French barrel clock

Hi Jason

Clock oil see HERE ( Meadows and Passmore) - not cheap but pretty much anything you need for clock work. ( the bottle will last you for the rest of your life!) When you apply the oil use VERY little, put just a drop ( from the end of a cocktail stick maybe) into the hole where the wheel arbours run in the plates. DO NOT apply to the wheels themselves.

Regards

Norman

Any simple pendulum has a period of

T = 2 π SQRT(l/g)

where l is pendulum length and g is acceleration due to gravity.

Weight doesn't directly influence the period.  

BTW The character after the 2 was Pi when it was input - doesn't seem to display well after submission.

Edited By David Jupp on 27/08/2013 13:40:31

Edited By David Jupp on 27/08/2013 13:40:56

Don't tell me about pendulum length earlier this year I made a clock and matching hall table for a client and spent the best part of £1000 on a kieninger movement and could not get it to keep time it was always running slow no matter how I tried the adjuster on the pendulum. Eventually after lots of e-mails and me asking for a replacement the supplier realised they had sent the wrong length suspension rod so it was always going to be about 3" too long.

Hi Jason,

Oil, as Norman says, use proper clock oil from M & P. Don't fill the the "oil sink". Just introduce enough to fill the minute radial gap between the pivot and the plate. A drop on the end of a small needle is enough. The oil sink is just an aid to getting the oil into the pivot.

Pendulum mass; the more the better. The pendulum Q factor is directly proportional to the mass of the bob. The higher the Q the less the period is affected by variations in friction and driving force. Of course you have to take account of the strength of the suspension. Probably best to make something that just looks right for the length.

As has been said don't oil the wheels, they should be completely dry, the only exception being a tiny amount of oil on the escapement pallets which of course is transfered to the tips of the escape wheel.

Russell.

No need to guess, multiply the number of teeth on the third wheel pinion by the number on the escape wheel pinion and by 3600 then divide by the numbers of teeth on the centre (hour) wheel, on the third wheel, and on the escape wheel. That will give you the full period for the pendulum.

Russell.

Jason, on the back plate there will be a couple of numbers stamped, find those and input them on the link below which is Meadows and Passmore's site, it's an on-line calculator which will give you the correct length according to the numbers on Your movement, saves fannying around doing calculations!

If you have just dunked the movement in degreaser without stripping it, you will not have got rid of the WD40, nor the muck and grit you will have successfully washed into the pivot holes in the process!
Any lubricant you introduce now via the oil sinks will simply turn the WD40 residue into a goo and any grit in them into a very nice grinding paste!
Sorry, but your first course of action (if not done so already) will be to strip and clean it properly, Then assemble and lubricate once the pivots have been cleaned repaired and burnished!

I a long time ago stopped paying ludicrous amounts of money for commercial clock oil!
I use a lot of the stuff so make my own using 0-30 synthetic motor oil and Slick 50 in a 50/50 mix, I've never had a clock fail due to lubrication issues neither have I had one dry out and no visible signs of wear after some years of use!
PM me your address and I'll mail you a small pot sufficient to do your clock!

As previously said, no lube on any wheels, a small spot on each oil sink, not forgetting the single cock on the motionwork intermediate wheel!
Also put a small spot on each pallet, the escape wheel will transfer a tad to each tooth tip!
If it has a Brocot adjustment on the top of the crutch (the suspension spring will be pinned inside it), check the picvots and state of the wheels there too, the suspension block tends to sieze causing the gear wheel on the adjustment rod to either strip the teeth, or turn the rod inside the gear, the pivot hole may also have excessive wear if the previous owners were conscientious pedants with its timekeeping qualities!

I've just ruined a batch of Horolene cleaning out a Comtoise wall clock which had been liberally sprayed with WD40, and I'd previously cleaned every single part by hand soaking and brushing with acetone, even then I had to final clean every component with lighter fuel to totally rid them of the vile stuff!

I have several cases here that would house a similar orphaned movement, but a good conversion for you would be to turn it into a 'Skeleton Clock', in which the movement is mounted on pillars or into a brass frame of your design, loads you can do with it!
I have my own ideas in this vein, but I'm saying nowt at this stage as I'm intending to write up a project for amateur clockmakers!

John.

**LINK**

BTW, I also have a box full of pendulum bobs for those movements, they are invariably heavy brass units if you've never seen one, but the main variant to this is a decorative grid iron type used on Napoleon III Portico or Empire clocks, they use the same style movement, but the gearing is slightly different as the rod is much longer and why the numbers on the backplate are important!

Also take a good look on the backplate for any stampings, if there is one (usually a circular or oval stamp) it will be the maker's mark and you'll need a loupe to read it!

I may have a few rods kicking around too, I'll dig them out later and see what types there are!

I'd also recommend Not using cocktail sticks anywhere near a clock movement, the wood contains acids that are detrimental to longevity, use boxwood (pegwood) sharpened to a point for pegging out pivot holes, and if you don't have a set of clock oilers, a steel needle or bit of small diamter blued pivot steel with a small flat on its tip for placing oil in the sinks, needless to say it should be spotlessly clean, also keep any oil pots covered when not in use as it will soak up dust like a magnet!

John.

Edited By RJW on 27/08/2013 18:15:33

Edited By jason udall on 27/08/2013 19:27:36

Edited By jason udall on 27/08/2013 19:28:52

The age of that movement it will probably need new springs anyway DON'T try to remove or replace them without a spring winder

Roy

Prrops used to sell clock and watch oil in tiny containers for very few bucks.

Neil

Those French drum movements are about as good as it gets for any clock movement, the quality of manufacture and finish is consistently superb across the entire range whether countwheel (yours), rack striking or timepiece, and whether unsigned or bearing trademarks of Japy, Marc or Marti!

Can't argue about the 'Vallet' suspension, never bothered to research them, I only fix them when they've been inconsiderately abused (butchered), but the adjustment device is by Brocot, which is what I generally refer to them as, you'll probably find the name stamped into the gear wheel!

Hmmmmmm, Please forget an unstripped cleaning Jason, it's a shit way of cleaning a clock to be frank and what cheapskate dealers do to get one up and running sufficient to get rid of what was a non runner, even leaving the barrels out of the solution!

No matter how well you clean it, even in an ultrasonic, you will also Not get crap out of the mainspring leaves or the barrels if you do dunk them, or get the congealed oil out of the holes, and as sure as God made little apples, you'll end up with a slurry gathered in whichever part of the barrel is lowest when sitting in the tank!
You may get some of the crap running out of the lever hole in the barrel cap (slot for prying the cap off), but you will not be able to properly clean the springs or oil the mainspring!

The oil previously used in that clock will have been fish oil based (and why some stink enough to make you want to puke), ultrasonics don't get it out or off, it doesn't work on watches either, and you will always need to remove dried oil residue with a stick of pegwood before cleaning again!

Use it as a learning experience, they're not that bad to do unless you're into serious re-bushing where the top pivots are getting on for pocket watch sizes when

it all gets a bit tedious, but if you just strip it to clean and inspect and forget repairs at this stage, they're quite nice to work on!
Use a digital camera and take loads of photo's at each stage of disassembly and you wont go wrong!
Just beware on reassembly though when placing pivots, if you grip the plates too tightly together to keep those little buggers in place you've managed to capture, and you try sliding one across the plates that's slightly off it's hole, you'll probably do one of two things, (a) put a nasty scratch on the plate (not pro' and (b) snap a pivot off - mainly because the sods that tend to be out of place are the top ones on the escape wheel and fly, they're around 0.5 - 0.7mm diameter and hard as nails, they won't flex one iota and those arbours are a nightmare to pivot - Trust me on that!

Nothing to be afraid of, just make sure you let the mainsprings down first before stripping it otherwise you'll be nursing Very warm and tingly fingers for a while

John

M & P oil at less than £4 for a supply that will last the occasional clockmaker a lifetime is hardly a problem surely? This is the pukka stuff after all. For John, who presumably does a lot of clockwork, then a "homebrew" is probably the best course. BTW John I'm a bit surprised about the cocktail sticks containing acid - luckily I don't drink cocktails ( or much else) these days! . As you suggest , when I've occasionally worked on clocks, I've used pegwood but I thought that might be an unfamiliar term to Jason.

Jason - I afraid the way to make a job of the cleaning IS to take it apart. If you are unsure why not visit a car boot sale, junk shop or such like, seek out a cheap clock, and practice. You'll probably find it much easier than you fear. Do heed Roy's warning about springs though.

Norman

I appreciate the concern some have about spring removal, and in some circumstance it's advice to be well heeded, but spring removal on these is a piece of cake, no winder needed and frankly, overkill for a 'one off' job, just gently pull the spring out from the centre and when it releases (you'll feel it want to go), keep the spring cupped in your hand (use a glove or thick rag if need be) and let it gently unwind, keep a good grip on the barrel though otherwise it will do a zebedee across the room from the recoil, there's not really that much power in them unless you try flicking the click of the rathet pawl when fully wound!!
I generally hold the spring and let the barrel rotate!

As a general rule on this type, they're around 18mm deep and 0.20mm thick, so quite weak compared to a British Enfield or Kienzle / Keininger movement, but even those I pull out by hand, the only springs on which I will use a winder is a Fusee, those buggers really Are scary!
For winding them in, I use my watchmakers lathe with the arbour in the chuck on small springs, wind it up slip a cut wire hoop over it, slot the barrel over it, and push the spring in, it can be done in any lathe - even fusees, but I'll use my winder for those and always use the click And stand well to one side of them with Nothing on the bench!

If the spring remains fairly tightly coiled, then it's probably dead, but to be perfectly honest, I've rarely had to change springs, although several times had to cut off the end and form a new hole for the hook, because the spring eye cracks due to over ambitious winding!
If the inner eye is cracked, you can turn the spring inside out to repair it, but they're a pain to do when that end goes, but still 'do-able'!

John

Edited By RJW on 27/08/2013 21:19:55

If you take it apart do check if the barrels are marked for which train they are, they look very much the same but should go back at there original place. Springs from these movements are not a great problem if you know what you are doing, the weakest spring is usuall for striking. I cannot remember ever using a special springwinder, normaly they are of no use for the springs I work with. The largest I remember was from Kalliope musical box with a length of 10meter, heigth 60mm and thick 1.10mm. Even this you can do by hand, it makes it more interesting, but using a lathe is safer. Niko.

Norman, I don't think the acid content in a cocktail stick would do much damage to you, but if pushed into a brass pivot hole, there could be some sap residue left behind which could damage the brass and hence steel, especially if oak, they're not designed or manufactured for pegging out clock plates under pressure anyway, and impurities would most likely be depositied!
The advice came to me originally from a professional member of the British Horological Institute, sadly he's no longer with us for me to ask his source, but it seemed good sense to me then and still does!

Beware too of pegwood being sold on eBay, I bought some and it looked (and smelled like) pine rod created by shoving a stick of wood down a counterbore, similar to how carpenters make dowels, it all went in the bin, lesson learned - stuff on eBay ain't always what it seems!

Niko makes a very good point about marking barrels, and something I do regardless!
On many clocks they can't be mistaken because the barrel gear diameter is often very different between Time and Strike, but on French drums, they are mostly interchangeable and have the same size springs in each barrel!
I usually scratch an 'S' on the strike drum and 'G' or a 'T' for the going or Time train, but do it on the cap and barrel too on these as they are mostly interchangeable!
I use those letters because sometimes you will come across a clock which has had Johnny around the barrels (French lettering), the strike will have an 'S' usually (Sonnerie) but the going train may well have what looks like a 'W' but which is 'M' for Motion or Marche, so put your own marks on!

With a weakish time train spring, the strike spring can often be swapped over to good effect, as curiously they never seem so coil bound as the time spring, possibly because the strike spring winds down faster due to a faster moving train, and I've found that even a very weak time spring will drive the strike train on these with no noticeable difference as the train speed is limited by the fly anyway!

Generally in most clocks, the strike train will have the heavier spring as it has to drive more wheels, cope with the fly acting as a brake, lift the hammer from the pin wheel Plus the weight of the hammer, and lift the locking lever off the stop pin to release the countwheel - on a rack strike movement, instead of the countwheel it has to drive the flirt which lifts the rack!

For anyone recoiling in horror about yanking out a spring on Jason's clock and to help put things into perspective, they are almost invariably approx 80mm diameter on the plates, and both maninspring barrels approx 32mm diameter externally, they're pussys compared to most springers!

John

welll, as a child(7-10 ish)..I took apart gramophone motors..even got a few back together,,Once..ONCE.. opened a broken spring drum...enough residual rage to put me off until now...those drums are 3-4 "dia. and 2-3 " wide...much springness. ...

so it looks lke nothing for it...shame clock strikes and fast ticks(no pendulum ) fine.. letts see if I can at least make it no worse.

btw this is what I have.come to understand as vallet suspention

Edited By jason udall on 27/08/2013 23:35:21