Hi Olivier

The pitch of a typewriter is measured like the threads on a nut and bolt. Over here in North America, threads are measured in threads per inch (TPI). In Europe, typewriter pitch like threads are measured in millimetres per character or distance between the crests of a thread as expressed in mm.

For example, a standard 5/16" bolt over here is usually 18 TPI. An 8mm bolt in Europe is typically 1.25 mm between crests. Typewriter pitch over here is most commonly 10 cpi or 12 cpi. The most common typewriter pitch in Europe I believe is 2.3 mm per character. This pitch is often referred to as European Elite and comes close to 11 cpi (clarification or correction requested).

As for the differences in individual letters, these come down to the typeface with which the typewriter was ordered. When you are typing up an e-mail or drafting up a document on a word processing program on your computer, you have the choice of many different fonts for your document.

If you were ordering a typewriter from an office supply store back in the middle of last century, the sales clerk would show you a booklet containing the various different typefaces available for that particular make and model of typewriter. Once you ordered your typewriter, that's the typeface is had built into it. Most people who could afford a typewriter, could only afford one, so they would make sure it came with a typeface they liked. Hope this gives you a rough idea,

Sky

Hi Again

As long as the tubing clears the slots in the paper tray and the rollers turn freely, it will work. When I tried using 3/16" braided neoprene fuel line for this application, the outside diameter was slightly larger and the rollers would not clear the slots in the paper tray, so it wouldn't work.

The braided fuel line would clear the slots in the paper tray when I first checked it for size, but once pressed onto the metal core, it would not. The fuel line was a snug fit onto the core, and sliding it over the core expanded just enough for it not to work. Hope this makes sense,

Sky

Hi Rob

Now that's what I call thinking outside the box. I use the Stens P/N 120-114 fuel line clamps in my small engine shop and had never put the two together. I think the clamp metal may be a little thicker than the original C-clip, but with a little experimenting, I'm sure it could be made to work. All the best,

Sky

Hi Again

For attaching ribbon to a Skyriter or S-C series 3 spool without the clip, here's what came to mind. One method would be to wash the ink out of the end few inches of ribbon and stick the ribbon to the core of the spool with Scotch Tape or something similar. Here are a couple of pictures of spool and C-clip.




Hope this helps and all the best,

Sky

Hi Ferulebezel

Typewriters like early Harley Davidson motorcycles and Briggs & Stratton engines used a lot of now discontinued threads. On these machines, 1/4"-24 was regularly found on American built machines up until the 1960's, if not later. I had to buy a #10-36 threading tap for cleaning up threads in carburetors and #4-44 for some of the governor linkages.

Because many of these threads are now obsolete, I don't think you're going to have much luck finding modern replacements for the various screws. The only supplier of screws that might fit vintage typewriters would be a gun smithing supply company.

When working on these typewriters, a completely clean and clear work area is a must so any screw that gets dropped cannot find its way to the floor. As for the slotted screw heads, no other means of driving small screws had been invented when these machines were built, but for the exception of Robertson which never caught on in the USA as it was a pre World War One Canadian invention. Hope this gives you some food for thought,

Sky