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).

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