Thursday, May 25, 2023

Big Underwoods are in the area

Not often seen in-the-wild at thrift stores around here; large Underwood standard typewriters.

The first standard spotted was this venerable Underwood 5.

Sharp-angled front plate, so pre-1923. Has a backspace, so post-1907. No variable line-spaced pull-out knob, so pre-1914 or so. At least a century old then. 

There should be a serial number there - the area is however covered in orange-red rust.

With a bit of spit & rubbing, it became readable. Nice, curly, old-fashioned numbers. Later checking against The Database, serial-number 287069 makes this I think a 1908 machine. 

It seemed complete and mostly undamaged, but rather rusty.

Although it is was a magnificent typewriter, this amount of rust and a 30 Euro price-tag meant it stayed put at the thrift store.

The second standard seen was a modern, streamlined Underwood SS.

It is a strange machine; on the one hand looking modern with the crinkle paint and chrome trim, but it still has the basic old-fashioned shape of the original early 1900s Underwood. Could be said to be a dressed-up Nr. 5 almost, but actually nearly every part is re-designed; all castings are different, the linkages are different and it's got segment shift. But it still very much echoes the Nr. 5. 

This machine was missing the left chrome trim, had jammed-up keyboard, mixed-bag key tops and did not work. The state of this typewriter probably destines this one for recycling. Many (most) of the big standard machines offered for sale never get bought and will ultimately end up being handed in as scrap for recycling.

The serial number 11-6195525 would make this a 1947 machine. Am not very clear on the actual model-names for this period, but I assume this is an 11" platen model SS.

The draw-band is present, but flopping about the insides. That's only one reason the carriage doesn't move, the escapement also doesn't work when pulling the carriage along by hand.

Although as a post-war machine it's outside my collecting scope, this is a big standard that I did actually buy - for the reasonable sum of 15 Euro. Two metal spools included (already taken off in the pictures).

Before this one's eventually going into the smelt, parts will be taken off to fix other machines. (The parts salvaged a few years ago from a rusted-up '29 Remington Portable fixed several machines already.) This big, damaged standard will also provide US-threads slotted-head screws - otherwise hard to get here.

Still a very imposing typewriter - very heavy too :)

This one will be a parts machine, donating bits to repair other machines.

Friday, May 19, 2023

Small cosmetic tweak; red ribbon selector on the Underwood 5 typewriter

After testing it on the reference Underwood 5 typewriter, and seeing the difference a proper bright-red key-top makes, also wanted to replace the faded paper on the color selector key of the 'good' Underwood

This machine however, had the nickel key-ring very firmly in-place. The word 'limpet' did spring to mind.

Knowing that in case of serious mishap there'd be the reference-machine to donate a replacement, decided to try to force the keyring off. After carefully bending the tabs open, the red key was placed with the glass-side supported on a stack of cardboard disks. Gentle taps on a sharp screwdriver held on the edge of the nickel ring then got it loose, without any damage to the glass. Then going round, tapping the ring to make it move off 'straight', the keyring came off with only one small nick on the lower edge where the screwdriver pushed it. Barely visible, especially when mounted to the back and out of sight :)

With the ring off, the glass disk comes out for cleaning and a new paper insert can be cut out. In this case two disks of red paper were stacked over the original, faded paper (that had fused with the metal cup). The side of the cup was cleaned from dirt and corrosion, and then the keyring pushed back firmly on the stack. Very gently bending the tabs to finish, and the switch can be placed back on the machine.

A small, cosmetic tweak - that somehow does make a difference for the whole appearance of the machine :)

(As practice for more cleaning on the Underwood 5 to fix a now-sluggish 'S' key, first started with cleaning the segment and type-bars on the reference machine.

Once you get the hang of it (but only then), type-bar removal and placing-back is surprisingly easy on the Underwood No. 5.)

Sunday, May 14, 2023

Impression strips for the Hammond Multiplex typewriter

The Hammond typewriter uses two wear-items; the impression strip and the ribbon shield. These two items were originally sold at modest cost by the Hammond Typewriter Company. The ribbon shield is essential to print cleanly without smudging by adjacent characters. The impression strip is important to even-out and dampen the impact of the steel hammer through the paper onto the hard-rubber type-shuttle. As is advised by several sources; Do not type on a Hammond without impression strip!

From literature and some pictures found online of surviving originals, these strips were probably made of rubber vulcanised onto a cloth base. The reinforced ends have holes that allow the strip to be stretched over the pins of the typewriter's carriage.

After making several new ribbon-shields, the second wear-item -the impression strip- is relatively straightforward to make.

Because there may be some variation between machines in the actual distance between the pins, start with measuring this span. Also the vertical pitch in case of two pins. Drawing these dimensions on a sheet of paper (or card) gives the template for making new impression strips.

Several materials can be used to create new impression strips, e.g. cutting to length from 1mm rubber sheet ~15mm wide. For reinforcing the ends thin aluminium sheet (e.g. scraps from making the ribbon-shield) or metal-tape can be glued to the rubber - these help with the appearance and strength of the ends. 

Punch the holes (~3mm) at a few mm less than the span of the pins on the template to give the strip some tension. This then quickly makes new 'platens' for the Hammond.

The more fancy (and easier) way is to use electrical- or insulation-tape. This is low-cost and available in colours too (fancy impression strips!). This material is 'stretchy' and will cushion the impact of the steel hammer similar to rubber. Because it is 'stretchy', reinforcing the ends is essential. Otherwise the holes will distort and the strip will crease. For this, simple card-scraps are included in the 'tape-sandwich'. For extra strength and to further limit the risk of creasing, a cloth ribbon is added in the middle of the strip. (As bonus, a cloth-core is also prototypical :-)

To start with, a length of black 15mm wide electrical-tape is itself taped over the template, adhesive-side up. The card end-pieces are pasted in-place on the tape, again allowing a few mm for tension when mounted on the pins. The end-pieces have the holes and the desired outline marked in black (i.e. in high contrast).

To suit the desired 'weight' of the strip, one or more extra lengths of electrical tape can be very carefully placed over the base-layer between the card end-pieces - again adhesive-side up. Take care to let the tape 'recover' after tearing off a length and before adding it to the strip being formed. It is a slow-deforming material, it does 'relax'.

In the same way, a length of cloth ribbon is placed on the black tape between the end-pieces. Also here do not stretch it, but place it onto the stack without tension.

Unless the cloth ribbon is exactly same width as the tape, cut away the excess width. Either now as or later as a last step, cut away any ribbon that protrudes over the sides. If using a scalpel with a ruler, use very light pressure and multiple passes to cut - the strip is elastic and would otherwise deform and mess-up the straight cut. Scissors will work too.

To add the back of the strip, one or more layers of another color electrical tape - adhesive-side down of course. In this case brown. The reason for using a color is that these are translucent and the outline and location of the holes can still be seen.

With hole-punches and scissors the ends are cut to the desired pattern. (Hole-punches are by the way surprisingly expensive, but also surprisingly one of the more useful tools for this tinkering around typewriters.)

This type of tip is much fancier than the square-ended original Hammond impression strips. It does however look 'nice' and ornamental, in keeping with the machine itself. Also, the fancy-ends pull-tabs could be justified by saying these make mounting of the strips easier ;-)

It remains to be seen how well the electrical tape stands up to the striking of the hammer over time.

In case this impression strip wears quickly (although a Hammond of this vintage is today not a machine to be used extensively), it is easy and low-cost to make several spares. Variations with different thicknesses are also easy to prepare. 

(Also duct-tape was tried as ingredient for making an impression strip, this however was not ideal. The weave-texture does not help with clean impressions and duct-tape is prone to creasing under tension.)

Friday, May 5, 2023

He Dunks Typewriters in the Kitchen Sink

When a typewriter mechanism is very dirty, with congealed oil, dust, eraser crumbs and general dirt, I've resorted to dunking the whole mechanism in soapy warm water. Using a lot of washing-up liquid and thoroughly drying and oiling afterwards it works, but still felt a bit 'uneasy'. (Also taking care to not get the keys wet, water would get under the glass (or celluloid) and mar the card keytops.)

Stumbling on an article in the February 1957 issue of Popular Science magazine, this dunking in soapy water is actually recommended as a method used by professional repairmen too. With illustrations, using an Underwood portable that would've been ~30 year old by then.

The article:

On page 215 it does say that paper covered with glass should be kept out of the water, but the spraying with water still seems a risk to the paper keytops, would be hesitant about that. One other thing is that I've not yet dunked a machine in our kitchen sink. Have been using an old, large baking tray instead.

Other than that, the article pretty well describes the method. 

(Admission; I did place a machine in our kitchen oven at a low temperature setting to thoroughly dry it :-)