Monochrome Watches
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In The Works: Sarpaneva’s First Tourbillon Watch

| By Frank Geelen | 3 min read |

Sarpaneva, one of our favourite Indie watchmakers here at Monochrome, is preparing a new watch: his first tourbillon watch! A few days ago Stepan Sarpaneva showed us some photos of a tourbillon cage, featuring the typical grid-like design that resembles the dials on many of his watches. He’s already testing and fine-tuning it and told us that most-likely he will introduce his first tourbillon watch at Baselworld 2015 and it will probably incorporate another complication. What complication will that be? 

Developing an entire tourbillon movement is something that costs years of developing and millions of euros. No business for a small Indie watch brand like Sarpaneva, or except that the price will be north of € 100.000k Euros (like the new Grönefeld Parallax Tourbillon.) So the only way to go is to use a tourbillon movement that is already available on the market. Enter Technotime with the “off-the-shelf” tourbillon calibre TT 791.

Technotime calibre TT 791 – tourbillon movement

This tourbillon movement is the base for Sarpaneva’s tourbillon, and it comes in several variations. The version that Sarpaneva uses is the calibre TT 791.53 tourbillon movement – the “.53” addition means it has an additional small seconds hand on top of the tourbillon axis and a power reserve indicator at the 3:30h position. The movement is powered by two main springs, which deliver 120 hours of autonomy when fully wound. The balance  vibrates at 28,800 vph (4 Hz) and the tourbillon makes one full revolution every 60 seconds.

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Modifying a standard tourbillon movement is not as easy as it might sound

The Technotime movement features a rather standard tourbillon bridge and cage, as can be seen on the photo above. The long bridge over-stretches the aperture with tourbillon cage and is screwed onto the main plate. This “standard” long tourbillon bridge is apparently not to mr. Sarpaneva’s liking, so he created a new tourbillon bridge, to replace the standard bridge of Technotime calibre TT 791.

Tool for finishing the tourbillon cage

Don’t think to lightly about this, as many tourbillon parts weigh *almost nothing* and the newly designed parts must have the exact same weight of *almost nothing*. If one of those tiny parts weighs just a fraction of *almost nothing* more it can totally throw off the balance that the part has on a pivoting point. When the part is not balanced anymore, it can seriously compromise the precise time-keeping of the movement, and the wear and tear of these fragile parts over a longer period.

In order to finish new parts, or standard parts to your own specifications, you need tools. For instance a tool to hold the part you want to finish. However these tools cannot be simply bought somewhere, so they have to be made, just for this purpose. Above you can see such a custom-made tool and a part of the cage before it was finished.

Sarpaneva tourbillon cage with straight brushed finished flat surfaces, and angled and polished edges

Above you can see more of tourbillon cage, which is already partially assembled. These parts have already been finished; flat surfaces have been straight grained, the edges have been angled and polished.

The new tourbillon cage and bridge feature the typical, and recognizable, Sarpaneva design “language.” These parts even show a lot of resemblance with the dial of my own Korona K1 (1st generation) that I bought back in 2009. The grid-like design still looks kind of rough, and is probably unfinished; meaning flat surfaces still have to be straight-grained and the grid-holes have to be deburred.


Sarpaneva made his own tourbillon cage and will be testing and fine-tuning that. For that purpose he mounted it inside a Korona K0 case, Sarpaneva’s dive watch case. The bridge, in which the tourbillon axis pivots, makes an almost full circle over the entire dial, again featuring the iconic grid-like design.

Sarpaneva Tourbillon

Sarpaneva already mentioned that an additional complication could be part of his new tourbillon that will probably be officially introduced at Baselworld 2015. Now what kind of additional complication would the master of moon-phases add? (yes, that’s a rhetorical question)

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