Carriage cleaning of the Burroughs Portable adding machine

This Burroughs Portable adding machine has the wide carriage option; a 12 and a quarter Inch carriage with tabulator stops.

The brightwork on this wide carriage was very dirty and/or corroded. Most of the brightwork originally would've been shiny nickel-plated, but now with the dirt of decades and some spot-corrosion:-no longer very bright. One of the tabs below cleaned back to a shine proved it was mostly dirt.

This wide carriage of the Burroughs turned out to be not so easy to take apart for cleaning. Several collars are pinned onto their rods and even the platen-rod has a ratchet-wheel doweled in-place. Taper-pins are very hard to remove. So for now only limited cleaning of the most exposed (and reachable) parts. Removing side-plate mounting screws allowed the side-plates to be shifted just enough for the tabulator rack to come off.

As can be seen in the image below, the main spacer-rod behind the paper-tray was not removed and still has a brownish hue. However, the tabulator bars and springs did come out quite nice. (And no longer look like you'd catch something off them at five feet.)

One detail when re-assembling the carriage is the positioning of the ratchets. The Burroughs has two; a driving ratchet wheel and a holding ratchet wheel on the platen rod - both visible right next to each other in below image. The holding ratchet wheel is fixed in position on the platen rod by a screw.

This holding ratchet wheel must be adjusted so that in the holding rest-position the driving pawl on the driving ratchet-wheel is only-just released and drops free again after a line-feed.

This was the cause of the carriage line-feeding issues of the machine. It would only do a line-feed when set to dual-spacing and block the platen from reversing using the knobs. That was because the pawl could not drop free, but was kept under pressure (and failing to fully advance the platen). Very likely this was not adjusted at the machine's last servicing - perhaps in the 1960s still. After assembly it was set to dual-spacing and the carriage did feed, so no more attention given.

During cleaning; one little artefact of the manufacturing process of screws; the slots of screws were cut. On this one screw (right), the slotting-machine must have been set a little too low, neatly splitting the entire head.

Cleaned and carefully tightened back in place. The split head makes it a weak screw, but it held the paper-roll bracket on for 97 years and should do so for another 97 years.

New gasket for the Burroughs Portable adding machine

Many Burroughs Portable adding machines don't have it anymore, but originally there would have been a rubber gasket between the top housing and the base-plate. It may have perished (as rubber can do), or maybe it simply wasn't put back after a servicing. This U-section rubber gasket is shown in the patent image - circled in red.

A length of suitable, rounded rubber U-channel of 6 x 6 mm with a nominally 2 mm slot could be sourced, found online.

With a hole-punch, half-circle cut-outs were made for the gasket to clear the threaded-bush of the front-mounting screws. Then pressed onto the sides, cut to length at the back and the ends glued together.

Before fitting the new gasket, a nut was soldered in as replacement for the missing front right threaded bush. No idea what thread it is, but fortunately two screws and a nut of the correct thread were in the tin-with-bits salvaged from a 1940s Underwood.

The top housing now fits very snuggly on top of the baseplate - the rubber will help against dirt and dust getting into the machine (and maybe against noise, but I doubt it).

The spool-cover tops are already re-painted and the spool-nuts spruced up. The rusty tops of the spool-covers were sanded completely back to bare metal and re-painted. To mimic the textured lacquer finish, some 'meandering' was added with a fine brush on top of the base layer of flat-black paint. Then the spool-cover was finished with a satin gloss. When viewed from a distance, this blends in well-enough with the original finish of the machine.

The carriage still needs to be cleaned-up, but this Burroughs Portable is starting to look very solid and dependable already (it would feel right at home in a bank ;-)

Tune-up for the wind-up gramophone (and playing records)

Spending some time last weekend playing records, the bright colors of some labels do impress. From the way these were stored, they'll have been shielded from sunlight. Sleeves are usually a bit faded, yet these orange labels really stand out.

The records from the 20s and 30s found here in the low countries are quite international. Much is relatively local, German, British and French, but this Crown is a US record and e.g. the Odeon is from Argentina.

The sleeves make a point of the music having been electrically recorded. This was something new that quickly became the standard from the late 1920s. 

And also the below Dutch record sleeve proclaims; "The latest invention is the Homocord Electro - the electrically recorded disk".

Electrical recording really did improve the quality of the sound. Playback was still mostly without electrical pick-up (that started emerging in the late 1930s for (expensive!) home equipment). These ~1930 records would've been expected to be used with an acoustic reproducer. For example on a portable wind-up gramophone, like this 1929 HMV model 101.

During playback however, some louder sections of the record suddenly sounded 'off'. The gramophone was not keeping speed. As it had been a while since servicing, very likely then that the motor badly needed a tune-up. Maybe even a re-greasing of the motor spring.

To do a service: slide off the circlip, switch the brake to 'off' and lift off the turntable. Give the motor time to fully unwind - when servicing a wind-up motor there should be no tension left in the spring. After removing the four screws in the corners of the motor board this can be lifted out, front up first and sliding the motor 'block' from under the rear deck and forward.

This time the motor was kept on the board; the whole board was placed upside-down on the rims of a baking-tray with a towel for protection. Removing three small screws allows the motor cover to be taken off. Then another three larger screws out of the pillars allows the motor plate to be taken off.

Again; take care to not loose the small bearing-ball under the main turntable-shaft (likely held firm in its grease, but still). Also note the washer between the arbor-shaft and bottom-plate - it will have stuck to either the motor or the plate.

The gears were very 'gummed up'; the brass of the intermediate gear had turned green and the teeth filled with 'gunk'. Slowly growing corrosion in the gears mixed with grease could also make a motor lose power - and of course the governor was in dire need of fresh oil on the friction pad. Seeing these issues, decided to leave the spring itself alone - its greasing of ~10 years ago likely still good enough.

The gears were all cleaned, stubborn dirt removed with wooden tools (not scratching). New grease with this time also some graphite applied to the gears. 

The pressure angles of the gears driving the governor are really steep; will need good lubrication. For speed control the governor's friction pad and disk need to be well oiled - and the sleeve-with-disk that is moved by the three weights should move on the shaft without friction for proper speed-keeping.

The motor and gramophone put together again, it seemed to run just a little bit smoother. With 50Hz incandescent lamps becoming rare, strobe disks are getting more of a hassle to use for adjusting the speed. Today however a small application transforms a smartphone into a modern instantaneous speed tester. Nifty!

Testing with a record too (extra drag), the gramophone is again able to keep speed - no more false notes.

Placing another record on the instrument.

Plays great!

Electrically recorded in July 1931 in New York - played back mechanically in May 2025 in Holland.

:-D

Re-activating column 7 and 8 on the Burroughs Portable adding machine

When entering numbers, all columns seem to work. For example, entering 7777 on the left-most columns makes all segments rise and print as they should.

When then doing a total, the columns 7 and 8 segments do not rise and do not print, but the column 6 and 5 print, as does '*' (total sign) on the right-most printing column.

The print-out confirms that columns 7 and 8 are not working in totals.

That was an interesting fault - when the machine was taken apart earlier, the register wheels were spinning freely; no binding. That they print fine when simply adding confirmed the problem was not in the register itself.

Staring at the operation of the machine (with covers off) during adding and when a total is taken, tracing how the parts move, pointed to the problem being in the keyboard. The differential-bars slide under the keyboard for every column.  In adding it is stopped by the peg of a number-key at the right position to cause that number to be added to the register.

At the front of the machine is a rocking bracket for every column - this is rotated out of the way if a number is entered or when a total is taken. When a total is taken, the differential bar (and connected segment etc) needs to slide all the way until stopped by the register-wheel - that's how the value on the register is retrieved for printing a total.

The rocking brackets for columns 7 and 8 did rotate their 'stop' tab down far enough for the differential bar to slide over them. The columns 7 and 8 were snagged and thus always a zero was registered as the totals-value on columns 7 and 8.

Some more peering at the mechanism revealed that very probably the tab that holds the rocking brackets in the keyboard key-locking-bar was bent for the columns 7 and 8. They were angled slightly different from the rest.

These rocking brackets are exposed when the mechanism is out of the case. Looking at this, actually it's likely that this fault was accidentally created by me when working on the mechanism- perhaps when giving the keyboard a thorough scrubbing to clean the keys, dod not take enough care to not put any pressure on these exposed bits.

Slowly and carefully bending these tabs back so that the differential bar just clears the little stop-tab re-activated the total working correctly. As seen in the print-out of all sub-totals for testing if the bending was far enough - first column 8 re-activated and then column 7 came back too.

Just to be sure, adding 333 and 222 indeed gave 555 back in the left-most columns. 

Feeling confident enough to test the tens-carries; multiplying 12345679 by 8 - that also worked fine and printed the expected answer.

(The printing line is a bit obscured by the ribbon. That's because the machine is now fitted with a standard half-inch or 13 mm ribbon. This fits and works, but the machine is made for a 7/16" or ~10 mm ribbon, just like a Hammond or an Oliver. We'll have to see if a well-inked 10 mm ribbon can be arranged for this machine. Until then, a regular 13 mm ribbon does the job.)

This machine is proving to be a grand puzzle, and very much understandable/repairable - more cleaning and some restoring to do.

:)

Burroughs Adding Machine Company hidden marking (Portable Class 9)

Clearly marked; Burroughs Adding Machine Company.

That was an unexpected spot to find the company name. This is on the bottom-inside of the damper or dashpot of a Burroughs Class 9 adding machine. The dashpot needed re-filling, the yellow color in the image above is the remaining original oil. To get at this marking (and re-fill with oil), the top of the dashpot could be screwed off.

Like most lever-operated adding machines, it has a dashpot -and like many ~100 year old machines this dashpot needed re-filling. Oil will have evaporated through a small gap round the plunger-shaft - or if the machine was stored on its side, it could have leaked out (and made a mess). 

To re-fill the dashpot, it needed to be taken out first. This dashpot is mounted at the rear-right side of the main module of the Burroughs adding machine. To get good access to this dashpot for removing it, the main module was taken out / made free from the connected modules. Undoing the retaining nut for the plunger and removing the frame's base-bracket allowed the dashpot to come out.

Next to the dashpot, at the rear-left side of the main module (at the right in picture above), are by the way the rocking tooth-segments that drive the totals-register. Even though this a relatively modern 1920's machine with a modular design, these segments are still quite similar to how the original 1890's Burroughs machine worked.

To get the main-module free, the core-mechanism was taken apart in its three modules. There is the main-module (with dashpot, segments and the differential-levers for the keyboard to interact with), the totaliser-module (with the register and carry-mechanism) and finally the hammers-module with top-plate that helps holding the lower two together. These three modules are the core of the machine. With screws the rear base mounting-bracket links the main- and totaliser-module. Another two screws plus two hexagonal-bolts fixes the hammer-module to the top of both.

This core-mechanism was taken out of the housing. It is mounted onto the housing base (or pan) with four screws. As it was out and one foot was missing - this machine's pan was fitted with four new reproduction feet. New 3D printed feet in TPU to the dimensions taken from remaining original feet.

The keyboard is another module that needed to be taken off the top of the main-module. It is fixed by two screws at the rear and hooks over pegs at the front. To take it off; remove these screws, then lift it up at the rear and slide it a bit to the rear and lift free. Well, that is the simple version - in reality there will be lots of wiggling and extra preparations (note that little spring on the right!). Putting it back also needs care - not a simple insert and screw-tight. For example; the front-left key-release-rod must be engaged with the rotating fork coming out of the main-module and care must be taken that all levers at the right-side of the machine are on the correct side of the levers of the keyboard.

I.e. yes the whole machine is fully modular, but there are complications. E.g. the core-mechanism has a few 'extras'; there is e.g. a long lever (pitman) that must be unscrewed and wiggled free (has ju-ust enough clearance) before the totaliser and main modules can be carefully pried apart.

Removing and replacing the housing top shell is however a simple matter - it is held in place mainly with the carriage-module that in this case is held with four screws onto the top-plate of the mechanism. Two more small screws in lower-front to hold it form there too. That then is a complete Burroughs Portable adding-listing machine that needed its dashpot re-filled.

This Burroughs Portable adding machine, Style 9 08 02 was a generous gift and will be cleaned and repaired over the coming months/weeks. It had been stored in family-attics for probably more than 50 years, occasionally taken out to be experienced and played with (children!). This machine had been given to the family, when a neighbouring small accountants-office modernised. That office may well have purchased the machine already second-hand - the serial number dates it to 1928.

These Burroughs Portable machines were introduced 1925/1926 and with several (cosmetic) changes were produced into the 1960s in large numbers. These Burroughs machine are thus pretty common and should be readily available on the usual marketplaces - this was and is a a common machine. That's because Burroughs had a strong sales organisation and marketing to banks and businesses in general - but I think also because it actually is a good design. Am really looking forward to exploring it further and repairing it.  (Wrt "Portable"; it is! Compared to the previous generations of Burroughs machines these machines are definitely portable - i.e. it is possible for one person to lift and carry it.)

Re-filling the dashpot was just one of the fixes. Admittedly this was a bit daunting, having to take it apart that far. But it had the bonus of seeing the hidden Burroughs Adding Machine Company marking. A little 'Easter egg' in these machines that's probably not often seen/found.

Easier fix was e.g. finding replacements for several missing screws (American-size and/or obsolete threads!). 

There are still many more repairs to be done - e.g. figuring out why column 7 and 8 don't work - these simply refuse to print for totals. And the carriage line-feed is 'temperamental' :)

Another repair -already successful- was getting the subtraction to work again - it would either add or simply block the machine. Following the explanation with great drawings by Mr Allen Asa Horton in US patent 1,853,050 it was possible to trace the fault to a single bent lever and then fix it. How that lever got bent is however still to be discovered. Documents helpfully shared by Mike of Burroughs Info (Thank you again!) made clear that the handle should dis-engage in fault-conditions. The machine currently does not - some safety mechanisms not working may have caused this damage to the mechanism. More puzzle! :-)

Nevertheless; the machine is now again capable of calculating its own age:

Not bad for almost a century old!

Experiment with rubber typewheel for the Blickensderfer

The platen of the Blickensderfer 7 typewriter is rock-hard - like slate. When it was new and still rubbery, it would have cushioned the impact of the hard, vulcanite typewheel and have evened-out the pressure to improve the quality of the imprint.

Instead of getting new rubber on the platen (tricky for a Blick), tried a quick experiment of putting the resilience on the typewheel; use a stiff rubber typewheel with a rock-hard platen.

To manufacture a 'rubber' typewheel, this was printed in TPU - a synthetic rubber that can be used for FDM 3D printing. The limitation is that TPU cannot really be used on a fine 0.2 mm diameter extruder-nozzle, so the model modified for a coarser 0.4 mm. A relatively stiff TPU (Shore 98?) was used. That's very stiff and not 'grippy'.

As can be seen in below image; the TPU wheel is less finely detailed than the PLA wheel.

Despite the coarseness, it does type legibly!:

The quality of work is actually better than expected from a 0.4 mm coarse typewheel. This hints that there is some effect of the TPU being ever so slightly 'springy'. However, the finer detail of the 0.2 mm hard PLA typewheel still makes for better work.

Handling both the PLA and TPU wheels, there is actually not such a great difference in the resilience - this stiff TPU is good for printing, but is not very 'rubbery'. A TPU with Shore 95 or even 85 could be better for cushioning the impact on the platen.

Conclusion from the quick experiment; making the typewheel from Shore 98 TPU is not an improvement over 'hard' PLA with fine detail.

Perhaps still a try with a Shore 85 or 95 material, but for now sticking with using backing-sheets : )

Cut-out drawing of the Underwood 4-bank portable typewriter (why?)

Inside the lid of the carrying case of the typewriter, there is a nicely cut-out image of the typewriter itself.

This label is present in more (all?) of the early Underwood 4-bank portable cases, so almost certainly this was pasted inside the lid by Underwood themselves.

It's a nice touch. Having looked at it a bit more, did start to wonder what the reason was behind this little pasted label. As owner, you'd know this was the lid for your Underwood 4-bank. In the 1920s it would I think anyhow be most unusual for anyone to own more than one portable typewriter. And a shop or dealer would for sure know to match a lid with the correct typewriter.

There is no additional text or advertising copy - and that would in any case be a bit late; when looking at the inside of the lid, the viewer most likely already is the owner of the machine. For adding advertising copy to the machine, a more likely chosen solution would have been to visibly stow e.g. the instruction leaflet (as e.g. on some Royal portable).

Perhaps it was simply an expression of the pride they took in their new 4-bank Standard Portable. (Do late 3-bank Portables have a 3-bank picture inside the lid?)

The decision for the extra cost of making and pasting this label was probably documented and written about in Underwood company internal memo's and work instructions. These will however all be long gone.

So whilst it's a nice touch, it does leave me wondering on the thinking behind it.

Difficult to date, timeless construction (from 1884)

Once very common and still found on flea-markets and in thrift stores, the pocket spring balance. In this instance, a Hughes Pocket Balance with the scale marked in kilos.

Above the legend stating it is a Hughes Pocket Balance, there is the knot and arrow logo of Salter. Near the bottom of the faceplate, it states 'patent'. And indeed this is a patented construction for a low-cost mass-manufactured pocket spring balance. 

The patent was applied in Britain (granted as British patent 800 of 1884) and in several other countries. Inventors are John Hughes and Thomas Bache Salter, assigning to George Salter & Co. of West Bromwich - makers of spring scales since the 1790s. The drawings of e.g. the Canadian patent 20,397 show exactly the clever construction of the item above.

The single metal sheet at the back forms the frame, with the several shaped pieces slotting into and onto the spring and frame like a sliding-puzzle. Only a few rivets needed to create a working unit, no brazing or soldering. 

The top of the frame sheet is shaped with 'flaps' as shown also in the above figures from the US patent 390,522 applied for in 1884 and issued in 1888. These flaps are folded over to form the top wall of the frame, slotting into the top-eyelet that is attached to the spring. Even though this specimen was heavily corroded, the flaps are visible.

The construction of these pocket balances has not changed much since 1884 - they are still being made new today with the same design and construction.

This makes these items also quite difficult to date, it is hard to estimate when a specimen was manufactured. 

The marking of Salter's pocket balances seems to have changed from Hughes to Salter over time, for example in the picture in a 1921 advertisement the faceplate is marked Salter. Of course not certain if all products changed from Hughes over to Salter, or if it perhaps varied per type or batch even.

The knot and arrow trademark was registered in 1884, so that also does not narrow it down in any way. Specimens with hollow 'pop'-rivets instead of solid rivets would however be more modern, e.g. 1950s or later. A post-war item would also be expected to have a 'made in England' marking.

All this merely narrows the date-range down to anywhere between 1884 and perhaps 1920-ish. The style of engraving on the brass faceplate is fits that range - for example the below Salter-marked specimen with a more modern-looking engraving is likely to be from the 1920s or 30s.

Impossible to date exactly, this slightly battered Hughes Pocket Balance probably dates from around 1900, with about 15 years uncertainty either way.

A proven and timeless design :-)

Silver-Reed 100 sitting on a chair

(Typed with a reproduction wheel 223 "Print Type" on a Blickensderfer - a bit blotchy from a freshly over-inked pad.)