Home BB1 BB2 Super Rural Rural Sonore 9.5 16 17.5 28 Pix Miscellany
HOME TALKIE
The story so far. I related in BB1&2 my attempts to uprate the lamp on the Home Talkie (HT hereinafter). This saw the fitting of a 15v 150w QI lamp, and a cooling fan on the end of the lamphouse.
Well it didn't work. With the 15/150, the lamphouse becomes unbearably hot,
far too hot in my view to use because of a risk of serious damage. So I tried a
24/150 instead. Rather to my surprise, it worked tho' light output was obviously
well down. Tho' the heating problem was less bad, I was also now finding the
motor getting much too hot and feared I might cook the wiring. So I tries the
front-mounted fan I mentioned earlier somewhere. (Again, all without making any
alteration that I cannot reverse.). This cools the motor, but not the lamphouse.
On once more taking up the cudgels to battle with 17.5, I tried a new approach. A piece of 1cm plastic channel can have a fan bolted to one "leg", and the other leg fits rather neatly under the lip of the amplifier cover. I tried this with an 80mm DC fan, then ditto mains, then both, directing air onto the back of the lamphouse. Didn't work.
At this point I started to get the bit between my teeth and decided to have a
bit of fun. I got a 120mm mains fan, two "reducers" to drop the aperture to
80 then 60mm, then a piece of semi-flexible 60mm ducting from Halfords. I made two
aluminium adapters, one to go in the end of the lamphouse to take the ducting
(see below left, looking straight into the lamphouse; the lamp can be seen in
the centre), the other to go on the "reducer" and again provide for coupling up
the ducting. I tried this fir
st
with just one stage of reduction and the 80mm mains fan. Could hardly feel
anything coming out of the ducting; most of the air seemed to be going out the
wrong way at the back of the fan! Th
en
on to second stage of reduction and the 120mm fan. You can see the total
assembly to the right. (Note the mains switch for power to the 80mm mains fan
mentioned above which, with
the aid of a large washer, fits into an existing vent hole in the amp cover). Finally,
this did give me some air,
but frankly not a lot and again most of the air coming out of the fan the wrong way. Seemed
rather better when I set it to suck rather than blow. At this point, I got a bit
discouraged and went away without actually testing, which I suppose I'll have to
do. Not very hopeful tho'. (No idea where I'm going to put the fan anyway - no
room on top of the projector.) What next? Maybe a hair dryer with the
heating element disabled?
This is what I ended up doing in order to test. We in the trade have a technical term for this - we call it "a right lash-up". Two 80mm fans, one mains and controlled by the switch seen in the previous pic, one 12v and wired to come on with the motor, are providing external cooling. The big fan with the ducting is connected separately to the mains and set to blow and held roughly in place by some orange wire; the 80mm DC fan at the front of the machine is disconnected at this stage. With a single reel, there was some evidence that the lamphouse was rather cooler than before, so I was emboldened to try a full 1000ft. This, too, seemed to be OK, but it was noticeable that the motor was starting to heat up quite a bit. Next test is with the big fan set to suck. If this works, I can eliminate the front fan; if not, I shall have to wire it back in.
I have a 17.5 Home Talkie with no end cap for the lamphouse. So I've had to make one. Here are pix of the cap; note shallow recess on outer end and internal baffle to try to reduce light spill. I suppose I could make up a bit to match the vertical section on the original cap, but right now I can't be bothered. The recess referred to will take a paper copy of the original end cap, as improved on the computer. Sprayed over with clear lacquer this should be reasonably durable.
The reason I was
making the end cap was the prospect of a sale. As you know, I always find this
painful, but I steeled myself and let my spare (fully working but cosmetically
challenged) Home Talkie go. However, this has
spurred me on to re-commission another, of which I have most bits save the spool
arms, the amplifier cover and, of course, the lamphouse end cap. So I have had
to make a second end cap and, this time, I am trying to make the upright bit,
too. I
will
show you this as and when it's finished. I have made the amp cover. Construction
is exactly the same as the original, except I have used a filler/glue material
instead of spot welding to fix the ends to the m
ain
body. I have also left the double holes at the back, rather than opening them
out to slots as in the original. This is because I have used thin alu, and I
thought it would help to keep it a bit stiffer. Now, of course, it has to be
painted, as does the main casting, seen here as sanded down in preparation. I
would point out that I am responsible only for one of the extra holes, viz the
one for a separate lamp switch alongside the original combined motor/lamp
switch. All of the insides of this machine have gone, and the other holes secure
a tranny etc. I shall endeavour to make them as unobtrusive as possible, by
countersinking the screw heads and painting them black. Although it will be far
from original, it will I think be able to show 17.5 quite successfully. I
haven't decided about the spool arms yet - one idea I am toying with is using a
16mm long-play device instead, which has its own motor drive for take-up.
I have now
painted up the amp cover, plus my now-completed end-cap,
the
shield tube leading the reflected light of the soundtrack to the photocell and
the lens-holder. I will show you these later, also the base-plates I had to
make. Still plenty to do. tho'. Left you will see a pic of the Home Talkie
reflector mirror. Someone had glued it in place or something; by the time I got
all the gunk off, this is what was left. I looked on the internet and tho' one
can do some form of silvering at home, it's complex and needs various stuff -
not worth the time, money or effort, wot I do not got anyway. Out of curiosity,
I tried spray-painting it with a metallic-look paint but, of course, that didn't
work. I have had a mirror re-silvered before, but it cost something like £25,
and that was several years ago.
The mirror from a Bolex P8 is a close match - the hole is about 41mm and the P8 mirror is 40mm - and I have in the past hacked about the P8 mirror surround to get a rough fit. Quite a bit of light spill tho' as the P8 surround is not quite right. I just tried making a ring to cover the size difference, but it's very hard working with such a tiny thickness of metal - not a lot of strength in it. I achieved some sort of result, tho' I am not dreadfully happy with it and I am unlikely to do it again unless I can come up with a better idea. Also, the P8 mirror is much thicker than the original, so the plastic back which holds the original in place is no use. I have fudged up a strip of tin across the back to keep the mirror in place for now - I have a friend who has done metal spinning and might be able to help. One has to bear in mind at all times that there is only just room behind the lamphouse to give clearance for what is nominally the lower loop.
Here are some pix Ian Green found for me on French ebay. They show the inordinate lengths to which your true cine nerd will go; the first pix are a conversion to 9.5 of a 17.5 Pathé Natan, (tho' I have since learned that similar experiments were done on other machines, including the silent Rural). The last two I'm not too sure what is going on. The last pic may show the way Pathé did the "direct reading" of the sound track that was referred to in adverts for the 1938 blimped Home Talkie - still no sightings of that, tho'.
However, the most important thing for me is that they provide
pictorial evidence of the principal difference between the Natan and the UK Home
Talkie. I noted this as far back as Big Brother 1,
but didn't really have the pix to show what I meant. Now, whether the Natan was
ever sold with just the "island" plinth and not the bigger one, I know not.
However,
Grahame Newnham told me that the Natan was sold without amplifier, for
people to hitch up to their radio's or, I suppose, to the Rural amplifier, which
was a separate unit and not integral. What we need is a French, English-speaking
17.5 enthusiast to tell us all about it. The piece left about the Natan was
found by Dave Richardson.
Have been doing painting/repainting of some parts of the Home
Talkie. As you can see, I have made an end cap for the
lamphouse
complete with the upright bit. I made it in two parts and fixed them together
after. You can also see that I chickened out of copying the punched, folded tabs
that hold the sound chute on the original and opted for a simple nut and bolt
fixing.
As you will have seen, my new Home Talkie lamphouse end cap hav no logo. I scanned an original in, then cleaned it up. When I came to print, the colour cartridge was running out and produced a rather nice pink version, so I made a blue one as well. If you need one, you should be able to copy and print whichever one you fancy.
The last pic is an actual, on another end cap I made, complete with the upright section and, as you can see, I am a traditionalist. It's glued in by clear lacquer under and on top and, as you can see, it's stained the paper in different places. Makes it look quite authentic.
I find that the design phase of a project can take me days of thought and false starts. The question of spool arms for the 17.5 Home Talkie I am refurbishing is a case in point. The drawings you will see below - still only theoretical as work has not started - are the third major design attempt over a period of many weeks. As I have no spool arms and am starting from scratch, I thought I should at the same time make them suitable for 2000' reels - the normal 1000 ft capacity means a reel change every two reels. But the securing/locating pins built into the machine seemed to me a tad lightweight for this job - they are simply studs fixed into only about 0.25 inches of casting. The extra weight and leverage of a full 2000' spool seemed to be asking a lot. So I came up with the idea of using the bolts that hold the two halves of the main mechanism together as extra support. All this, of course, is in pursuit of a solution that makes no permanent alterations to the machine which, as you should know by now, is one of my main rules.
My solution is to add a block to the machine, using the existing pins for location and with one of them extended to use as a fixing just the same as the original. Extra strength comes from a steel plate at the rear. The block is then drilled to take spool arms as per the old style B&H machines, round-ended arms into a hole, but with pins to ensure the arms go in on the correct alignment. You will note the two arms are not in identical alignment; correction for this will be made when I come to the spindles at the other end. I also have to consider how to drive the take-up. Will the existing method suffice, maybe with a double pulley part way up the rear arm to which the existing belt would go, with another belt from there to the end?
Inevitably, some changes have had to be made during the actual manufacturing process. I found that the existing spool arm securing pins were not, as I had hoped, removable, so I couldn’t simply insert a longer one as planned. Instead, I made a rod thick enough to take a matching screw thread. (As I ought to have guessed, the thread on the original pins is not a standard one, so required purchase of a special tap and die.) This meant a larger hole through the block, leaving less room for a hole to take the rear spool arm, so I had to reduce that to 9mm. The other significant change to the original design is that I decided to make the rear support plate follow the profile of the bracket block. It may all sound straightforward, but involved many hours of work for me.
My original intention was to take some 12mm square aluminium rod I had to hand, round off one end to an exact fit into the hole in the bracket block and make spool spindles to fit. However, given the amount of work I had already done, I baulked a bit at this. I happened to have a pair of old-style B&H spool arms and, as I intended anyway to use 16mm split spools….. The point about 16mm splits is they can be widened slightly with a washer. I would intend just to have 3 or 4 such spools and to build up films before showing and return them to their normal spools after. Also, the spindle size is actually the same as 17.5 so, with holes for the 17.5 pin to engage into, they can if needed be used on a standard 17.5 spindle, although for my present purpose this isn’t an issue. The B&H arms also have a well-proven take-up arrangement that handles 1600 – 2000 ft reels, something I was a bit dubious about just using a simple belt arrangement as per the Home Talkie.
What I did, therefore, was to make adapters to fit into the B&H arms at one end and the new block at the other, with screw-in knobs as retainers – as usual, to avoid any material alteration to the originals. If I had my time over, I would make one or two things a bit different. The adapter for the rear arm would be enlarged to the same diameter as the B&H arm and gently tapered down to the bracket block. This is cosmetic, but more significant is the fact that the internal bores of the B&H arms, never having been intended for use, are I think off-round slightly and also are stepped and tapered. Much closer attention to fitting the adapters more exactly, and more deeply, into theses bores would give a firmer fit. You will see in the last pic I tried two different approaches, a lump on the side to fit into the slot in the B&H arms, and a longer, straight-through securing screw. I think it still needs more work to ensure the whole arrangement cannot twist, eg under the pull of the take-up.
Another thing I found was that with the longer spool arm at the rear, the take-up belt, even when correctly crossed, fouled the flywheel. Fortunately, a simple solution was possible by lengthening the projector thru bolt and adding a couple of Meccano ™ pulleys. (Now I never knew that typing TM and then trying to put brackets round it would do that.). As you can see, I need to shorten the belt a bit - the B&H belt is tight, relying on the arrangement at the end of the arm to provide slack.
The other issue, which I have yet to address in detail, is whether the arms line up with the film path sufficiently well for practical purposes. As you may recall, the hole for the rear arm had to be offset slightly to clear the original mounting pin. I had planned to deal with this simply by where I fixed the new spool spindles I planned to make. We shall see. The reason I have not yet done a full road test is simply that I want to leave the parts I have newly painted as long as possible to harden before re-fitting everything – this is why in the pix the machine is mounted an a wooden baseboard (it falls over else with those long arms on). There is more yet to do – arranging the sound reading, covering various holes in the base and of course painting these new bits wot I have just made, and maybe the B&H arm too. The mechanism itself also needs work – I don’t think it has an oil-tight seal (I think it runs with a small puddle of oil at the bottom, which is picked up by the main gear wheel, which is about 4” diameter, and splashed about the insides generally. I suppose, come to think of it, you’d like some chitterling pix as well while I have it dismantled.
Well, here it is at last, the day you have all awaited for so long - the inside bits of a 17.5 Home Talkie, which I promised you a long time ago.
Dull, isn't it?
I am struck looking at these chitterlings for the first time in many years at the simplicity of the mechanism. There are just two gears, with the single sprocket on the shaft of the large gear and, directly mounted on the motor shaft, a double cam which imparts a completely square motion to the claw, a thing I always thought excellent. I came across one or two twiddly bits which might help someone if they ever fiddle with a Talkie. The sound flywheel can only be removed and, more important, put back, when the two castings are at least partly separated. It may also be impossible to screw in the tiny lens for the sound reader when the flywheel is in place; it may, however, be possible to create enough slack to overcome this by loosening the rear bearing pin. It strikes me that the edge of the sound drum on this particular machine is actually a tad too far away from the sound reader, tho' I have yet to be able to test. This could mean that too much or the wrong part of the track is read, creating nasty noises. It cannot come any closer, because then the larger rear part of the flywheel fouls the projector body. I am considering a little thingy to sit on top of the reader lens, with a small slot in it to limit the width of track read. I am also trying to come up with a way to make it possible to adjust the reading position while the machine is running (as most 9.5 sound machines do). The position can be adjusted, but the retaining screw you need to access is under the sound chute, and you end up with trial and error, and no easy way to cope with varying track positions from reel to reel or, indeed, within a reel which I found with Lorna Doone.
If you look at picture 3, you will see slightly above and to the right of the claw frame two brass-lined holes. These are the two stops in which the pin of the moveable sprocket roller retaining assembly locates (open or closed position). They are clearly later additions, presumably because of wear. I found that the special screw on which this assembly pivots had in a similar manner partially stripped its thread and would no longer grip. The thread was not one for which I have a tap to hand, so as well as making and inserting a threaded brass sleeve, I had to make a new screw as well, so I could use a thread I do have. I've also had to make a screw for the lamphouse pivot, and a replacement roller to replace one of an incorrect design - this assembly and its correct functioning are critical. Fortunately, I have another machine to copy from.
It would appear that the machine is supposed to run with a puddle of oil in the bottom. There is a sight glass; others I have seen require you to keep the oil about half way up the sight glass. It is, however, very difficult to attain a complete seal; the sight glass is especially difficult because, of course, you actually need to be able to see through it afterwards so cannot simply smear it with gunk. That springy arm on the claw frame may be to splash the oil about a bit?
There was the usual good-quality instruction book for the Talkie, which I have scanned in and am gradually cleaning up.
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