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MST436| Harrison
The MST/Roamer 44 jewel movement





Housing: Roamer MST, Solothurn, approx.. 1965, gilded, patented housing construction, Brev. 305467,305776,307382,308491., high-grade steel work tank is pressed with glass in the housing, divided elevator wave, marked crown, reinforced Hersalithglas, 35 x 34 mm volume: Wempe Jeunesse, leather, gilded thorn latch work: Roamer MST, Kal. 471, 44 Jewels (basis work: 19. reduction transmissions: 8. free-wheels: 2 x 5, rotor camps: 7)auf ruby balls stored central rotor, elevator into both directions of rotation over patented Freillaufkupplungen and 3 reduction wheels, Glucidur balance spring, Incabloc, patented Rueckerfeinstellung over Excenterschraube and mobile Spiralkloetzchentraeger, Antikorodial antikorodial-Federhaus, 21,600 A/h, gangreserve 44 hr., present/immediate datumswechsel dial: silvered, sun cross section, indices presented, date with 3 o'clock, leuchtpunkte and pointer, presented elevator ring with Minuterie condition: G1-2, z0-1, w1-2, b1, glass must be polished, second wave on dial height broken, course deviation over 48 hours under 2 minutes Technical cream bit: For the Kal. Roamer, actually Meyer & Stuedeli S.A., 4 patents announced 471: for the ingenious, waterproof housing construction, the free-wheel and the Rueckerfeinstellung. Contrary to other housings the work is pressed here including glass and soil into the upper section. The construction permits a waterproof housing without screw connections (please now, after 30 years, no more do not try out).


MST was been around for about 100 years and used to make
clock movements; ni the teens and twenties they went with
the flow and made watch  (pocket and wrist) movements.

They were ok - not great not awful, about the same quality as any other mass producer of movements.

Then sometime in the 70's an utterly freakish thing happened, they built an automatic movement that was 30 years ahead of it's time, by that I mean the ETA 2892-A2 (sp?) and Rolex 4130.

The problem with all automatics is the stress on the selfwinding gear train and these gears get chewed up on a regular basis. At some point all the replacement gears are gone. This is what makes the 23 jewel Bulova movements worthless today - no parts - which is a shame because they're adjusted to six positions, highly finished and good to a second a day in many cased. Not bad for a watch you can by for 11 dollars off eBay all day long.

So, there is one MST caliber that stands out: Cal 436 (437 has date); this watch has 44 jewels, including 5 ruby ball bearngs for the rotor and 5 ruby roller bearings in each of the two reversing wheels. To date nobody on the planet has made such good reversing wheels and unlike other bogus high jewel count movements all the jewels are functional. The gearing is set so low on these it takes almost no effort to swing the rotor and there is very very little torque transmitted trhough the selfwinding geartrain. Morseo the gears are utterly massive. This thing will just never weat out and sure enough none of mine show the sligheest evidence of wear.

It's like riding a bicycle, pretend you're in high gear and try climbing a hill. That's what every other automatic movement is like. Now switch to low gear - that's the MST/Roamer. Oh, MST decided to produce watches as well as movemnts and invented the name Roamer.

The finish on these things, a thick rhodium plate is very well done and they have a glycidor balande and navarox spring and a good (offset? I forget) regulator. Th're accurate, look great and are the only vntage automatic that will not wear out or chew itself to bits.

The movement was made *completely* in house, even the screws.

Apparently the ruby ball bearings cracked in some cases and the later version Cal 471 (473 has date) used steel bearings and ruby bearings are NLA.

So, anytime you see a roamer with "44" on the dial it's one of these. Ditto, "28". For all but the earliest watches the caliber numbr is part of the serial number on the back of the watch. look for 436, 437, 471, 473.

Now, they made these in the 70's so case styling is typical for the era, that is some of them, particularly the Mustang series are (at least to me) just freakin hideous. But they also made dress watches that look like a plain Omega Seamaster DeVille from that ear. Very plan. They're "container" cases, so the bezel pops off leaving a container of the back and crystal; you pry thew xtal off, pull the stem off and now it's all in your hands, When the seals are new they're quite waterproof.

Roamer/MST 44 Jewel Cal 436/437

This movement is an absolute freak. MST began making pocketwatch and clock movements in 1888; they were medium grade movements. When the wristwatch revolution came they made wristwatch movements and somewhere in the 1930's they made their own watches under the Roamer name. They were the ubiquitous pin lever junk - nothing special. You can read a history of Roamere here - if you happen to read Finnish. Roamer was bought by an Asian company in 1993 and makes, frankly, some pretty cool watches that are completely unknown in North America. Brush up on your Italian and look here.

Somewhere in the 1970's a very odd thing happened. They made one of the best thought out wristwatch movements ever made. The mechanism is unique in several respects: it's entirely made in house, right down to the screws; has less stress on the automatic winding train than any other movement, and has 44 jewels - in places no other movement has jewels - but should. This movement is utterly incapable of wear as it's geared in such a way there is virtually no torque in the automatic winding train which is the great bugaboo of almost every other automatic movement made.

As you can see from the picture they are no screaming hell to look at as watches go; they are quite plain - just a simple, thin watch in cases typical for the era in steel or gold fill (no solid gold - arrg!). The watch here above would be, I guess the dress model. The movement also appeared in the "Mustang" and (?) some "Searock" and "Stingray" sport and divers models. Those are beyond ugly in that special way only LSD inspired 70's cushion cased slugs of metal can be. The picture below was ripped of some lamebrain Internet dealer who claims they have 25 jewel ETA movements. Dolt. One of the ones I own was claimed by the eBay vendor selling it to be a 17 jewel ETA movement because "that's what most watches are". There may only be 11 people in the world who understand what these watches are.


NEXT

Roamer/MST 44 Jewel Cal 436/437

Kif shock protection, 28,000 BPH, glycador balance with Nivarox spring, exocenter regulator.

I don't have enough pictures of all the little bits with exploded diagrams explaining how the automatic winding train works to go into any great depth. Walt Odets I aint, but in a nutshell, think of the last time you rode a 10 speed bike. Would you try to go up a hill with the chain on the big gear at the front and the small gear on the back? Not a chance, but that's how all automatic movements are geared. To use the bicycle analogy the MST 436 (no date) / 437 (date) would be like being in lowest gear. This is important in a selfwinding watch movement as it minimizes wear. The winding teain bits are always the ones that wear out and as anybody whose ever tried to get parts for, say, a 23J Bulova or (insert favorite old movement here) once those parts are worn out and you need new ones and you find there are no more new ones, you're screwed. In this movement the toque is divided down 4 times before driving the actual winding barrel. For a handy comparison, an ETA movement lying around was photographed.

The rotors are pretty much the same sire (if not exactly so):

Look at the size of the gear that's driven by the rotor:

And then here's the MST:

Now, look at the two reverser wheels in each photo. The ETA, like almost every automatic movement on the planet has two stamped out wheels. Their role in life is to go in one direction. Any backlash contributes to inefficiency in the winding mechanism. Very few movements have reverser wheels with no backlash (Omega Cal 501/503 is another one that got it right). The MST movement is an ingenious design with 5 rubies and 2 cams and has no backlash. Here's the reverser wheel opened up:

So, there's 10 rubies just in these two wheels. Is that a cute little thing or what?

The MST movement was also the only movement every used that that has ruby ball bearings in the rotor bearing. The "Swiss Automatics" book says they were prone to cracking and of the 3 I have 2 have steel bearings; the ruby bearing parts are no longer available. Perhaps they wern't such a good idea although some have obviously held up alright In all fairness the twoI have with steel bearings were well and truly butchered by hack "watchmakers" - there's no telling from what I have what's held up or not. They're a royal pain to photograph but you might be able to make out a hint of red here. It's plain as day when you look at the part in real life.

I'll close with a few quotes from my watchmaker concerning this movement:

"This is the movement Rolex SHOULD have put in the Sub".

"I've been doing this for 25 years and I've worked on everything; THIS movement still excites me. It's just brilliant."

There's a few pictures of different models that used this movement on the this page.

Richard Sexton
July 2001