Friday, February 23, 2024

Blowing out dust - period style

Over decades of neglect, an old typewriter or calculator will collect a lot of dust. Even inside a machine's housing, there often is a surprising amount of dust and debris in the mechanism. 

To clean this out, a soft brush is of course useful - taking care to e.g. not disturb any small springs. Another way is to blow out the mechanism with air.

For a smaller repair-workshop and prior to aerosol cans, there could be used a dust-blower. A wooden cylinder, in this case the 'universal dustcleaner':

These are still fairly common, especially this brand of dust-blower with the flowery label. It is a wooden, rolled tube (veneer) lined with cloth and has a wooden plunger with a leather seal.

The leather-seal on this specimen had been folded back, over the wooden plug. Originally it probably would have been folded forward into the tube, thus sealing against the sides with the air-pressure. Some time in the past this dust-blower was opened and the plunger inserted with the leather wrapped over the plug. To be fair, it's quite difficult to insert it correctly from the back, originally it likely would have been pulled in from the front before gluing on the spout.

The leather had hardened completely, making it difficult to shape it back. A lot of leather-wax was added, to hopefully make it a little pliable again. The seal could be replaced with new chamois, but as it's mainly a historical artefact may just be left as-is. Some extra felt rings were added underneath the leather 'dampeners' on the shaft that also had gone hard - to dampen the plunger 'hitting the buffers'.

From appearance, it could date from anywhere between 1880 and 1920. In fact, most of these are much more recent. The actual manufacturing date is stamped on the plunger; this specimen was made March 17, 1938. (The white dust in the image below is talcum powder, added to make it go smoother.)

It does work - not quite as effective as a pressurised-air can for sure, but durable and very sustainable :)

Friday, February 16, 2024

Carriage on the Standard Folding typewriter

Moving on to the carriage, the front support studs first needed aligning. These three studs are set-screws that were adjusted in the factory and then fixed in their correct position by 'pinning' then from the front. (That is the cause of the small holes in the front-edge of the base, and why there is a central cut-out in the front carriage-clamp.)

The centre stud had become loose and lost its position, luckly it had not yet worked itself completely free. Against a ruler and using the wear as an additional guide, it was re-fixed at (probably) the right height.

With the same method as before, all parts and screws of the carriage were cleaned and bagged ready for re-assembly. 

The feed roller was left in place (could not work out how that would have to be removed). The combination margin-stops / paper-bails are ingenious. The paper-bail finger is always at the edge of the paper, just out of reach of the typing :)

The carriage slides on the machine-base on the two steel bars or strips at its edges. It is simply metal-on-metal sliding, no rollers of any kind. The rear strip rides in a slot in a profile on the base. The front trip rides on the tops of the three studs.

The carriage is then held in place by clamps at the front and back. The front clamp was missing on this machine - using the useful images of Standard Folding 2's on The Typewriterdatabase and especially the clear photos at Words Are Winged, a functional replacement was crafted from 1 mm aluminum sheet. This is not a strong as the steel original, but should hold the carriage on well enough - this typewriter is unlikely to ever again be used heavily.

Painted satin-black, it works to hold the carriage on its rails. It is now again safe to fold the Standard Folding typewriter!

A length of waxed hemp as draw-string and the escapement works! The spring somehow slips its anchor and won't keep the full pressure needed for the entire travel. Maybe this will be looked at, but maybe not - this typewriter will not be used heavily. Rather, the goal of this restoration is for the machine to be preserved. Ideally it should become functional again, but not to the level of it being a practical typer

Now complete with carriage and platen, the little typewriter is starting to take shape - progress :)

Friday, February 9, 2024

Starting on the top-assemby and broken worm of the Standard Folding typewriter

Continuing with the top assembly of the Standard Folding typewriter; the carriage was taken off (is was barely hanging on anyways, with only one bracket left). Then first the carriage base-assembly with the folding-arms was taken apart. End result is a pretty bare baseplate and lots of grimy bits grouped in bags. Only the escapement rack and the rear guide-rail were left in-place.

The baseplate is a fairly basic 'slab' of aluminum, also with the dull, passivated finish. The normal cleaning with soapy-water and vigorous scrubbing would have damaged this finish. As an alternative, the part was washed in acetone, 'scrubbing' gently with a soft toothbrush. (Outside/well ventilated and gloves.)

Bag-by-bag all the groups of parts were cleaned with the usual techniques. The spool-bases had originally been blackened and by now become rusty. These were sanded smooth to the bare metal and painted with a satin-black finish.

Result then; a nicely clean baseplate and a collection of clean sub-assemblies. As stated in service-manuals of the time, assembly is the reverse of disassembly.

So it is.

One unexpected complication was the worm of the right ribbon-feed. This was broken! Somehow it got a knock that spread the worm-thread wider in one spot. This made it jam on the sprocket of the spool capstan; it cannot have worked after that damage. Weird that it even broke the worm where it is fixed with a pin to its axle, but did not destroy the flimsy spool-base. Must have been a very targeted knock.

Fortunately it could be tweaked back into functional shape - well, bent-with-brute-force really and some filing too. The broken and bent-back two parts of the worm were locked on the axle with cyanoacrylate. (In case the worm would've completely disintegrated,  a new worm would have had to be made - could probably have been done; tin-plated copper fuse-wire is soft and available in suitable gauge.)

Mounting the rest of the parts on the baseplate is fairly straightforward. Some bending needed for the escapement plate to straighten it, was bent and would jam in its guide. Probably another damage that happened to the machine after it was last used. Fitted back onto the typewriter base, the little Standard Folding typewriter is taking shape - next the carriage (and several missing parts).

Friday, February 2, 2024

Mounting keyboard and typebars and dulling aluminum for the Standard Folding Typewriter

In preparation for mounting the keyboard 'tapestry' back into the frame, the linkages were sorted on length. They are not numbered, so were kept in sets of 14 for left and right sides of the machine to allow every linkage to be placed back in its original spot. (And of course all were cleaned and rubbed with a bit of vaseline.)

There may be a way, but it didn't seem possible to attach the outer linkages to the key-lever when inside the frame. To avoid that puzzle, deviated from the procedure shown at Words Are Winged and already attached the outermost 4 linkages for both left and right. Also the distance-bushes were added, of course.

This whole assembly was then wiggled back into the machine from the front. The three rods fixed with the screws through the frame-sides. Some painters masking-tape on the front bar to prevent scratching of the paint during the process.

The next step was mount the typebars - these were also laid out in the correct order just like the linkages. A little cloth with oil to give every screw a little dab and tweezers to manoeuvre the linkages back into place.

The typebar-rest on the Standard Folding is mounted onto the front-panel and is what determines the height of all the keys. This front panel unfortunately lost its original dull, passivated finish during the paint-stripping. To get rid of the shiny aluminum and make it suitably 'dull', the panel was glass-bead-blasted -very carefully.

The above image shows the left-half already blasted, the right-end still shiny. The blasting was done carefully; only very low air-pressure and especially a very constrained supply of blasting-material. With aluminum there is a very real risk of creating such surface-stress that the part will warp and deform. First practiced on a scrap test-piece. Fortunately, the panel survived unscathed and is now nicely even and dull/matte.

The rod for the springs was bent ever so slightly - either from a 'bang' or from a century's worth of the springs pulling it (although metal should not relax that way). The rod could be rotated a bit to now be pulled straight - all the springs will stop it from turning, so no need to 'fasten it tight' with the screw-thread.

The original typebar-rest felt was kept, merely given a gentle lukewarm wool-wash and turned over. It is clamped between panel and its support bracket at both ends (and some glue-stick glue on the bracket).

The base of the Standard Folding typewriter is now mostly complete; of course all adjustments remain to be done after the whole machine is fully assembled. (A bit daunting; the segment of a Corona 3 is already a bit tricky; this is 28 separate segments to tackle :-)