Saturday, June 24, 2017

Remington Portable ribbon mechanism assembly

Getting round again to tinkering with the 'lost cause' Remington Portable 2 typewriter, the next step after mounting all the typebar linkages was the ribbon mechanism.

The change of ribbon travel direction is done by sliding the shaft to the left or right, engaging either of the spool holders with its conical drive gear. To keep it in engagement, there is a spring loaded mechanism located under the left spool.

Two cups are held with a single spring-clip, pressing against a thinned section of the shaft.

The shaft has nicely flattened areas for the set screws to get a proper grip. The thinned section can be seen jutting out of the hole in the spool-base. When assembled, the spring-clip should fit underneath the shaft, pressing the cups into the two holes either side of the spool-base.

The spool holder can then be screwed on, consisting of its base gear, spool-plate and the pillar.

The conical gear on the advance shaft is in engagement with either left or right spool holder when the shaft is pushed in its left or right position. The pillar is stationary and the gear with spool-plate rotates. (The slots in the spool-plate hole engage notches on the special Remington Portable spools. Spool-plate not yet screwed on in picture below.)

At every keypress that actuates the universal bar, the ribbon advance shaft is rotated a little by a push against the advance gearwheel. To prevent it from rotating back again, a pawl locks it in place. When sliding the shaft with all its parts back in position again, this pawl needs to be lifted on top of the advance gear.

As can be seen in the above picture at the arrow, that is what I failed to do. The pawl that can be seen hiding in the dark should have been lying on top of the finely geared advance wheel. (Something we'll know about a next time :)

The shaft can then be fitted with the end control-knobs. These also have the cam-slopes that are actuated by the prongs on the ribbon-fingers that 'measure' the amount of ribbon left on the spool.

In this machine, the parts are oddly of the old pattern - more usually found on older, pre-'25 Portables. This also goes for the spool-locking clips. It seems that the British factory still assembled some machines with the old pattern fittings as late as '27.

With the knobs fitted again and a little tweaking on the position of the gears, the ribbon and spool mechanism is again in place.

 (The dastardly pawl has since been lifted to its proper position.)

Friday, June 9, 2017

Produx pocket calculator

A very simple mechanical calculator of the Troncet-type, more commonly known here as 'an addiator'. This Produx was probably the main competitor to the Addiator. 

This particular little calculator likely dates to the 1950-ies. The protective sleeve is made of a plastic (PVC or vinyl) and it is made in Germany - West.

The Produx was manufactured mostly unchanged from the start around '28 (?). Even though the competitor Addiator became the generic name for these calculators, the Produx was made by Otto Meuter who was the inventor of these little devices. Addiator was founded by Carl Kuebler who licensed Meuter's patent. (May be that the royalties from Addiator sales then enabled Meuter to set up his own manufacturing.)

It is of very simple and low-cost construction. The Produx is quite compact at 4½ by 2¼ inch and very thin. The stylus made of rolled-up brass is a bit too flimsy; the tip is often broken off as it is in this case. A toothpick inserted in the stylus makes it usable again. Both adding and subtracting are on the front of the calculator, making it a bit more convenient to use than the original Addiator.

The sliders protrude through the bottom of the device, so resetting to zero is a simple pushing back - set it on the desk and push down.

These take a bit of getting used to, but then work surprisingly well :)

Thursday, May 11, 2017

Replacing the paper tray on a Remington Portable 2

Already a while back the paper tray of this black Remington Portable 2 typewriter was replaced with a nicer specimen. From having bought a parts machine and a box of assorted Portable parts, there's a range of parts lying about here for this model typewriter. Out of this stock was picked a cleaner paper tray with less (no) rusty spots and still shiny on the bare metal side.

Then to fix it on the machine. Preferably with least dismantling of the machine.

An unavoidable first step is to remove the platen from the machine. Removing the platen knob (loosen screw) and pulling out the rod allows the platen to be wiggled out of the machine. (Images on a previous posting of April 2015.) Again a good idea to keep the line feed parts in place with a rubber band or such.

The machine then needs to be turned over, upside down. Obviously with the typebars flat. It is best placed on a thick wad of rags or an old towel to prevent damage and to not bend parts of the ribbon-reversing mechanism. (The ribbon reverse pillars can stick out and are easily bent out of shape, causing the automatic reverse to fail. I know now...)

Upside down, extend the carriage as far as it will go left and right and remove the hinge pin left and right. In the picture below is shown the carriage pushed all the way to the right, bringing the paper tray hinge in view. The rod may need a gentle tap from the right with an awl or small screwdriver to get the knurled end to protrude from the hinge. When it sticks out enough, it can be grabbed with pliers and gently pulled out, rotate and wiggle a bit and it should slide out fine. 

Remove hinge rod at other side too and the paper tray will drop off. This also gives easy access to the paper feed rollers, both front and back. The front rollers assembly is merely held under the spring-rod and can even just be taken out. To replace or fix the rollers, it is however probably much easier to pull out the axle rods by the knurled end. (Don't pull the other end, that'd be the hard way.)

For re-assembly, the reverse procedure applies. The knurling of the rods being pushed into the hinge holds the rod in place.

The little Remington Portable then had a shiny and rust-free paper tray :-)

(Next up still is the lifting tray. That's much harder, as the clean replacement part did not quite fit. Some 'forming' of parts and frames will be needed to make it all work.)

Monday, April 17, 2017

Colourful Columbia

Playing music from a stack of records from the early thirties...

Quite a few American records were in there that somehow found their way across the Atlantic. (The market here always was very international.)

Unusually colourful record sleeve by (American) Columbia records. (Ergo a colorful record sleeve.) Few companies spent the money to print these in colour; makes for a very neat period image:

Tuesday, April 4, 2017

Safari sightings

In the few local thrift shops, there hardly ever are typewriters. Maybe they're gone quickly, or just not brought in that often. This time round however there actually were typewriters. Three of them even.

In oder of encountering them; first a dilapidated Remington standard. The tabulator keys are neatly labeled for 'name', 'street', 'subject' etc., in English. The keytops all have small handwritten labels stuck on with Dutch text, so 'hoofdletters' instead of 'shift'. It's seen better days. (Didn't look to see the asking price...)

The second machine was this exposed Olivetti Lexikon 80. These tend to turn up mostly with wide carriages somehow, rather a sizeable beast. The asking price of 59 euros for an incomplete and common machine seems a bit optimistic perhaps.

The last machine was this little beige Olivetti Lettera DL portable. It probably was 'played on' a bit, but the typebars unjammed fine. With an asking price of 20 euro, this is likely good value when wanting a working machine to type on. Looked a decent, little-used and clean typewriter.

No prizes for guessing what was bought; none of the above... (At least, not today, not by me...)

May check again there for perhaps a neat pre-war machine. The online platform's become a bit costly here. Bidding for clean, older machines quickly goes to even 3 figures.  Perhaps typewriters are now truly in-fashion, perhaps also it's because a few dealers (Etsy) are buying machines for their store. So perhaps the local thrift will be a source for a neat machine - at least a source to see and discover some :-)

Sunday, April 2, 2017

Boxes - archeologists tools

Unexpectedly, two typewriter shipping cases turned up in a small local archeology museum. Hadn't expected anything this modern there. These were on display as part of the archaeologists tools. (With a theodolite stacked on top.)

The lower box originally contained a Remington Special, serial number Z113216, that was shipped as order number 13054. From the serial number, probably some time around 1928.

On top of that is another wooden crate, lettered for a Regal-Royal typewriter. No details. From a quick glance around the online hive-mind, Regal was Royal's own rebuilder of typewriters that promised to make their machines "Like-Nu".

Unsure if the Remington Special was ever connected with the archaeologist van Giffen or that particular dig, but the period is about correct. The major excavation took place from 1930, though he'd been active for several years prior to that in excavating the mounds.

These mounds (wierden) contained artefacts from probably at least the 7th century BC up to around 1200 when dikes took over their function. A lot was dug out of the few mounds that were excavated. Alas many (most) were already sold off for the fertile earth, to be scattered on the fields.

Both the small village of Ezinge and the museum are well worth a visit. Even if merely dropping by virtually. (Keep going straight towards the church - the street view car nearly made it round the church ;-)

Saturday, March 4, 2017

Magnification table and butterfly wing scale dimensions

As far as I can tell Bausch & Lomb didn't include a magnification table inside the lid of their microscope cases. This was common practice for most European makers. Sometimes filled out by hand for the objectives and eyepieces included with the instrument, sometimes it was a table of the full range with the included pieces underscored or circled.

What B&L did include with their instruments was the booklet on the use and care of the microscope. And on page 31 of the '37 printing is included a magnification table for their entire range.

Here reproduced to be able to print and rectify this small oversight of Bausch & Lomb. For reference (if you happen to have a B&L biological microscope), though multiplying the two values is not too hard of course.

What can be handy is to know the working distance - the 10 and the 43 objectives with distances to the object of 7.0 and .06 mm are confocal (or near enough). The 4 objective with a working distance of 38 mm clearly could not be mounted to be confocal. (An Olympus 4 times objective actually is just about confocal with the other B&L objectives, incidentally.)

One other number that can be handy to pencil in on this table is the diameter of the viewed image. To determine this, a calibration slide was sourced. From local, reputable dealers in matters microscopical these are startlingly expensive. However from the global 'dime-store' that is the internet, these can be had at very affordable prices including shipping half-way around the globe. These do not include a calibration report and certificates of course. As such these cheap 'calibration slides' are probably unacceptable for proper laboratory use, but excellent for the hobbyist.

Viewing the linear scale of the calibration slide using the 10 x eyepiece and successively with the 4, 10 and 43 objective yields the diameter of the image viewed at about 4.3 mm, 1.6 mm and 0.4 mm.

Looking at the scales of a butterfly wing, then for example the size of the individual scales can be estimated. The below image was taken with the 430x magnification, thus the diameter of the image is around 400 micron. The width of the scale in the centre of the image is thus about 76 micron.

Zooming in further on the digital image shows the ridge-pattern of the individual scale. Also very clearly evident is the very small depth of focus at this magnification. Note that viewing whilst fiddling with the fine-adjustment gives a much better impression of the object being viewed than a static digital capture.

These individual ribs on the centre scale can be counted (about 49), making these ridges approximately 1.6 micron apart. That is quite impressive and close to the maximum achievable for a light microscope.

And that for an 80 year old instrument too.   :-)