• The online Bulletins and Mart and Highlights are currently unavailable due to a failure of a network piece of equipment. We are working to replace it and have the Online publications available as soon as possible. Thank you for your patience.

Query time keeping

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
Hi Everyone.
I’m just regulating an hermle 1151 movement. The movement has just been serviced etc and it’s working very well!
However I just have a query.
I’ve just set the time Exactly at 20:45 hours. By the time 21:15 was reached it looked as if it had gained 5 - 10 seconds. I waited until 21:45 and the time was exact! I’m just a little confused as to why it looked as if it was gaining slightly but obviously looks as if it is not?!
My initial thought was a slightly bent centre arbor or a chapter ring that hasn’t been marked out correctly!
Any thoughts on this please?
The minute hand isn’t slipping - it’s an exact fit on the square !
Cheers :)
 

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
On closer inspection it keeps spot on time between half past the hour and the hour but THEN as the minute hand advances past the hour the time gains 5 seconds rectifying from half past to the hour again ?? How strange!
 

Uhralt

NAWCC Member
Sep 4, 2008
5,221
683
113
Country
Region
Play between the wheels of the motion works? Before the hour the weight of the minute hand pushes it back. After the hour the weight of the hand pushes it forward.

Uhralt
 
  • Like
Reactions: NEW65

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
Thanks Uhralt.
Yes it makes sense what you describe. And sounds like that could be the problem as I cannot think of anything else that could be causing it.
It is keeping spot on time between half past and the hours.
I’m not really sure what to think now. It seems a lot of trouble to go to split the plates and try to rectify this small fault. I just wonder if there is anyone who could advise how to rectify this or at least improve the problem?
I’ve never encountered this issue before.
Thanks
 

JimmyOz

Registered User
Feb 21, 2008
1,009
259
83
66
Gold Coast Qld
Country
Region
As Uhalt said, the motion works, therefore you do not have to split the plates, however if it is constant, at only 5 seconds every time and no actual gain every hour It seems good to me as is. If it is gaining 5 seconds every hour just adjust the pendulum.
 
  • Like
Reactions: NEW65

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
Thanks Mark and jimmy.
Jimmy, I’d say 5-10 seconds at worst position then it realigns as it gradually improves Again. It keeps spot on time between half past and the hour.
I dare say that most folks wouldn’t notice it but I am not most folks.
As I say I’ve never had this issue before with a minute hand. I have seen this issue with an hour hand though.
If anyone can comment further on this I would be very grateful.
Thank you
 

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
I should add that the pendulum has an extremely wide swing so if there is an issue with the time train ( that is, with play in the gears) then surely it’s not a significant problem.
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
47,574
2,216
113
North Carolina
Country
Region
I wouldn't worry about 5 seconds. It's not worth taking the time to fiddle with.
 

R. Croswell

Registered User
Apr 4, 2006
11,141
1,204
113
Trappe, Md.
www.greenfieldclockshop.com
Country
Region
The Hermle 1151 is hardly what one would call a precision clock movement, so the question should be is the observed behavior normal, or is it a problem? I would say probably normal. Normally there must be some backlash or "free motion" in gears or they would bind. A few clocks use special measures that allow backlash to be reduced to zero but I do not believe that this is one of those. Your clock apparently is keeping time over the long run, one should expect a few seconds +/- deviation from a constant rate from a striking clock, which has already been mentioned. '

I dare say that most folks wouldn’t notice it but I am not most folks.
That's probably true. If you want the kind of precision that you would appreciate I suggest that you consider acquiring a true precision regulator (non-striking) clock, but beware that most clocks that the word "regulator" on the front are not real regulators.

RC
 

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
Thanks chaps for the reassurance. It’s mire than 5 secs more like 15 -20 secs but tbh not that noticeable and otherwise keeping good time. I’m just watching it for a few more days. Thanks again :)
 

Bruce Alexander

Sponsor
NAWCC Brass Member
Feb 22, 2010
7,627
880
113
Hanover, PA
www.testoftimeclocks.com
Country
Region
Personally I think you should evaluate accuracy in terms of a full winding cycle. How fast or slow is it at the end of the week? Supposedly atmospheric conditions can have an effect on a pendulum's swing as well. The weights may interact with the pendulum when they drop even with the Bob.

I'm with RC. Get yourself a floor standing or long hanging time-only regulator with a temperature compensating pendulum and jeweled bushings. ;)

Just out of curiosity NEW, what are you currently regulating with?
 

NEW65

Registered User
Nov 17, 2010
1,584
75
48
United Kingdom
Country
Region
Hi Bruce :)
I regulate all my clocks with my iphone::D I presume it keeps consistently good time... well, I certainly hope it does ;)
I’ve never had a regulator before but it would be quite nice to own a mechanical clock that keeps great time! Cheers :)
 

Bruce Alexander

Sponsor
NAWCC Brass Member
Feb 22, 2010
7,627
880
113
Hanover, PA
www.testoftimeclocks.com
Country
Region
Hi NEW,
Yeah, I agree. It would be very nice to have a well cared for, highly accurate mechanical "Regulator" clock.
Even so, it won't outperform your iPhone's time server link. :clock:
Regards,
Bruce
 

shutterbug

Moderator
Staff member
NAWCC Member
Oct 19, 2005
47,574
2,216
113
North Carolina
Country
Region
You might consider an Atmos clock. 30 second pendulum rotation, so any error is not multiplied very quickly :)
 

Forum statistics

Threads
168,891
Messages
1,473,716
Members
48,640
Latest member
irishbogs
Encyclopedia Pages
1,060
Total wiki contributions
2,955
Last update
-