Sunday, April 25, 2021

A century old, new arrival

Picked up yesterday.

The central paper-finger (pinkie?) just above the writing point already identifies the machine. This is the quintessential old typewriter. As my first real deviation from pre-war portable typewriters, this was the one typewriter model I had been looking to get a nice specimen of

Desktop cathedral - the decals are nearly all there and the machine looked in pretty good condition. For this style of more ornate decal, I think it's a very late machine. From browsing the various 5's at The Database, it seems this style of decal was mostly replaced by a simpler lining around 1917. Nevertheless the serial number places this typewriter in 1920 - it only just turned a century old.

Strictly speaking, this could also be termed a portable typewriter. It comes complete with its protective case with carrying handle. Certainly not light-weight though - it really illustrates how amazingly compact and light the 1920s portable typewriters were at the time.

With a glass-topped standard 'qwerty' keyboard, it still is an international machine with all the texts on the control keys in French - 'espacement en arriere' (écrit sans accents...).

This venerable writing machine had been stored in an attic, left untouched for probably 35 years or more. That is great for the machine, as it is complete and 'unmolested' - e.g. no tell-tale signs of children having operated the machine or parts missing. There is some corrosion and plating-loss to the nickel parts, but not too grave. One of the rubber feet has fallen apart and one screw seems to miss half a head, again nothing fatal. What is more worrying is that the machine likely was exposed to heat (hot attic?) - this probably is the cause of lacquer crinkling in spots and the decals looking very fragile. 

The paper-tray decal e.g is complete and looks lovely, but also looks like the slightest touch will flake it off - this is something to think about, how to stabilize.

There were no spools or ribbon, but a ribbon and spools of the correct pattern were quickly fitted. Then after a very light oiling of the carriage guide-rails, the sluggish carriage 'woke up' and the machine sprang to life - as far as I could see everything works as it should. Machinery that was built to last!

Only given a light cleaning and removing of dust, this centenarian will be slowly and carefully 'spruced-up' over the summer. (First continuing the fixing-up of its younger and lighter cousin, the Underwood Champion portable.)

Thursday, April 22, 2021

Progress for the 1939 Underwood Champion typewriter

When doing some research on the 1939 Underwood Champion portable typewriter, the "Salute to Progress" is one of the items found - an advertising booklet published by Underwood for the 1939 World's Fair. On page 6 it advertises also the Champion portable typewriter: "the acme in personal writing machines".

(The booklet's pages are also shown on page 125 of Janine Vangool's book "The Typewriter: A Graphic History of the Beloved Machine".)

The booklet also -of course- advises the use of Underwood supplies for best results. It shows a whole row of various ribbon tins with art-deco graphics; the item 5 in the picture.

Amazingly, when doing a half-serious online scout for some Underwood ribbons there actually were a few of this type of tin available. Even tins that still contained a spool too! 

A bit of an indulgence, having these shipped especially from the US, but the seller's postage was very reasonable and the tins+spool not too costly so two tins with spools (and old ribbon) were acquired. (Postage from the US to Europe in most cases has become really too much to still be considered seriously, by the way. This seller was a happy exception.)

The tins have the art-deco style graphics similar to that shown in the booklet, but probably date to the 1950s. Still; not entirely inappropriate for this '39 Champion - and both contained the correct type of spool for the machine.

The remaining length of old ribbon left on one of the spools was replaced with an old, but still good ribbon. One end of this 'new' ribbon had lost its grommet, so a new one was put in. A bit larger than the original, but it'll work fine for tripping the ribbon-reverse mechanism.

Now with a record black 1/2" ribbon and the proper Underwood spools the machine is yet another step closer to its proper state.

The temporary 'buffer' or abutment (Ames) I'd put on the segment (quickly cut from some red neoprene sheet) was replaced with a black rubber strip. This will still need a bit of tweaking on exact thickness for its optimal function. From the dimensions of the segment I suspect the original probably was a strip a quarter inch wide and an eighth of an inch (~3,2 mm) thick.

This new strip is about Shore 70, so should help give the type-bars a quick and springy return motion. And in all-black it does look a lot better again.

Progress for the 1939 Underwood Typemaster Champion portable typewriter :-)

Tuesday, April 13, 2021

Cosmetic improvements, screw removed and platen of the Underwood Champion

The first polishing-up of an old typewriter is always very enjoyable and rewarding. Even this rather 'battle worn' Champion with paint-loss, scratches and parts lost is coming out looking much better.

A thing that was done before fitting the body-panels again, was removing one unsightly screw. The spacebar on the 1939 Champion portable needs a small metal tab protruding inward from the front of the frame as a 'stop'. This must have broken off long ago and was replaced by drilling a hole in the front of the frame and fixing of a screw (with nut and bit of rubber hose). This screw was also jarringly off-centre, so really had to go :-)

This tab will have been a weak point in the design. The 1944 Ames service manual shows the spacebar-stop to have been re-designed as two extended prongs from the spacebar-levers being 'stopped' between the flanges of the front frame. Much more robust.

The old screw was duly wrenched loose and removed.

This of course left the frame with a hole and the need to create a space-bar stop. The remnants of the tab on the inside of the frame provide a basis to mount a new solution.

Sanding the thicker plate down to bare metal, it was then covered in solder (ample flux). The same was done with a brass M4 nut and this was then let drop in place with the solder on the thicker base inside the frame (as it was being held upright against a wooden board).

This then provides the mounting point for a filed-down M4 brass screw with some black-tape padding as buffered 'stop'. This new solution is certainly not as robust as the screw through the hole, but should be fine for normal spacebar use (I think...). The new 'stop' can also be unscrewed and taken out before dismantling the machine. Some shimming of the bracket under the space-bar to get the tripping-points correct and a little black paint finished the inside. With filler the remaining hole on the outside was filled-up, sanded smooth(er) and blackened.

Not completely invisible, but much less jarring. 

In the above image the paint loss can also be clearly seen, as well as somewhat 'tired' black lacquer. This was given a polish (car wax polish, black) - using minute amounts of polish and some buffing the transformation is quite noticeable. The bare (rusty) areas were toned down to black with various black ink-markers. As a final touch, the mounting screws were blackened and fibre washers were used to mount the body-panels (fibre washers punched out of 240g card-stock).

One other thing was a bit of an experiment tried on the platen and bail-rollers. Not without risk, but the bail-rollers had turned hard and were starting to crack. To soften the outer layer and hopefully prevent deeper cracks, they were given a day to 'marinate' in petroleum jelly. This is not without risk, as the lighter components of the jelly can penetrate and further destroy the rubber. So far, the rollers have indeed softened and not yet completely lost all shape, so hoping all's well.

The platen of the machine was also quite hard, rather scratched and felt 'brittle' at the edges. Some small chips had already broken out. The platen was taken out and rubbed with a light household scouring cleaner using a cloth. Then with the smoothed-down 'open' surface it was coated with a thin layer of petroleum jelly. This was given 6 hours to penetrate the scoured surface before being wiped off. After another day of 'settling in', the platen actually looks smoother, has grip and the top-layer is a bit more resilient (fingernail test...). It still is not without risk and certainly no substitute for a new rubber platen, but it is hoped it reduces the chipping-risk and will hold up over the next years to be usable. Time will tell...

Still many little puzzles to work out (and new feet to be manufactured), but by now the Underwood Champion is already fairly usable as a writing machine. Shiny too!

Friday, April 9, 2021

Adjusting for uniform key pressure on the Underwood Champion typewriter

It took a while to figure out, but one of the things that made this typewriter 'uncomfortable' to type on was differing 'feel' per key. Most of the force of the downward stroke of a key is provided by the the Ribbon Universal Bar, but there is also a spring for every Keylever that does contribute a noticeable part.

The Ames manual is again very useful with a clear diagram (thank you!). The service manual goes into some detail on various trip-adjustments, but does not expect individual Keylever Spring adjustments. This particular machine however must have been completely re-built - and was put together again 'imperfectly'. When this machine left the factory, the Springs surely would all have been identical - today there is however a varied assortment of almost-identical Springs.

There is a few mm of travel for a key before it hits the Ribbon U-bar. These first mm's is when the Keylever Spring pressure can be felt (and measured). A few keys had a high starting force of about 90 gram force (gf), most were in the 40 to 50 gf range and some were effectively zero (less than 10 gf).

So on to the Keylever Spring Adjusting Screw Locking Plate. This plate is mounted with two screws (green circles).

This perforated Locking plate is fairly flimsy and can get caught on the Adjusting Screw ends, so best pried loose with some care.

Using small pliers (or a special tool, probably) the Adjusting Screw can be given a few turns to tighten or loosen the spring - to increase or decrease the starting force of a key.

Keys should not have a 'zero' force; then the Keylever will not be held up to have the keys aligned and the Typebar will not be held onto the Typebar Rest. Turning the adjusting screw for some of the zero-keys had no effect at all, however. Investigating further, it turned out that these springs did not have a 'crimped' end, so would not be caught on the shoulder of the adjusting screw. The Spring just slid right over the Adjusting Screw (left image).

So the Adjusting Screw and Spring for every 'zero'-Keylever was taken out. One end of the Spring was carefully given a squeeze so that it would sit on the shoulder of its Adjusting Screw (right-most image).

The taking out and especially the placing back is a bit fiddly, with tweezers it can however be done without having to dismantle the whole machine.

With all Springs now adjustable, all keys were measured with a small force-meter over their initial few mm of travel and adjusted. All keys were tuned to have a starting force of between 40 and 45 gf. This is enough to keep the Typebars properly seated and the keys up, and feels right for the start of a key-press.

End-result is that this Underwood Champion portable now has a reasonably uniform typing 'feel', the major cause of the 'uncomfortable' typing resolved.

Cannot imagine that many typewriters would need this to be individually adjusted - factory adjustment should last forever I'd think. But just in case, this is how it's done.

(And if you e.g. want all vowels to feel heavier than the consonants, you could so adjust your keyboard :-)

Sunday, April 4, 2021

Adjusting shifting force on the Underwood Champion

Continuing the small fixes and adjustments on the Underwood Champion portable typewriter; now for the carriage. From what I've read, the Underwood 'Typemaster' portable should be capable of being a fine and smooth writing machine, so 'adjustments' is probably the way to get there.

In addition to the individual key-pressures still being very un-even, the carriage-shift felt very heavy, as did the carriage return. Almost as if everything was adjusted to the maximum - similar to Helen Howes' assessment of how the top-tension is near-always found on old sewing-machines.

Measuring the shift-key force, this machine needed 450 gram force (gf) or 4.5N to move the carriage. That definitely feels too heavy and probably is too heavy. Measuring some other portables for the force needed on the keys to shift, there's quite some variation. As expected, a Corona Speedline is the lightest, with the Champion indeed the heaviest. The 400 gf value for the Remington Portable 2 is probably mostly due to dirt gumming-up the mechanism - this had significant hysteresis; a delta of 200 gf for the returning movement whereas the other machines generally were in the 50 gf range.

Having established that it really was too high, first read up on how to adjust this force in the Ames' service manual on Underwood portables. The weight of the carriage is compensated by a shift-balance torsion-spring. The manual has a small paragraph about adjusting this shift-balance spring.

So - this tension should not be disturbed. That sounded a bit worrying - in a "here be dragons"-style worrying. Also the need to form the free end of the spring (a pretty stiff, strong spring) was notable. However, when then comparing the drawings in the manual (1944 printing) with the parts on the actual machine (1939 manufacture) this paragraph becomes clearer and probably makes sense.

The drawing shows the spring is held on the shaft without an adjustment ratchet - the actual '39 machine however has an extra, teethed collar on the shaft with an adjustment ratchet mounted on the spring. Maybe the Ames drawing was simplified, or quite possibly the design was changed by Underwood some time after 1939 to leave out the shift-balance adjusting ratchet.

Either way; by adjusting the spring, the force on the shift-key can be readily adjusted to taste. Note that this is only changing the net-force and not the mass of the carriage that needs to be moved. With a heavier carriage, a heavier shift will be needed for fast typing. Otherwise the carriage will not have returned to lowercase before the next character is typed. Myself preferring a lighter machine and taking it a bit slower, the shift-balance spring was wound up a few notches to counter the weight of the carriage.

The ratchet that is fixed to the spring is held by a set-screw. This set-screw needs to be removed completely, as it depends on where the ratchet-collar ends-up in what threaded hole it needs to be mounted again (to always permit screw-driver access).

With the set screw removed, the spring-mounted collar can be pushed out of its engagement with the fixed collar on the shaft and rotated. This really can not be done by hand, but will need the firm grip of a pair of pliers. The 'posed' image below shows the parallel-beak pliers that were used for this. (Best practice would be using some protection (card/wood) to prevent marring the spring, but this machine's pretty rough already so skipped that - luckily it didn't scratch.)

Firmly held with the pliers, the shift-balance spring was wound-up only a few ratchet-notches at a time. As always when working with springs - it's important to not let go halfway the process! Move the ratchet back in engagement carefully whilst keeping a firm hold of the spring. Only then let go.

When shifting-key force is at the desired value, re-mount the set-screw and tighten lightly. 

Net-result of the operation is a carriage that will now shift with 250 gf on the shift-key. This I found is a pleasant, 'light' shift. With this balance, the carriage still drops down snappily, but with perhaps a bit less of an impressive thump on its stops. (Although it probably is too light to work reliably for fast typists.)

The further adjustment of the carriage is of course the drawband-tension. This also was very heavy, from 500 to over 800 gf over a return-motion! Adjusting this force is fortunately a very easy affair and exactly as was described in the Ames service manual.

With a newly light and snappy carriage, the Champion is starting to show potential :-)

Friday, April 2, 2021

Typebar linkages of the Underwood Champion

Investigating the source of the squeaking-noise, looking closer at the mechanism revealed it must have been re-assembled at some point rather haphazardly. The linkages of a typewriter are meant to all line up beautifully, forming a regular pattern across the basket. In this typewriter, the wire-links definitely do not form a regular pattern, and some of the sub-lever's look suspect as well.

It's explained in the service-manual that the typebars are numbered, as are the sub-levers - but the links are not numbered. At disassembly these should be carefully stored on a peg-board in the correct order to enable assembling in the same order. This may have been overlooked - or the table fell-over and some parts got trampled on.  (That actually might explain some of the other weird damages inside the machine.)

The order is definitely not correct (orange lines - do not line-up). And several typebar-links are not original, but bits of bent wire with 'improvised' loops (red circle). The sub-lever shown with the red line looks to be in a wrong spot too.

Some of the typebar-links have large loops at the end and a few are simply straight, so likely that some will be fouling their neighbours too. That could be a source of its 'heavy' typing or possibly some of the noise.

This whole jumbling of typebar linkage-bits also turned out to be the cause of the key for the letter 'o' to be disconcertingly out of line.

Most of the keys could already be aligned nicely by adding a 1mm strip of paperboard padding to the 'lip' of the panel right behind the keys - this is where the top of the keybars rest against (green oval). This should also help a little to further reduce noise, dampen the thud.

This new anvil-strip lines-up most keys, except the letters 'o' and 'v'. The cause for the letter 'o' was a wrong typebar-link that was too long. It was taken out and a new link was bent from ~1mm wire. (It needs to be fairly stiff, so a paperclip of a just under mm diameter was used - soft steel wire would likely not serve long in this function.)

This new typebar-link, with an attempt at following the original pattern of bends, was then placed back in the machine. The ends and sides of the loops are filed down to facilitate inserting it in the eyelets of keybar and sub-lever - and also to reduce the chances of it fouling any neighbouring part.

With the new, shorter link in place, the letter 'o' again sits nicely in line with its neighbours. 

Taking out a link and especially putting-in a new link turns out to be extremely fiddly. Near impossible when trying it without fully taking the whole machine apart (and not keen on doing that, yet). So even though there are several 'wrong' links of various wire-gauges, these will not be replaced like originally planned. They'll have to do for a bit longer.

What still remains is the slightly dropped key for the letter 'v'.

After lots of peering into the mechanism and poking around at things, the most likely cause of this is a fouling of the sub-lever with the keylever. The sub-lever eyelet-end is bent sideways to accommodate the curve of the basket. This adds a risk of it catching the keylever, and this one does - at the spot shown in the mechanism diagram above with a red circle.

Despite attempts to give it more clearance by 'forming' (bending, when intentional) and even some filing-off of a spot at the top of the keylever (yes, felt guilty about this...), I'm going to have to admit defeat on the 'v' key for now. 

It's clear; 'v' is for Victory - the Champion's... 

Moving on to the next fixes to make this machine a winner again :-)

Sunday, March 28, 2021

Underwood Champion re-assembled with new felt-lining - and Singing Typebars!

After the tinkering with the carriage, wanted to temporarily re-assemble the whole typewriter to experience the result. The re-fixing of the ruler had a very noticeable effect on the carriage and how it holds the paper; much improved.

(For tinkering and test-typing, rolling a sheet around the platen is handy)

Before putting the body-panels on again, I did want to replace all the sound-proofing padding. This old (paper-pulp?) padding was warped and fouling some mechanisms, plus it is probably the main source of the moldy old-house smell. So the remaining sheets of padding were removed and used as template for cutting new patterns from stiff card.

Could have used a bit thicker card still (a next time), but the idea was to use a paperboard backing to stiffen/dampen the thin metal body-panel and cover the paperboard with felt as the sound-proofing towards the mechanism.

Thicker felt for the rear-panel, thinner 1mm felt for the side-panels and the cover. First totally covered the card patterns with a paper-glue (stick) and then placed on the felt - to let it settle flat placed a large, heavy book on top. When set, the laminated panels are cut out of the felt sheet with scissors and glued to the inside of the body-panels (card to the panel, felt facing mechanism).

The margin-release button with its push-rod now is clear from the side-panel padding (lower left). The margin-release again works and the button pops back as it should.

Exercising the machine a little now that it's re-assembled, it still is not a very comfortable typewriter with a very uneven 'touch' of the keys. Not what I would expect from an Underwood machine. Despite a good clean (with white spirit, should have removed most old gummed up dirt), it is still uncomfortable to type on. What is more and worse - it now squeaks! Like there's mice.

Looking in a bit more detail at some of the typebars quickly revealed more 'issues'. Not sure if this is contributing to the squeaking, but typebar-links are not supposed to look like that.

That thin, spidery link is not an original Underwood part. Several more typebars have 'suspect' linkages. Have not seen something like this before; how does this happen to a typewriter?

So now up next is tackling Singing Typebars...  :-)