Sunday, November 29, 2015

Polyphase N4053-3

A mahogany and celluloid Keuffel & Esser slide rule. A 'Polyphase', type N4053-3. Similar to the Rietz system, but with small differences on arrangement and how the S and T scales are done. The S is linked to the A scale rather than D scale and the mantissa scale L is at the back of the slide instead of the front.

Complete with its 4053-3S leather protective case and including the instructions on adjusting. This adjustment mechanism with screws is what the patent number on the stock is about. The metal strip protecting the edges of the strap has US patent number 2,000,337 stamped on the edge. Now without that hint, would never have spotted the ingenious locking strips for the tongue underneath.

These K&E are probably very common across the pond, but relatively rare here. Curious for this one and it looked clean in the pictures, so went for it. It indeed is clean, however the plastic slideblocks of the cursor are cracked and the spring very rusty. This seems to be a standard fault with these, the celluloid disintegrates with time. The lower slideblock was also warped a bit, skewing the cursor a little. The cursor screws are corroded and won't budge, but some shimming with strips of thin adhesive paper label inside the slideblock brought it back perpendicular to the scales.

The top cursor slideblock also notes it is patented. Reading the claims, patent protection for rounded corners also happened back in the thirties.

Another unexpected item was that the sine scale is half a millimeter or so off. The celluloid window for the S&T scale on the slider is a bit loose or perhaps warped. Other than all that; it is still straight and serviceable! 

It's rather short and light, compared to e.g. some German slide rules. The cursor even partially slides off the ends at the index positions. Single line cursor also and no C markings. Clean and compact.

From online resources, the serial number puts this slide rule as produced in 1943. (The amount of resources online on sliderules is astonishing, by the way. On the internet, there really is no subject so 'niche' that it doesn't have its collectors society.)

How does a '43 slide rule end up in Holland? Come to that, hadn't realized that slide rules continued to be produced throughout the war - essential tools. (Not consuming too much important raw materials either, may have counted as well.)

Did this little engineering tool come over with allied forces? Or was it perhaps part of Marshall plan items sent over? Or was it just simply exported and sold here after the war from stock. (The here more common makes were not producing much right then, I suspect...)

Analog technology and again a snippet of history :)

Friday, November 20, 2015

Remington Portable with feet for clamping the angled backplate

When a Remington Portable typewriter from the twenties has the extra angled backplate and when not is a bit vague. A mid '27 machine has it, a late '27 does not. The '28 'lava' machine does not and a '29 machine does have it again.

How the plate is supposed to be mounted onto the outer frame also wasn't completely clear from seeing old machines. The backplate has two embossed lugs that align it to the back of the outer frame. The '27 machine had two thick washers between the frame and backplate. Looking at some pictures online, there is mostly a space between the plate and the frame. Ergo it seems likely that the plate was originally mounted with the extra washers. Unclear why that is - it does make the aligning lugs useless as they no longer reach the frame. (See sketch, without washer left, with washer on right.)

What however was clear is that the feet design I made earlier wouldn't fit with the backplate. The quick fix was to stretch the top flanged diameter a mm to also take the backplate. (This won't take the extra thick washers that were on the machine.) The front feet base diameter section then also stretched a mm to keep it all 'on an even keel'.

The feet were then printed on an FDM machine in polyurethane rubber (Ninjaflex). Printed again by Martin's Hub via 3DHubs. He's got the machine settings for this material pretty much perfected by now and it prints very clean and to correct size. The printed feet snap right in the outer frame.

To create feet that will also take the washers to create some space between the backplate and bottom of the frame would take just some extra stretching of the CAD model. It does make the whole machine sit a bit higher. Judging the height of the machine from the rubber pads on the case base, it can't have been that much higher than this. That would make the original rear-feet design have a very thin base, almost have it sit on the case base. Oh well...  :-)

The 3D model (Sketchup) for the adapted feet and the STL files are on Thingiverse here. If you've got one of these typewriters with dodgy or non-existant feet, highly recommend getting some new feet. For a machine without backplate, of course just manufacture a set of four 'front feet'.

(Another small mystery that remains is why the '29 backplate has a small hole at the rear-left of the machine. Surely the Remington Portable #2 doesn't have a shift-release prod?)

Friday, November 13, 2015

Remington Portable in tangerine and cream

Comes out a very bright and sunny looking machine!

New feet were manufactured to order for the machine. That sounds very excessive, but is not too bad really. More expensive than 20 cents for a simple grommet, but at just over a Euro for a custom made foot it is an entirely affordable extravagance. This machine has the extra angled plate at the back, so a slightly changed 3D model was made for front and back feet to allow for the thickness of this plate. These were then ordered to be 3D printed like the previous set in PU rubber.

The machine is now assembled and works, but still needs a lot of adjusting and tweaking to make it work smooth. These Remington Portable typewriters are capable of being very light and easy to type on, just takes some work to get them there.

It has the platen from the parts machine that is still 'soft' and rubber-like. The wooden core needed to be shortened a fraction of a millimeter. Probably from moisture damage it had swollen uneven and was fouling the brackets. This pressed the linefeed ratchet against the bracket and return-lever, making the line-spacing unreliable. The end-flanges of the platen screw off and the platen core can then be sanded down carefully (at right angles) and put back together again.

The newly made decals didn't come out quite as hoped. Discovered that the bonding agent I used corrodes the copper in the gold ink. A next time we'll know about that...

The case lid from the parts machine cleaned up well. Strong detergent in warm water removes most of the accumulated dirt. On some areas cleaned with a brush to loosen and then a rag to take up the dirt. A general brushing up with wax and polish revived the leathercloth. Most of the rust on the fittings came off with the Moto-Tool and steel-brush. The leather handle taken from the old case to complete it; now again a presentable and functional carrying case.

Showing off the two-tone orange and cream color scheme... (yes!, in an unusual angle)

(To go with this late twenties' deluxe typewriter :-)

Tuesday, November 10, 2015

Parts machine, a #2 with early features

This is a parts machine. It was advertised as non-working and the seller delivered exactly as described :)

This British assembled Remington Portable typewriter NV700212 has been dealt several blows, deforming the typebar lifting mechanism and the protecting hooks so that it won't move at all. It also had repairs done over time, with some keycaps getting new rings and losing its right carriage adjustment parts. Today it is very dilapidated, dirty and not working - designated a parts machine.

For a 1927 machine it has a few uncommonly 'early' Remington Portable #1 features. It still has the narrow disk-like ribbon reversing knobs and the old style ribbon spool locks. Also no bulge in the ribbon color-set slot, this one is still straight. The top-plate also is of a different design, looks much more like the older #1 design with the flat endings. However it does have room for the #2 hooks and mechanism.

There was clearly a lot of variation on details with these machines. The change from #1 to the #2 is a bit diffuse, with many new design elements gradually being implemented (and reverting also). Maybe especially so with production at their international factories.

The carrying case still is quite decent. That will come in handy as a replacement for a moldy case-lid. Also the platen looks to be in very good condition.

An unexpected nice touch. A label stuck to the inside of the case lid with 'the moving finger' poem by Omar Khayam. (Well, the English translation...)

Apt perhaps; the moving finger certainly did write on this little machine.

Friday, November 6, 2015

Markings on ruler and line-guide

The ruler on older portable typewriters is generally a stamped bit of metal with embossed markings. The markings are usually coloured in with a contrast colour, white lettering on a black ruler. Now this lettering today is often faded, dirty, rusty or partially flaked off.

How to revive or re-apply the contrast colour is very helpfully explained in the book "Algemeines Anleitungsbuch Für Schreibmaschinenreparateure". A general manual for typewriter-repairers is exactly what we need here! Though the book is oddly low on pictures, it is very rich in useful advice.

Must have been a very useful book back then in '26 and it is so again almost a century later. Many thanks to Georg Sommeregger for scanning and sharing this!

On page 59 the improving of rulers is explained. A combination of zinc-white and wax is recommended, heating the ruler a bit and then rubbing it on. A mix of zinc-white and wax, now that would be a white wax-crayon. Heating the ruler a bit (~70° C) with the crayon, this indeed rubs nicely in the embossed markings. The excess wipes off clean, leaving the wax solid in the markings as it cools down

The ruler of the Remington portable typewriter being refurbished was unreadably rusty, so was totally stripped clean and repainted. Now also with new bright white lettering from white wax-crayon.

Found that there's a difference in quality of the wax crayons; the 'cheap' items don't contain much (or any) wax. They're probably purely synthetic. These don't work at all for this. Proper wax crayons however work well and soften and melt as you'd expect wax to do. (Used Caran d'Ache brand wax-crayon on this ruler.)