Corona 3 - 100 years old foldable typewriter.
This machine came to me from a lady who’s husband was using it for countless years. After he passed away the machine was not used much, gathering dust. Luckily the machine avoided hands of unskilled amateur who would spray her with WD40 so when I got her she was still typing although segment was cluged with dust and the mechanism was working with delay due to dried oil.
Apart from dirt there were only a couple of problems: platen was (of course) very hard and developed cracks. There were no ribbon spools. Draw band was reaching its end of life.
I started disassembling. Carriage assembly is removed very easy by just unscrewing 2 screws from folding brackets. Platen removal was standard - with set screws on the knob and platen. Body of the machine is its frame so there was not much more to remove to get better access to the mechanism.
Closer inspection of the platen revealed cracked rubber in many paces. Wooden core is visible due to shrunk rubber.
I want to use this machine so platen re-coating is a must. I used my standard technique: the rubber got sanded on lathe, to compensate for new rubber. Once done and cleaned it gets bicycle inner tube unrolled inside-out. Sanding to make it even and grippy and done!
Paper roller developed minor flatness so I sanded it to regain cylindrical shape. Rubber is still grippy and elastic so no need to replace it.
I cleaned the carriage assembly and noticed how bad the draw string is. Better change it already now before it snaps.
Out of curiosity I opened the spring motor to see in what shape the main spring is. No problems here - fresh as new. Very conveniently the whole escapement mechanism is right there, easy to access for cleaning and adjustments.
Main body cleaning followed. Flushed the segment and type faces with mineral spirit + oil, cleaned all key faces and rings, aligned skewed key legends.
Interesting to see marks left after typebar adjustements - old technique of punching the metal to locally deform it and thus slightly bend the whole shape.
Clean and oiled: carriage rollers, ribbon driving mechanism, hinges - in total 2 drops of oil on the whole mechanism. I assembled all parts and tried the action. Working fine now, no hiccups.
Body panels and frame got waxed with Fulgentine - avoiding decal areas, to keep them gold. Fulgentine, if applied on gold decals, turns them silver.
The machine came without spools which is quite unfortunate because this model uses proprietary spools, universal spools are too wide and will not work with ribbon transport mechanism.
I found Facit/Addo old spools, made of steel, which match the needed diameter.
Old ribbon is still very inky - almost too wet. I rewinded it to use later and moved onto modifying the spools. External clamping features are not needed on this machine and the central hole is too small to fit Corona 3 spool pins. These spools are riveted with the central pipe. Removing it - to gain needed 5mm internal diameter hole - is causing spools to fall apart.
I use transparent UV-hardened epoxy to mount needed parts together.
Strangely enough, this American machine is using metric threads on spool pins. Moreover - both of them are right-handed. I could use standard M5 nuts here but I got fancy and made my own, from brass. Some personal touch, I suppose.
Test typing in two colours. All good. This machine has no ribbon reverse. I thought that it would use the same mechanism as Erika 3 foldable that is: spool pins rotate in opposite directions, loosing one nut and tightening the other is doing ribbon reverse. But not on this machine: both spools turn in the same direction so in order to reverse a ribbon one needs to switch spools. Still the supply spool should have its nut loose, otherwise the ribbon gets slack. Only receiving spool should have tightened nut, to draw the ribbon and keep it tight.
I have not yet checked serial number on Typewriter Database but it seems that my machine is very early model. Later models had Erika-type ribbon reverse.
Some more pictures of this beauty.
In folded stage it becomes surprisingly compact and lightweight package.
Almost as small as Blick 5!
I’ll need to make a carrying case for her but for now I just enjoy using her! Not as smooth as later designs, not as easy to type as Erika or Remington but this machine has its charm.