Hamilton Intra-Matic - Buren Cal, 1281

[WillFly]

I was very taken with an article in Mark's blog on a Hamilton Intra-Matic watch that he'd serviced - one with a Buren calibre 1281 micro-rotor movement. So - some days ago, I found one on the German, Ranfft "bidfun" auction database, put in the minimum bid - and came back from Devon today to find I'd been successful in my bid. (Even on holiday, "watchitis" continues apace...).

 

Lovely movement, and I'm looking forward to getting this one.

 

[Gary]

Very nice!! 

[Geo]

And here's me thinking you had gone to ground, I should have known better!

Cracking watch Will, I really like it.

[bobm12]

Excellent looking watch, very clean by the pic, and to me a unique type worth of your wonderful collection! Sometimes I think "watchitis" is not too bad when you find gems like that one! Way to go Will!...and welcome back from vacation!

[Jim]

wow grats on that wonderful find   micro rotors are really cool that movement looks pristine 

 

Sincerely

Jim

[WillFly]

Well, the watch arrived today - ticking away like a good auto should - and I've had it on test for two hours or so on the wrist. So far, keeping nice time. I've appended my own recent pic of the movement, which looks beautiful. I'm not a huge fan of automatic movements, mainly because the rotor obscures the details of the movement, though I do have Seiko and Mido autos, but this little micro-rotor is the bees knees. I wonder why they weren't as popular as the more conventional and larger rotor-driven movements. Perhaps the servicing was more of a problem - perhaps they aren't as efficient in maintaining a power reserve or they were more fragile. Who knows. Anyway, I love all 30 jewels of it!

 

Edited October 15, 2014 by WillFly

[Geo]

I shouldn't Will, but I really covet that Watch. Very well sniffed out sir!

[WillFly]

Just looking at the movement, a question comes to mind: how the hell is it regulated?

[bobm12]

Hi Will,

 

Just turn the screw on the balance wheel, it is a cam that will do small adjustments with timing. Easy on it though!

 

I believe you were talking about that adjustment or maybe I misundestood?

Edited October 15, 2014 by bobm12

[Geo]

Hi Will, for course adjustment, push or pull the arm with the guide pins, and for micro-adjustment turn screw. The other lever that holds the hairspring stud can be moved to adjust beat.

[frenchie]

Hi Will,

what is this big jewel looking thing under the rotor ?

[WillFly]

The movement has a self-winding gear with direction switching, which works by a pinion floating between two huge jewels. This from the Ranfft database...

[Geo]

Good morning Will. I found this article http://people.timezone.com/library/archives/archives631988314105468750 on the the Buren microrotor movement that gives an excellent description of its workings.

In my previous answer regarding regulation I only mentioned the micro-adjustment for fast and slow. Having read this article, the screw furthest away from the balance pivot is for micro-adjustment of the beat.

[WillFly]

Thanks for that, Geo - just read it, and a fascinating article it is. The breakdown he shows is of the early, 17-jewel model, and he mentions how he'd like to get his hands on the later, 30-jewel model - which is what I have. I'm going to copy the article into my watch file.

 

The thing that really attracted me to the Buren 1281 was just the sheer beauty of its design and looks - and it's even more interesting to see its technical description.

[Geo]

Thanks for that, Geo

Your welcome Will.

You know me, I just have to know what makes them tick!

[noirrac1j]

Its  nice looking watch Will. The movement is a spectacular and clean design with all the Jewels.

 

JC