# Hamilton Buren Microrotor



## Silver Hawk (Dec 2, 2003)

In 1966, Hamilton acquired the Swiss company Buren...and a few years later, Hamilton started to selectively incorporate the highly innovative Buren Microtor (aka Micro Rotor/Microrotor) movement into small numbers of certain upper tier watches. I'm not sure how long these movements were made..probably only 2 or 3 years.

I have a couple of these watches but don't get to see the movements very often because they both open through the crystal. However, I had to service one over the w/e and took a few photos of these very unusual movements. The rotor is the half-moon shaped, grained lump of steel on the left hand side....the main advantage of these movements is that they are very thin compared to normal automatics.

This one is the cal. 620 and is from my Hamilton T-403. Anyone else got any micro rotor watches? Universal Geneve also dis one in their Polerouter series.


----------



## mjolnir (Jan 3, 2006)

That looks beautiful Paul. You don't seem to see a lot of microrotors about although I do recall a past microrotor thread on the forum where there were some stunning looking movements on display.


----------



## jasonm (Nov 22, 2003)

Interesting, if that works, which it obviously does, then why arnt all autos made this way?

Are there any drawbacks? More shakes to get going?

Like bumper autos, this looks like a neat way to keep the movement compact...

I wish the 7750 had a rotor like it and not the huge heavy thing that wobbles around like it does....


----------



## pg tips (May 16, 2003)

B)


----------



## Xantiagib (Apr 22, 2005)

Beautiful movement.... great pictures.

Of course tweak it a bit and add a Dubois-Duprez Chronograph module and you get whats in most navitimers and Heuers of that era...


----------



## minkle (Mar 17, 2008)

That movement is pure porn..what a beauty! :wub:


----------



## Stuart Davies (Jan 13, 2008)

Very very smart Paul - I like it a lot!

How accurate are these things and why weren't more movements made this way? Was it too expensive tp mass produce?


----------



## tixntox (Jul 17, 2009)

Hamilton do make lovely movements. Nothing fancy just nice engineering. I tweaked mine the other day and took ages to replace the back! I know! I need to get a life!


----------



## Agent orange (Feb 11, 2006)

The Buren Microrotor was a great movement but unfortunately not as efficient as a full rotor automatic. Not difficult to see why really but it looks fantastic all the same, excellent pics Paul.

It was most famously used in the Universal Geneve Polerouter, designed by GÃ©rald Genta. It used a microrotor (cal.215 I think) from 1959 to 1969.

Their other famous models that utilised a microrotor are the Silver and Golden Shadow, another GÃ©rald Genta design. They were the worlds thinnest automatic watches with a movement thickness of only 2.3mm, a record it held from 1965 until 1978.

Cheers,

Gary


----------



## James (Jul 17, 2006)

Very classic congrats on this 

And yes the Universal too, last revision I believe this 215-9, an older picture of one of mine in 18K pink. Still stored lol


----------



## Alexus (Apr 9, 2003)

Great pics Paul and indeed that watch is a beauty.

I have a Bulova "Ambassador" 1969 stored somewhere that has a microrotor movement.


----------



## Alexus (Apr 9, 2003)

I also have this *1966 Bulova* *"Ambassador"*.


----------



## delays (Jan 20, 2009)

Fascinating stuff, and also interesting to see why this didn't catch on - a shame.

However, thin-ness isn't really something I admire in watches, so maybe its just fashion?


----------



## Russ (Feb 7, 2006)

jasonm said:


> Interesting, if that works, which it obviously does, then why arnt all autos made this way?
> 
> Are there any drawbacks? More shakes to get going?
> 
> ...


Agree 100%


----------



## rjcole83 (Jan 28, 2016)

I didn't think this style had a 620. Is it still considered a t-403??


----------



## Daveyboyz (Mar 9, 2016)

That movement is a thing of beauty... thanks for sharing.


----------



## Littlelegs (Dec 4, 2011)

Looks a lovely movement, would be great to watch it through a display back. What sort of power reserve does it give in comparison to a normal sized rotor?


----------



## Mechanical Alarm (Oct 18, 2010)

I hope there's a LUC Chopard in my future!

This is stunning... and probably a lot more affordable!


----------



## Padders (Oct 21, 2008)

Microrotors you say? This crossed my path a little while back and I couldn't resist a poke about:


----------



## Will Fly (Apr 10, 2012)

Here's my Hamilton Intra-Matic - also with the beautiful Buren movement. Note the large jewel and chaton under the rotor.



















I'll just add that micro-rotors didn't really catch on as they were more fragile and less efficient than a full-size rotor. Mine runs down fairly quickly if not being worn. But I do love the elegance of the movement.


----------



## Silver Hawk (Dec 2, 2003)

:thumbsup: thanks for the blast from the past :thumbsup:

I'd forgotten about this watch...and I still have it somewhere, so must find it and start wearing it. :yes:


----------



## rjcole83 (Jan 28, 2016)

Here's my 620 Thin O inscription on back dates at 1964 so it may be a '63. Oh well, no pic today. Page freezes. My screen name is also my gmail. Please contact to share. I'm new to these old micros and have that thirst. Would also like to show you my Thin O


----------

