Junghans movement hints

[bsoderling]

Hi all,

I got another 60’s kitchen clock to work on. 

Movement photos are attached.

one of the wheels needed a bit of attention and I got that fixed and after some basic cleaning and oiling, the movement runs.

The overall design is however new to me and I would appreciate any advice on service and lubrication ”specials” as I’m a newbie on these ”big things”.

Fundamentally I guess it’s a pin lever design? 
 

The balance wheel appears to be ”floating” by using what I suppose are two opposite mounted magnets and there’s a thin metal wire going through the ”staff” to keep things in place. Should end with really low friction but obviously only works when the movement is correctly placed. Curious to hear if this needs any special consideration or just leave as is?

Thanks!

 

 

[watchweasol]

https://www.google.com/url?sa=i&url=https%3A%2F%2Fmb.nawcc.org%2Fthreads%2Fadjusting-floating-balance.144478%2F&psig=AOvVaw1oc_-vi0UeSBdRGDff653M&ust=1615889868482000&source=images&cd=vfe&ved=2ahUKEwjXkZD-iLLvAhUJgM4BHY2mBTcQr4kDegUIARCaAg      The extract from the NAWCC explains the workings of this "Floating Balance"  not quite Hermle but a neat Idea all the same.

[bsoderling]

Thanks watchweasol,

So Hermle was the big guys for floating balances? Makes sense as I tried to google for Junghans Exacta and had very little feedback.

Well, the movement is running and it seems I can adjust timing. It's a slow beat thing at just 9000 BPH.

The amplitude is not a lot,  appr 180 degrees between turning points but maybe that's what to expect from this design?

 

 

 

[watchweasol]

Its an odd beast using magnetism the very thing you try to exclude from clocks and watches, Yes Hermle were the big boys and Smiths made them , I think under license in the UK. They were very good balances too.

[bsoderling]

Yeah, it's a bit counterintuitive to introduce strong magnets, at least that close to the h/s. It took me quite a while to grasp what was going on there, with the apparent huge "end shake" in the balance...

Any idea what kind of amplitude one should expect in a design like this?

 

 

 

[watchweasol]

Considering the balance wheel/spring are operating in a magnetic field the spring strength must have been carefully calculated, even though the beat will be ponderous but well controlled with the magnets.

[Tmuir]

Thanks for posting, that is a new one for me.

[oldhippy]

I haven't seen this type before. 

[HectorLooi]

Nice! Could you post more photos when it's finished. 

[Klassiker]

Here's a picture of one of these balances stripped down. I wouldn't do it again, as it wasn't really necessary, and the wire has to be threaded through a tight-fitting hole through the middle of the balance, with a risk of introducing kinks.