• Important Executive Director Announcement from the NAWCC

    The NAWCC Board of Directors is pleased to announce that Mr. Rory McEvoy has been named Executive Director of the NAWCC. Rory is an internationally renowned horological scholar and comes to the NAWCC with strong credentials that solidly align with our education, fundraising, and membership growth objectives. He has a postgraduate degree in the conservation and restoration of antique clocks from West Dean College, and throughout his career, he has had the opportunity to handle some of the world’s most important horological artifacts, including longitude timekeepers by Harrison, Kendall, and Mudge.

    Rory formerly worked as Curator of Horology at the Royal Observatory, Greenwich, where his role included day-to-day management of research and digitization projects, writing, public speaking, conservation, convening conferences, exhibition work, and development of acquisition/disposal and collection care policies. In addition, he has worked as a horological specialist at Bonhams in London, where he cataloged and handled many rare timepieces and built important relationships with collectors, buyers, and sellers. Most recently, Rory has used his talents to share his love of horology at the university level by teaching horological theory, history, and the practical repair and making of clocks and watches at Birmingham City University.

    Rory is a British citizen and currently resides in the UK. Pre-COVID-19, Rory and his wife, Kaai, visited HQ in Columbia, Pennsylvania, where they met with staff, spent time in the Museum and Library & Research Center, and toured the area. Rory and Kaai will be relocating to the area as soon as the immigration challenges and travel restrictions due to COVID-19 permit.

    Some of you may already be familiar with Rory as he is also a well-known author and lecturer. His recent publications include the book Harrison Decoded: Towards a Perfect Pendulum Clock, which he edited with Jonathan Betts, and the article “George Graham and the Orrery” in the journal Nuncius.

    Until Rory’s relocation to the United States is complete, he will be working closely with an on-boarding team assembled by the NAWCC Board of Directors to introduce him to the opportunities and challenges before us and to ensure a smooth transition. Rory will be participating in strategic and financial planning immediately, which will allow him to hit the ground running when he arrives in Columbia

    You can read more about Rory McEvoy and this exciting announcement in the upcoming March/April issue of the Watch & Clock Bulletin.

    Please join the entire Board and staff in welcoming Rory to the NAWCC community.

Bulle Post Your Bulle-Clocks Here

sophiebear0_0

Registered User
Nov 5, 2012
94
19
8
Interesting observation about the impact of battery type on electromagnetic clock regulation.

I think there are 2 possibilities here:

1) The under load voltage supplied by the C & D batteries were slightly different. I have often observed that as the battery drains, the amplitude will reduce and the clock will run fast. Note that the model in question does not have an iso-spring to compensate for the change in battery voltage. The clock has the later cobalt magnet that is prone to lose its strength over time.

2) Steel cased batteries may impact the magnetic field and hence impact time regulation. My personal experience is that I have seen it with the small 1/4 second ATO movements where the battery sits very close to the magnet coil. I once made up a battery holder using a steel box and it played havoc with the regulation ! Of course the ATO magnet is a simple N-S magnet, rather than the S-N-S that you find in most Bulles. That said, the cobalt magnet for the clock in question will probably be a N-S magnet. I say "probably" because sometime 2 separate magnets are fitted, creating a N-S-N field.

With the Bulle clock in question, the coil/magnet assembly is quite high on the pendulum rod. So there is quite a distance from the coil/magnet to the battery which is housed in the base. So I would have thought any impact on battery casing would be a lot less than in the case of ATO clocks Personally I would look closer at Point (1) as a possible explanation, but I'm not sure I could totally rule out Point (2) if the battery voltages under load were identical.

It interesting to note that some of the 1/4 second ATO clocks actually has a small magnets mounted on the case, directly behind the main magnet. This was supposed to allow the user to fine tune the regulation.

Apologies for the over-long and meandering response. Hope it makes sense ?

Regards,

Peter
 

praezis

Registered User
Feb 11, 2008
498
40
28
Germany
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Region
It interesting to note that some of the 1/4 second ATO clocks actually has a small magnets mounted on the case, directly behind the main magnet. This was supposed to allow the user to fine tune the regulation.
Peter,
my bigger (1/2-s) ATO clock has magnetic fine tuning, too:

Ato_magn.jpg

Frank
 

sophiebear0_0

Registered User
Nov 5, 2012
94
19
8
Good point Frank. I have a couple of 1/2 second models that have something similar. And of course the Brillie type clocks also have a small magnet mounted about the coil.

The reason why I highlighted the 1/4 second ATO clock is the battery will normally sit between the primary magnet and the small magnet at the back of the case. So it is easy to envisage that this will impact the effectiveness of the fine-tuning magnet. This secondary magnet is not fitted to all 1/4 second movements. I must confess i always try and regulate my ATO's with the rating nut and leave the secondary magnet in the "neutral position". I also try and mount the battery as far away from the magnet where possible - or in a vertical plane and mid-magnet when space does not permit. The approach seems to work ok.

Regards,

Peter
 

focusrsh_b07732

Registered User
Dec 17, 2009
71
7
8
The electrical engineer in me has major doubts about the whole D vs C-cell comparison. I don't like guesses.
The Bulle I am restoring won't be done for another month or so (waiting on some materials) but when it is, I'll put an oscilloscope with voltage and current probes on it and measure what it does with different batteries. That should be interesting and fun. I'll report the tests here.
- Carl
 

Simon Holt

NAWCC Member
Mar 21, 2017
705
105
43
Shaftesbury, UK
Country
Region
Good afternoon, all.

I've been working on clocks as a hobby now for about four years. I've never worked on an electro-magnetic movement before, but I've been asked to take a look at this non-running Bulle clock. I've read all 600+ posts in this thread, and learned a great deal – thank you all for your contributions. But after an initial inspection of the clock I do have some questions that I hope someone can help me with.

First things first: the clock is serial number 54039 (which I gather is from 1926, although John Hubby's table is no longer available on the BHI web site):
2020-05-19 10.18.30.jpg
The clock has been in the owner's family for many years and he reports that he does not know of any work being done on it. He last saw it running about a year ago, so I'm hopeful that nothing is missing and that all I'm chasing is poor electrical conductivity.

Rocking the pendulum manually advances the crown wheel as expected. A meter across the coil shows 1200 ohms, so that's OK. The contact spring had fallen off the fork arbor. I've put that back on but it doesn't look original – it looks longer than the replacements I've seen on sale:
2020-05-20 17.50.16.jpg
Is that a cause for concern?

My second question regards the fork. I was getting very poor conductivity there until I applied some switch cleaner. It appears to be worn asymmetrically; this frontal view shows significantly more of the riveted-on material on one side than on the other:
2020-05-21 12.22.27.jpg
Again – is that a cause for concern? Supplementary question: what is that material? It looks like it should be an insulator, but if I've understood the principles of operation correctly it must be conductive.

Incidentally, the work I've done so far (re-connect the contact spring & spray switch cleaner on the fork) hasn't made it want to run. I'm waiting for some additional leads for my multi-meter so I can check the basic functionality of the coil, curved magnetic bar and pendulum but in the meantime I'd like to know if I'm likely to need any new parts.

Simon
 

focusrsh_b07732

Registered User
Dec 17, 2009
71
7
8
Does anyone know the gear-train values for an early Bulle? I've searched this entire thread but don't find anything.
What I'm looking for is the # of teeth on the crown wheel, the worm & pinion ratio, etc.
I want this so I can accurately set the rate of the clock without taking hours to sneak up on it. If I know the gear ratios, then it is simple to calculate the correct pendulum period and use electronics from there to measure and adjust it.
 

focusrsh_b07732

Registered User
Dec 17, 2009
71
7
8
I designed and built a precision DC-DC boost converter for the above clock. It generates a very stable 1.5V from a 8000mAhr NiMh rechargeable battery. The battery and converter fit nicely in the clock where the original 1.5V dry cell would have been. (It's attached with double sided tape.) The converter's quiescent draw is 19.4uA. In other words, during the pendulum period when the fork-toggle is not powering the coil, that is how much current it draws. My measurements and calculations suggest the clock will run well over a year on a single charge. (663 days, actually.) Since the battery is guaranteed to take over 500 charge cycles, well, we'll all be dead for many generations before it needs to be replaced.;)

I was thinking about doing V2.0 of the regulator if enough people are interested. It would have a precision trimmer so you could adjust the voltage from about 1.4V to 3.5. It also would have precision current sense resistors in case you want to measure the current on both battery and clock sides. With the battery, holder, regulator etc. it would be about $50. You can contact me with a private message if interested.

- Carl Dreher

regulator close-up.JPG regulator in clock.JPG
 

PowerClocks

NAWCC Member
Apr 3, 2004
76
2
8
Queensland Australia
Country
Region
Re: Newbie needs help

View attachment 272362 View attachment 272363 View attachment 272364 View attachment 272365 View attachment 272366 View attachment 272367 View attachment 272368 View attachment 272369 View attachment 272370

I thought some of you may be interested in this Bulle curiosity. It looks like a standard Bulle in an oak case with a very Art Deco design. However the movement is very unusual. It is the same movement as posted in an earlier thread (Unknown clock running too slow). It definitely appears to be a genuine Bulle ?

Some specifics which might be of interest:

1) It is a large diameter dial (ca 15 cm)
2) Unusual design of chrome plated front feet - no levelling adjustment
3) The contact spring is looped at both ends (rather than the usual loop & tag)
4) The fork is smaller than the conventional Bulle fork and the silver contact is a small circular riveted circle.
5) The contact pin is brass rather than silver. It is very short and has no method to adjust the depth of penetration into the fork.
6) This example has the iso spring fitted. It is hung from a short bracket. I suspect it can be adjusted but I haven't yet attempted that.
7) The magnet is horseshoe rather than conventional U-shaped. It is magnetised N-S-N
8) It has a serial number on the front - but no other makers marks (other than Bulle on the dial)
9) Wiring looks original and is standard Bulle type with standard connecting lugs.

The clock requires a strong pendulum swing to operate the cog wheel mechanism reliably. At the moment I have it running on 3 volts and it appears to be keeping pretty good time. I will try and reduce the voltage to 1.5 V once the clock has run for a couple of days.

I really don't know anything about the history of this particular design. I know John has suggested that it may be a relatively late model manufactured in Brazil ? I really don't know - but I do get a sense (gut feel) that it is a relatively late model which in a way is backed up by the overall condition of the movement & case. The dial face is quite badly scratched, but the movement and chrome fittings looked to be in good "clean" condition.

I'd be happy to share more details if anyone is interested, and be very happy to hear from anyone who has any additional information about this design of clock.

Regards,

Peter
Hi Peter, I recently bought a clock with a very similar movement, I have been told by the seller there may be parts missing and that he was unfamiliar with this model of clockette, I think he also thought it was not a Bulle but a clock made under licence, The one I have bought also says Bulle on the dial but since I do not have it yet I can not supply much information except pictures that described it on FleaBay, could you write to me on powerclocks@hotmail.com so I can swap information, my restoration could be easy, it could be a chore but it will get done with a bit of help, If I know what is missing, usually I either make the parts or buy them but good pictures are key to a good, undetectable job.

Graeme Power

Clockette 002.jpg
 

focusrsh_b07732

Registered User
Dec 17, 2009
71
7
8
I finished V2 of a regulator for Bulle, ATO and other low-voltage, low duty-cycle clock. It is 3.6cm wide x 3.5cm deep x 8.2cm tall. (~ 1.4" x 1.4" x 3.2".) This hides perfectly in the battery compartment of my 1921 clock.
Output is guaranteed adjustable from 1.4V to 4.5V. Uses a 1.2V Ni-MH 8000mA-hr rechargeable battery. This should power a Bulle for at least a year, but that obviously depends on where the output voltage is set, the adjustment of the contact fork on the pendulum, magnet resistance, etc.
If interested in one, please contact me via the forum Private Message.

- Carl Dreher

IMG_7232.JPG IMG_7231.JPG
 

rlwindle

Registered User
Mar 18, 2011
390
15
18
70
Dallas, TX
Country
Region
Need some info on this "Bulle" clock manufactured by Manufacture Francaise D'armes & Cycles de St-Etienne (French mail order co.).
The clock case was falling apart when I got it, and the clock did not run, both problems have be remedied now. The pendulum had torn away from the silk suspension spring, I replaced it and added a "D"cell battery compartment and battery, and viola it works.
I don't know that much about it, other than who made it. I would like to know when it was made.
The case is 13.25" Long and 10.50" in width.
Front of clock.jpg MF logo.jpg pendulum locked.jpg DSCF3436.JPG
 

sophiebear0_0

Registered User
Nov 5, 2012
94
19
8
Hi Russell

I have a couple of similar Manufrance Bulle clocks. One is identical to yours, the other has a slightly different design of case. The movements are the same.

The design feels like it is relatively late. The wiring is plastic-coated candy stripe. There is also no iso-spring. It has a retaining spring for the rating nut which presumably is required because of the very long threaded section. The normal Bulle method of using a split rod to hold the rating nut would not be effective over such a long distance. the magnet is a Bulle-type U-shaped iron magnet, but the vertical limbs are quite short. From memory, I don't think the movement has any manufacturer's markings or serial number ?

I've attached an advert for the clock that I assume came from Manufrance's mailing catalogue. Unfortunately I can't see any dating information. The Manufrance catalogues are readily available, so I guess it would be possible to trawl through them to find the advert. My best guess would be that the clock was made around 1970. But that is purely a guess. Other Forum Members may be able to provide a more informed view.

These clocks do come up quite frequently on internet auction sites, and in particular in France. They tend to sell for relatively low prices and so can be a good way to learn about Bulle clocks with a relatively low investment.

Pleased to hear that you managed to get it running.

Regards,

Peter

Manufrance advert.jpg
 

rlwindle

Registered User
Mar 18, 2011
390
15
18
70
Dallas, TX
Country
Region
sophiebear,
Thanks for your reply. I found that ad in my research on the clock but thanks. The pendulum is weird on it. It is crudded up but I have never seen one with a pointer on it (any suggestions on how to un-grud it). I think it was in contact with a battery that went bad at one time.
pendulum locked.jpg
 

sophiebear0_0

Registered User
Nov 5, 2012
94
19
8
Russell

The "pointer" on the rating nut is to hold it in the set position.

I usually use lemon juices / salt to tackle battery acid corrosion on brass. I guess soaking in any mild acid should be ok. You would then need to periodically use a stiff brush to try and remove the residue. It will probably take a while - but I'm sure you'll get there. You might be able to shift some of the outer crud with an ultrasonic bath. You also might want to consider a penetrating fluid to help free the rating nut from the threaded rod if it is seized. I don't think there is any major risk to this approach. Good luck.

Regards,

Peter
 

rlwindle

Registered User
Mar 18, 2011
390
15
18
70
Dallas, TX
Country
Region
Russell

The "pointer" on the rating nut is to hold it in the set position.

I usually use lemon juices / salt to tackle battery acid corrosion on brass. I guess soaking in any mild acid should be ok. You would then need to periodically use a stiff brush to try and remove the residue. It will probably take a while - but I'm sure you'll get there. You might be able to shift some of the outer crud with an ultrasonic bath. You also might want to consider a penetrating fluid to help free the rating nut from the threaded rod if it is seized. I don't think there is any major risk to this approach. Good luck.

Regards,

Peter
Thanks, Peter
 

sophiebear0_0

Registered User
Nov 5, 2012
94
19
8
Russell

You're very welcome.

Just for completeness, i have attached a photo of the other style of "Manufrance Bulle" that I own. The movement is identical.

I did spend a while trawling through images of Manufrance catalogues to see if I could match the advert style. It wasn't conclusive, but the advert style seems more in keeping with the 1950's. So perhaps the clock is a little older than I had first thought ?

Regards,

Peter

Manufrance 1.JPG
 

Mistyoptic

Registered User
Jul 8, 2015
27
0
1
Stafford, UK
Country
Good afternoon, all.

I've been working on clocks as a hobby now for about four years. I've never worked on an electro-magnetic movement before, but I've been asked to take a look at this non-running Bulle clock. I've read all 600+ posts in this thread, and learned a great deal – thank you all for your contributions. But after an initial inspection of the clock I do have some questions that I hope someone can help me with.

First things first: the clock is serial number 54039 (which I gather is from 1926, although John Hubby's table is no longer available on the BHI web site):
View attachment 591098
The clock has been in the owner's family for many years and he reports that he does not know of any work being done on it. He last saw it running about a year ago, so I'm hopeful that nothing is missing and that all I'm chasing is poor electrical conductivity.

Rocking the pendulum manually advances the crown wheel as expected. A meter across the coil shows 1200 ohms, so that's OK. The contact spring had fallen off the fork arbor. I've put that back on but it doesn't look original – it looks longer than the replacements I've seen on sale:
View attachment 591099
Is that a cause for concern?

My second question regards the fork. I was getting very poor conductivity there until I applied some switch cleaner. It appears to be worn asymmetrically; this frontal view shows significantly more of the riveted-on material on one side than on the other:
View attachment 591100
Again – is that a cause for concern? Supplementary question: what is that material? It looks like it should be an insulator, but if I've understood the principles of operation correctly it must be conductive.

Incidentally, the work I've done so far (re-connect the contact spring & spray switch cleaner on the fork) hasn't made it want to run. I'm waiting for some additional leads for my multi-meter so I can check the basic functionality of the coil, curved magnetic bar and pendulum but in the meantime I'd like to know if I'm likely to need any new parts.

Simon
Hi Simon, I can’t see that anyone has answered you so I’ll do my best. On the fork, one side should be insulated and the other a silver contact riveted to the steel fork. Insulator on the left side as you face the clock. Not sure the length of the contact spring is critical as long as it makes good contact (the rolling action of the arbor keeps the contact clean). When you check the magnet, remember the polarity on these is weird, i.e. NSN. There’s a good webpage from Australia explaining how to re-magnetise if needed. Have a look at some of the case histories on Pete Smith’s horological.com pages. They are a wealth of information
 

Simon Holt

NAWCC Member
Mar 21, 2017
705
105
43
Shaftesbury, UK
Country
Region
Hi Simon, I can’t see that anyone has answered you so I’ll do my best. On the fork, one side should be insulated and the other a silver contact riveted to the steel fork. Insulator on the left side as you face the clock. Not sure the length of the contact spring is critical as long as it makes good contact (the rolling action of the arbor keeps the contact clean). When you check the magnet, remember the polarity on these is weird, i.e. NSN. There’s a good webpage from Australia explaining how to re-magnetise if needed. Have a look at some of the case histories on Pete Smith’s horological.com pages. They are a wealth of information
Thanks for taking the trouble to respond, Mistyoptic. Someone (also in the UK) did respond, but via PM. Thanks to them, I was able to get the clock running satisfactorily and return it to a very happy owner. I developed quite a liking for these clocks and hope to acquire one at some point.

Simon
 

hans!

New Member
Apr 30, 2020
2
0
1
48
Country
Hello, I'm looking for some parts for my Type A Bull Clock. I need the weight of the pendulum below the coil and the isocronism spring attachment above. I can send pictures if yu want. Thank you, Hans
 

zzippy

Registered User
Mar 23, 2016
110
4
18
london
Country
can someone tell me the size of the gap between top and bottom plate of the Bulle suspension pls
 
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