Sunday, September 21, 2014

Restoring an Antique German Typewriter

Laptops are for suckers. Why put up with the hassles of a cord and wall outlets, when you can enjoy the unfettered freedom of a 40 pound block of manually operated, electricity free cast iron?! Also, if you start taking mortar fire while typing a memo, this guy's got you covered:

Unfortunately, this circa 1905 Kaiser-approved German desktop typewriter arrived in rough shape fresh from UPS. It needs a lot of TLC before we can even attempt to type with it, let alone rely on it or display it proudly as some beautiful, functional art.

So... let's fix it! Repairing typewriters is a joyful experience in my opinion. Nowadays, most of the machines we use require computer diagnostics, etc. to even attempt to work on them. Even if you understand the mechanics of things like cars, there are fewer and fewer things you can fix or modify yourself as a hobbyist.

With mechanical typewriters, you can fix almost anything with only some screwdrivers, oil, ingenuity, and gumption. I obviously have no formal training on these, but I can still figure it all out, because it's all just levers and springs, and you can reliably follow them around and puzzle it out in the end. It's a sometimes very challenging, yet an almost certainly solvable puzzle, and one that uses your eyes and hands -- the best kind!

First, we begin with just testing the features:

  1. The keys, of course (A) - What happens when you hit them? Well, what happens is that a couple of them stick ("H" and "^"), and the rest make it about halfway to the platen (the rubberized striking surface at J), before they meet with mysterious bouncey resistance.
  2. The space bar (B) - It snapped in half, but the lever seems to function.
  3. Shifting (C) - The buttons seem to work, but the carriage (the whole top assembly) is jammed or messed up, so they don't really do what they are supposed to. I don't think it's the shift's fault, though, intuitively. This can be revisited later if necessary.
  4. Caps Lock (D) - Same as shifting.
  5. Carriage return lever - It moves the carriage, but it requires a stupid amount of force to do, like there's a lot of friction, about halfway across. It also makes a horrible grinding sound from the teeth skipping on the gears in the back (the rack gear S<->T with the teeth of the escapement mechanism P). 
  6. Margin release - It's hard to see, but it's a button that pops out at F, when you hit the right margin. You can push it and give yourself a couple more letters if you need them (shame on you you bad bad typist! *ruler smack*). This doesn't work, because it's not attached to anything in the back (N - see the empty hole at the top of the lever).
  7. Ribbon advancing - The ribbon holder (H) is supposed to move whenever you type a key. The knob at G reverses the direction. Both seem to work.
  8. Platen knobs (I) - This is used for manually turning from line to line. One is missing, the other is horribly deteriorated, but there are no mechanical issues, the parts just need replacing.
  9. The platen itself (J) - The rubber is in good shape!
  10. Lever that lets the carriage slide freely (K) - Has the same friction and grinding issues with the carriage, but I don't think this is a cause, since it's just a minor input.
  11. A bar is missing that is supposed to hold the paper down (based on internet photos of the same typewriter) at (L).
  12. The single/double/triple spacing selector (M) - There was a spring that kept this in place that was out of whack. It took 2 seconds to pop back in position, and this now works.
  13. The backspace function - This is disconnected in back just like the right margin is. It seems to be missing parts (O).
  14. The escapement and main spring assembly (P) - This is grinding against the rack gear above it, but I don't think it is the originator of the problem, because it looks solidly attached and whole, etc.
  15. Arms that hold paper (Q) - These work. There is some gross mildewy felt under them though.
  16. The bell is missing (area below N), but the adjustable clapper that is supposed to hit it works (R).
General aesthetics -- Dusty and dirty. There are a few areas of uncontrollable rust, and a lot of minor rust. It should clean up pretty well, though, with some light abrasion and chemicals and elbow grease. The decals are in good shape (the back one and ribbon spools look awesome), the front one is dim but intact, and it seems to be behind a layer of flaky varnish or something. The side lettering is worn, but very easy to touch up. The paint looks great, I don't see many chips or flaws in the paint job. The keys are in mediocre shape. There's some stubborn tape or something on the top of the case.


Most of these issues can be steadily repaired and cleaned up one at a time. But the carriage issues are by far the highest priority. If they can't be fixed, the whole machine will always be useless, and so would any other repairs.

The symptoms the carriage is exhibiting are increasing friction toward one side and grinding gears. Gradual friction implies that two large moving parts are not properly aligned. Grinding implies that gears are not aligned. My first thought was thus that a major rail somewhere was bent. Thankfully, I couldn't find anything like that!

My next thought was that two or more large rails were just entirely not lined up, even though straight. For example, are screws holding the fram together missing? No. Is the FRAME straight (also not a great question to find yourself asking...). Turns out NO it isn't.  The frame has a difficult-to-see but large crack in the back near the foot (somewhat below point N in the above pictures):

This is not good, however typewriters don't actually experiences THAT much stress. The frame can probably be fixed with just a really strong 2 part epoxy (I also considered drilling through and bolting, but the surface area isn't large enough). Before doing that, though, I got a small C-clamp and just dry-clamped the sections together. What happened was that the friction largely disappeared, but the gear grinding didn't, and some parts were still knocking into each other. I futzed around until I found where:

A screwdriver just bent out the middle part by a couple of millimeters and it was fine (hopefully this doesn't mess up typing later! I don't think it will.). Next, the gear issue. Turns out that one of the two screws holding that rack gear on was rotten and the head fell apart when I tried to unscrew it (see points S and T above). Here is an over-dramatization of the rack being misaligned (in this photo it's entirely unattached not just loose) and the gear underneath it's supposed to interface with:

These screws from 1905 Germany aren't exactly standard modern thread sizes. I tried the hardware store, but it seems to be something ridiculous like M3.5 threading x 5mm long?? So instead, I found a random set screw of the same threading that wasn't doing much from elsewhere on the typewriter (see the remaining screw on the other side):

This screw was too long, so I clamped it in some vice grips and used my dremel to cut it down to the right size, then filed down the burrs on the end so it would thread (broken screw on the right):

(in its new home)

After fixing the rack, the carriage now moves smoothly (C-clamp still dry-fitted for now), and doesn't skip teeth. It does still have a couple of issues though. First of all, it's WAY too strong. I assume that somebody working on the typewriter in the past tried to ratchet up the power on the main spring to just FORCE their way past the friction from the broken frame (tsk tsk tsk!). As in, the entire typewriter was vibrating with force every time the rack gear moved at all. So I loosened the tension dramatically to make it safer and less damaging to the machine. I rocked this lever back and forth to slowly release tension one tooth at a time until the carriage was too weak to move forward. Then I re-strengthened it by a few teeth (you can just grab the wheel with your hand and turn it usually):

Finally, the carriage seems to sort of randomly stop partway across, and keys now sometimes work, and sometimes don't. When it does stop, it's a "soft" stop. It's hard to explain, but having used typewriters a lot in the past, it "feels like the typewriter doesn't want me to go further" not that something is broken and binding.

Sure enough, my intuition helped me figure out the problem after a bit of looking in the right places. Remember that margin release that was disconnected? Here's another photo of what should be there:

That missing arm is supposed to help keep the lever to the left UNTIL you hit the actual right side margin. The spring at the bottom helps hold it to the left, but was never designed to do this all by itself. What was happening was that the lever was too weakly held in its current state and was wandering randomly to the right side, then the machine thought that I was at the margin now and then, and it was dutifully stopping anything from working. For now, I just slapped some rubber bands on to hold it to the left.

SO now the carriage works! It moves one spot when you type a key all the way across and returns properly with good tension and no resistance. This is a big relief. The rest of the problems can definitely be addressed and are worth working on, now that the carriage works. I still want to keep it under observation while I fix some other things before I epoxy it, but we can move onto other things.


At this point, I also oiled the main rails and pulleys of the carriage. Oiling bars is always a good idea. Just be careful to not get oil in the springbox or in any very dense areas of machinery like the big block that holds all the typebars. Oil in hard to reach places can get gummed up and is very difficult to fix later. Getting it inside coiled spring is bad too.

DO NOT use WD-40. Use a proper machine oil. Something like sewing machine oil would be best. I'm a little lazy, and I'm just using basic 3-in-1 oil, but it's still universes better than WD-40, which will seize up in no time and make a huge mess later.

A dab will do you! I prefer to use an old toothbrush with a few drops of oil and not even pour any oil from the bottle directly on the machine at all. It leaves a medium-thin layer everywhere with no dripping into bad places.


  • The classic typewriter page has an excellent reference article on general amateur typewriter restoration.
  • The typewriter database provides year of manufacture estimates for most typewriter brand serial numbers and other identification images and resources.
  • The virtual typewriter museum similarly provides identification resources for a lesser number of machines, and for this one it had some very useful information about how parts are supposed to go together and what was missing on my own model.


I need to finish up all the remaining more minor mechanical issues, fixing some linkages and fabricating a part or two (backspace, margins, missing and rusty knobs, making a new space bar, new feet, new ribbon, new bell, unstuck "^" key).

There's also a LOT of cleaning to do - rust removal, cleaning crud and dust and grease in general, dealing with the weird varnish/tobacco mix or whatever is on the front plate, retouching gold lettering, polishing, waxing. At some point, I'll probably have to remove the surface panels and clean up individual typebars underneath too. Also, re-felting.

A couple specific photos of things still left to fix that I didn't include earlier. Top: a super rusted and old rubber platen knob. Middle: A completely missing other platen knob. Bottom: Another view of the remaining knob and a lot of surface rust on other levers and things.

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