Unpacking a new mainspring

Waiting for the new rubber grommets as feet for the #2 Portable. What did however arrive in the meantime was a new mainspring for the HMV102 portable gramophone.

A couple of months ago it started to have trouble keeping speed. At first only on some louder passages, but then on any record. Even after re-greasing the spring it was painful to listen to the false notes as the motor struggled and failed to keep speed. This meant that probably the mainspring was just spent and needed replacing.

Luckily and amazingly newly manufactured mainsprings are readily available, so an order was placed and duly received. It arrives tightly wound and held by a steel wire.

Unpacking a new mainspring is a bit tricky. To contain the force of the spring uncoiling and prevent the inch-wide steel spring from inflicting injury, it was first wrapped in a rag. With the spring in the rag the steel wire was cut, immediately followed by a roar and rumble as the spring expands against the rag. Slowly releasing the rag then gives a controlled uncoiling of the new mainspring (without injury).

For the HMV102, disassembly and taking out the spring is very clearly and helpfully described at a blogpost at Project Repair. Following those steps, the old spring was taken out again. Ultimately the new mainspring needs to be packed tightly again into this drum, but first it needs to be greased all over. Then its end needs to be hooked over the peg inside the drum wall. Can be done but the new straight spring makes this harder than it was with the old one.

Re-packing the new spring into the drum made clear that the old spring was spent. The new spring put up much more of a fight over being forced into the drum than the old spring. Again: do NOT let go of it when halfway.

Going through the steps in reverse order assembles the whole thing again. Hardest step is fitting the drum back on the centre shaft again, this is a very tight fit and the new spring centre hole does not centre over the drum opening. Several tries and some tweaking gets it back on however.

With the new mainspring fitted the HMV102 now keeps speed again.

Analog and fixable machines :)

Model C from Belgium

In the school playground I remember seeing other kids with the red Viewmaster (or View-Master), but never paid much attention. Vaguely remember looking in one and 'not getting it'. Until the recent post on i-dream-lo-tech about these stereoscopes, I hadn't realized how long they've been around for. That post made me very curious to experience one of these again.

The bakelite Model C (as I learnt) is remarkably common and before long a viewer that was made in the Belgian factory made its way to here. (From the hive-mind that is the internet this viewer can be dated as mid-fifties. The Belgian factory started 1953, the model C being sold up to 1956.) 

No different from the Portland-made viewers, but 'Made in Belgium' and with text mainly in French. Complete with instruction card (remove before use).

With already a few reels dating from the same period - I 'get it' now. The kids by the way also 'get it', were totally wow-ed by the images.

By now the 3D images have the added dimension of time. The views of Windsor Castle e.g. are very period typical, right down to a proper bobby pointing the way in the first image.

Nice :)

(Thank you Ton!)

How to wrap that around a platen?

The typewritten look must be in fashion. That's a sizable tablecloth (linen). Am trying to imagine how they wrapped that into the typewriter... :)

Adjustments, adjustments, adjustments

It's back.

With some tweaking and adjusting the machine, it now types again! Several surprises in the adjusting (and it's not done yet). The hardest part to get right so far, was the line gauge. The new rubber platen is very grippy. So much so that the slightest touching of the line gauge to the platen blocks the carriage advancing.

Bending the line gauge away from the platen however immediately interferes with the ribbon vibrator. Turns out there is a very narrow margin of adjusting the line gauge to be free of both the platen and not trip up and catch the ribbon vibrator (especially writing caps in red).

Another adjustment to be done was the carriage bearing rail. Worried about the sprocket leaving its track and any play, I'd initially over-tensioned the carriage. Given the four screws that hold the rail a turn to loosen and gently letting the rail move out a bit. That way a close fit without putting any pressure on the bearings was found. Another thing is that this is really best done without the outer frame fitted.

This outer frame blocks easy access to some screws. Best put on as a last step. Another tricky one is the crossbar that holds the rear bottom screws of the outer frame. This crossbar must be put in place before sliding the outer frame in place - there is no way to get it in afterwards. The tensioning nut on one end of the crossbar can be used to wedge it in place. Getting the tension on this nut wrong will block the shift, by the way. If the inner frame is pinched or pried open there, the shift levers are pinched and it won't settle back to lower case.

Next to the reference machine, the patents on the Remington Portable typewriter are also a neat source of information. These show the construction itself as well as some of the reasons-why behind the construction.

The actual tension on the carriage motor spring is a bit less critical. Just enough tension to accelerate the mass of the carriage at the very end of the line. With the adjustments removing all the little snags and frictions on the carriage, the spring can be released until the least tension that still works is found.

As a last step, the spacebar limiter bracket (part 76 with pads 77 in the figure) was fitted again. After fitting this little bracket, nothing worked anymore.

That was a bit surprising actually. When typing the carriage no longer moved, piling all letters on top of each other. Poking and prying around a bit, the cause was found in that the bracket kept the spacebar down a bit too low. When the spacebar is not let back up far enough, the lever that releases the escapement is not fully releasing the escapement mechanism. Then the escapement is stuck 'half-way' and nothing indexes anymore. Some careful bending and/or new pads (part 77) fixes that.

Still to be tweaked is the position of lowercase and uppercase against the platen, but it does now type again.

The new soft platen is a mixed result so far. On the plus side the grip on paper is solid and the sound a bit less harsh than a hard platen. On the down side the rubber is so soft that the imprint of the characters gets a bit smudged when striking a bit too hard. Overall it makes the machine very sensitive to the typing itself in quality of printing.

Maybe to take off again and replace with something more firm (and reduce the diameter of the right hand side a bit more).

Starting to look better (and type better :)

Waxed string drawband

The drawband of the Remington Portable typewriter was broken. With the carriage back on the rails, a new drawstring now needed to be attached.

By the look of it, the drawstring was made of waxed hemp rope. The hemp rope that was in the local shop was much too thick (24 lbs) and online sources are happy to sell you 5 miles of the stuff but not 50 cm. As a substitute to stay close to the original, simple packing string was used. A bit thicker than the original, but still fits the pulley.

The snippet on waxing string gave some practical advice on how to do this.

Ergo some wax, string and a spoon. Turned out that the easy way is not all that easy really. Perhaps the wax I used was not soft enough, but the method advertised is not helpful at all. End result of the attempt may not be the ideal waxed string, but at least a somewhat waxed string...

One end of the string is attached to the eyelet opening on the drum and the string routed around towards the pulley underneath the carriage (orange). From there the string can be led to the other end of the carriage fairly easily. By lifting the carriage release, the string drops in neatly into its path next to the indexing ratchet bar. At the far (right, left in image :) the string is clamped in the hook-plate that is held by a screw on the carriage. The hook-plate can be pried open with a sharp screwdriver and clinched over the new rope.

With the carriage all the way to the right (left in view from underneath...) is all the length that is needed. Some more won't do any harm, but too much rope takes up space on the drum and too much rope can make a winding jump off the drum. (Discovered that one, hard to unjam that rope from the drum axle.)

By turning the tensioning screw (blue) on the drum, the spring is wound and pull placed on the carriage. Make very sure the carriage is running freely when testing for the least tension needed that will index the carriage at every position.

The lever (green) next to the drum will release the spring tension. By rocking this lever, the spring is unwound a fraction of a turn at every click.

The fancy lava red Remington is getting there: placing a new drawstring was much less fiddly than expected. (Ensuring the carriage runs freely with adjusting the bearing rails and line guide was much more fiddly though :-)

New felt, type lined up

On the Remington Portable typewriter the typebars rest on the felt strip that edges the lifting table. Over time the typebars make a dent in the felt. Uneven wear over time per typebar leads to the row of type to be out of alignment.

To fix this, new felt was mounted on the lifting table edge. The black felt strip is rounded on the top and clamped by a metal strip on the bottom of the lifting table. To make it nicely rounded on top, the felt is bent double. Because the felt controls the position of the typebars in the raised position and needs to be out of the way in lowered position, the size of the felt matters. It's about 5 by 8 mm when clamped. (The original was folded double, the new felt that was at hand was thinner and folded over twice to get the thickness.)

The felt strip is clamped under the metal strip that is screwed underneath the lifting table. Some small  unevenness can be corrected by tugging and tucking the felt under the clamp. The old, original felt in the picture shows the dents made by the typebars.

With the new felt mounted and the lifting table back in, the typebars in the lower position lie flat resting on the felt and/or table. Also already mounted in the picture are the housing top and the outer frame. For mounting the lifting table, the housing top should really be removed for access to screws that clamp the lifting table to the lifting arms. (It's tricky enough even then.)

In the raised position, the typebars make an even curve that is approximately horizontal to the machine. (The paint on the lifting table is badly damaged, had a bit of a disaster there as well. So much tension in the paint layer that it just flakes off at the slightest breeze. Now fixed down at the edges, but messy.)

Now with the second attempt at a new felt strip, the typbars are good enough in both positions and can still take some 'settling in'. The left and right-most typebars are hardest to get right and to align nicely with the protecting hooks.

It's getting there. Adjustments next.

Reference material

Getting the carriage back together of the red RP2 typewriter showed up the limits of the pictures I took during disassembly. Just not enough detail. The mounting of the raising mechanism likewise could have done with some better photographs.

For the Remington Portable (#2) there is as far as I could find out no service manual available. Coupled with the fact that these really are charming little machines, I went for the totally decadent option of getting another machine as reference material. (Imagine doing that back in the twenties when these cost $60.)

I've read mixed stories about Ebay for typewriter buying, but took a chance on the British version of the site and bid for this machine that looked interesting and had very reasonable shipping cost from Britain to the continent. With an interesting bidding experience, won it and got it shipped very promptly with decent packaging.

Looks its age of course, but importantly it is complete. Now also have the sizes and pattern for all the grommets and the leather carrying handle.

The machine inside with some rust in spots, but otherwise decent. Nice green lining inside, no warranty label in lid. The decals are in the old, #1 style on the top of the machine. No decal on the paper-tray. The machine in the pictures is already cleaned with nickel polished a bit. The spools were badly rusted, so these have already been re-painted. Other than that, it is as received.

The Remington Portable above, ready for putting paper in and typing. The rubber of the carriage is in good condition. The platen is hard as expected (looks like slate), but all rollers are fine. Some sticky keys, yet everything seems to work and most importantly; the machine is complete (and assembled :)

The machine was (first) assembled in November 1927 - serial number NZ700077. Or perhaps it is 70007-7. The last digit seems to be added in a slightly different typeface and alignment to the main. Still wondering what the 6-digit serial numbers are for these machines, most machines have a 5 digit serial. Was the main number added in the factory by a numerator (would make sense) and the last digit manually for some machines? Was the last digit added only in the British assembly plant? The world of Remington serial numbering :)

The machine's keyboard is a bit wobbly, all the keytops are slightly out of alignment. The keyboard is one of the things that made me notice the listing; it has the + and = signs and even some Greek characters. These keys are clearly a later modification to the machine, the British fraction keys having been replaced together with all keytops. The typeface of the keytops looks too modern for the twenties, more mid to late thirties. Also the keytop-rings are I think of a different type than those of the standard Portable keyboard. The Greek character keys have engraved disk as keytops instead of the paper disks as on the other keys. Suspect the standard sheets of cut-out keytops did not have the Greek.

Now am wondering what profession would need a keyboard with alpha, beta, gamma and mu...

(Update: probably statistics.)