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.) 

Ink rolls for the Blickensderfer dry out, they also did so a century ago

Old, original rolls for the Blickensderfer typewriter will still contain plenty of colorant, but be completely dry - and the typewriter will not print. Online sources mention these can be revived with WD40 - though the mix of many different (mineral?) oils would give me pause to do so. Some of the heavier fractions of WD40 tend to set into a hard 'tar-like' consistency. The lighter fractions will however be effective in making a roll functional (until they evaporate), if of course the roll is still cylindrical and not worn down in the middle.

(Looking at old typewriter ribbon ink ingredient lists, reviving an old roll might be best attempted with castor-oil, neatsfoot oil or poppyseed oil. One or a mix of these was likely used as the original carrier for the pigment on these ink rolls.)

An alternative is of course to make new ink rolls from cylindrical felt and modern stamping pad ink. However, modern water-based stamp inks dry out rather quickly too. When typing on a Blick, a new roll needs to be fitted regularly. Or of course replenished with another drop or two of ink to soak into the roll.

Maintaining proper inking of a roll on the Blick is not a new challenge. It seems that maintaining a proper inked and clearly printing ink roll was also a concern a century ago when the Blick was 'current'. For faint printing; "a dried pad can be revived by allowing a few drops of Blickenderfer Pad Reviver to soak into it":

In the very extensive user manual for the Blickensderfer 7 and 8 typewriters published by the London Blick company, the price-list mentions a bottle of reviving liquid! For sixpence per bottle:

Very curious if any of these bottles survived - and if the contents could then be determined! (Equally curious what's included in the Re-inking outfit at 2/6.)

This manual also contains a very insightful section on 'Faults' of the machine - the manivaried ways that the Blickensderfer may be giving less than satisfactory results. Reading these it reveals that many of the issues encountered today were also experienced in 1913. (And probably right from 1897 - the text samples suggest that this booklet was originally written in 1897, this being the expanded 8th edition of 1913.)

With care and attention, my No. 7 gives reasonable output. Now having read these instruction, it may actually be that the machine is already performing close to 'when-new' levels :-)

Instructions For Using The Blick Typewriters No. 7 & 8 Models - available on The Archive.