Typewriter Talk / Olympia SM9 Single Binding Key

**Posted by FRParker** 10-5-2023 00:31:10

Hello everyone,

I have an Olympia SM9 (the style made between 1964 and 1969) that has a binding "N" key. No other keys bind in this way, and I have given it a very thorough cleaning while working all keys (I have found, if you can control the flow and spray, brake cleaner does wonders for my past typewriters and leaves no residue). It feels like the key arm (I guess that's the term) is rubbing or binding on something. There's no gumminess to the key before that point, and the typebar shows no rubbing when sitting in between the guides; in other words, it's not bent.

I do not know what this could be, so I come to you, the experts.

Thank you very much in advance,
Forrest

P.S: my apologies if I have not used the correct terminology. It's been a while since I have brushed up on my typewriter mechanical knowledge.

**Posted by Laurenz van Gaalen** 10-5-2023 10:12:39

Have you cleaned/checked the comb (the slotted plate that keeps the key levers in place)? Sometimes the comb contains dirt, or one of the teeth is slightly bend, which can cause the issue you describe.

**Posted by FRParker** 10-5-2023 11:16:21

Yes. It has some dirt, but nothing that would keep it from functioning. I think a lot was flushed out by the brake clean. What are the teeth of the comb? Are they the little hooks that have the springs attached to them?

Also, I've noticed that the "N" key squeaks, whereas the others do not. It sounds like rubbing metal.

**Posted by Laurenz van Gaalen** 10-5-2023 12:41:04

FRParker wrote:
What are the teeth of the comb?

The image below shows the comb of a SM8. With the 'teeth' I mean the metal with the rust speckles around the slots. If one of the tooth is bended slightly to the left for example, the slot on the left side of the tooth will be narrowed, wich may hinder the key lever to move freely through the slot.

**Posted by FRParker** 10-5-2023 17:57:05

I inspected the comb, and it seems to be fine. No bends are present or anything like that. The key lever can still move up and down (slightly, but freely) when it binds. I suspect the issue is further down the line. What would come after the comb?

**Posted by Pete E.** 11-5-2023 08:02:05

I would follow that single key-top to its type-slug and use a bit of lacquer thinner on all the pivots. Be careful with lacquer thinner as it will eat paint and some plastics and rubber, etc.

Or a bit of PB Blaster on the same pivots.

**Posted by FRParker** 13-5-2023 22:52:35

I have done as instructed, and cleaned thoroughly all the pivots. The "N" key is still behaving in the same manner as before.

Something I have noticed is that when I go to press any other key down (very slowly, so no inertia carrying the type arm), right when I get to the bottom of the key travel, all I have to do is press slightly harder to make the typeface mate with the paper rolled around the platen. The only key not to do this is the "N" key. Pressed in the same manner, it stops half an inch short or so of the platen.

I don't know if something needs to be adjusted, but I think the issue is mechanical in nature.

**Posted by robmck** 14-5-2023 18:15:01

I wonder if the N has a bent linkage (thus doesn't have the same range of motion) and that is rubbing against something else.

Like Pete said, the best way to figure this out is to inspect it from the key to the type slug. I don't have an SM9, but do have an SM3, which might be somewhat similar (typewriter manufacturers generally don't do massive changes between even major revisions - it's surprising how similar typewriters are when you pull the top off).

If you pop open the ribbon cover, you can see them (I'd start with looking at the keys on the far right or left to learn them, then move to the N, which will be harder since it's in the middle.

My SM3 has 5 parts to the key drive chain. The key cap sits on a key bar that runs most of the length of the bottom of the machine, but there's a very small wire linkage about 1/3 of the way back that goes to another lever arm mounted a little under the type bars. At the far end of this arm is a wire linkage that goes back in the machine to the bottom of the type bar, just aft of the type-bar's pivot.

I suspect one of those wire pivots is bent and rubbing.