Often after you resurface a platen, it slightly changes the configuration of the platen with respect to the typeface. As a result one usually may need to do three adjustments in a specific order to get things to align properly again. These can definitely be done at home with some patience.

Usually the order for tweaking is: * 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). Sometimes using a simple backing sheet can remedy a bit of this distance problem, especially on platens which have hardened or shrunk slightly over time. * On Feet adjustment (vertical adjustment so that letters are bright and clear and neither top or bottom of characters are too light/faint) Repair shops will often type /// or a variety of characters with longer ascenders/descenders to make sure that the type is clear from top to bottom. * Motion adjustment (the lower and upper case letters are at the same level with respect to each other) The best way to test this is to type a center character like HHHhhhHHH to see if they line up on the bottom (the last three Hs are usually done with the Shift Lock on to make sure that's properly set).

You can search YouTube videos for your model (or related models) and these words which may uncover someone doing a similar repair, so you have a better idea of what you're doing and where to make the adjustments.

Here's Joe Van Cleave describing some of it in one of his early videos: https://www.youtube.com/watch?v=C0AozF2Jfo0

The general principles for most typewriters are roughly the same with slight variations depending on whether your machine is a segment shift or a carriage shift. You should roughly be able to puzzle out which screws to adjust on your particular model to get the general outcome you want.

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

You might find a related repair manual for your machine with more detail and diagrams for these adjustments via the Typewriter Database or on Richard Polt's typewriter site.

For those not mechanically inclined you may be better off taking it onto a repair shop for a quick adjustment. https://site.xavier.edu/polt/typewriters/tw-repair.html 

Reply to u/Acethease at https://www.reddit.com/r/typewriters/comments/1d76ygx/got_a_as_a_gift_corona_3_recentlyish_and_i_need/

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.

Olympia SF Companion adjustments<br /> by [[Typewriter Justice]]