The SM3 and SM4

26 Mar

When I picked up that SM3 at Goodwill, I was confident that it would be worth the $9.99 because: (a) That’s only 10 bucks! and (b) I’m interested to see the differences between the SM4, my first manual, and the earlier SM3, which I assumed was just the SM4 with the keyboard tab system. I could interchange parts, and use them as examples when things weren’t mutually broken on them.
Upon opening up the SM3 for its inaugural cleaning and bushing replacement, I discovered that there were more differences than I assumed. I present to you my observed differences, I make no claims as to being an expert on Olympia features and manufacturing, the conclusions I reach here are largely intuited. I also don’t know the names of a lot of these typewriter dealy-bob things, so bear with that as well. Let’s start at what you see first, the typing area, the Schreibwerk in the Olympia’s native German.



Looking down at the writing workshop, we see that the SM3 and 4 have different designs. The SM4’s design is easier to thread the ribbon into, so I count that as an improvement.


Here are the keys of the SM3. You can see that the keys that don’t have spring levelers, the backspace and tab keys here, are thin instead of later SM3s and the SM4’s which are molded to the same size as the others.


SM3 Paper rest

The SM4 adds ruling to the paper rest so that you know how many lines you have left. Handy feature, that.

SM3 paper table

The SM3 has a smooth paper table/paper rest on the carriage, to aid inline corrections with a pen, I suppose. This consideration has vanished from the SM4, which has crinkle paint to match the rest of the case.

SM4's filthy paper table

Left side of the SM3 carriage

The left side of the SM4's carriage

A few differences here on the carriage. You’ll note that the SM3 lacks the left side carriage release that the SM4 adds. The SM3’s carriage return lever is fastened on with a large slotted screw, the SM4 slims the profile and streamlines manufacturing by making this a straight pin.

SM3, rear

Here are the manual tab sets on the back of the SM3. You push these in towards the inside, and you disengage the sets from a toothed track, and move them side to side. It takes a little logical deduction to set up the tab sets like this, but it’s not unreasonable.

SM4 rear

The major difference with the SM4 is of course the automatic keyboard tab sets, and you can see how they kind of work here. Those metal things towards the center will raise and lower these teeth when you push the tab set or clear buttons. I thought these were pretty cool when I figured out how they worked, and when I got the auto tab set keys to work.

Let’s open up the ribbon cover and check out the guts a little. I’m not going to go into every difference, because there is a lot of variation just within the runs of the SM3 and the SM4, I would assume, and you probably don’t want to hear about every screw and linkage.

SM4 Typeslugs

Both of these machines are 11pt. Olympia Elite, which as far as I can tell is pretty similar between both machines. The typeslugs are rounded on the SM3, they get squared off on the SM4 or perhaps later in the SM3 run, probably to reduce the complexity of their casting.

SM3 carriage lock switch mechanism

Here is the left corner of the inside, I want to focus here on one example of the mechanical simplifications that reduced manufacturing time from 1955 to 1960. You’ll see in the center the mechanism of the carriage lock. This is totally independent of the margin release key, whose bar runs below this just to the left in the image. The carriage lock rides against that black pin/tooth on the right, and there is a spring there to add tension.

SM4 carriage lock mechanism

Here is the SM4’s analogous area. You can see that this linkage is dramatically simplified, and both the springback of the margin release key and carriage lock ride are the same spring/wire thing under the center. The spring now has a wire loop that locks the carriage switch. The black metal pin that used to serve that purpose is gone. I know I can’t really describe this mechanism, I’m far from a technical writer. This wasn’t seated properly when I first got the typewriter, the spring wasn’t loaded, it was loose. I placed it on the point of the carriage lock mechanism, and it returned both to function. This change reduced the amount of parts needed to accomplish the exact same task, and you wouldn’t even notice if you didn’t stop to examine it.

Also, note that the spring holding the ribbon cover has moved from the front panel on the SM3 to the more solid main case on the SM4. The ribbon cover also attaches to the guts of the machine on the SM3, but is hinged on the case on the SM4.

SM3 ribbon cover hinge

Well, that’s about all I can do for now, there are countless other little differences in number of screws and fasteners, which were generally reduced in number over time. Here’s a comparison of type samples:

So these machines are a bit more different than meets the eye. You could probably swap the frames between the units, but then you’d run into trouble with the ribbon cover, and the carriages are definitely not interchangeable. I was briefly considering this because I like the green of the SM3 and the smoother action of my SM4. Alas, not very possible I’m afraid. Other things I forgot to document: the paper bail is hinged differently between the two, the SM4 has that little lever on the right side of the carriage to clear all the automatic tab sets, and the SM3 has its serial number etched onto its carriage, as well.


15 Responses to “The SM3 and SM4”

  1. Richard March 26, 2011 at 1:54 pm #

    You have a good eye! It is really fun to discover little differences like this.

    The left-side carriage release is a major advantage in my experience.

  2. SnohomishWriter March 26, 2011 at 3:21 pm #

    I didn’t know that there are that many differences, having never had an SM-4. My SM-3 has the ruled paper guide, like your 4 does, but the other three that I had in the past had the earlier style. Interesting.

  3. b r March 26, 2011 at 3:57 pm #

    This is a fantastic post; thanks for the knowledge–and the photographs !

    [ typewriter poetry ]

  4. Cheryl March 26, 2011 at 7:43 pm #

    Nice research on the differences, this post is likely to become the definitive reference on the subject!

    • Marcello August 15, 2015 at 2:42 am #

      It seems that, what belongs to Woody Allen is particularly rare…..maybe….

  5. Duffy Moon March 28, 2011 at 6:49 am #

    Excellent work. Can’t believe no one (to my knowledge) has really done this side-by-side before (I’m thinking now that W. Davis has, at some point, done this, but I don’t recall seeing it on his site).
    Very well done.

  6. Adwoa April 10, 2011 at 12:03 am #

    Fantastic post, and great pictures to go along with it too. I agree with Cheryl that this will become the definitive reference on the subject. Many of us will have seen these machines before and glossed over the differences, but it is truly marvelous for beginners and veterans alike to have this thorough guide.

  7. Neal June 30, 2012 at 7:04 pm #

    Can you tell me if the cover that goes over the ribbon is interchangeable between SM3 and SM4?

    • Harry Cordner April 14, 2013 at 9:06 pm #

      The mounting is somewhat different, they are generally not interchangeable.

  8. shordzi December 15, 2012 at 5:13 pm #

    I just got an Olympia SM4 myself and really appreciate your comparative study.

  9. Ethan July 9, 2013 at 9:31 am #

    Do you happen to have a user’s guide to the SM4?

  10. Victoria Flint December 17, 2013 at 9:38 am #

    I’ve got an SM4, but it differs in that it has a Roper’s logo along the the standard Olympia and it only types in italics. Any idea what kind beast this is. Lucky I found in mint condition… but alas, with no paperwork, just an importer’s tag.

  11. Jf March 25, 2015 at 1:45 am #

    Hi, you mentioned the spring on your carriage lock mechanism was loose. Mine is also loose and it does not stay unlocked. I have to hold it down. Can you please explain further what you did to fix that issue?


  12. April 30, 2015 at 1:13 pm #

    How do I unlock the keyboard to an sm3?

  13. Alan Brody July 22, 2015 at 5:27 am #

    I have an SM3 with the pin instead of the bolt on the carriage return arm, a textured paper table, and a ruled paper rest. I would have thought it was an SM4 if it didn’t have the tab sets on the back of the typewriter. I would guess that the differences reflect early/late in addition to SM3/SM4.

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