The Bambinos came out of our active inventory and did not need any major work beyond some 1/8" NPT pipe spacers to jack up the lamp base and a new cord to feed it. Could not have been more simple. The rest of the lot were bought off of E-Bay and were in really bad condition. The exterior appearance - once the stencil for where they came from was painted over, was what the designer wished for - surface rust, dings, dirt and all so at least that part did not take much effort. The worse condition the fixtures appeared to be in the better and the designer was quite satisfied given the photos included. This not even including the barn doors for them which were so ratty looking I did not even want to touch them beyond having been shipped two that would not mount in the fixtures and needed a ring welded to their too small of mounting rings in making them fit.

The interior and wiring of the fixtures on the other hand needed to be in optimum condition given the use of them and my standards. This meant that in addition to having to get the lamp base extensions manufactured to fit the new lamps, - the welder didn't make my life easy there due to his extreme lack of accuracy; all wiring had to be replaced, rust had to be removed and re-painted, it's workings had to be cleaned and oiled, and all lamp bases had to be completely re-surfaced with various parts replaced.

This and the 2K Fresnel came with asbestos wiring and even an asbestos insulator tape between lens and frame that had to be scraped off. It came from another studio and came shipped in a box filled with packing peanuts but without a bag around the fixture in preventing them from getting into the louvers. I was constantly finding more peanuts inside of the frame as they would work their way loose. Such 2Kw also fixture came dissembled and with missing pieces including it's switch assembly that I had to manufacture. Lucky I bought some Mole paint otherwise the switch looked even more out of place than it does. It’s well done but one can tell that a exterior weatherproof “Bell Box” will not have been used on the fixture. While given the exterior look of the fixtures perhaps a standard “1900" series duplex box with some of it’s knock outs pushed in will have looked more appropriate and scary, I error’d on the side of doing it right. This paint also used to remove the studio’s stencils since I’m sure they will not have liked to see it used by us.

Of the 5Kw and 10Kw Mole fixtures, four out of eight of the porcelain supports for the lamp base contacts were broken either in transit or more likely with long term abuse and heat. Came out of the fixtures in little chunks. Another one broke when it was being removed. So one set of porcelain insulators had to be bought given for the 10Kw fixtures at least I was able to use some 5Kw Altman 5000L lamp bases instead. These at least I have in mass quantities given a lot of 2Kw and 5Kw fixtures in the inventory and a past upgrade from Altman that used a completely different lamp base in making the old version surplus. Should have bought more because another cracked as I was installing the lamp. Luckily it was not bad enough to require immediate replacement but it will need observation. All these sockets will have to be inspected before shows by the crew chief for potential replacement - it probably won’t be cheap to keep them running dependably. Something about the design of the cast aluminum mount for it allows for it to warp inwards which causes the porcelain touching it to flex than crack. All aluminum castings should really be replaced I fear. Granted this is the one below I was heating and pounding upon that might have caused the problem of a warp that breaks the porcelain to become worse. Could not see a way of un-bending it or grinding it flat again.



Lamp base (note crack on bottom-left)

On this type of lamp base no matter the brand, melted contacts is common given the current going thru them. Once you get to a 2Kw and above lamp, slight problems with contact to the pins will result in extreme arcing and destruction of lamp pins and base. I now including two forms of Altman, one for the Stand and two for the Mole lights have five completely different types of Mogul Bi-Post or G-38 lamp bases in the inventory I have to stock amongst many other types.

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Lamp base inserts (both old and new) :: Click on each for to enlarge

Only the upgraded Altman and the un-changed Strand lamp bases don't require a lot of effort and inspection, the rest need almost constant replacement and re-surfacing it would seem when not taken care of. Luckily because of this I have gotten decently good at it. The Mole style seem to just plain suck seemingly in lack of surface area in contact with the pins but are the easiest to repair. This hopefully will not be as much of a problem now that they are round again in the same radius as the pin. Some bases I received showed a small amount of past care of sorts by way of rough grinding them down to do the surfacing - but it left lots of large scratches on them that even if now bare exposed surface still would not conduct very well. Much less the grinding was not evenly done to them. Almost will have been better not touching them. I doubt any form of de-oxidant was used to protect the surfaces from corrosion in improving this either. Than again on a 10Kw fixture I’m not sure what I will have used that would work anyway.


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5K Lamp bases: Bottom-left shows the modification to the 5K Bambino (note the lamp type). The other two pictures show a 5K slide platform :: Click on each for to enlarge


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Modifications made to the 10K Lamp bases :: Click on each for to enlarge


These problems in addition to something I have never seen before. Galvanetic Reaction to this extent. That's where dissimilar metals touch each other such as in this case with steel touching aluminum. While the old thru bolts that hold the lamp base to it's aluminum mount were plain steel, the replacement yellow zinc grade 8 bolts the studio was using for some reason rusted to a greater extent where they touched the aluminum and in one case even welded itself to the aluminum lamp base mount. Don't know how they continued to use the fixture given you could not tension the lamp base with a stuck bolt but apparently good contact was not important for them or that’s why they sold it. Heat from a blow torch, penetrating oil, pounding on it with a 5# hammer and torque by way of vise grip would not un-stuck it. Took a pneumatic impact wrench to get it free.


New, Origional Square Head and Stuck Grade 8 Bolts, notes the rust on the bolts and part of the bracket

Curious assortment of surface rusted but still serviceable plain steel verses rusted worse where touching aluminum - Grade 8 bolts in use, and aluminum verses bronze thumb screws and other parts on these fixtures. All the plain steel bolts were able to be saved given a coating of Teflon oil applied to them, the others had to be replaced and also coated. Even the bronze and brass parts had to be resurfaced and re-tapped. Anything with a tapped hole on it needed re-tapping and care.

Given all fixtures came out of a major motion picture's studio I will have expected them to be in much better shape. Believe they were sold to be in working condition. About the only thing these fixtures will have been suitable for will have been non-working props at some amusement park or theme burger joint. Granted we only paid about $2,400.oo for them which will have about bought two new 5Kw Mole fixtures and certainly not all of them otherwise, if you add up misc. parts and my labor we will have been about 2/3 of the way there to buying new fixtures. This as opposed to our Bambino and Altman fixtures that at the same wattage are about half the size and weight, much less are well taken care of to the extent of using inspection mirrors with flashlights before every use to verify the lamp base and other components are in good condition. Always interesting to see what others make use of verses the care we put into our equipment.

Still it was a fun project. I love working on gear like this much less modifying it to do other things but in doing so being able to not skimp on parts.

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10K Fresnel being tested using a 20A power supply (Left) and a 5K Fresnel on stand (Right) :: Click on each for to enlarge

[Les]

I see these huge fresnels on ebay all the time. I would love to buy one just to use as decoration for my house.
I have a lighting instrument made by Mole Richardson in my garage right now. I'm not sure what you would call it, but it's an open-faced unit. On the side it has stenciled on it "Double-D". Not sure if it was from the studio it came out of or the factory. It has 2 lamp bases that appear to accept the large srew base incandescent lamps and 2 large switches on the back. It's really cool and appears to be in good working condition, but no lamps. It looks to have a good whip and regular 120v edison connector. The best part is that I got it for free. I would still like to have one of those fresnels though.....

[ship]

Funny, you are the second or third person that has mentioned a interest in similar fixtures for home use. Kind of large in my impression of them, but that's coming from someone that already owns some large lighting - just not as large as a 10K with the exception of my follow spot. Another person mentioned that he was thinking of taking them on his own tour and mounting some form of moving light or strobe with color changer inside of them.

Just remember what I found above about the condition of these units, I would not expect much of what's on the market to be in good operating condition.

In addition to these, the shop has some large Q-Lite like fixtures open faced RSC fixtures, some 8" 2Kw Mole Ellipsoidals, a PAR 64 six-Light Audience Blinder, and some single, six and nine light audience blinder PAR 36's. The last two are still very much in the inventory given the switches were removed for touring use and a total re-wire and some other modifications. Actally, five of them were even converted for a tour they I think are still out on to be fed directly by a Socapex cable as if a lamp bar. These plus a few fans on stands that also weight a ton. Good rugged equipment that has not changed much in the last 40 years. Stuff that when new also would cost an arm and a leg.


Switches are attached to the backs of the fixtures or on a cord to turn them off before un-plugging or in your double lamp fixture to half the output of it without needing to dim it. Your fixtures are probably still available at www.mole.com

Old and odd lights are fun.

[Mayhem]

Just a quick message to alert those of you that have already seen this post

Ship and I have been working on adding some more images and additional information. I have been working on this for about an hour or so and have just double checked to ensure that it is working.

Most of them link to a larger image for those of you who wish to take a more detailed look.

[Peter]

Nice work on the pics! The top bunch work really well for me. The bottom ones dont show up in the message though, but all but one (that i tested anyway) do show up when clicked on. There is a good chance this is not b/c of what you are doing, but because of my spotty internet connection. Thanks for the the Pics!

[Peter]

Hey, they all work for me now!!! Good work!! Thanks!

[Les]

Wow these are big. I think I would just use them as an interesting conversational piece at my house.
On a completely different note, in high school we found that a 6" Altman Diecast Fresnel lamped to 1kw is great for unthawing a lasagnia. It was a long, long workday and it was in an aluminum pan so we couldn't put it in the microwave. lol Took a while but it worked. Works best when the light is clean and there is no gel