Details: Category: 16mm

PRECISVOX

Might as well start from the pix I have shown you before, together with one of a completely different and much more conventional-looking Precisvox I found on the internet; apologies to the source but I forgot to note the name.

Above is a series of pictures of the machine as I dismantled it. I must apologise for some of these pix; they are very much workshop pix and not as prettified as I usually give you. From these and the next set of pix you can see just how generally distressed and dirty the machine is. The paler paintwork in particular seems to attract a very stubborn layer of dirt that is most reluctant to shift. Note also the aluminium corrosion on the amp cover and the apparently very thin plating, which I assume to be nickel, which has worn away extensively. I was driven to the conclusion that a re-paint was the only option, as removing the dirt also tended to remove some of the paint which was, as you will have guessed by now, pretty thin to start with. Note in particular that pix 1 and 2 are AFTER a fair bit of cleaning. In pic 4, none of the labelled parts are parts of the infrastructure of the machine - they just sit on top, barely secured in place and adding nothing to the strength of the construction.

precisvox in_bits_008

As can be seen from this second batch of (mostly outdoor in this case) pix,the basic construction seems to be a bit like an old-fashioned car, with a chassis from which the rest of the bits depend, but with hints of monocoque construction in the reinforced wrap-round skin and the steel strips at each end which wrap round much of the base. These strips actually make the machine difficult to pick up, as you basically have to use the strips, which cut into your hands. There is a curious circular strip protruding at the front; this is part of a mechanism for raising and lowering the front of the machine.

I suspect part of the dirt derives from a feature that I have not yet quite bottomed. More or less in the centre of the assembly of stripped-down parts is a section with a long bent rod and a thin brass tube, attached to a sort of cylinder at the other end. My guess is that this is in fact a “press to oil” button, with the bent rod acting as a piston and the cylinder being an oil reservoir. You can see a tempting button at the end of the bent rod, which is just visible in the first pictures of the complete machine, sitting just in front of the lamphouse cap behind the top sprocket. My problem is that I cannot see how the oil gets into the reservoir in the first place – there is no way in other than the brass pipe or, just maybe, the plunger itself; however, I cannot remove the button to see if this is the answer and I am reluctant to use too much force. Anyway, my point is that over-eager use of this could help explain all that dirt. Together with the fact that the projector is probably pre-war, according to what I am told about the amp design, and any Belgian projector of that era could have had an adventurous life.

A fair bit of Bakelite is used in the construction. One of the side “wings” – dunno what else to call them – has broken at some point, and the ends of two of the decorative side strips are missing. There is also a break in one of the fitments for the lens housing, but generally the bakelite has survived well. The principal use is for the complex sprocket assembly, see pic 3 just above. The knob on top foxed me for a bit as it just turned uselessly, until I realised that pushing it down gave me an otherwise-absent inching knob. The sprocket retaining rollers are apparently fixed, ie no spring-loading or pivoting, altho’ these are present for the sound drum. There is also no way of dismantling the roller assemblies since, as with numerous other parts of the machine, they are made with rivets or similar and are not designed for easy cleaning. The cooling fan seems to be impossible to remove without damaging the machine by untwisting or bending numerous fold-over tags that are the method used to hold everything together. All the (now thinly-plated and worn) decorative strips on the amp cover are riveted in place, making any re-plating impossible and re-painting problematic. A triumph, perhaps, of style and cost-cutting over durability and practicality.

The outer cover is joined to the chassis partly by threaded inserts in the decorative bakelite strips along the side, plus sundry screws, but is cushioned by a strip of what looks like paper but is now totally saturated with oil. The arm assembly for the spool spindles is incredibly light, due to the use of incredibly thin-walled aluminium tube. But the spool spindle assemblies do at least come apart for cleaning.

The amplifier is a largely self-contained unit that is relatively easy to remove, but you do have to thread the photocell unit out. This is a separate little unit at the end of an “armoured” cable from the amp, and includes the PEC itself plus a valve and what is presumably a pre-amp circuit. Getting it out is a bit of a tight squeeze as the unit is quite substantial and has to pass thru the projector chassis. As I have mentioned, the valves and circuitry seem, according to my electronics advisor, to indicate a pre-war date. Construction of the amp is decidedly odd, because it actually sits over the top of the motor, surrounding it on 3 sides. The connections to the valve bases underneath the chassis are not direct; instead connections go to a disc about 1.5” away, incorporating various capacitors, resistors etc along the way, and connections to other parts of the amp are made from there. The amp unit also incorporates the control panel for the machine, including the lamp and motor switch. Labelling of this is done very much on the cheap, by means of a piece of thin, printed card with holes in to go over switches and sockets, and covered in turn by an equally flimsy sheet of transparent plastic. The original was rather the worse for wear, so I have photoshopped it. It refers to a tone control, which is not present on this machine. The “source” for the PEC is not an exciter lamp, but an inverted main projection lamp. This is the standard, pre-focus base type. I have never seen a lampholder as flimsy and inadequate as this one. It is constructed of very thin aluminium sheet and is almost impossible not to bend. It sits in a complex structure of thicker alu sheets, which is very difficult and fiddly to take apart, as taken apart it must be because of the filth that cakes it. Overall, apart from the amp, which is at least removable more or less in one piece, little is designed with maintenance and repair in mind.

I have marked on pic 4 in the second big set above the location of the mirror that directs light from the sound track to the PEC. The scrappy (curved) little mirror was held in place by Blu-tak when I got the machine; this alone will probably dictate a conversion to a modern cell, as there seems little or no support for the mirror and the correct positioning is going to be a bit of a trial and error game into which I do not wish to enter.

Probably the most difficult part to restore to a decent appearance is going to be the amplifier cover. This suffers from "alumiium rust", where some form of corrosion lifts the paint, produces white powder and leaves behind a pitted surface. It also has numerous teardrop shapes, whose nickel plating has worn thin and which are each fixed to the cover by two small rivets. These would be very difficult to remove without damage and equally difficlt to replace satisfactorily. Probably not worthwhile; needs more thought. Pic 6 in the second main set of pix above gives the clearest view of the lamphouse cover, which I cleaned off, again because of aluminium rust, with a paint stripping device running at high speed in a drill.

Details: Category: 16mm

B&H

BELL & HOWELL

You are of course aware of www.paulivester.com (click on films when you get there), where there is an attempt at listing all known B&H machines.

I have always been totally confused by B&H projector model numbers. I have found this, which helps, tho' I suspect there was a whole range of other models in the US.

Variations on a Theme

I (foolishly) bought a B&H silent (a Model 129 "auditorium" machine) on American eBay. It arrived damaged, of course, as no-one knows how to pack a projector to withstand the antics of carriers. It arrived with a broken pivot bolt. It's very like this:-

but without the resistance at the top of the lamphouse and is, I think, a later model. You can't see much of it in these pix, but behind the base of the lamphouse is a "box" into which all the wires come from the base of the projector. This box has a plastic cover, which was damaged by the wires pulling against it once the pivot pin broke. Incidentally, it's quite difficult to get apart, as the wires have to be disconnected inside the base first. What you can see in the second pic is the "tail" of the box lid, a conduit for taking the wires down into the base. I have finally finishedfabricating a replacement out of aluminium, as well as making a new pivot bolt. The fittings are much the same on some of the more domestic 16mm machines, but of a slightly different design so I couldn't just swap.......

I put it back together to test and it works fine, except there is no speed control. Either it's worn out, or the bit of brake "shoe" used in this regrettably archaic bit of mechanism has shifted because of the jolting. This means another major dismantling job.

The pivot bolt had simply sheared, allowing the mech to flop about, pulling on the wires from the base that passed thru the, now busted, Bakelite cover (above) to the wiring box under the lamphouse. Not too simple to copy. I also found when I had dealt with these two faults that there was no speed control - I assumed the brake shoe which rides on the face of the fan to brake the motor had been jolted out of place. I was right, but I've managed to fix it, so the projector is in full working order. However, some of the parts of the brake mech seemed to have gone missing. The speed control knob visible from the outside is hollow. But all there was there was a short piece of brass rod, which was nowhere near long enough to go inside the hollow knob and then extend far enough forward to press on the brake shoe. I inserted a spring and fitted a longer rod, which seems to work OK. To get access, there is a ring of bolts (marked in pix 4&5 below) joining the motor and lamphouse as a single unit to the block containing the gearbox and claw mechanism, plus the gate and sprockets. In order to allow the motor to move enough, I had to remove the rear spool arm. It was a bugger to re-insert the motor, as there is a mech on the end of the shaft that engages with the clutch lever, and this did not want to go back in past the lever.

I have been noticing differences between this "auditorium" machine, the earlier one I already have and comparable "domestic" models (all 16mm). The later auditorium machine has only a single line of teeth on the sprockets and a sound-style double claw. Clearly, it became apparent that even silent films were printed on sound stock. It also became apparent I was going to have to do pictures, so I bought some domestic models out of the "spares" zone to use as examples - the machines themselves are only moderate to scruffy in appearance. Let's start, tho', with the auditorium models.

They are both, in fact, Model 129, but the later one (pix 5 & 6 above) has the suffix "H" on its nameplate. It is also described as the "Showmaster" on the switch panel. The earlier model has a quite different gate and sprocket arrangement - see pic 4. The film retaining rollers are carried on a slider with a travel of about an eighth of an inch. The retainers can only be opened when the gate is open, and close automatically when the gate is closed. This seems quite a complex arrangement and it is not surprising it disappeared. The early one has a resistance on top of the lamphouse, but this seems to relate only to the lamp and is presumably adjusted against the built-in ammeter. There is a separate adjustment on top of the motor for matching to the voltage of the lamp in use (pic 3). In pic 5 you can see (but not very clearly 'cos it's too shiny as I ent painted it) my replacement cover for the connecting box at the base of the lamphouse. Both these machines are designed to be runnable on DC as well. Note that one has to reach over the top of the machine to get at the clutch lever. I expect there are a great many other minor variations, too. The last pic is one I can't identify, but it looks like a 70's designer got his hands on a 129 and created this horrible thing.

The very elegant machine in pic 1 is not, in fact, from the spares zone. It is interesting in having the same sprocket arrangement as the early 129 above. Unfortunately, I do not have any other details to hand. I have found a string of pix of another variant; see below. The extremely manky object in pix 2-4 above is an early domestic Model 613. The resistance control on the top of the lamphouse seems to be the mains voltage supply adjuster, with a fixed 400w for the lamp. It still has oilers; note tho' the quite different arrangement for feeding wires from the base to the mech. This machine may actually be incomplete since the later machine (613H, pix 5&6) has something more like, but not the same as, the auditorium machines. We have, however, moved on to the more modern style of sprocket retainers, but we do not yet have the front-mounted clutch control as does the later 613H. Note also that the clutch mechanism seems to have changed, with a button on the end of the motor casing rather than the lever actually reaching inside. No oilers, either. You do wonder what it cost to make all these changes. Also, for some reason there has been a later addition to the early 613 of a gear under the inching knob. I do not know what it was supposed to achieve.

Finally, a weird analyser machine with a frame counter and a manual crank, a Model 173. A particular feature of this machine is the knob at the back of the motor, which is graduated in numbers that are presumably RPM. This makes it a variable, fixed speed motor, such as I have previously met only once, on a Bolex G3. One wonders why this sort of system was not used for sound machines instead of that noisy centrifugal governor arrangement. Incidentally, I have come up with a possible reason why B&H stuck with the braking system of speed control for so long. Anyone who has used a Bolex DA or most other 9.5 notched film projectors will have noticed how the speed of the motor changes quite a lot as the load changes at stills. There is, however, a smaller effect even during normal running, with the motor changing speed as it and the rheostat warm up or the load changes a bit depending on the characteristics of the film. This more minor effect might be overcome by having the motor permanently under load from the brake shoe arrangement. Not sure I am convinced, nor is it obvious why this should be so important, but I thought I'd run it up the flagpole and see if anyone salutes.

I can't identify the first machine beyond its "Diplomat" title. It's really here as another example, and also as an extremely rare example of a box which has survived in excellent condition. Picture courtesy Pat Moules. The rest of the pix I can't recall anything but what you see. Note it has the old-style sprockets and I suspect a resistance under that lamphouse cap.

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I have a B&H 643 (pic 1), quite a late version I believe (Paul Schimmel says the 8D prefix it has shows this, pic 2), manual threading, incandescent lamp (valve-type base), optical and magnetic. Given that the projector looks quite well used, I was amazed to see an original worm, looking to be in perfect condition and allowing the projector to purr along quietly. I was so impressed I changed that dreadful Jones plug input for a Euro-plug type. They really did not want people bypassing their work. There are, of course, 4 pins to a Jones plug; this is quite unnecessary, as all it means is there are two live input pins. Inside, the colours of the wires seem designed deliberately to confuse, not corresponding to any of the usual colour codes. Once you remove the original receptacle, the holes are of course in the wrong place for a replacement. What I did was to make a flat plate the same size as the original receptacle, and offset the euro plug (I always find this confusing - what you stick into it is a socket) to one side. It is secured by one of the original screws and by a screw into an extra hole in the plate. The other original screw fits as before. I had to slightly file out a couple of holes is all. Incidentally, I think the extension speaker sockets are also a weird type. so I'll have to replace them, too.

Pic 1 is an unusual -looking machine to British eyes, tho' it got here somehow. 2 is a bit more familiar, but still a long way to go, and then we move to the end of the line.

Details: Category: 16mm

Debrie

DEBRIE PROJECTORS

A short digression

Although the name Debrie is virtually synonymous with 16mm projectors, there was an (obviously aborted) plan for a 9.5mm Debrie once. Here are some remarkable pictures Alain Gomet sent to me. They seem to be of none other than a prototype Debrie model for 9.5mm. It seems to have been based on the 16mm MB216 and is designated the MB295. Looks to have mag sound, too. Oh, what mite have been!

'Oo'd a thort it, eh?

Now back to the plot.

Here is a link to Debrie Instructions.

Please remember to take great care with Debrie motors. They have a separate start winding, with a centrifugal device that disconnects this winding as soon as the motor is up and running. This centrifugal device can jam and, if it does, the start winding stays connected and burns out in about 15 seconds flat, leaving you with a motor that will run if you give it a good twist, but won't start on its own and is not repairable short of an expensive rewind. It's easy enough to get at the centrifugal mech, which is at the rubber drive wheel end of the motor. You still have to remove the main fan, (but see below) however, which is at the other end. I just did one - there was a roll pin thru the fan centre and the motor shaft, tho I am not sure whether this is original. It can be difficult to remove the fan because, it being very old Bakelite or similar, it is very easy to break if you apply much force. What I did was to get little bits - 0.25" upwards - of metal rod, of a diameter just a bit less than the motor shaft. Carefully place these under the big plastic screw cap on the end of the fan, while holding the motor vertical, then tighten the cap, and with luck the metal rod should push on the end of the motor shaft and, as you gradually increase the length of the metal rods, pull the fan off. Ideally, one would find something else with the same screw thread as the cap to avoid the risk of breaking it. There is only a very short thread on the cap, so you can only move a little at a time.

To get at the innards, remove the two screws at the drive end and the motor rotor should pull out from the other end (this is why you have to remove the fan) enough for you to get at the entrifugal mech and ensure it all moves freely. It's pretty obvious once you actually see it. Here is a pic. See the brass weights and the pivots the spring etc - just oil lightly and ensure all that can move does so freely.

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I have warned before (see above) about the risk of almost instant burn-out of a Debrie motor, particularly one that may not have been used for years, if the centrifugal start mech is not working. However, I have found an alternative method of access to the one I described earlier. I have previously found it impossible to remove the rubber drive roller on the opposite end to the fan, but with 2 motors I have tried it has removed easily. It is important to note that the roller has a left-hand thread. With this removed, one can avoid removing the fan - here is a pic that shows the level of access possible.

I have arrowed the two weights - if you push with a blunt instrument (nothing too sharp!) they should move against a spring. I have used ordinary light oil (very sparingly!) and switch and contact cleaner, which is much less damaging to electrics in large quantities than oil or WD40. Just for your info, I noted that this operation loosened the fan end a bit too, so that it looks like the end of the motor won't screw back on properly. Just make allowance for this and it goes back fine. One of the rollers had two opposing holes drilled in the end of the metal core underlying the rubber drive. It occurs to me that with one of those jeweller's/watchmaker's things one might be able to get much more leverage. These have a pair of pins that can be set to match a pair of holes like in this case, set in a handle for leverage. Might be worth seeing if it is possible to make holes in those cases (one out of the two I have been fiddling with) there are no such holes.

This is quite a late Debrie catalogue, I think - I acquired it with a machine. You could add mag sound.

I thought this was a rather fine pic of a black Debrie. It is particularly interesting for having what might be a curved gate for the sound.

Ken Finch has sent me some explanation.

"Having looked at your latest picture of the Debrie, it looks extremely similar to the old pre war Pathé Debrie. I had one of these. It was my first 16mm machine and although it looked very similar to the later models there were a number of mechanical differences. The intermittent although the same design was slightly simpler.

The sound head gripped the edges of the film at the curved sound gate on top of the cell housing similar to the 17.5 mm machines. The film then went round the sound drum to the lower sprocket. There was no compensating roller as on the later models or smoothing rollers before the sound gate. The base held a pre amplifier, the bump at the rear being a cover for 2 valves. The main amp was in a separate metal casing with one of those perforated metal covers." He also sent this snippet from ACW; the line drawing at the bottom makes the point re the sound set-up.

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The leaflet shows a type of Debrie amp I'd not seen before; the pic is a similar but probably valve-based one from Argenteuil 2009.

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This is a genuine Debrie double band machine, but it looks like it's been used in a lab or some such, as there seem to have been many changes to input/output plugs and wiring. It even has an additional, half normal size sprocket on the projector side. There are micro-switch controlled rollers at the front. It has substantial, proper sprocket retaining rollers, and a chimney on top. Also an unusual gate. Obviously a chequered career.

I have completely dismantled a Debrie D16 picture head, down to the last nut, bolt, roll-pin etc. Why, you ask yourself, does a nerd who so loves projectors do such a thing? Well, a) because I want to; b) because I need the space; c) because I have a surplus of Debrie picture heads for which I cannot honestly ever see a use; d) it is a great source of bolts and nuts and occasionally other bits - I am forever rummaging thru my collection of random screws to find just the one I need; and e) how else does one learn how a projector ticks and generally learn and practice stuff that helps to preserve other projectors?

Care is needed with old, disused Debrie motors. They are condenser start, and can get fried when the centrifugal mech jams and fails to cut the condenser out of circuit as soon as the motor has started. Open the end up and make sure its working before running (see above).

For those interested in this sort of thing, these pictures show the main ticking bit of the Debrie, viz the claw mechanism, from the back. There are two cams, the in/out cam being exactly like that on a PathBaby. Unusually, the upper and lower arms that ride on the main cam are not in a single piece - there is a gap at the back (left in the pic). This presumably helps to ensure a completely square up and down movement. The in/out cam follower has a slot that rides on the in/out cam, and this follower moves up and down on the thing I have labelled slider in response to the movement of the main cam. The triple claw is fixed to the carrier by something that looks very like an elongated cycle chain clip.

I have tried labelling these pix, but it don't seem to come thru on the web version.

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Debrie Spool Arms

I have long been baffled by Debrie spool arms, in particular how they come apart to remove the arm and, more particularly, to get at and replace those easily-broken bakelite bits. So I took a damaged machine and dismantled it, with a series of pix to help those who have been baffled like me.

Instead of separate images, I have a PDF for you, but I will leave the miniatures below - just don't expect them to work!

Debrie_arms.pdf

We start with the top spool arm, untouched. Three screws to remove the sprocket; note that altho this one seems to be in one piece, it is really a fairly thin sprocket wheel with a spacer (see pic 12). This exposes a taper pin securing the next bit; find which is the thinner end/side and knock it out. This needs care because a0 it is easy to break the bakelite and b) over-heavy force may bend the shaft. Find a way to support the immediate area of the pin. Pic 3 is the back, 4 showing the cover removed. In 5, we move on to the pin having been knocked out and the underlying ring removed to expose a very specialised nut. To remove it, you need a tool something like the one shown in 7. I got it in Maplin, labelled as a thing for undoing watches. The bakelite bit and the greasy felt washer under it can then be removed. Three more screws finally get you to the bottom of it. The gear must relate to the oil circulation mechanism as there is no drive to the upper arm.

10 - 14 give you an abbreviated canter thru the lower arm. Note particularly (pic 13) that here the bakelite part is located by two steel pins visible either side of the specialised nut. They don't seem quite symmetrically placed; also they are not fixed, so take care they don't just fall out.

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Here is a pic of a serious Debrie I don't think I've shown before.