nevenbekriev

This is a swiss movement, but in most cases - impossible to determine the manufacturer. Everything is in place, only the hairspring seems to be bent. And, of course, balance staff can be broken.

Very often happens that someone buys old pocket watch with the intention to start restoration project, then He finds that the balance staff is broken and gives off… Yes, the price of making new parts is high and buying watchmaker’s lathe is expensive thing. But, if one have enough enthusiasm and time, nothing will stop Him to build his own lathe, good enough to make good quality balance staffs, screws, winding stems and some other things, and learn how to do this things by himself. And, having lathe doesn’t mean that one will ever learn how to use it. Actually, the old watchmakers often have lathes, but they don’t use them. May be they have tried once few times and realized that it is not easy to learn and will not pay off easy, and since then, they said that they don’t have time for this… That’s why I decided to start this project. The main aim is to show, that turning parts is not so complicated and is absolutely possible without having sophisticated high precision and expensive tools. I choose to make a simple t-rest lathe with spindle. Yes, the lathes with still centers are even more simple, but using them for turning balance staffs, especially the pivots, is a bit harder for a beginner. I decided to make the lathe directly out of an electric motor, thus simplifying construction – no belts, spindles, etc… The motor has two sides, each will have a permanent chuck: the front side with 8-screw chuck, and the rear will have wax chuck. Thus construction is further simplified – no collets. Wax chuck is something forgotten long ago, but has great advantage – it is simple, and with some experience – easy to use, and gives perfect centering. I choose a motor from a not big vacuum cleaner. This is a brush type motor. They are easy to control, but this will need a special topic. The motor has two ball bearings (in my case 608).This is important, as they will give perfect performance and no need of constant oiling, adjustment of free-play and so. But, the bearings must be in perfect condition. If worn, better replace them – this is easy, use bearings with rubber covers to prevent filling with dust and shavings. I made the lathe and took a lot of pictures of the making process. Hope that pictures will make all clear, but I will try to explain everything and answer all questions if needed. The problem here is my English… Here are videos with the pictures and the process of forming both ends of the motor shaft (the chucks). Here is the link for the gallery with the pictures https://postimg.cc/gallery/5CxbkFX Here is a video of real time balance staff turning on my new lathe. I must say, that making good video appeared to me to be harder than turning the staff… And doing both things together is twice harder. So, please excuse me for the quality and speech missing… The quality is the best my mobile phone can do. It has good resolution, but focusing on small objects is real problem… I just hope that it is clear enough to understand how the staff is turned… Also excuse me for this Filmora water mark! I am a beginner in video making and I didn't find so long beter and free software to prepare videos...

Here are some pictures I took when making clock barrels. They had to be two and equal. [/QUOTE]

Hi Dell, Yes, when there is a crack in the cylindrical part of the barrel, this is really bad. But even then, it is better to turn a ring out of steel tube and press it on the barrel. Of course, if there is enough space for this ring in the movement. I know the theory that brass will harden 3 days after heating, but I am not sure if it is true. May be some sorts of brass really harden a little, but I have seen a lot watch or clock wheels, that somebody has heated (in order to anneal the steel pinion to ease drilling for re-pivoting), where the brass table of wheel has become soft and good for nothing. And no time hardening happens there at all. Another option when barrel has crack is to make entire new barrel, or which is a bit easier – to cut the cylindrical part, to turn a new one and solder it in place with soft solder.

Hi Steve, I can't see what is the condition of the stone, but it is clearly seen that down side pivot of balance staff is broken. So, You need somebody who is able to turn a new balancs staff. On the other side of plate is the down side balance bridge. There are two stones on it - hole stone and end stone. The end stone is in a small plate, shaped like a peg. Shift it and it will go out, then You will be able to see the hole stone.

Hi, all Yes, this is a good way to make a new hook, which is used mainly in big clocks. @Dell: My advice is not to solder the old hole with silver solder. Pegging is needed only for aesthetic reasons, which is reasonable in torsion clocks. Hearing drum to temperature of solder melting will make the brass soft. We don’t need that as teeth may bend by the torque of the spring. Using of soft led-tin solders will not soften the brass.

I just copy-pasted it from an old book: To fit a new mainspring hook to a barrel, first drill a hole in the side of the barrel at a slight angle pointing away from the direction of pull of the mainspring. The hole is then threaded slightly undersize. Taper a piece of steel wire by filing and cut a thread with a screw plate, holding the wire in a pin-vice. Remove the pin-vice, cut the wire close to the screw plate and shape the protruding piece of wire into a hook by filing. Unscrew the threaded wire from the screw plate and insert the small diameter end of the wire into the hole in the barrel entering from the inside. The protruding wire on the outside is now held by the pin-vice and the wire is screwed into position by unscrewing from the outside. The hook should project into the barrel a distance no greater than the thickness of a piece of the mainspring. When in place remove the pin-vice, cut off the wire on the outside, file down close to the barrel and finish with an oilstone slip.

Hi Bob, If the loss of the second hand is no problem, then just make the pinion of the escape wheel to rotate free on the shaft and fix the shaft to the frame. No need to put another shaft on different place. But You must put on the shaft some kind of separator to keep the two wheels little away from each other. This separator must be fixed to the shaft. Involute teeth have many advantages. There is no friction in teeth, they rather roll on each other. The torque is transmitted absolutely smoothly. But there is a disadvantage – they create force that wants to increase distance between gears. This force acts to the bearings and thus leads to increased loses due friction in bearings. In watches and clocks, they use cycloid teeth. They create this kind of force too, but much, much less then in involute teeth. Also, historically, cycloid gears appeared much earlier and earliest watchmakers didn’t know involute gears. And, cycloid gears are easier to make (without CNC machines) In clocks and watches, a Wheel always consist of Table and Pinion. Table is the big gear, usually made of brass. Pinion is the smaller gear, phrased of steel. The pinion has two smaller diameter cylindrical pivots on both ends. The pivots, together with the holes in the plates, form the bearings. This is the traditional way of clock building, and it has many advantages. At least, loses because of friction in bearings this way are minimized. But, building of clocks with plywood gears is not traditional at all, so no rules here…

Hi Bob, OK, there is something wrong in the design of this thing... You have built it in the way they build some reducers, but this type of reducers usually work exactly in opposite direction – the fast rotation of weak and small electric motor is reduced to slow rotation with big torque. As I see, You use shafts that stay still, and the bearings are in the gears. Thus the size of the bearings is the same for all the gears, and gears can press each other… OK, this is not so bad, but price is too much loses. You gears are with involute teeth profile, which ads some more loses. But the main reason for You problem is that the shaft on which seats ‘scape wheel is connected hard to it and must rotate with it. Further more, on this shaft there is another wheel, that rotates with different speed. This wheel is pressed by the next wheel and creates great friction forces in shaft’s bearings in the frame and in it's own bearing… Believe me, this will never work! The most simple thing You can do is to make this shaft still as the others, and put bearing in the ‘scape wheel like in the other wheels. You must put a spring washer on the shafts to prevent the wheels from pressing each other, especially the ‘scape wheel. This means no seconds hand… But You can paint a seconds hand directly on the table of ‘scape wheel. It will rotate anticlockwise… In normal clocks, there is only one wheel between center wheel and ‘scape wheel, this way rotation direction is normal. l

Hi Paul, Can You pleas show a picture of the spring end and one of the hook inside barrel? This is a large barrel (compared to those in pocket and wristwatches) and there is no problem to form a new hook, there are different ways to do that, but let us see if this is needed or not.

OK, this is better. You have 7 wheels, I was thinking they are 18... But still, only 5 wheels are needed for building of 8-day clock. More wheels means more transformations of energy, and more losses… My English is not so good, but as I know, what You mean by 'shaft', in watchmaking is called 'pivot'. The wheel on which the chain seats, rotates very slowly, but the torque and force in bearings are great. Tre escape wheel rotates fast, the torque and force in bearings are small. In order to reduce friction losses, they do pivots and bearings on different wheels with different diameters. Usually diam. of esc. wheel pivots is about 0.6mm, and diam. of chain wheel pivots – about 6 mm. The friction in 0,6mm bearing is much less than the friction in 6mm bearing. And 6mm bearing will bear much more force than 0.6mm… The bushes of the bearings in watchmaking are made usually of brass, sometimes of phosphorous bronze. This materials have lo friction with steel, but need oiling. Plastic bushes are not traditional, their use is possible, but have in mind that most of lubricants make plastics to shrink in long periods of time. In watchmaking, lubrication is applied ONLY to the pivots, and never to teeth of wheels and pinions. No polishing by hard abrasive particles it used for pivots, as particles may charge in surface of bearings. Burnishing is the process they use on pivots. Burnishing is done by burnisher – something like a very hard steel file, but with no teeth. Burnisher surface is prepared by grinding, it must have traces of grinding, parallel to the direction of it’s movement. In the process of burnishing, almost no material is taken from the pivot, but the surface of pivot is rather ‘smashed’ and plastic-deformed, and thus, surface hardness is significantly increased. Only oil is applied on burnisher surface. To show pictures here, You need to upload them in some picture site, like postimage or imgur or so. Then copy the link to the image and paste it in the message…

Hi Bob, Yes, some pictures will help to understand where is the problem. But there is one thing that is bothering me: I red that there are 18 gears in the train??? Is this a typing mistake? See, 8 gears is too much, 18 is absolutelly out of range... Also, not only the material of pivots and bushes is important. Their size is werry important. And, in watchmaking, no polishing with sandpaper is used on pivots - thus the surface will charge with abrasive particles. You need to burnish pivots instead...

Hi, If self-winding is OK, then no need to worry. Nothing is broken, just lubrication of reverse wheels in self-winding part has dried out. A normal cleaning and oiling of movement in regular servicing will solve the problem.

OK Dell, If I understand correctly, on the first of Your pictures is the back of the chuck, and on the second – the fitting part for the arbor. If I see right, the fitting part looks as on this drawing Then the wax chuck face must be turned as shown in the drawing, this will reduce it’s thickness only by 1-1.5mm and will ensure correct centering.