Today's Lesson: Smith-Corona Portable Ratchets

I'm making some good progress with the 1948 Smith-Corona Silent that I picked up the other day. One of its most serious problems is a free-spinning platen. I've managed to solve most of the issues just by comparison to a Corona flat-top portable that I own. It's a testament to a good design -- or corporate intertia? -- that I was able to use two other typewriters from twenty-years apart to solve issues with this one. Comparative anatomy for the win!

With the line-advance lever working again, I now have a platen that turns freely. There's a hole in the left knob where a rod should exist, and the typewriter has a funny rattle. What does it all mean? In the case of Smith-Corona portables of a certain age, that means removing the platen. In some machines, this is a recipe for madness -- I'm looking at you, Hermes -- but the Smith-Corona designers and engineers made some excellent decisions that pay handsome dividends to the amateur repairer.

I have a couple of 1950's S-C portables, and although it's not immediately obvious, it is possible to remove the platen with no tools. You need to follow a certain magical spell:

1. Disengage the ratchet
2. Disengage the line-advance
3. Lift the panel on the right-hand side of the carriage
4. Find the smallish spring-tensioned lever on the right side that is holding the carriage down and hold it back with your left hand
5. With your right hand, gently left the right-hand knob of the platen and pull it up and to the right: it should slip right out leaving you a view like this:

Honestly, it's easier than I'm making it sound: once you've found all the parts you need to move, it's easy. On the 1948 model, the process is much the same,though the whole business with panels and levers is simplified. There's less body in the way, and on the right hand side, all you need to do is slide a little spring-tensioned restraint out of the way.

Here it is in animated GIF form:



(Please excuse the crud on the machine, these are all pre-cleaning pics.)

So, already I'm loving the engineers for making this easy. I pulled out the platen of the machine, and found a part rattling around inside. The missing ratchet-engage lever! I set to work at once figuring out how the parts fit together... and got it backwards. It wasn't until taking that first photo that I realized my mistake.

Unlike Royals and Olympias, and maybe a few other makes as well, Smith-Corona has a "pull to release" mechanism on the ratchet. There's a little rod with a ball permanently attached to the end, and that ball engages or disengages the ratchet. Since I had so much fun with that first animation, here's another one to demonstrate how it works, next to a closeup of the business end of the platen. It's scaled down to fit on the blog: click through for the readable version.



My diagram is overly simplistic, but the general idea is that there are two flaps inside the platen that trigger a pair of tiny spring-tensioned "brake pads" (for want of a better term.) Here's the platens from the two machines here -- my new 1948, my working 1957.



The flaps don't show up in this photo, but they're there, trust me. This design evidently worked so well that it remained unchanged for years. I was able to drop the platen from the older machine into the new one with no problems (which is how I tested that the mechanisms worked OK in the first place.)

In typing position, the brake pads are pressed up against the ridged inner edge of a metal cup that forms the left-hand side of the platen assembly. I laid a pencil in the carriage so you could get a sense of scale, and see the tiny ridges near the tip of the pencil.



The part that was rattling around inside the platen of my machine was the push-rod that meshes with this mechanism. The end of the rod is threaded, so evidently the old knob or handle that used to fit here got removed at some point in this typer's past. Spending some time in the parts aisle at the hardware stored turned up a brass knurled knob that fits pretty well, though the threading isn't exactly correct. You can see it in these photos showing the knob pieces as they would be assembled in the typewriter.







Normally, the whole mechanism sits in the carriage with the knob attaching to the exposed end that fits through an opening in the side. The squared end of these parts fit into the squared opening in the inside of the platen. Pretty clever!

Now I just need to get the body panels back on -- somehow the frame of the typewriter grew about 2mm after I got the outside panel off -- and figure out what a dangling spring is supposed to attach to, and I think this machine will be back in typing shape.

Just Following the Code, Ma'am

THE TYPEWRITER CODE (abridged)

Keep a close eye on the keys



Stripes make everything better



It's OK to celebrate your finds in private



But it's more fun to show off

---

Usually a wasteland of typers except for smoke-smuggered seventies electrics, St. Vincent de Paul came through today with a lucky, lovely find. Elation turned to mild displeasure as I catalogued the issues in the store:

• The ribbon color won't come out of red,
• The ribbon vibrator isn't moving, though it can be moved,
• and ribbon posts aren't advancing, though the mechanism looks clean. 

I suspect a common cause, which will probably mean shelling this machine to see what's up.

• The line-advance lever... isn't
• The ratchet is turned off, and there's no button in the left-hand knob
• Something's up with the paper bail so it's not touching the platen

A size 3 knitting needle will easily fit into the opening, though, so maybe an exploratory poke is in order. It's handy to have hobbies that intersect with one another.

Issues aside, and they are legion, it's Just. So. Pretty. Those stripes! Those keys! All the main typing operations function, and it's still got a full set of tab stops resting on the rack in the back. I'm hoping the problems are recently introduced, and easily reversed. What fun is it only having one or two repair projects waiting on the bench?

---

Update: In the comments, Rob Bowker correctly noted the similarity between this machine and a flat-top portable.

I'm curious - just HOW different are these from the original Corona 4s? From ribbon vibrator through paper fingers all the way to the key tops - it looks the same but in different clothing.

He's right of course: except for the newer machine's backspace key moving to the opposite side to make room for the tabulator, there's very little different between these two machines in my collection:

c. 1939


c. 1948





They're so similar, in fact, that I pulled out the flat-top machine last night to inspect the line-advance mechanism. In turn, I found and corrected the problem on the newer machine this morning -- someone had flipped a small spring-tensioned part around its pivot point 180 degrees, and this is the part that engages with the toothed ratchet wheel on the platen. Flip it back into place, and the line-advance lever works properly (almost.)

This also corrects the issue with the paper bail, since that part sat in the way. Now it's back in place and all is right with the world.

The platen still spins freely, though, and this is where the flat-top won't be much help, since it doesn't feature a mechanism to disengage the ratchet. I removed the left knob from the newer machine just to see if I could make some progress, and I can force the ratchet to re-engage if I push the shaft into the machine with a fingertip. I know all the parts are in there and working, so I just need to learn how to make them work all the time.

Update 2: I just remembered that my newer Smith-Corona machines have a pull-rod on the left knob to disengage the ratchet, not a push-button. Suddenly this makes all kinds of sense. Looks like I'm off to check the newer machines to see how they work, too.

Anyhow, two mysteries solved already, and I've got clues for a third. A productive twelve hours!

Update 3: And I think I've got just about everything solved. The color-select lever was just jamming up, probably due to the mechanisms not having been moved in how many decades. I shelled the machine to follow the linkages and check for impediments, worked the mechanisms, and now the lever and ribbon vibrator are behaving properly AND the spool-posts are turning. It's a repair trifecta.

I've got positive news on the ratchet front, too, and I'll share that in a future post. Hopefully a typecast!

The Rhino Unboxes: A Photo Essay

FIGURE 1: THE RHINO MAKES A DISCOVERY


"O hai! A present for me!"



FIGURE 2: ALAS! VERTICALLY CHALLENGED


"Little help, plz?"



FIGURE 3: DECIPHERING AN EXOTIC TONGUE


"Insert 'upside down/down under' joke here, k thx bye."



FIGURE 4: WHEREUPON WE ARE RIGHTED


"Mr. Remington, I presumes?"



FIGURE 5: THE RARE BURROWING RHINO


"HALP!"



FIGURE 6: THE PATIENT IS READY


"This won't hurt a bit."



FIGURE 7: OBLIGATORY MACRO SHOT


"I can haz teh shiny?"



FIGURE 8: LEARNING AT THE MASTER'S FEET


"Chamfer? I hardly even know her!"



FIGURE 9: OBLIGATORY OLD VERSUS NEW



Right on time, the replacement lever for my busted Underwood Noiseless arrived yesterday, and whether by chance or because of the mystickal frission that binds the Typosphere together, Scott posted his own experiences with repairing his Noiseless. Spooky!

I opted for the plain stainless steel finish on my part, instead of the antique bronze that Scott accidentally chose.The plain steel lacks the lustre of the chromed parts that it will be living alongside, but I'm not going for a historically-perfect restoration. At first I thought I might buff and polish the surface a bit, but now I don't think I will. There's a slightly pebbly, imperfect look to the new part that I like. You won't mistake it for original equipment, but it's not immediately evident that it's only a week or so old. The part is very well-made and much smoother to the touch than you might expect, and I really like the extra details Scott added to the model -- the loose "S" shape to fit your fingers, the Deco-style ridges on the end. It was well worth the expense and the wait.

Now I need to take some careful pictures of the spring arrangement in the return lever, and dig up some tools to make the necessary adjustments to fit this piece in place, and get this old beauty back in typing shape. And maybe I'll let the Rhino help a little, too.

Dear Mr. Remington: Well-Played, Jerkface

Is there no depth to which my old nemesis refuses to sink? I was ticked to find that Scott's 3-D printed part should -- with some care -- fit my new/old Underwood Noiseless, and while I wait for his part to be printed and shipped, I've been looking at the drawband problem.

Here, in essence, is the problem:


(All that hair is actually wool fibers from the homemade typing mat.)

That piece of cord doesn't extend very far out of frame, and only a few molecules of that classic waxed twine is left on the carriage end. No matter! I have replacement code left over from my last Remington re-stringing, and I see that this has the same, annoyingly-small hole in the side of the drum. On the Monarch, I had to expose the spring to retrieve the old cord's knot and feed in a new knot. Scary, but not impossible.

So I've got the Underwood (née Remington) on its back, and I prepare to undo the back plate of the drum to get at the spring. And here is where Mr. Remington's cleverly-laid trap was sprung! (Every pun intended.)

Against all reason, the spring on this machine is sealed up tight -- the drum is crimped together like a tin can. The screw that I thought held the backplate on actually fastened the whole drum to the machine. The damned thing just fell out in one piece, which is why you're looking at a photo of it sitting on a typing mat, and not a photo of a spring seeing sunlight for the first time in decades.


(What's missing from this photo? See the other photo.)

Clever, Mr. Remington, very clever! Did your repairmen have a big box of new spring-and-drum-and-cord assemblies to fit in, or did your salespersons just try to upsell the next model to the poor suckers customers who walked in to your shops with a bad case of Dangling Drawcord? It's Draconian. I salute you, sir.

Maybe, just maybe, I could pry the drum apart to get at the remainder of the cord, get a new one in, push the drum together again, and it will all work fine. Or maybe, just maybe, I don't want to suffer. So I'm going to see about finding or fashioning a tiny hook and attaching my new line to that hook, and if that works, just clipping the old line away at the edge of the drum. It's been kicking around that spring for 70-plus years, and it would be shame to break up the set.

[Shakes fist angrily in the air while striking a heroic pose]

I will defeat you, Remington! Do you hear me? Remingtonnnnnnnnnnnnnnnnn!