Agelist for Underwood frame numbers (left-foot numbers re-visited)

Spurred on by extra datapoints of Underwood typewriters left-foot numbers on The Database (Thank you James!), and now looking only at the Underwood 5 samples, there are enough points to reasonably map a relation. 

It is not quite a linear fit (the portfolio mix of Underwood was evolving), but a polynomial fit gives a pretty good correlation. Using that fitted relation and the serial numbers from the agelist, then an 'auxiliary' agelist based on frame numbers can be created:

year frame number

1905    75,000

1906   115,000

1907    154,000

1908   206,000

1909   260,000

1910   329,000

1911      410,000

1912   515,000

1913   639,000

1914   769,000

1915   883,000

1916   998,000

1917 1,141,000

1918 1,287,000

1919 1,422,000

1920 1,601,000

1921 1,812,000

1922 1,948,000

1923 2,130,000

1924 2,323,000

1925 2,520,000

1926 2,768,000

1927 3,005,000

1928 3,214,000

1929 3,386,000

This agelist from frame numbers (a.k.a. the front-left foot numbers) probably has a margin of about a quarter-year either way. Note that after 1926 the first digit of the frame number can be missing, but the full number likely still stamped on the carriage side.

This 'auxiliary' agelist very likely can also give a year-estimate for Underwood typewriters that fall in other serial number ranges than the 5, but were built from the same frame-casting and assembly line.

There's more information still to be had from more data - e.g. there are hints that 1916 saw a significant, sudden shift in the Underwood portfolio -or factory set-up. Also there are hints on batch-sizes, and production buffering was not completely first-in first-out either.

I.e. as more frame-numbers become known, the data will improve and more information can be extracted. 

But already possible is a rough "front-left foot agelist"  :-)

Marchant carriage shifting mechanism repair

The carriage shifting mechanism of the early Marchant calculators is very recognisable, it gives these machines a distinct profile. This mechanism is subject of a 1916 Marchant patent and is quite exposed on the front of the machine - putting it at increased risk of damage.

One of the levers was indeed broken on the target machine, the broken-off piece fortunately still held inside the mechanism.

To try fixing this, the lever was taken out. Fortunately the rod that holds it all in place was freely movable, so slid over to the left and the parts taken out (hold the spring as you slide the rod, to prevent it shooting off into the distance).

The right shifting lever was indeed broken, and actually had an old repair that had failed!

The original steel lever arm (rocker arm) had originally broken where it's weakened by the hole for the connecting rod.

To repair it, some time long ago a brass plate had been soldered to the side and two drilled/pins were added. The solder connection of the brass to the rocker arm had however failed and the part again broke.

After very thorough cleaning of the part, the old repair was re-soldered. The pins could now also be embedded in solder and extra care was taken (flux, much flux) that the solder reached the entire contacting surface of the brass plate with the lever. Hopefully the solder will hold, to be able to keep the original levers on this machine; they are stamped with the last digits of the serial number - parts of machine 70049.

The whole carriage shifter design seems a bit 'out of character' with the rest of the calculator. Even though it works well and is easy to use, it looks (overly?) complicated in its parts design. Even the lever is assembled from three separate parts; three stampings (needing multiple tools!) and a turned rod. Below shown as loose parts; the two different (!) rocker arms and the keypad - these need assembling and 'riveting' together.

That's not even mentioning the complex locking-pin, the swaying gear assembly and complicated casting details of the base. Quite a few parts to be assembled, with a few very tricky springs to insert as well. Here in in the factory; assembly of the full-size Marchant A, not the Pony:

It does however work very well, is surprisingly easy to use and is an (the) original Marchant-specific part of the calculator.

Comparing to the donor-machine, there are again multiple small differences also in this mechanism. These machines are probably very close together in time; the donor machine (shown on right) will date to late 1919 (November?) and the target machine (shown on left) probably is an early 1920 machine.

The levers are different; an extra spring-hook and a changed order of plating the part. Different torsion springs, even the base-casting is different!

Also the locking spring-plate of 1919 (left) is entirely different from the 1920 item (right). The pin from the donor machine was filed to fit the target machine; to replace the pin with the broken-off carriage-release tab.

All put together on the target machine and the carriage shifts again as it should! :)

Pinwheel drum of a Marchant Pony B - cleaning and its manufacturing

The pinwheel drum of the donor-machine was blocked - that is, no column would operate all pin-positions, pins were rusted solid in retracted position. Part as a rehearsal for overhauling the drum of the target-machine, partially to see if this drum could be better and partially just out of curiosity; taken apart for a cleaning and overhaul.

To take the drum out of a pinwheel calculator, one of the sidewalls has to be removed (i.e. a 'bracket', in Marchant-parlance). Then the drum itself can be taken out and apart. First step for that is to remove the pinned gear at the counter-side (the left in image below). Second is to remove the holding nut (red arrow).

The biggest challenge in cleaning this drum was the loosening of the holding-nut. This needed heat (soldering iron) and even some carefully-aimed hammerblows to start moving. (Clamp shaft in vise with protection, eg copper, don't apply any force to the disks!) The taper-pin of the counter-gear on the other hand came out easily. With the counter-gear and holding nut removed, all the sections of the drum simply slide off. Then a collection of 9 pinwheel disks, 3 carry-segments, clearing-arm, clreaing-arm-ring, a collar, one holding-nut, counter-gear, locking-comb, comb-pushpin, comb-spring and of course the main shaft:

The pinwheel disks are held together by two screws and a cover-plate. The carry-pins in disks 2 to 9 are peened in-place and cannot be removed. A brass disk, operating-ring, detent_spring, 9 pins, 2 screws and a retaining plate:

All disks (or dials) are different, specific to the angles of the specific dial digit-position. The timing of the pins and especially the tens-carry is staggered over the drum. The dimensions of the parts for every dial are thus different. Angles are given in the setting of the dividing-table of the slot milling machine.

The diameter of the drum is divided in 37 positions. Central 9 positions are needed for the setting pins, slightly staggered from disk-to-disk -to spread the load of turning the numeral wheels over the turn of the crank. Outside of this centre setting-pin 'field', there are the 10-carry pins spiraling out from dial 1. These carry-pins need one position offset from disk-to-disk to allow a wheel to do a full carry before the next engages.

The steel cams that reset the ten-carry levers are most clearly different; shown in this below drawing - these cams are all stamped with their position number.

The position-specific parts of a dial are all marked with their position number (an obvious and very useful thing to have in manufacturing) - below for example dial number 7:

Dial parts were cleaned individually: steelwool to de-rust the plate and metal-polish for the pins and ring. A very small amount of light, clean mineral oil (sewing machine oil) in assembly and some vaseline rubbed on the retaining plate against rust. When put together again, all pins move - although perhaps not quite as smoothly yet as they would have when new. 

Taking apart the drum also revealed markings from the manufacturing process.

The drum of the donor-machine is marked at the outside of dial 1 with a date and initials. This suggests that employee RA assembled this drum on October 15, 1919 (a Wednesday). 

Several -not all- of the pinwheels (or dials) are marked with initials TH scratched on the retaining plate. Individual disks were assembled separately, with employee TH scratching their initials into every disk they made on the obvious surface to do so. 

Dials were first assembled and stacked per dial-number onto a stake on a wooden plate. There are even photographs of this in the Marchant factory around that time. A store of assembled dials in a 'vault' cabinet from a 1918 article and stacks on a workbench in a cropped detail of a 1920 photo captioned "service department" (?):

Another thing found out when comparing the two drums (and trying to exchange) was that the large driving-gear is not in a pre-determined position to the drum. That was surprising. It is a press-fit onto the drum-shaft that has the keyway to orient all the dials and parts. The gear teeth position appears to have been random, but at a first assembly of a machine the crank-handle shaft would be drilled for the handle. Thus the two shafts are matched in the angle of gears, they work on that specific combination. This was concluded from the gears on the drums of the donor and target machine not being at the same tooth-position. 

The small angular-offset if mixing parts between machines is probably not too noticeable for a regular Pony, but for a Special with the check-dials it means that the check-dial gears won't mesh perfectly centred with the gear on ste setting-dials:

Effect of all this is that replacing a crank-shaft may mean also needing to exchange the drum-shaft. They are matched sets.

Anyhow, continuing the drum re-assembly in 2026. All the clean parts laid out and slid onto the shaft:

And put together again.

And then mounted into the target-machine - both drum and crankshaft from the donor-machine.

The target-machine original drum actually worked relatively fine after a little oil and a work-out. This donor-drum may in the end not be kept in the machine, it does however enable using the straight crankshaft. A restoration choice to be made later; straight shaft, but not the original for machine 70049 - an authenticity question...

The set of drum and shaft from 70049 now out of the machine, to get the same deep-cleaning and rebuild - no scratched-in date, but a stamped A-number instead. Maybe there are some hidden markings on the internals yet to be found :)

Carriage rebuilding of Marchant Pony B

The carriage of both Marchant Pony calculators were partially seized - multiple positions completely unmovable. Additionally, the 18th position of the result-register of the restoration-machine was missing (!), and mangled wingnuts.

At some moment in its past, this machine was radically repaired - repaired from a 'catastrophic event', e.g. being dropped, being hammered. That event is probably also when the main crank was bent, levers broken and the 18th a wheel lost (how??). Not just the numeral-wheel, also its ten-carry lever plus gear was taken out. A small piece of brass was soldered in its viewing aperture in the cover. This was then neatly painted black, making it a 17-digit machine. 

As a start, the target-carriage was completely emptied of all parts - the usual stubborn screws and hardened old oil, but also the counter numeral-wheels were jammed solid between the carriage sidewalls. In the end, an empty and clean carriage; a brass casting with a simple steel strip screwed to the bottom as the sliding surface.

No pictures of rebuilding the counter register - this was hard! to do and was assembled and taken apart at least ten times! One surprising feature and difference with the donor-machine were brass plates or shims between all the numeral wheels. 

These very thin brass plates were all somewhat mangled, probably from brute-force clearing attempts or perhaps a botched assembly. When this shim is not aligned with the main rod, the clearing-pins would 'notch' the brass as the rod is pushed in - this makes extra thickness and pressure on the stack - causing it to be blocked. It is doubtful that all positions of the counter would have worked well after the old repair.

These shims also made it impossible to exchange some wheels with the donor. To accomodate for the brass shim, the wheels are about 6.75 mm wide, whereas on the donor all wheels are 7 mm wide. Well, they really are just under 6.985 mm. This is an American machine; the pitch of the columns is not 7 mm as they would be on a Continental machine, but on the drawings is given as 0.275". Inches and fractions...

(The making of many parts of the Marchant Pony are shown with good explanations, drawings and photographs of the actual tooling in a great 1919 book on Punches & Dies. The book also shows several stamped parts for the Noiseless Typewriter and some Smith Premier typewriter parts. The book can be found in full on The Archive.)

From both donor and target machine, a glut of numeral-wheels. A total of 35 specimens in various states of wear - cleaned and to be sorted on quality. 

Again small differences, the target machine wheels are about 24.5 mm diameter, the donor-wheels are 24.0 mm on average. Probably simply batch-to-batch variation.

Many wheels - a 35 digit register; that'd be a 116-bit register - the actual 18-digit Pony B is already not bad as a ~60-bits computing device :-)

Cleaning, fitting and filing of the the tens-carry levers, then on their rod and screwed in-place. The left-most levers have extra prongs to trigger the overflow-bell (carriage here seen from behind).

After these levers are fitted, the springs and tiny plungers have to be cleaned and fitted to every lever as a rod is pushed in from the left to lock things in-place with an intermediate gear next to every lever.

These are the little spring-loaded pins that keep the tens-carry levers in the out- or in-position. The parts of the target machines are not original - these springs are offcuts of a different size, and the plungers are rounded bits of varying length. Good replacement/repair effort, but not original. The circled three are original Marchant pins with a bevel.

As the rod is pushed in one lever at a time, the springs and pins are selected to give an even, reasonable force needed to flip the lever between positions. Some spring shortened, lengths of pin and springs matched. (Below picture is of a test-fitting, gear-wheel for column 17 needs to be added still.)

Also here the 18th wheel was given a test-fitting - to check if there was something wrong in the carriage-frame, causing the 18th position to be removed. No problems, all works fine. Likely that one numeral wheel or other part was broken, then leaving off the 18th position is the way to solve a lack of parts. The repairer decades ago won't have had a donor machine :)

After the gears-rod is fully inserted and all the intermediate-gears plus all carry-levers are in place, the register can be filled. Starting from the right one position at a time.

To test, first placed on the machine with the first two digits only. The holes vsible on the register main-rod shows that several clearing pins are likely replacements, only few original pins remained. So many pins needing replacement does suggest mis-use; excessive force on the clearing wingnut is needed to shear off these pins - or forcing wheels (perhaps breaking a wheel). The scoring of the numeral wheels also hints at brute-force attempts to move blocked numeral-wheels. This machine really needed to be seriously rebuilt!

The springs for the overshoot-prevention rockers need to be placed with care. When simply pressing everything in place, springs don't enter their pocket and will be mangled and the rocker will be very stiff (blocking?). Several springs were indeed mangled - now replaced with good springs from the donor. 

When everything is in place, the front rack-bar can be screwed in-place. The entire carriage is now clean and functional - well, mostly functional. 

The clearing-flange of the counter is mounted upside-down; that vane should be at the bottom. With the new wing-nut and the pins being what they are, I simply cannot find a position where all wheels clear and no wheels are fouling when zero. In comparison, the 18-digit result register was easy to get to work.

The gear surfaces that slide over the detents are still rough (hard to polish); excercising the digits hopefully will make things smoother. For now the result is one basically functional carriage of a Marchant Pony B calculator :-)

Another Pony to attempt repair of the Pony

It was local pick-up, but last year's purchase of a Marchant Pony B Special was a mistake. Had already seen on the listing that the machine was in cosmetic bad shape (fixable), but had not realised quite how many parts were missing. Too many parts to be recoverable, so first put away in a box.

Just recently however, luck would have it that another badly-damaged Pony B appeared for sale online! The bidding interest in this incomplete and blocked machine may have been puzzling, but it looked to contain just the bits needed to attempt a repair of my Pony number 70049, frame nr. A1007. (The actual meaning and reason for these extra numbers is another thing to be explored.)

So now here a team of Ponies:

The target machine (top in photo above) already partially dismantled and both carriage registers taken out. The bottom machine will be the donor - serial number unknown (no back-plate), but frame number 1828. This donor-machine is a regular Pony B; so no input control-registers as with a 'Special'. The frame and housing of both calculators is mostly identical; to convert a regular Pony to a Special would only (?) require adding the control-register sub-frame (mounting holes are present in the base) and changing the left side-frame and top-cover.

Comparing the two, there are several small design changes visible. The (overly-complex) carriage indexing mechanisms are e.g. subtly different between the two and the revolution-counter is different too. Many/most parts should however be identical (fingers crossed).

Surprisingly the carriages are not interchangeable. The carriage base-rail of one machine is about 0.3 mm wider than the other - carriage 1007 will only fit on machine base 1007 and carriage 1828 will only fit on base 1828. That might be from a small change in the design, but may also be simply variations in size of steel-strip used for the carriage-base - or damage sustained over the past century.

Given the overall character of the machine and its Oakland, CA manufacture it is hard to imagine that this would not be a tightly controlled dimension. Interestingly, though probably simply because it's not relevant at the stage drawn, the carriage-width is not a dimension shown in below part-drawing of the baseplate of a Pony A:

Similarly the carriage indexing/holding pawl looks filed-down to fit its specific carriage - and stamped.

So at least the carriage, base-casting and indexing-pawl need to be matched with these assembler numbers, even the right side-wall of the 70049 machine is stamped 1007! 

The machine covers are then all stamped 49 - for machine 70049. 

Oddly, the carriage cover of the donor-machine has 1828 written (pencil?) on the inside - hard to make out, but it's there. That is odd because a snippet of the serial number is expected there.

Both machines show evidence of major, old repairs (and major mistreatment too). The crank-rest of 70049 shows for example an old repair, the casting fixed with brass (brazing?).

This casting had probably been broken by a major impact or fall, as also hinted at by the mangled crank-handle and a slightly bent main crank-shaft. Crank and shaft will be replaced by the straight specimens from the donor machine.

Another hint that this calculator really has seen mis-use; about half of the clearing-pins on the register shafts are 'new', so something caused all these original pins to be broken or needing replacement. Evidence that it was pretty bad is that the whole carriage is actually bent! See the offset against a straight steel ruler:

Now with an extra parts machine, a repair will be attempted of 70049. To start with, a full dis-assembly of the machine and cleaning of all the bits. One sub-assembly at a time, starting with all the carriage bits.

A full rebuild of one (hopefully) working machine from two damaged ones is admittedly a lot of effort for a Marchant Pony B Special. These Marchant Ponies are not that common overhere, but also not so rare that a decent sample couldn't be obtained in time. In this case it is now more about enjoying the puzzle and discovering the mechanism and design choices of Marchant in 1917.

Finding out how the first American manufacturer of Odhner-lineage pinwheel calculators evolved its design :-)

Spotting a Portable being carried

Adding machines or calculators don't show in contemporary imagery all that often. At least, they feature less frequently than typewriters - makes sense as they would only be found in very specific business settings.

Here one instance where a Burrougsh Portable adding machine is visible in a film. Very appropriately, it is being carried. Handled here in the crime (noir) movie "The Undercover Man" of 1949.

When it's been placed on the table, clearly visible as a Burroughs Portable adding machine with the narrow paper-roll platen.

As the company said; easily carried from desk to desk :)

Forto - least known Dutch typewriter factory?

The three "Forto" typewriters that just topped the Typewriterdatabase list of recently edited galleries are marked 'Made in Holland' by 'Forto N.V. Bussum'. The Forto portable machine has been described before and identified as a Consul machine, a typewriter made by (the) Zbrojovka in Brno, Czechoslovakia. The serial numbers suggest that all three Forto specimens were manufactured in 1961; a relatively rare name-variant of the Consul. But - 'Made in Holland' ?

There was quite some post-war typewriter manufacture in The Netherlands. E.g. by Royal (moving into the premises of a defunct cigar-manufacturer in Leiden), Halberg (later bought by Royal), IBM or Remington. However, Forto NV in Bussum is rather more obscure.

Was this even a factory? Or simply a badging dreamed-up by Zeta/Consul to sell into the US? Doing some browsing through some online archives, it seems that Forto actually was a real company producing metal goods.

The company name "Forto" of Bussum turns up first in 1937, when they get type-approval for their Forto-brand bicycle rearlight. The company 'Metaalwarenfabriek "Forto"' in 1939 gets type-approval for a second model of rearlight (with reflector).

The address associated with the company then, Ruthardlaan 2, is a residential address - the office or perhaps residence of the owner/director (or both). Certainly not a factory.

Then in the above 1947 job posting for experienced die and tool makers a more industrial location is given. This 2e Industrieweg 4 location is a relatively small-scale industrial development of 1936, with multiple workshops around a courtyard and the complex itself surrounded by residential streets. Not certain if this was the primary site, or e.g only a toolmaker workshop.

The entrance to the courtyard, image from an article on the site of the Bussum Historical Society.

In the 1950s they occasionally advertise jobs; mostly girls for assembly-work and boys as press or lathe operator.  (Retirees are also invited to apply.) The job postings indicate the company has presses, lathes and does some assembly-work as well. They perhaps have their own tool-making or maintenance. One of the products they manufacture are weighing scales, as indicated by hiring for the 'scales-department'.

In October 1959 they start hiring for the typewriter department (afd. schrijfmachines); openings for an assembly worker, packer and trainees. (Again, also open for pensioners to apply.) This seems consistent with the typewriter manufacture mostly being the assembly of kits from Zeta/Consul.

The address given is again a residential address. Initially only number 17, then 17-19 suggesting they have taken the whole of the semi-detached villa near the railway station of Bussum.

From all this can be concluded that the Forto brand for typewriters was not created by Zeta/Consul, but was already the registered brandname of a Dutch metal goods manufacturer. They had been doing stampings and assembling relatively simple metal products since at least the late 1930s.

From the -admittedly meagre- indications found; in 1959 they were a factory with experience in metal goods production, but so far there is nothing to indicate a capability to manufacture (under license) a product of the complexity and precision needed for a typewriter.

Most likely is that somehow Zeta and Forto found each other to arrange the local Dutch assembly (with perhaps some parts locally manufactured) of 'knock-down kit' typewriters from Czechoslovakia. Likely done for the sole purpose of giving the machines a 'Made in Holland' wrapping for selling into the US.

By the end of the 1960s most companies have left the relatively cramped premises of the 2e Industriestraat courtyard. Also the Forto company moved out (if they ever were there, it may have been a secondary site). Uncertain from when exactly, but in the 1980s they are located at the Energieweg 35 on an industrial estate in nearby Naarden. Job-postings show the company is then still active in metal stamping, bending etc.; i.e. general metal goods and parts manufacture. 

The Forto company is declared bankrupt in 1994 - the sale of assets announcement shown above gives an overview of their machinery. Presses and milling machines as expected for a general metal goods/parts factory. That is probably what Forto was throughout its existence - even though briefly in 1959 - 1961 they were Holland's Finest factory of Precision Engineered typewriters!