Detailing a projector

Looking After

 

DETAILING A PROJECTOR

 

Detailing a Projector

Detailing is a term I first came across in the context of classic cars; it basically means a high-standard, minutely-detailed refurbishment/restoration that may start with a complete strip-down to nut and bolt level and even go beyond simply returning to as new condition by adding refinements. I am not necessarily suggesting this for projectors, although there are some that would be worth it, but a great deal can be done to produce a smart-looking, functional machine. (Brian Giles has done some amazing work with 28mm machines, way in advance of what follows, and I am trying to persuade him to write it up). What I mean is a thorough clean and polish, maybe accompanied by some careful sanding and painting, perhaps a replacement part or two, damage repair, re-wiring (preferably to more modern standards), a lamp conversion and, of course, restoring it to be able to show films, at least for demonstration purposes. I am sure I do not need to add that, as far as humanly possible, all this should be done without bodging, damaging or otherwise making permanent changes to the original. In fact, I do not understand why the restoration and presentation of projectors seems to have played virtually no part in our hobby.

But remember in all things the First & Second Commandments:

1. Thou shalt not bodge.

2. Thou shalt not throw anything away.

I was triggered to write about this by a recent projector acquisition, a 9.5mm Peerless. The same machine was also sold as the Triplico, the 9.5-only version continuing as the Triplico Junior, the Senior handling 8mm and 16mm, too. Its an unusual machine, not one I had seen before, and although dirty, a bit rusty in places and slightly battered, appeared to be more or less complete. Naturally, the first thing I did was to take it apart. Here I what I ended up with:-

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The problems with it included the following:-

Lamphouse cap seized on, probably due to Mazac distortion in the lamphouse, and a bit rusty:

Mechanism cover, finished originally in nickel plate, quite severely corroded and pitted, lens jammed in place;

other plated parts corroded, principally sprocket retaining roller assemblies and spool spindles;

pins in projector end of spool arms, for locating arms in raised position, both broken off;

wiring deteriorating throughout and wires into motor, right up to where they disappear into the windings, had crumbling insulation;

motor bearings had felt reservoirs which were completely dried out:

speed control made projector body live;

parts of gate corroded;

mechanism jammed (apparently the result of a Mazac crack in the main body casting)

paintwork; numerous spots where paint had been knocked off:

generally dirty and tired-looking.

You have to accept that a proper clean basically involves considerable stripping down and dismantling, although I tend to stop short at gear-boxes and similar unless I have to go in. Otherwise you simply cannot access all the corners and anything you can do will be let down by the bits you don't do properly. Ideally, one should record in writing and photographically each stage of the job, to make it easier to re-build; one can never be sure quite how long it will take or what other things might supervene to delay you. In a year's time, what now seems clear will be obscure. Being experienced (and a bit daft), I don't do this enough, but one thing I always do is to keep all the parts in pots, often different ones for different parts of the machine, so I know I have all in need in a defined place, however long it all takes.

Lets talk briefly about cleaning before we go any further. There are important pitfalls to watch out for. One of the most difficult things to clean is the crackle/wrinkle finish of so many older projectors, (which it seems is quite impossible to reproduce today) especially so when its not black. I have found that turps/white spirit actually tends to make things worse, often leaving a pale residue. Meths can remove the finish on some machines (I noticed this first on a Bolex G3), and one should be wary of all types of solvent. They may interact with the layer of oil and grease to make things worse. Metal and/or car polish are suitable ONLY for smooth surfaces - you can never get it out of the wrinkles. WD40 tends to be OK but is not going to deliver a really clean result. Even soap and water can have the same effect as turps, and abrasive cleaners such as Cif should only be used with extreme caution - they will remove paint. Literally spit and polish and sheer elbow grease seems to be best in many cases. Obviously an endless supply of clean rags  -old cotton sheets cut up are good - is essential. And I would very much welcome information on ideas anyone else has found to work. 

I have devised a way of cheating with old black wrinkle finish; if you can find a colour match, it could work with other colours. I must emphasise that this should not be undertaken lightly it is, after all, detracting from the originality of the piece and, as we know from the Antiques Roadshow, collectors often frown on this sort of thing. Having got my parts stripped down, I clean grease off with turps (yes, I know) and apply masking tape to all areas that do not need paint. Screw holes etc I fill with screwed-up masking tape. I then give a fairly LIGHT single coat of black satin-finish car aerosol paint (neither matt nor gloss seem to give very good results). This goes a long way to cover up dints etc, but without leaving the mess that spot application of paint to individual patches makes. It also brightens up the tired finish of the main areas, without affecting the look of the wrinkle finish. Parts that don't lend themselves to spraying can be brushed, using a small artists brush and some of the aerosol sprayed into a small receptacle. The paint is quite thin, so brush-marks are not an issue, certainly on wrinkle-finish (I aim to experiment one day with the light-grey finish one sometimes finds, which turns brown with oil exposure, which is impossible to clean and really ugly). Smooth paint finishes dont lend themselves to this approach quite as well; chips in the old paintwork are more noticeable and, of course, you have to achieve a much higher standard of finish if it is to look good.

I must emphasise that this will not give a durable finish; it is essentially a cosmetic exercise for a display model. One thing above all that you should NOT do is to spray without dismantling or masking. You will ruin the appearance and make dismantling difficult if someone else wants to do the job right. I have seen some dreadful examples of so-called re-painting. I have a Super Vox which someone has simply over-painted by hand, without dismantling, in hammer-finish Hammerite, leaving it patchy, blotchy and looking entirely wrong. Far, far better to do nothing than to bodge and leave things worse than when you started. But I digress. 

My plan, before that digression, was to work through the faults I listed earlier, explaining what I did, no doubt with other digressions along the way. So, revenons nos moutons.

Lamphouse cap

There was nothing I could think of other than fairly brute force. I held the body of the lamphouse lightly in a soft-jawed vice, put a thick, flat bit of brass to the bottom edge of the rim of the cap, then 'it it wiv a 'ammer, being careful to direct the blows so that they pushed the rim up but didnt impact significantly on the body of the lamphouse; this being Mazac, and having obviously already distorted a bit, needs to be tret fairly gently. The cap is steel, so the softer brass should avoid messing it up too much. Proceeding gradually, turning the lamphouse repeatedly, I was eventually able to separate the two. As I have a lathe, I could do a bit of turning to avoid the long labour of manually sanding the inside of the cap to enlarge it so it would fit back on. As usual, the cap was a bit rusty and lacking in paint, due to exposure to the heat of the lamp. I also noticed that the finish of the metal under what was left of the paint was poor, not helped by the pitting left by the rust.

I decided therefore to experiment with stripping the cap of all paint and turning, sanding and polishing to see if I could get a better finish. A particularly helpful tool was a 6" diameter sanding drum this is made of foam rubber, with a circular sanding belt on the outside. In a high-speed drill (with a device for making it free-standing) this drum can do serious removal of material. I have a very old sanding belt which has been worn pretty smooth and so is much less harsh. I also have various other paint-removing, polishing etc things to go in the drill, so I can process a wide range of projector parts. Sometimes it is best to put the part in the drill and apply the polishing mop to it as it rotates; this is what I did with the knobs that hold the spool arms to the projector. Using a drill in this way can be dangerous both to you and, more important, to the part you are trying to clean. I have had parts snatched from my hands because the polishing mop in the drill caught a corner or whatever, and zing off across the workshop. Trust me, this does not do parts any good, either cosmetically or even, at worst, functionally. You need to ensure the rotation of the drill is always tending to pull the part you are polishing AWAY from you. Things can get hot, so wear old gloves (thinnish, or you can't hold stuff properly). Circular parts with a central bore can be held firmly in the drill on a suitably sized bolt, or held in the hand with a screwdriver or similar thru the bore you can easily control the rotation of the part on the screwdriver by finger pressure.

Above all, just take care and think safety ALL the time and do not try to run before you can walk. Simples.

Anyway, I ended up with a nice, bright-metal cap for the lamphouse. Given the depth of pitting one so often finds, the perfect finish is not possible, but this looks good and, if a return to originality is required, it just needs painting. One problem I had was that there is a baffle plate just inside the cap, held to its top by a couple of riveted spacers. The less-than-gentle removal of the cap broke one of these; in the end I replaced both with miniature threaded spacers and bolts. The brass heads of the bolts make a nice detail.

Mechanism Cover

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Actually, I did this before the lamphouse cap, which is what gave me the idea of leaving the cap un-painted. Removing the lens involved a lot of twisting and polishing accessible bits etc until it finally came out, then pretty much as per the cap. Sadly, most of the nickel plating had gone and pitting is quite severe, limiting what could be achieved.

Other Plated Parts

Roller assemblies and spool spindles are among the most difficult parts to clean up effectively, as they are relatively small and fiddly and you often can't easily get into all the corners. The roller assemblies were of riveted-type assembly, ie they couldn't be taken apart. This is where techniques I have developed over the years come in. First, one needs plenty of rags and some decent metal polish; I use two, Chrome Magic, which is non-abrasive, for steel, brass, chrome, nickel etc and Alu-Magic, which is abrasive, for aluminium. There are of course many others; the above and others are available at www.frost.co.uk. Another particularly helpful item is a small, bench-top vice with SMOOTH jaws. A vice with the normal serrated jaws will destroy the finish on your parts. In fact, I have both as there are uses for the serrated jaws; both are held to the bench-top with the usual screw-mounting device that means they are easily removed rather than permanently fixed. What I have found helpful is to fairly gently hold the relevant part in the vice, in any way that will hold it fairly still but not crush or bend it - cushioning with rags can help. Often one has to adjust position a number of times.

I then thoroughly impregnate a rag with the polish and drag it to and fro across and thru the part, using a hand at each end of the strip of cloth. You can get much more force and effect this way than simply rubbing with your fingers. With the trapped rollers of the assemblies from this machine, pushing a bit of rag behind them with a screwdriver so that you can drag it to and fro is about the only way to do it. Obviously, one cannot reach every corner like this; that is when judicious use of a screwdriver comes in, heavily wrapped in rag and pushed into the corners again, much more force than can be achieved with fingers but watch out the driver blade does not get thru and scratch. If things are so bad some sanding is needed, get some fine wet & dry sandpaper, tear off a strip and use in the same manner as the rag - I had to do this with the spool spindles.A variant of this can be applied to sprockets and similar circular parts. Hold the sprockets in the (smooth) vice across the flat sides and apply the polishing rag as above; I have found that by varying the angle, you can actually clean all round the sprocket without having to re-position it in the vice. A final variant is useful for pulley grooves and similar. Instead of the pulley, the polish-impregnated rag is held tightly in the vice at one end, then stretched out taut. The groove of the pulley can then be pulled to and fro along the rag, for cleaning.

Another technique I use frequently is to lay the rag (works for sandpaper, too) flat on the bench top and find a way of stretching it out taut - I usually do this between my fingers and thumb. Flat surfaces can then be polished with considerable force. I often use this approach to clean screw-heads, which can otherwise mar the appearance of a projector. Don't forget to clean the bores of sprockets etc - push the rag thru with a small screwdriver, then twist or drag in and out. Knobs with knurled or milled edges can pose a particular challenge. A toothbrush dipped in polish and/or a (brass) wire brush can help, or maybe dip but see below under Gate. I have subsequently found that a circular brass wire brush in the drill can do wonders for milled edges. Eye protection is vital, as bits of brass can fly off. No amount of polishing is going to restore badly corroded plating, and the plating on the cheaper machines is often of poor quality anyway, but it is surprising how much better parts can look if rust and the general surface corrosion, dirt and oil is removed or at least toned down. I do wonder why people think projectors should be kept damp in the first place.

Spool Arm Pins

This refers to the commonly-used system for making spool arms foldable. The arm is held by a central threaded bolt; the pin is off-centre and locates into a hole, maybe several holes for different positions on the projector mounting point. Obviously, without the locating pin, the arm would continually be working loose and drooping. Loosening the bolt far enough allows the pin to disengage so the arm can be folded or moved to another position. In this case, the pins appear to have been made of Mazac and maybe someone didn't know to undo the bolt far enough. Anyway, they had broken off. The (very rough photocopy) Triplico instructions I have actually specifically emphasises the need to avoid shearing the pins. I had to use a milling cutter to drill out the remains - drills don't work as the drill wanders off line. I then found some steel rod of about the right size and glued replacements in place with Gorilla Glue.

Wiring

Much of the original wiring of an old projector simply has to be discarded. It is highly likely that there are hidden as well as visible defects and it's not worth taking chances. Its likely you will have to make some changes anyway, eg to fit an earth or to replace the original resistance if it hasn't disappeared over time. Basically, I chucked all the original wires. However, motors are a special problem. In this case, the motor wires looked as thought they had first melted and run, then hardened off and were now gradually turning to dust. As the motor is hard-wired, so to speak, the problem extended into the casing. One thing you will certainly have to face if you restore projectors is going inside motors to fix them, so you might as well learn. It is important to remove the brushes before dis-assembling, and to remove the connecting wires to the brush housings before trying to remove the field coil. 

Most motors are held together by two long bolts or rods with nuts at each end (or a bolt-head in place of one of the nuts). You may of course have to remove a pulley or gear on the motor shaft, which can be interesting, especially if retained by a taper pin. Then remove the end cap that does NOT have the brushes. They can be pretty well stuck, but you need to be gentle as they are often made of Mazac. Usually the shaft and the rotor/commutator will come out with the cap - take care not to damage the windings; motors are a very tight fit with minimal clearances. Some will only come out thru one end of the casing; don't force it. Two further screws normally hold the field coil in place. But BEFORE you touch these, look at the mountings where the brushescome thru into the casing. Frequently, connections to the brushes are made by spring loops soldered to the wires, the loops passing round the brush housings. If you try to remove the field coil before slipping these loops off, you will stretch them and leave yourself a really tricky problem. I know, I have been there.

Here is an H motor the springs are not actually on the brush sockets but are clearly visible you can see the grooves where they fit. In this case, I also had to remove the springs from their wires as the insulation had more or less vanished and had to be replaced. A major problem I find once inside a motor is that the old wire cores, to which you have to solder 

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new bits of wire, are most reluctant to take solder. I have tried cleaning with turps or meths, and sanding the strands to clean them, but its still difficult. In this case, I resorted to entangling the old and new strands together as best I could and soldering over the lot. The solder is probably doing a mechanical joining job rather then anything else, by sticking to the new wire and stopping it escaping from the old. Replacing the spring loops was a particular problem. For this sort of work, heat-shrink insulating tube is an absolute God-send; as well as insulating joins and bare wires, it can add significant mechanical strength, tho' as a disadvantage, it is less flexible than wire. You do have to remember to put it on before making a join and slide it onto the joint after - you cant fit it except via a free end. One of the problems is being able to keep the heat-shrink from being affected by the heat of the joint as you make it some - sort of heat shunt in the shape of a crocodile clip, pliers or whatever, can help. Otherwise the tubing shrinks and cant be moved into place.

There are of course two wires from the field coil to the brushes. Which one goes where is what determines the direction in which the motor rotates. It is very irritating to find once you have re-assembled the motor that it turns the wrong way and you have to dismantle again. Needless to say, this motor turned the wrong way. The motor has little end-caps in chrome (to be cleaned, of course), one of which states clearly it is 110v. It seemed to run very quietly but maybe a bit slow. I tried increasing the voltage a bit with a Variac, just in case it was really 240v, but no. In fact, the 110v of the Variac made the motor run better, so I adjusted the tranny I had been using to feed the 220v tapping rather than 240v. We're actually supposed to be 230v now, so this change should deliver a bit more oomph.

Might as well segue straight into the motor bearing point. Under those chrome end-caps is a circular bit of felt that acts as an oil reservoir for the motor bearing. The thing is that, while one should not over-oil in normal operation, the chances are that a restoration project will have been disused for a very long time and the oil will have dried out. A drop every x hours of use will not deliver anything to the bearing soon, if ever, so these wicks need to be soaked through before normal oiling can be resumed.

Speed Control

Some tears ago, I acquired a Heurtier triple-gauge silent machine. It had no earth, so I promptly fitted one, only to find that the motor would now only operate at maximum revs. Part of the resistance circuit, if not actually thru the body, was in contact with it. I didn't like it then, and I dont like it now. In this case, the rod connecting the wiper on the resistance to the external knob was steel and simply passed thru a hole in the body, inevitably making contact. This seemed to me not to be a good idea. But fixing it was a nightmare and even now I'm not too happy with what I have achieved. What I managed finally to do was to cut the rod and insert a non-conducting plastic section, tho it took many attempts to make this work. I have since found some insulating nylon spacers which I think would do a better job, but I'm not going in there again! As with the rest, all the wires involved in the circuit had rotted.

PLEASE NOTE THAT I HAVE SINCE DISCONNECTED THE 110V PART IN THE TRANNY BELOW - IT BLEW THE FUSES TOO OFTEN; MUST BE A FAULT IN MY IDEAS. 

Moving on to the re-wiring, I need to digress a little into power supply. The lamp in the machine is 12v 35w, a small globe. I dont know if this is original; the Triplico instructions refer only to wattage, 50w classroom (!??) or 200w. Not that this is desperately important, as for machines like this with no fan cooling I dont think anything more than 12v 100w is viable. What I did here was to take an empty 50v 200w transformer case from a 200B and fit a Eumig P8 tranny into it. Here is a pic of the tranny. Wired in this way I can get the 110v for the motor and 12v for the lamp. In order to get an interlock between the motor and lamp switches, I wired 

detailing-a-projectorthe projector with one lamp wire coming via the motor and lamp switches, this being the common wire and so not needing a separate connection for the lamp. The other lamp lead connects to the 12v cable via a banana plug. It is, of course, vital to connect this plug to the correct side of the 12v output socket or there could be a bang, puff of smoke, damage and even personal danger! I could perhaps have found another way, but this was the simplest I could come up with, and I don't like not having an interlock. Note that the two output cables are sandwiched between the shiny strip you see across the gap at the front and another ditto, lying in this pic on the left. When swung back across and held down by the giant bolt-heads that secure the top, this forms an effective cord grip, with added help from cable ties on the back vertical pins. Having done this tranny, I have now got a useful power supply for general use.

As a further digression, I had made a lampholder for a 28mm KOK and needed a power supply to test it so, naturally, I turned to my newly-made one. The first lamp failed, the second and third exploded (fortunately for me, inside the lamphouse) and my aging cheap analogue multimeter went up in smoke. I took the power supply apart and re-checked everything, but no good. I finally traced the problem. Some years ago, I built a sort of Hi-Fi Tower to take my AV amp, DVD player, cassette player, laser disc player and even VCR. These all took power from a series of sockets in the base, one of which was a sort of "master" and fed the others. As soon as I opened this up, it was obvious that I had made a glaring error when I first set it up, and reversed the polarity of the live and neutral wires. Nothing else I have ever connected that has been fed by this same socket has ever given any problem, but the auto-transformer/common neutral wiring of this power supply exposed the fault.

Gate

The apparent corrosion of parts of the gate turned out not to be too bad - the worst bits were where they could be sanded off and repainted. I did re-spray the main fixed plate. The rest was the usual cleaning and polishing. One thing I find helpful, with caution, for removing rust is what I call dip, after Who Framed Roger Rabbit. Basically, you leave stuff in it and it gets rid of rust and scale without damaging paintwork or eroding good metal. Care is needed tho I once dissolved some springs in dip as there was not enough thickness in them to survive. It does not, of course, do anything about the pitting that is the concomitant of corrosion; it can often be surprisingly deep and beyond any realistic removal by sanding all the surroundings down to the same level. Dip can also be useful with things like knurled knobs, which can be very difficult to get looking good.

Mechanism

Once removed from the distorted Mazac casting and oiled and cleaned, the mech proved to be very free-running, so I avoided any further dismantling. The trouble recurred on re-fitting, of course. I got it working finally, but it was a bit of a struggle, and the pic was poor and lacking focus. The Mazac issue caused several problems. detailing-a-projectorThe mech would barely fit back into the body without jamming up and the pic was out of focus across the screen, both due I suspect to Mazac distortion. The other big problem was that only one of the sprockets had a rim. Whether I put the rimmed one top or bottom it caused problems as the film just wandered off the sprockets. The sprocket was actually about 14mm wide, and the film retaining rollers just sat on it, doing nothing to guide the film. Because of the width of the sprocket, washers would not work so I came up with the approach illustrated. The brass bits on the top sprocket fit round and over the edges of the sprocket. Being slightly greater diameter than the sprocket, they guide both the film and the retaining rollers and correct the problem. The only other option, making a new sprocket, is beyond me. Coarse framing is by rotating the bottom sprocket until the limited range of the lever can come into play for fine tuning.

Paintwork

This is pretty much covered under the introductory bit above, but I would like to re-emphasise that adding daubs of paint to individual chips is not a solution I commend. It is impossible to avoid the paint spreading beyond the boundary of the chip, or to get a precise match. The result may look OK from a distance, but close up its not nice. With some machines, especially smooth-finished jobs, a really thorough-going strip-down and proper multi-coat re-spray may be the answer. It is hard to know what paint to use, however. For the sort of cosmetic coating I described earlier, it doesn't matter a lot, but for a proper job car paint seems too soft, enamels don't seem to stick too well sometimes, Hammerite is a bit toxic tho gives a closer approximation than most to the sort of thickly-painted finish found on many old projectors. The satin finish I have found to be the most useful. One problem Hammerite and some other paints have is that they are susceptible to attack from chlorinated hydrocarbons, ie the solvents found in various film-cleaning fluids. I have often used a tissue impregnated with eg Cresclean in an attempt to give a bit of moisture back to films by putting it with them in a can (dripping it on is nbg if you use as much tape for repair as I do, since tape is also susceptible). I went back to find the tissue stuck to the paint. I don't know what they used originally on spools, but some I had re-painted had polyurethane paint, and this seems good and not susceptible to cine solvent attack. I am currently experimenting on amachine with acryllic spray paint.

General

One of the most frequent details that needs fixing with old machines is rubber feet that are missing or eroded or turned to vile gunge. I keep a large stock of replacement feet I don't worry about originality here. Often the screws have gone, too, so I keep any and every screw I come across. I have improved projectors such as the H (which never had feet at all) by drilling into the front feet (you really need a lathe for this) and tapping the hole for a screw to hold rubber feet on. The back of an H is more difficult, I don't like to fix feet to the base plate as the screws that hold it on go straight into the bakelite of the base and the threads are fairly soft and easily damaged. What I have done instead is to use longer bolts in two of the four holes for securing the motor mounts; these holes pass right through the Bakelite (and have brass inserts so are stronger). They can then be used from inside to provide support for columns that go on to meet the base plate. For one, an existing hole in the base plate is OK, the other needs a new hole but I think this is worth it to deaden the noise an H can make on a hard surface with those solid feet. Sometimes, even where there are feet, they are a permanent fixture and once the rubber has gone manky can't easily be replaced. Then I resort to the method I described for the H front feet, or figure out something somehow.

Lenses need to be carefully cleaned, and maybe (better) replacements found. For example, a Vox can be sleeved up to accept eg B&H lenses, although many machines seem to have such idiosyncratic optical arrangements that only the original lens will work. Lamps need to be converted to QI - no permanent changes, mind! - tho' some ingenuity is needed to avoid change. Spring belts need to be replaced where rusty, if they are present at all. Base covers may be missing, are usually rusty (good candidates for dip and re-spraying) and, if they are there, most of the screws have vanished and wrong ones have been put in, it seems with the deliberate aim of damaging the threads. That's without even thinking about sound. but watch this space.

There is, in short, a huge amount of work that can and very often should be done to raise standards in the way we look after and present projectors. I am sure that the rusting, oily, tatty mess that sometimes passes as a vintage projector is one part of the negative image of our hobby that has kept us from attaining the wider levels of interest displayed in magic lanterns, old radios and tvs, mechanical toys, pre-movie moving picture devices like Praxinoscopes and all sorts of other stuff.

Finally, the finished article.

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