Sunday, November 1, 2020

Typical Remington Portable (1) typewriter

With serial number NK30243, this was the 243rd machine manufactured in the month of April in 1923. By then, the design of the Remington Portable typewriter had stabilised somewhat, and this machine is probably a good example of the most common, typical Remington Portable of the era.

This one was bought locally last week - it looked too good to miss-out on (and vintage machines are getting rare online). The seller got it only recently out of a house-clearing and although it was now stored in an unheated garage, it must've been kept in a warm and dry place for the past half-century. Probably in the back of a cupboard where a previous generation put it away after the last use.

The spools may still be the original, from looking at some machines of similar date on The Database. The ribbon is dried-out, as it would be if this is the original 1923 ribbon. 

The case has lost the leather handle (as is common), but otherwise very clean and even comes with the original brush clamped in its original spot. The dust on the back of the case suggests it's been stood upright and untouched for decades. Likewise the machine itself, just a little fine dust and dulling of the nickel. (All pictures were taken before any cleaning.)

The wear of the decals and paint-loss is what you'd expect from frequent use, not damage from mishandling. (I.e. not taken out in 1971 for the grandchildren to toy with it.) There is some evidence of older touch-ups with black paint on the usual wear-spots. The machine was used and taken care of.

Although the ribbon today leaves barely any ink, this 97 year old typewriter works fine. Everything moves as it should and is free from rust. Even the rubber is in amazingly good condition. The feed rollers are as-new and even the platen is not completely rock-hard. 

This will be taken as a slow-project. Nothing major to be done on this typewriter, as it is in great original condition. Some light ('sympathetic') cleaning and polishing - and probably making a new leather handle for the case.

And of course winding a new (or revived) ribbon on the spools for the new owner - these are still great writing machines :-)

Friday, October 23, 2020

Faber 1/54 (and how to take care of your slide rule)

 The number is on the box.

Again a fine and solid instrument made by A.W. Faber Castell. Around 1935 they moved from the 3-digit type-numbers to a 'slash'-code system and that year also introduced a 'Darmstadt' slide rule as the 1/54.

This slide rule was a bit yellow with ageing and also seized-up, but otherwise fine. Complete with no damage, chips or worn spots and still straight as a rule. The date-codes stamped in the wood of the base at either end of the slide rule show it was manufactured in Germany in May 1941. Date-codes '41' at left, '5' at the right end. (There's also a 'D' stamped in the left end-face of the rule, meaning unknown so far.)

Brief instructions on the back (label 'K8d'), and at both ends a transparent celluloid section with the gauge-lines for the Log-Log scales on the back of the tongue. The goniometric scales have been moved to the front edge of the scale and the linear scale to the far edge. At the spot where there'd be a linear scale on a 'conventional' Rietz, there is the Pythogarean scale P - ergo a 'System Darmstadt' slide rule.

Even inside the well, there is a cm-scale extension. Every surface serves a purpose. This also means there is a complex 3-sided cursor. This is constructed from aluminium brackets holding Plexiglas plates. (It is a German slide rule, so Plexiglas, in English this'd be called Perspex and in North America Lucite.)

The slide rule was a lucky find on a German auction-site - the instruction booklet to go with it was also sourced from Germany (albeit much less of a bargain...).

Much like wanting to have the vintage items functional, there is some satisfaction in completing an item with the correct paperwork - to come a bit closer to experiencing the product as it would have been purchased originally. This booklet is reasonably correct for this rule - second printing, dated February 1945. Had not expected that by that time there would still be materials for the printing (with colours) of a slide rule instruction manual. Perhaps deemed important - but I'd think the situation had become rather dire in Germany by then. (This particular rule is more likely to have had a first printing of this edition of the booklet, d.00001 was from April 1941 - but to hold out for a first printing 'd be pushing things a bit too far perhaps.)

The illustrations match the slide rule, these are definitely the instructions to study :)

The text is of course thoroughly informative, exact and precise. Likely because I'm not a native-speaker of German, but this made its sudden use of the word 'ungeheuer' unexpected. (Bottom paragraph of the page 11.)

The scale R is indeed 'enormously' useful, but as non-native reader I read it as 'monstrously' useful - 'Ungeheuer' as noun also means 'monster'. To a native speaker the phrase very likely would not be remarkable at all, but it made me smile :)

There are extensive instructions with examples on how to get the best use out of this precision instrument. Very importantly, it also contains a paragraph on the maintenance of the slide-rule. The "How should one treat his Castell slide rule?" paragraph.

Obviously one should keep it out of direct sunlight and not expose it to large variations in temperature or humidity. For cleaning the scales, the celluloid surface can be wiped with petroleum or white spirit. (Never with alcohol! This dissolves the celluloid - indeed it does, rather rapidly too.)

An alternative method given for cleaning the celluloid scales is a soft eraser - that is excellent advice and it worked wonders on the old, yellowed surface. The white stripe across the rule in the picture below shows the effect of only a brief application of the eraser - with some time spent going over all surfaces the whole sliderule becomes much cleaner again.

Further advice is to apply a little vaseline to the sliding surfaces of the tongue. This does indeed help to revive a long dried-out rule. In this case it also needed a little (little!) talcum to reduce the stick-slip effect that remained, but vaseline is I think generally good advice for a wooden slide rule.

Again a functional instrument! Obsolete of course, but fascinatingly ingenious and it will be entertaining to discover from the instructions how to work it.

Monday, October 12, 2020

Faber 375

The number is on the box.

A fine and very solid instrument, made by A.W. Faber.

This sliderule was seized-up, but otherwise undamaged. No chips or worn spots and nearly completely straight still, but the tongue was held very tight - nearly unmovable. Even the cardboard box is still in good shape. The instrument needed only a little light cleaning to be very presentable. The tongue being 'stuck' made it 'unusable' however. It is obsolete of course and not for actual use, but I do like the 'analog collectable objects' to be as functional and working as possible.

Loosening the five (5!) adjustment screws that control the 'grip' of the stock would yield a gap between tongue and stock (i.e. much too loose) and still the tongue was barely movable (i.e. much too tight). Somehow the sliding surfaces of the parts had become roughened to 'grip' with even the lightest clamping force. Having tried a few remedies, what finally brought the friction back to usable levels was applying a very little vaseline. (This was actually the method advised by Danish manufacturer Diwa for their sliderules.)

Like most continental sliderules, it has the Rietz arrangement of scales - the scales are not marked, but follow the conventional arrangement. Being an older sliderule, it hasn't got the inverse C scale.

Instead of the more usual mahogany, this sliderule is made of Swiss pearwood. This makes it relatively light in colour and surprisingly heavy. In comparison, a Keuffel & Esser Polyphase sliderule weighs about 57 grammes, this Faber sliderule weighs 113 grammes. Though the Polyphase is admittely slightly smaller, both have a 25cm scale and offer the same functions and accuracy.

The datecode on this sliderule is a simple '1' on the right and a '9' on the left - these should be for month and year (in the 1920-ies). From the information in the Sliderulemuseum, this would mean this Faber 375 sliderule was manufactured in September 1921 or January 1929. The German patent 365673 listed in the well was issued in April 1922. The sliderule does have the patent's construction - so it will be January '29.

Whichever exact year, it was made during the Interbellum for export to The Netherlands. The table with conversions and constants is in Dutch. The seller was able to share that it was owned (and probably purchased new) by a teacher in a technical college. Probably well cared for and little used.

The A.W. Faber or Faber-Castell company is still in business. What's more - until very recently at least you could still purchase a new (NOS) sliderule from them online. Since last year however, this article seems to have been taken offline...

No need to buy a new one though. This instrument is still in good shape - obsolete of course, but very usable :)

Friday, October 9, 2020

New brushes for the E6 motor

Putting the E6 motor together again with the fixed parts, it unfortunately still did not work. It seized up and the current draw was too high as well - tripping the circuit breaker used to protect the battery. (That circuit breaker is an original ~1937 Meccano item made exactly for this purpose - 'Retro Tech Holland' here :-)

Measuring the windings of the armature and the stator suggested these were all as they should be - in the 1 Ohm range. Comparing with another E6 motor of similar vintage, showed that the main difference was the resistance of the brushes. This motor has copper-filled brushes with very low resistance, unsure if those are original or later replacements. 

Additionally the brushes are very worn, short enough to tilt and wedge themselves between holder and commutator. Even though the armature rotated freely, when powered the brushes seemed to wedge and lock-up the armature - totally blocking the motor.

Buying new brushes for such a motor is a bit of a challenge, not a common size today. Unexpectedly, there is a ready supply of graphite rods sold as electrode! Sourcing a couple of graphite electrodes of nominally 5 mm diameter was easy enough and surprisingly affordable. The rods are "almost round" and closer to 5.2 mm, but readily ground down to about 4.8 mm (3/16" probably). Then sawing off two lengths of almost 10 mm (3/8" seemed right) and adding a slot gave reproduction electrodes. ('Repro Tech Holland'...)

With the new graphite brushes, the motor again runs - starting up fine without tripping the circuit breaker. With hardly any arcing/sparking too.

To give the motor a test-run - bring it into use again - it was built into a simple crane model out a 1928 instructions booklet.

It still needs some adjusting, as one direction runs smoother than the other. This is not unexpected, probably needs further tweaking of the positions of the brush holders relative to the motor-axle and of course some running-in of the brushes.

How well the graphite electrode brushes will stand up to wear remains to be seen of course, but for now they will do. 

So, the happy outcome is that this wrecked 87 year old E6 motor is again 'up and running' :)

Saturday, September 19, 2020

A fixed part for the E6 motor

Continuing the 'repair shop' treatment of the old Meccano electric motor; now the fixing-up of damaged parts. The base plate of the switch was damaged, with all four mounting pins broken off and a corner chipped. Not sure what the 'plastic' part is made of, possibly bakelite - notable is that it wasn't fully moulded, but at least partly machined. The studs were not moulded protrusions, but separate pegs that were inserted in drilled holes. Edit: or a previous owner tried to repair broken-off studs by drilling holes to fix with screws.

The pegs form studs that hold the switch in place when sandwiched between the motor side-plates. The holes in the side-plates are 3.2 mm diameter, or rather, 1/8". The holes in the switch base seem to have (had) thread, quite likely 6BA for mounting with screws. (Screw-mounting was used on earlier versions of the motor.) For repairing this motor, could have used new screws, but plastic pegs would be more correct for this 1933 Meccano motor, so scouting for 1/8" plastic pegs. 

Where to get black, rounded-top plastic pegs of 1/8" diameter?

It took me a while to realise, but there was a ready supply of 1/8" plastic rods in the house!

The Lego-brick is originally an English invention, and even today has a bit of a mix of imperial and metric dimensions. The base-dimension is 1/16" (~1.6mm), the wall-thickness of the brick. The height of a brick is 3/8", with the tile-bricks 1/8" thick - also the rods and antenna's are 1/8". Using the vast online marketplace for Lego parts, sourced a few extra of part 3957 (Antenna 1x4) in black.

The holes in the switch-plate needed drilling out to 3.2 mm. It's been remarked before that these motors are not precision instruments, the plate again confirmed this. The holes are not placed at the centre of the sides, but one set was significantly offset to the front. (Probably contributing to the chipping.) In the factory, a jig would surely have been used for drilling - this particular part must've been placed sloppily in the jig. (Or more likely - a wandering drill if done by a previous owner as a repair.)

With the plate clamped between the side-plates, the holes were drilled out without too much damage otherwise.

A short length of the rod makes a peg that was then glued in place. The chipped areas also built-up again with PVA and cut to create a reasonably flat surface again. Still visible as damage, but less glaring.

The pegs now jut through the holes and look exactly as the originals would have looked.

Next up to re-assemble and see about the windings.

Monday, September 14, 2020

A disassembled E6 motor

The Meccano E6 motor dates from an age when things were made repairable. It is mostly screwed together (of course - it's Meccano) and comes apart easily.

(The notion that you could make an expensive consumer product and explicitly design it so that it is near-impossible to repair was probably not yet mainstream.)

After disassembly and cleaning, this is what we've got:

The brass was only cleaned (soapy water) and not polished, except for the electrical contact surfaces. Decades of patina increase electrical contact-resistance and will slow these motors down or prevent them from running at all. Normally not visible, the switch-contacts are now brightly polished.

Nominally it is a 6 Volt motor, but by the look of the area around the brushes it may have been used at higher voltages, would not be surprising if a previous owner ran it at the 20 Volt that later Meccano motors needed. Not only does it look like it sparked fire, the commutator is also visibly worn down.

Now that they're clean, the fading of the paint can be seen very clearly from the difference between inner and outer face of the side-plates.

Were it not for the nicely surviving decal, these would be up for a re-paint. Maybe later - first to make it functional again. 

The bent lever of the switch was easily corrected - protecting the part with card, holding it in a vise and use parallel-pliers to gently 'form' the bent bit. (From typewriter-repair; 'forming' is bending when you mean to do it.) The brass pillars that hold the laminations likewise needed some straightening, probably more tweaking to come.

Up next; find a way to build-up and fix the broken black switch-base.

Friday, September 11, 2020

A damaged E6 motor

Vintage items bought online nearly always arrive well packed in boxes with lots of padding, some are very well packed indeed. Unfortunately this particular vintage item was merely put in a plastic envelope with two small, loose bits of foam-pad. It did not end well.

This is (or was) a Meccano E6 reversing 6 Volts electric motor. It's very sturdy, but also very heavy and got a nasty knock...  This bent and broke the switch-assembly and knocked the pillars out of shape, making the armature foul the stator. The seller was very good about the unfortunate event (he had completely run out of boxes that week), however leaves the question: what-to-do with this ~80 year old item.

As with every niche-subject, there is an astounding amount of information on the internet on Meccano and Meccano motors. From various detail features this specimen can be identified as an E6 manufactured in 1933. Originally it would have had bright brass and the paint would've been red.

The red & gold decal still looks fair, although the originally-red paint has faded to an almost-orange. It must've spent decades sitting on a shelf in a shed in the sun.

These motors are not exactly precision-built instruments, these are to a fairly 'rough' design originally dating back to around 1916. This means it should be 'forgiving' and practicable to attempt a re-build - seems a shame to have to discard (or dismantle for parts) this 87 year old toy motor. 

Will be having a 'tinker' to see what can be done.  :)