Monday, July 12, 2021

A digital machine (with a bell)

The new arrival shown in the previous post has a carriage and even a bell - mounted on the cast-iron base-plate. The larger view from the rear with the covers off shows the bell, the input-check register on top and some of the safety-interlocks to the side of the register.

The front view without the main covers shows the pinwheel drum and the carriage with the result-register and the revolution-counter - all with 10s-carry. The bell rings the alarm when there is an overflow (or an underflow) in the result-register - very nifty. (A very clear demonstration of the workings of a Thales machine can be seen at this link.)

The 'paddles' on the front of the carriage are for stepping left or right - squeeze both for carriage-release. The crank at the right is of course for driving the mechanism, either adding (cw) or subtracting (ccw). The wing-nuts at the carriage-ends are for clearing the result- and revolution-counters.

 
This is a Thales model CE calculator. This a fairly common model of a pinwheel calculator - a four-function mechanical calculator.
 
There is no single 'Database' for calculators and serial-numbers, but there is a vast and diverse range of informative web-pages on mechanical antique calculators. From browsing some of these enthusiasts' sites, this calculator could be identified as the model CE even though it is not marked as such. The model C-range of Thales also had tens-carry in the revolution-counter (very handy, quicker multiplication) and the extra E denotes it has an input-number display (Einstellkontrollwerk).
 
From the serial 67878 and style/features, this machine was probably made in the early 1940s.

Four of the decimal-markers are gone (as is common), but otherwise the calculator is in decent shape with the oil and grease still 'soft'. Some light extra-oiling and cleaning - and it functions. (Well, almost everything - the machine fails on the right-most digit in the result register when trying to subtract from '0' to '9' due to very worn teeth on a gear.)

The drum with pinwheels is from brass and steel, fortunately no zamac anywhere. In the picture above the pinwheel itself is shown with the first four number-wheels showing 4, 3, 2 and 1 set, i.e. four of the pins 'up' on the first wheel, etc.

Even though all it does is adding or subtracting the number on the drum (EW - entry, on top) to the result register (RW - results, lower right), with the extra revolution counter (UW - turns, lower left) on a sliding carriage it enables a whole host of calculations. Repeated addition is fairly simple multiplication - the tens-carry in the 'UW' helps reduce the the number of turns (e.g. 89 x 89 reduced to 3 turns from otherwise 17 turns). Together with the bell to alert on underflow, repeated subtraction allows for quick long-division. 

With a simple extra 'trick' it is e.g. possible to do exponents. As example; when wanting to know the precise amount of cubic cm in a cubic inch, that would be 2.54 cm to the power of 3. First multiplying 254 by 254, gives the square in the 'RW'. By then working from left to right on the 'UW', add turns to make the 'UW' copy the digits in the 'RW'. (Working left to right preserves the next digit to work on, no need to keep notes.) This then results in the 3rd power to be in the 'RW' - giving 2.54 cubed as 16.387064. (Repeating this same copy-to-'UW' procedure of course keeps raising the power.)

Another not immediately obvious technique is to split the 'EW' and 'RW' in two areas, e.g. to be able to do a proportions calculation in one setting.

Overall a fascinating little machine that is surprisingly heavy - packed dense with gears and levers - with much to discover. Not certain if the '0' to '9' issue on that single digit can be fixed, but with some light cleaning/oiling and occasional exercise it should remain 'stable'. 

An ~80 year old and very ingenious digital machine :-)

Saturday, July 10, 2021

Something different (with a bell)

A new machine! - not a typewriter.

It does however have a bell - taking off some of the body-panels revealed its position. Well hidden inside on the base of the machine.

Have not yet figured out how to remove the carriage. More to discover and cleaning to enjoy.

More pictures to follow :-)

Tuesday, June 29, 2021

L C Smith - the ball bearing Office Machine

A small promotional booklet published by L C Smith (& Corona) of Aldwych House, London on their programme of standard office machines.

The booklet explains the standard L C Smith typewriters and the many varied attachments that are available for them. Apart from platens in different hardness, also a variety of specialty platens. There must have been thousands made also of these special platens, but haven't seen any of these - perhaps not many survived.

Even though this is very much about the large standards, the booklet ends with the Corona - they are also the makers of The Personal Writing Machine!

The complete booklet about the L C Smith ball bearing Office Machine is available on The Archive.

Saturday, June 26, 2021

Parts exchange between an Underwood 5 and an Underwood 5 - platen and feed rollers

 The 'reference' Underwood 5 cleaned up quite well too. It types still, although the 'a'-levers are a bit wonky and the line-lock needs fixing. (A replacement for the missing set-screw for the line-lock was found in the special typewriter-bits tin - adjustment is an adventure that will be tackled later.)

It is a 1928 machine, but looks a bit anachronistic with its more modern ruler and the large, plastic platen knobs. The carriage-rack is also a later replacement. It means it has a nice corrosion-free lever, but the rack just fouls the backspace-mechanism when pressed down (carriage release). When moving the carriage with carriage-release pressed down it goes into a high-pitched squeak (should drive dogs wild). Despite all that, it types and is very much an Underwood 5 Standard Typewriter.

Compared to the 1920 Underwood 5, there are a myriad little changes. From the ribbon-mechanism contrates now being spoked, to an entirely different frame casting. Partly because of different mechanisms for the ribbon and for the butterfly-scales, partly the differences seem stylistic only. The pillars at the corners of the frame no longer have clear 'capitals' and the bevels at the front of the frame are also slightly different. Even the carriage casting is different, the right return 'hook' has a different form from the 1920 machine.




One obvious change (and an improvement I'd say) is the tensioning mechanism for the spring. This is an easy adjustment with a knurled knob that works via a worm-wheel to adjust the carriage spring. On the 1920 machine it is a winding handle with a separate escapement to control releasing the tension - plus a locking screw.

One justification for getting the 1928 machine was its cork platen. The rubber on the 1920 machine was rock-hard and liable to damage the type-slugs. As I'm not sure yet if I can get cylinders re-surfaced with rubber locally, a cork platen is a great alternative. It may not be as 'grippy' as a new rubber platen, but it will keep its resilience and should last near-indefinitely.

So removed the cork platen out of the 1928 machine. As bonus, it has a matching set of cork feed rollers. Four rear and four front feed rollers:


Then to remove the platen from the 1920 machine. 


Surprise; it has three front feed rollers! The paper tray is in much nicer condition than the later '28 machine, but they are again different parts - not exchangeable. (Did Underwood just randomise these things?)

When lifting out the paper trays (they just lift out, not held), luckily the mounting brackets for both sets of rollers turned out to be still identical. So also the paper tray was exchanged together with the platen and feed rollers. The front feed roller rod just lifts out from its brackets. The rear rollers need to be wiggled out - pressing down on the holding bracket against its spring should provide enough clearance to slip it out from under the little protruding tab right next to it.


In case there is not enough clearance for this, the rear feed rollers bracket holding collar may need to be loosened. By undoing its set-screw, it may be nudged down a little bit more (green circle). After re-mounting everything the tension can be restored to what it was and the set-screw tightened again. (I should have taken more pictures!)


One more thing that was done, was putting felt pads on the paper tray. Now that the platen was out of the way and also the paper-tables removed for safety, this bit was accessible. Originally there would have been rubber tube slipped over the five tabs at the rear of the tray. Similar to the buffers under the spacebar, these would perhaps help 'dampen' any vibration of the paper table. Anyhow, they had long crumbled and gone. From self-adhesive felt for putting under furniture (3mm thick), pads of 11 by 6 mm were cut and placed in position on the tabs (yellow arrow).

With all parts exchanged, the shiny 1920 Underwood 5 typewriter now has a cork platen and rollers. This is much healthier for the type-slugs and the quality of printing also is clearly improved. 

Apart from having had to swap paper-trays too, this is all as was the plan.

(However. Letting the '28 machine sit with the rock-hard platen now seems 'off' and a pity. To scout for a way to re-surface a rubber platen locally...)

Sunday, June 13, 2021

A typical Underwood 5 typewriter - now cleaned-up

This magnificent typewriter cleaned up wonderfully well. Most of the nickel bits regained their shine and the whole machine looks very well for a 100 years old.

The decals on the paper-table and on the front-panel were in very good condition, but looked fragile. Especially the paper-table letters appeared to be at risk of just flaking off. To stabilize these, an artist's protective varnish was used - this is sold by art-supply shops to finish (varnish) paintings or watercolours. This is applied from spray can and is promised to be non-yellowing and not attack or make run the underlying artwork - so sounded a good lacquer to protect the machine's artwork.

Before this could be applied, the parts of course had to be cleaned. Especially the paper-table was very dirty - it had dulled from an overall dark covering of decades of dirt. This was very carefully washed away, working around the decals. Using a soft cloth with warn soapy water, the dirt was loosened and then a clean, soft cloth used to take off the water plus dirt.


This protective varnish was first trialed on the paper-table of the test-tinkering machine - to make certain it did not attack the decal or original lacquer. One learning from this try-out was that a wipe with a dusting-cloth right before applying the varnish helps to catch any stray dust-particles.

Also this Underwood had a type-bar rest with a text that marks this as being especially for the Underwood machines with 42 typebars (that'd be a No.5 then).

On this type-bar rest bracket the original lacquer came out from underneath a century of dirt. A deep, glossy black that would have been all over the entire machine - these typewriters must have been a sight when new!

The type-bar rest on this 1920 machine was more tricky to remove than on the 'reference' machine from '28 - so far for its utility as a reference. The 1920 mechanism has an extra lever with boss that protrudes into a slot in the type-bar rest bracket (green oval). Loosening this lever allowed it to shift sideways on its way-rod to wiggle out the type-bar rest.

With the type-bar rest and front panel removed, the typebars were given a polish and the segment slots rinsed with white spirit. This made the 'edge' characters type as light as the 'middle' characters again - the typebars and linkages at the sides (the a, q) are slanted and will have collected more dirt and grime, making them noticeably more sluggish compared to 'middle' typebars (e.g. the g, h or j). (Did not take out the type-bars for a proper cleaning; did not yet feel comfortable loosening the segment - maybe after more tinkering with the 'reference' machine...)

An attempt was also made to adjust the 'L' typebar slug. This was bent such that only the top of the 'l' (or digit '1') printed - making reading typed text a bit difficult. This should have been done with a special tool, but made do with some pliers. Most likely the cause of the mis-alignment was that the slug's solder had come loose and allowed it to shift - and not a bending of the typebar. The slug could be tilted a bit on its typebar. Not wanting to risk re-soldering or brazing the slug, a little cyanoacrylate glue was allowed to seep into any cracks. We'll see how this holds up.

The nickel was polished (Brasso!) and the frame washed. The paper-table and front-panel regained a deep, black shine from their protective varnishing. The frame was given a light rub with petroleum jelly - works against rust and restores a little of its original black lustre.

The rulers' celluloid face was cleaned carefully with damp cloth - any scratches on the celluloid become much less visible after also giving these a light polish with petroleum jelly. Some oil on the carriage way-rod and the whole machine looks most presentable already!

That bell is by the way very tricky to mount with an assembled mechanism. Bell-mounting lug on the frame is again different from the 'reference' machine.

The tabulator rack polished-up magnificently. Unfortunately I made a terrible mistake with the tabulator-ruler. The mounting screws on the '28 machine are NOT exchangeable with the 1920 machine's screws - they are a different thread of different length. Not sensing this quickly enough, I accidentally sheared off the large head of the tiny screw-thread in its hole (a terrible feeling). It is now provisionally fixed in place using some cyanoacrylate, until I can perhaps get a replacement top-bar for the tabular-rack. (Still feel bad about this, I broke it! Despite having a reference machine - actually, because of the 'reference' machine...)

I'll try to forget about that little screw - here looking at the machine from the typing position it does look magnificent :-)

Thursday, June 10, 2021

Dusty (Against better judgment - a reference and test-tinkering Underwood)

Contrary to the genuine intention to not get a reference machine, I did get another Underwood 5 typewriter as a 'reference machine'. Had not meant to get another one of these magnificent 'desktop-cathedrals', but it was local, not too expensive - plus it had a cork platen and some good nickel to perhaps replace a few badly rusted parts on the 'good' 1920 machine. So; one more Underwood Standard Typewriter:


Going by the serial number, this is a 1928 machine. It has however been serviced and 'upgraded' over its working life, up to at least the 1950-ies. It does not have its original ruler (but a later style of Underwood ruler) and it got larger, plastic platen knobs (not Underwood items I suspect).

This typewriter was not protected by a case, but it did come with a dust-cover - probably also a 1950s article. Despite having this dust cover, there is some dust...

Luckily it is very 'loose' and fluffy dust. Have been cleaning it up and exploring ("What comes off when I undo this screw?"), starting to learn how to take these apart (and put them back together!). Thankfully there are many excellent resources available on these machines. Especially the postings on the Underwood 5 by Mary E at MyOldTypewriter were very helpful with lots of clarifying pictures. (Thank you!)

Am however starting to see that the original plan to use the cork platen+rollers and some of the nickel-bits is hitting a snag. Those Underwood 5 typewriters may look pretty much alike, but...   ...they are surprisingly different!

Tuesday, June 8, 2021

An object from another era

When looking at this little item, just realized that it is very much an object, an 'artifact', from another era.


This little tank wagon was bought last month to go with the toy train-set we occasionally lay out on the living room floor. All the track and trains are of course 'old', dating from the mid 1920-ies up to the early fifties. It also all looks 'period' of course, with the clockwork little steam engine (that is surprisingly solid and heavy), all-metal wagons and the tinplate rails - depicting standard British railway practice of the early 20th century. 

Nevertheless it all still works fine and is great to be played with by a kid today (and parent too).

This wagon was played with of course and has scuffs and scratches, but still looks much like it originally would have. A picture of the bright, new article is in the 1928 Hornby catalogue; a scan from the site of the Brighton Toy and Model Museum:

Our little toy railway wagon probably dates to 1928 or thereabouts. So do some of the other items he (we) play(s) with - but this little petrol tanker really struck me especially as 'from another time'.

Like our other wagons it is quite large and fairly crude as a model (it's a toy). Also it is all metal (unlike any modern toy train). The chassis with the spidery, open 'W-irons' (pre-1930 Hornby) adds to the quaint look, but also the fact that it is a petrol tanker from an oil-company. Somehow that makes it seem even more 'from another age'.

A nice addition to the 'set', and an unexpected marker of change.