For the ribbon vibrator portion, they had to choose at least one key to check, and likely choose one of the repair person's favorite default alignment keys.

It's used in alignment because the capital H is both wide and tall and the lower case h goes above the midline which neither m nor n do. On serifed faces (especially), the HHHhhhHHH combination creates a pretty nice visual baseline to ensure the the type has the proper "motion" and is "on feet". These Hs at both ends of the platen and in the center help to check print evenness when doing the ring and cylinder adjustment. They're also useful when adjusting the level of the line indicator though other letters like m, n, z, and k aren't bad either. Letters like v and i are thinner or almost non-existent on the baseline in comparison.

They also frequently use the / character which extends both above and below most other characters to ensure proper alignment with respect to both a bichrome ribbon and the strike against the platen. You want a nice even imprint from top to bottom. % is also good for this as well.

Some of the repair manuals at https://site.xavier.edu/polt/typewriters/tw-manuals.html as well as some of Ted Munk's manuals available through the typewriter database describe many of these adjustments and suggest specific letters for easier visual inspections.

I'd be curious to hear other repair people's favorite letters and characters.

Incidentally, for installing ribbon, many but not all manuals will suggest putting the bichrome setting to red and then simultaneously pressing the G and H keys so that their typebars gently jam together just in front of the typing point. This raises the ribbon vibrator to its highest point and makes it easier to thread the ribbon into it.

reply to https://old.reddit.com/r/typewriters/comments/1ovt8ry/but_why_the_h_key/

reply to u/SlumberCrow at https://reddit.com/r/typewriters/comments/1orwxqq/type_writer_leaving_small_divets_in_paper_when/

A new platen will certainly help, but it's also a question of having a proper ring and cylinder adjustment across the length of your platen and segment. Often letters that punch through tend to be the . , and o which are at the extreme end of the segment. Some machines have adjustment screws at either end of the carriage and the adjustment should be checked at not only the center of the platen but both ends. If you don't have an experienced mechanic who knows how to do all of this properly you can easily get issues which will most often show up at the far ends of the the segment/platen.

Beyond a proper adjustment, it's also the case that the surface area of the . and , are smaller than other characters and so they tend to get more force even when actuated by the weaker fingers on the right hand when touch typing. Some older manuals and training films will suggest putting less pressure on these keys when typing. This is likely even more important for those who hunt-and-peck and are likely using the full force of their index fingers.

Unless your ribbon is obviously dry or marginal, replacing your ribbon isn't likely to help much. Slugs are made out of hardened steel and you'd have to do something incredibly drastic to damage the slugs, so don't sweat that too much. Backing sheet will help as a stop-gap particularly on machines with older/hardened platens, but there's only so much help that will do without a good platen and a properly adjusted machine.

reply to question about tension control at https://reddit.com/r/typewriters/comments/1orxtvt/strange_lever/

Joe Van Cleave has a great video on this with respect to the Smith-Corona 5 series that will give one an idea on the entirety of adjustment points that are at play in some typewriters. https://www.youtube.com/watch?v=OYOXgqiHBmg

Personally, I've yet to run across a vintage Series 5 machine whose user-facing control lever was adjusted in a way such that it did anything at all because the linkages were so far out of whack. I suspect this may be the case on a lot of vintage machines.

On some machines the adjustment isn't controlling the amount of finger force one must apply, but it's controlling springs relating more to the return of the typebars and the slugs so that touch typers can type much faster without having issues with typebar return jamming things up.

Further, on many machines the dynamic range of forces involved is so narrow that most hobbyist and occasional typists aren't going to really notice a significant difference. This may be different for those who are more experienced and used to typing on a manual machine for several hours a day.

https://www.reddit.com/r/typewriters/comments/1mp43lf/a_sticky_shift_issue_olympia_sm9/

Over time, dust and oil can clog up in the bearing and along the track that the segment glides up and down on causing this sort of issue. You can flush it out with mineral spirits (or something similar) while you actuate the shift key to remedy the issue. When you're done, then add back a drop of light (sewing) machine oil.

While you're at it, most basket shift machines load them with large springs to assist with the weight and to help the return. They're typically attached to metal brackets that can be easily formed with pliers to either increase or decrease the force as necessary to suit your touch and preferred response. (YouTube videos may help here if necessary.)

If that doesn't remedy it, then take the hood off and look closely at the mechanism to see if something is physically impeding it.

https://www.acmetypemachines.com/restoration-process<br /> archive copy

a reasonably nice list of typewriter adjustments for a restored machine

via u/TypewriterJustice https://www.reddit.com/r/typewriters/comments/1m1w6s2/tune_up_key_strokes/

The adjustment points for the on-feet and motion on a Royal Arrow (and similar for the Royal Quiet De Luxe). The outer screws (one on each side) is for the lower case and the inside set is for the upper case.

https://youtu.be/qrlt6VyC8D0?si=USFciplj-5rOIPhb&t=537

via TypewriterJustice at https://www.reddit.com/r/typewriters/comments/1lb8brp/type_slug_question/

(Some summary of ring & cylinder adjustments based on other notes)

A new platen in many cases will help to solve some of the proximal problem, but you'll still have heavy wear on your paper/ribbon and your new platen over time as a result. The first adjustments a pro typewriter repair person would make after installing a new platen would be to check the ring & cylinder, on feet, and motion which can all be subtly out of alignment with a new platen.

Pretty much every typewriter in modern era has adjustment points for this. All three of the machines you name definitely do. You'll find some of the basics and adjustment points for several machines described at https://typewriterdatabase.com/1945-AMES-OAMI-MechanicalTrainingMan.v1-ringcylinder.manual. If you look at the manuals for specific machines that Ted Munk has collected at the typewriterdatabase.com, you'll find how/where to make those adjustments. Several on Polt's website describe the adjustment as well: https://site.xavier.edu/polt/typewriters/tw-manuals.html#servicemanuals

Some sources may describe the adjustment as hammer and anvil as opposed to ring and cylinder.

You're also likely to find YouTube videos on them as well (I'd check Phoenix Typewriter's channel first, though I do recall he mislabeled one once on a S-C Skyriter which was really an on feet/motion adjustment.) Duane's also got a really subtle and uncommon adjustment on a Royal QDL here: https://www.youtube.com/watch?v=KOET0i3DsR8

Gerren gives an adjustment nod for the Olympia SM series here: https://youtube.com/watch?v=2jnC6ODB834&t=670s And here's a blogpost about the adjustment points for an Olympia SF: https://ber10thal.com/blog/repairing-a-1961-olympia-sf/

Related blogposts from Munk for a Brother JP-1:

• https://munk.org/typecast/2022/01/23/adjusting-ring-cylinder-on-a-brother-jp-1/
• https://munk.org/typecast/2013/07/30/typewriter-repair-101-adjusting-vertical-typeface-alignment-segmentbasket-shift-typewriters/

Hopefully your machines and hardware appreciate the finer adjustments and wear better over time as a result.

Happy typing!

Smith Corona Vintage Typewriter Margin Rack Alignment Stop Adjustment by [[Phoenix Typewriter]]

Typewriter Video Series - Episode 216: Double-Striking for Effect by [[Joe Van Cleave]]

Who is Byron L. Wolfe, Author of OAMI Noiseless Typewriter Mechanical Training Manual? by [[Theodore Munk]]

Great, simple list here of all the adjustments for typewriter repair.

Olympia SM3 Carriage removal timestamp 5:14

Actual removal process timestamp 10:46

Part 3.5: COMPLETE Olympia SM3 service guide and tutorial: NICE RACK! Jammed carriage issues by [[The HotRod Typewriter Co.]]

Part 3: COMPLETE Olympia SM3 Service/Set Up Guide- Carriage Adjustments/ Ring and Cylinder by [[The HotRod Typewriter Co.]]

Not mentioned in the video is that, at least on his model, most of the common adjustment points have screws or nuts which have a brassy look rather than silvery almost as a means of highlighting them as subtle adjustment points for improving the performance of the machine.

Sometimes the carriage lock mechanism on the Olympia SM3 may not clear the carriage rail completely and this can result in it rubbing on the returns which results in a zipper or grinding sound. Forming the bar that connects the lever to the mechanism can quickly remedy this issue. See timestamp 2:17

Fore and aft adjustments on carriages

Details at timestamp

Side to side adjustment on carriage:

Details at timestamp

Forward and backward carriage adjustments (on both sides):

Details at timestamp

Adjustment for the spacing between the carriage rails:

This adjustment is rarely done unless there is something drastically wrong with the machine Details at timestamp

Adjustment on the carriage stoppers for how much bounce the carriage shift might have as well as how high or low the carriage sits at it's lowest point using the triangle sliding bracket on each side of the carriage with two screws. If these force the carriage too high, it can affect where the type sits in terms of potentially interfering with the bichrome settings to make letters (especially the tallest ones) have two colors when they should only have one. Details at timestamp 8:14

Adjustment on the rear springs for how light or heavy the carriage shift may be. Raise the spring and then adjust the small "nut" on the top. Details at timestamp 9:52

Ring and Cylinder adjustment for Olympia SM3<br /> Details at timestamp

Gerren doesn't seem to understand (or perhaps doesn't discuss it) some of the mechanics behind this adjustment beyond the distance of the platen to the typeface, but the usual suggestion is that the typeface shouldn't actually strike the paper and/or the platen. Ideally there should be just enough space between the typeface and the platen that an addition sheet of paper can be easily slid between the two along with the ribbon and another sheet of paper. This will allow the typeface to just kiss the ribbon and force the ink onto the front sheet of paper. Doing this will help to protect the integrity of the paper being typed on (ie, no deep imprints being pressed into the paper -- often seen with the period), as well as the integrity of the platen (preventing chips and imprints into the rubber, especially if it has been hardened), and the longer term integrity of the ribbon which can tend to be cut into by the typeface if it's too close.

From a physics perspective there is some minor amount of flex in the typebar arm between where the "hammer" at the bottom of the typebar hits the "anvil" (aka ring) and the top of the typeface which, when typing at speed will tend to "throw" the typeface a tad farther than it would hit when the hammer hits the anvil when simply holding it against the ring manually.

Royal QDL Quiet Deluxe Typewriter, Left Margin Stop, Alignment Adjustment, Repaired uneven edge by [[Phoenix Typewriter]]

How to adjust the margin stops on a Royal Quiet De Luxe and related portable models.

Test typing and adjustments

• Ring and Cylinder adjustment (distance of platen from typeface; the type shouldn't touch the platen or you'll find you're imprinting on your paper, making holes in the paper and/or ribbon, which isn't good) [Interestingly Dul doesn't mention this particular adjustment]
• evenness of the letters (on feet)
• alignment between capital and lower case (motion)
• margin consistency
• line scale height
• adjust escapement "so that it's moving the proper distance both up and down to prevent skipping or missing spaces"
• adjust the height of the ribbon, this is done to make sure the entire letter is printed (and presumably so the bichrome is properly usable when available)

This idea of re-evaluating at regular time points can be a very useful and powerful tool in more areas than just writing.

Society as a whole needs to look carefully at where it is do do this same sort of readjustment as well.

It's the same sort of negative feedback mechanism which is at work in the scientific method and constantly improving the state-of-the art.