You are not logged in. Would you like to login or register?



02-8-2017 18:00:43  #1


SM-3 carriage interference

Olympia SM-3 with some kind of mechanical interference to carriage motion..

If you push the carriage left-to-right in a return direction it makes a hard stop at about dead center. It's not the carriage locking mechanism. It's not the margin. If you lift the carriage a bit you can clear the obstacle but the carriage makes a growling noise for the rest of the return if you don't hold it up.  Once you are past the problem spot you can type normally and the carriage moves to the left and over the catch point without issue: it only catches when you move the carriage to the right.

Some rack is cracked in the middle?   Has anybody encountered a similar problem?


"Damn the torpedoes! Four bells, Captain Drayton".
 

04-8-2017 17:42:40  #2


Re: SM-3 carriage interference

One more observation : I developed the technique of pressing a shift key while returning the carriage and was typing happily with the conventional thoughts about how fine this neglected looking 60 year old machine was when I noticed there was a fault line in the center of the page: every line drops a fraction of a mm when it passes the center point.

I am more confident in my diagnosis but uncertain if its worth trying to fix it.


"Damn the torpedoes! Four bells, Captain Drayton".
     Thread Starter
 

04-8-2017 19:25:25  #3


Re: SM-3 carriage interference

Hi Repartee

​What you're describing is indicative of collapsed suspension bushings between to case and the mechanism, so the carriage is catching on the right side of the body shell. On these machines, the feet don't attach to the main frame on the machine, they attach to the outer housing. The main frame is then suspended within the housing by 4 rubber bushings which tend to squash over time. I have known people to use tap washers as replacements for these bushings. When I did the reconditioning on my Olympia SM-4, I cut the bushings from 5/16" rubber conveyor belt material. Hope this points you in the right direction,

Sky


We humans go through many computers in our lives, but in their lives, typewriters go through many of us.
In that way, they’re like violins, like ancestral swords. So I use mine with honor and treat them with respect.
I try to leave them in better condition than I met them. I am not their first user, nor will I be their last.
Frederic S. Durbin. (Typewriter mania and the modern writer)
 

05-8-2017 21:17:15  #4


Re: SM-3 carriage interference

Hey, thank you Sky! That indeed points me in a new direction. The machine is at work so I will have to examine this Monday.


"Damn the torpedoes! Four bells, Captain Drayton".
     Thread Starter
 

05-8-2017 23:31:20  #5


Re: SM-3 carriage interference

Yes. Squashed bushings are a really common issue on these. I replaced mine with stacked washers from the hardware store. There was an old blog post that describes the issue in detail with photos here.

 

06-8-2017 10:14:59  #6


Re: SM-3 carriage interference

I've encountered something similar on a small Dutch made machine where the action attached to the bottom of the case through rubber bushings which had disintegrated. I also replaced them with stacked washers and was mighty proud of myself until I realized the typewriter now made a high-pitched ringing sound with every keystroke!

I will try to find some more sound-isolating solution here -- despite age, neglect and a hard platen the sound is still tolerably subdued and pleasant and the thing feels like an SG-1 with a smaller footprint.


"Damn the torpedoes! Four bells, Captain Drayton".
     Thread Starter
 

07-8-2017 18:38:30  #7


Re: SM-3 carriage interference

Sky, you are a lifesaver. Armed with that insight this became a twenty minute repair at lunchtime -- I backed out the rear screws and shimmed the squashed bushings with four or five thickness of plastic coated business card. Carriage moves without a hiccup now.


"Damn the torpedoes! Four bells, Captain Drayton".
     Thread Starter
 

Board footera

 

Powered by Boardhost. Create a Free Forum