Eumig Mark S
Q. Just been having a very enjoyable browse around your site, which I came across as a result of searching for info on a Eumig Mark S projector. I haven't yet received the machine, but Im anticipating the need to overhaul it before use.
I was wondering therefore if you might have a circuit diagram for the amplifier that you might be kind enough to let me have a copy of. I have a few years under the belt with steam radio restoration so I don't anticipate too many problems, but its helpful to have a map before you set off!
Strangely, the need for a Standard 8 sound machine originated with a print of The Telegoons I was lucky enough to find; something I'm quite looking forward to seeing!
A. You are hereby sentenced to 1 week of corrective reading of CINERDISTAN.
Because, in the 8mm section, under Various 8, you will find a full instruction book for a Mark S, including a circuit diagram. I have attached another from a different booklet in case there is any substantive difference.
The biggest single problem with the Eumigs is getting them up to speed. 3 major elements:-
1) The motor/fan unit tilts and the bearings rot. Details of the problem will be found as above.
2) The tilting is what actually engages the mech, by bringing a knob on the end of the motor shaft into contact with a
rubber wheel. Time is not kind to this mech and it frequently runs slow; one way forward is to slightly roughen the
rubber to give the knob a better grip.
3) The grease they used originally has gone solid and makes the whole drive train stiff, including up the spool arms.
Ideally, it all needs removing and new lubricant adding.
Enuff to keep you going?
Q. M'lud, I plead reading the website during my lunch break. In further mitigation, perhaps it was your mention of plastic and transistors in the intro to the manual that threw me, knowing I had a valve one... ;)
The diagram's great thanks. Everything clicks into automatic: first thought was "replace C21, 10nF output valve grid feed"!
You may like to inform your readership who may wish to work from these diagrams (unless you already have and I've missed that also) that the voltage readings quoted would have been measured with an Avo 7 or 8 meter. Measuring with a digital meter (with a far greater input resistance) will tend to report higher values than those quoted on the sheets, as they don't load the circuit you're measuring so much.
Thanks for the advice also on the dried lubricants. My photographic nerdity concerns restoring/repairing old still and cine cameras and the lubricant problem is a continual bugbear - particularly, I've found, with Russian equipment and Agfa focussing helicals!
I'll tell you something about my experiences with your favourite Eumig P8 which may amuse, though at the time I found little to laugh about. I found one of the Phonomatic variety some 25 years ago, with all parts still sealed in the plastic bags. Attached a mains plug and gave it a go. Found out the hard way the projector casing was at mains potential. The cause of this was the mains cable: remember I unsealed the package myself. The plug on the projector end had been wired with the earth and live reversed (perhaps the artisan in question was red/green colour-blind). So I never liked them since - and never did work out why they took up film the 'wrong way'!
Later. Q. Just to close this one out, a note to say many thanks for the info you supplied and posted on your website. I've taken delivery of the Mark S and its immaculate everything free running and undamaged with the exception of the motor pivots, of which there is no trace remaining! I'll be following your advice to manufacture same.
A. Nice to be appreciated.
(This is distilled from a much longer exchange).
Q.
I have a Specto 9.5mm film projector and a 16mm one; the problem I have is on the dual machine the double claw goes left and right but has stopped going up and down. Do I need to be into the gearbox to fix this problem, if so do you know the procedure to get into the gears.
A.
I've come across Specto's running backwards, but not your problem. There ar
e two cams (see pic). The one nearest the lamphouse you can't see as it's behind a retaining plate; this is the up and down cam. The other, nearest the lens, is the to and fro. The problem may be as simple as the round cam assembly being loose on the shaft. There are usually one or two little grub screws that hold it to the shaft. You can see the screw hole for one of them in the pic.They may well need an Allen key rather than a screwdriver - take care to use the right size or you may damage the heads. It needs to be in synch with the to and fro movement. It sounds unlikely in principle that the gearbox would go at all if there was something wrong with one of the drive shafts. I assume you've kept the gearbox oiled. If you feel you need to go into the gearbox, I assume you have viewed the Specto pix in the multi-gauge section of my site; I don't know of any written material. Basically, you have to remove all the chain drive and sprockets from the back, and the inching knob, to remove the cover plate. Please make a point of telling me how you go on - I'd like to know what's wrong!
Q.
On looking closer with magnifying glass, I noticed the shaft is moving as I turn the cam manually. I put a small dot on the shaft that holds cam, and noticed it rotating the same as the cam. I got into the gearbox and found that the gear that drives the cam was running loose on the shaft. There is a flat on the shaft to help secure it.Is it usual for the claw to have a tapping noise when projecting a film? The Specto 16mm instruction book it says the gears are worked with oil only, and the dual is a mixture of grease and oil. Could you by any chance describe a ghostly image and what causes it?
A.
Oh well, Ive now learned something new re Specto gearboxes. (We also discovered in the course of correspondence that there are at least two different sizes of bore and front-to-back dimension of chain sprocket in the drive train).
Interesting about the lubrication - I can't be bothered and use oil and sometimes a bit of spray grease, which is nice and thin. In the old days, I used Vaseline on claws/cams.
Ghosting is most easily seen on titles, and takes the form of streaks of semi-transparent stuff below or above the letters. It is caused by the shutter being incorrectly set, presumably as a result of the stuff you've had to do with the mech. It's fairly easy to fix on a Specto; the shutter is held onto a shaft by the usual grub screw and will turn freely once released. You then turn the machine over using the inching knob, with the lens holder open so you can see what the claw is doing. You need for the big blade of the shutter to be juuuust about covering the gate aperture when the claw starts the down stoke, and for it still to be covering the aperture until the claw stops going down. (The small blade is called a flicker blade and is just to reduce flicker. It won't cover the aperture enough to stop streaking.) That way, none of the movement of the film can be seen on screen, which is what causes the streaking.
You need to check at the other end of the claw stroke, to make sure the aperture is still covered when the claw stops moving down. Only just again - the shutter blocks light so to maximise light on the screen the main blade is kept as small as possible, so it has to be adjusted just right. You may have to compromise a bit to get the best balance of covering the aperture at each end of the claw stroke. Then you just tighten up the shutter and it should be OK. You may need to do a bit of trial and error, tho. Watch the fore and aft alignment of the shutter - you don't want it catching the inside of the lamphouse as it turns. Really a silent projector needs three blades to avoid flicker but manufacturers were always trying to find ways round it. Trouble is, as light output rose, any flicker became more noticeable. Nonetheless, the Specto is pretty good; I believe they avoided problems by a fast shutter rotation rate.
You often get a clicking/tapping noise with film - it varies from film to film. Only experience will tell you if it's actually a problem - make sure the film isn't being damaged. Best way to do this is to make up a short loop of film and let it run thru 50 times and then see if it's getting scratched or if the sprockets are getting "picked" or strained.
Q. Another Specto question. Other than a mistimed shutter can you think of what may cause a ghosting to appear on mainly intertitles. Is this something that could be caused by the claw?