- Uwe
- Moderator
Offline 
- From: Toronto, Canada
- Registered: 12-3-2013
- Posts: 4,410
Re: Tab Brake on Olympia SM9
The SM models have to be among the most incorrectly identified typewriters made. It's incredible how many times I've seen people describe a SM2 as being a SM3, for example. There were ten different SM models, and some variations within those models, so I get that's it a little confusing for neophytes, but maybe the safe alternative would be to just call them a SM and forget trying to identify their model number.
The pronoun I has always been capitalized in the English language for more than 700 years.
- RWWGreene
- Platen Punisher
Offline
- From: New Hampshire, USA
- Registered: 14-11-2013
- Posts: 86
Re: Tab Brake on Olympia SM9
I would love to see definitive guide to the SM series. I have a 4, a 5, and a late 9, and I love them all.
- Uwe
- Moderator
Offline
- From: Toronto, Canada
- Registered: 12-3-2013
- Posts: 4,410
Re: Tab Brake on Olympia SM9
I have started a SM spotter's guide and will eventually post it on my website (when I get around to launching it). They are worth collecting one of each.
The pronoun I has always been capitalized in the English language for more than 700 years.
- esmiller
- New Member
Offline
- From: Seattle
- Registered: 07-2-2016
- Posts: 6
Re: Tab Brake on Olympia SM9
Hello, thought I would share my own experience in troubleshooting the same problem--that of a seized up tab brake--encountered by the OP. I recently acquired a 1974 SM9 that was suffering from this issue. After a long and laborious disassembly process (first times for everything!), here is what I found inside of the brake drum:
Amazingly, the bits of cork were more or less intact. But two of the brake shoes seem to have, well, exploded somehow. Perhaps from an uneven distribution of force over many years? The cracks in them don't go that deep and they're still more or less solid, but the outward distortion seems to have resulted in an insurmountable level of friction for the brake mechanism to overcome.
I took out the two faulty shoes and reassembled the brake, however it just doesn't produce enough resistance in that state. I guess I'll need to figure out some sort of replacement to get it working right again. Any suggestions? In the meantime I'm just being careful to keep multiple tabs set, so that if I inadvertently hit the tab key the carriage won't go crashing all the way across.
Anyway, thought this might be of some curiosity to those who had originally chipped in on this thread. Cheers!
- thetypewriterman
- Key Master
Offline
- From: Leiston, England
- Registered: 29-5-2013
- Posts: 925
Re: Tab Brake on Olympia SM9
I have seen this before. Possibly the brake shoes were made from low-grade Mazak, sometimes known to engineers as 'pot metal'. It can corrode like this. The best solution (if you are handy at metalwork) would be to file up a couple of new shoes from a piece of aluminium scrap. The machine will actually work OK without a tab. brake. The SM8 didn't have one to keep the cost down !
- Uwe
- Moderator
Offline
- From: Toronto, Canada
- Registered: 12-3-2013
- Posts: 4,410
Re: Tab Brake on Olympia SM9
The first thing I noticed is that the cork has worn to different lengths. Wouldn't having equal length pieces in the shoes would help things substantially by distributing braking friction more evenly?
The pronoun I has always been capitalized in the English language for more than 700 years.
- M. Höhne
- Key Master
Offline
- From: Maine
- Registered: 14-3-2013
- Posts: 640
Re: Tab Brake on Olympia SM9
thetypewriterman wrote:
I have seen this before. Possibly the brake shoes were made from low-grade Mazak, sometimes known to engineers as 'pot metal'. It can corrode like this. The best solution (if you are handy at metalwork) would be to file up a couple of new shoes from a piece of aluminium scrap. The machine will actually work OK without a tab. brake. The SM8 didn't have one to keep the cost down !
"Mazak" in the UK but more widely known (at least in the US, where it was developed) and in its original form as "Zamak", this metal is notorious for disintegrating (not "exploding" as some earlier poster claimed). It is also known as "pot metal" and, unhelpfully, "white metal". Many are the nice little things that have just crumbled with age. (Hmmm, that says more than I intended.)
Its low cost and easy workability when fresh appealed to a lot of manufacturers who either didn't test it or didn't expect that their creations would last very long in any case.
The shape is pretty simple and it looks like you could indeed carve replacements from aluminum or, even easier, wood. Good Luck
- esmiller
- New Member
Offline
- From: Seattle
- Registered: 07-2-2016
- Posts: 6
Re: Tab Brake on Olympia SM9
I have seen this before. Possibly the brake shoes were made from low-grade Mazak, sometimes known to engineers as 'pot metal'. It can corrode like this. The best solution (if you are handy at metalwork) would be to file up a couple of new shoes from a piece of aluminium scrap. The machine will actually work OK without a tab. brake. The SM8 didn't have one to keep the cost down !
I wouldn't go so far as to say that I'm handy at metalwork, but I might give your suggestion a shot all the same. I had also thought about simply filing these back down to the proper shape, I'm just not sure how long it would be until they went to pieces for good. You're right the machine works fine without the brake--much better than with the faulty brake, that's for sure!
The first thing I noticed is that the cork has worn to different lengths. Wouldn't having equal length pieces in the shoes would help things substantially by distributing braking friction more evenly?
A good observation. Before resorting to any metalwork, I might try cutting more generously--and evenly--sized pieces of cork for the two un-corroded brake shoes (currently seated opposite one another in the brake drum) in the hopes that that provides a bit more friction.
Thanks for the suggestions!
