Checking the Bellows The one part of note because of its expense is the bellows also called the motor. It is the large round "bowl shaped" object on the back of the clock. The current replacement cost that I charge is $250.00 (if needed). A refill of your old bellows costs $150.00 and can be done about 80% of the time and keeps the clock 100% original. Many on the Internet have advised people to place the entire clock is a freezer for a few minutes. Please don't ever do this because that exposure will leave either water vapors or droplets on everything and will eventually rust all the moving steel parts. The bellows winds the mainspring. Before you test the clock make sure that the clock has power by letting the clock be exposed to some temperature fluctuations (5 degrees Fahrenheit or more) over the next few days. This will wind the mainspring if all is okay. These temperature changes will cause the bellows to expand and contract therefore winding the mainspring. The bellows power is passed on to the mainspring via the brass chain that you see at the roughly center of the movement. When the bellows is good it contains sufficient gas (ethylene chloride I was told) to exert pressure on the chain (indirectly). The following check MUST be done at 68 degrees Fahrenheit. The chain comes out of the bellows chamber (the large round bowl like piece) and makes a left turn (as you face the clock) around a pulley. It continues to travel around to a second pulley. This second pulley is the one which is actually attached to the mainspring arbor and the chain end makes a counter-clockwise wrap around this second pulley. The result should be that the chain end is now underneath the second pulley. If the chain end is resting on top of that second pulley then the bellows is flat (or you live in a freezer) and therefore needs replacing. Anywhere in between the bottom position (roughly 6 O'clock) to the top position (roughly 12 O'clock), the bellows has lost some gas and it MAY have enough gas to continue the wind the mainspring. The closer the chain end is to the bottom position the better. The best way to see if the bellows is good is to take the bellows chamber off the clock. The chamber is held in usually by two or four brass nuts. I use a 5/16" closed end wrench to remove these nuts and they are actually 8mm but either will work fine. A word of warning here because the above mentioned chain is attached to a fairly strong spring and that spring will "push" the bellows chamber away from the movement as you remove these nuts. On the caliber (model) # 540 the bellows chamber is removed by exerting a counter-clockwise (bayonet fitting) turning pressure with your hands and be sure to turn the "inner" part of the drum. In other words turn as close to the frame as possible. Once the bellows chamber is removed you measure the depth from the top lip of the bellows chamber opening down to the top of the actual bellows. This will be obvious once you have the bellows chamber off the movement. Do NOT remove the bellows itself for this measurement. At room temperature the depth should be between 22 to 26mm, if the depth is 26 to 32mm then the bellows is questionable but should still provide years of service. Anything over 32mm the bellows must be replaced because that means that there is no gas contained within the bellows. The "real" check is how many winds on the mainspring. If the mainspring has 4 or more turns then the bellows are doing their job regardless of their depth. For the caliber 540, the depth should be between 20 to 24mm, and 24 to 30 for a questionable bellows. Anything over 30mm should be replaced. Again the check, for the 540, is at disassembly and the turns on the winding wheel or ratchet wheel (both turn at the same rate) and not the mainspring. The winding wheel should have at least 3 turns, which translates into 9 turns on the watch like mainspring inside the barrel. As a final check to make sure the bellows is indeed okay, you can place the entire bellows chamber in the freezer for about three to five minutes. If the bellows is good it will collapse to almost flat which would give you a measurement of about 40 to 44mm. Or you can place a piece of ice on top of the bellows and is should begin collapsing within about 15 seconds. In either case above do NOT allow the bellows to be exposed to the cold any longer five minutes because you can damage this very expensive piece. Return to Index Replacement The bellows or "motor" contains the following: 1) Motor knobs (either two or four nuts); Part # 3519. 2) Motor protection plate; Part # 3546. 3) Coil spring (70mm); Part # 3547 4) Metal (brass) drum; Part # 3580 5) Bellows; Part # 3581 6) Drum cover; Part # 3582 In order to replace the old bellows for a new one you first remove the entire "motor" or bellows chamber (see above). There are either two or four brass nuts which hold the motor to the back of the frame plate. I use a 5/16" closed end wrench to remove these nuts. A word of warning here because the above mentioned chain is attached to a fairly strong spring and that spring will "push" the bellows chamber away from the movement as you remove these nuts. On the caliber (model) # 540 the bellows chamber is removed by exerting a counter-clockwise (bayonet fitting) turning pressure with your hands and be sure to turn the "inner" part of the drum. In other words turn as close to the frame as possible. To remove the old bellows you must make sure it is fully compressed. An old bellows with all of its gas leaked away will measure about 40 mm from the top of the metal drum to the top of the compressed bellows. Most usually have some gas (ethylene chloride) remaining. Therefore you must compress the bellows yourself. Some place the chamber into the refrigerator but I like to use ice cubes. Usually one ice cube is enough to fully compress the bellows in about a minute. Once it is compressed, push down on the drum cover (part # 3582) to loosen any bonds that may have formed on that cover and the coil spring (part # 3547). On the caliber 540, once the bellows chamber is removed from the frame, the bellows casing has a bayonet fixing in which both halves must be turned in opposite directions, with the back of the drum moving counter-clockwise. Use an ice cube to collapse the bellows when both removing and installing. Once satisfied that the coil spring is "flexible" then push down on the drum cover and turn it in either direction until the four (4) tabs are fully exposed from under the four (4) tabs which are located on the metal drum. Caution should be used because of the tension in the coil spring. This tension will make the drum and the cover separate rapidly unless you supply the "containing" force so they do not spring apart quickly. The rest should be common sense and you do exactly the opposite in order to place the new bellows inside the motor starting with the ice cube. Return to Index Suppliers of Atmos Parts The following is a Web site that explains how the independent repair person can obtain Atmos material and part supplies.Return to Index Replacing Soldered Bellows I have a file for replacing the older soldered bellows without having to desolder. It's located at Bellows.doc a Microsoft Word file, or Bellows2.pdf an Acrobat file. Return to Index A service from, E-mail address: Mike@atmos-man.com Mike Murray Founder of Clocksmiths A specialist in Atmos and 400-day clock repair. Also, I overhaul most plug in electric clocks. In continuous service since 04/01/1982. Mike's Clock Clinic Memberships: AWCI, Clocksmiths, & NAWCCObtaining Atmos Parts
Return to Index Manual Winding There are several ways to manually wind the Atmos. By far the best way is to remove the metal drum (part # 3580) which contains the bellows (part # 3581). Once it is removed you will see a coil spring (part # 3494) with a brass chain (part # 3491) running through the middle and attached to the end of the chain with a brass cap called the spring guide (part # 3493). This is all held together by a bent steel straight pin called the chain stopper (part # 3492). In order to wind the mainspring properly you simply become the bellows. Push the coil spring in toward the movement until it will not compress any more. Then remove you hand and the coil spring will try to go back top its original position. This going back to the original position is the actually winding taking place. By pushing in the coil spring, the clock "prepares" for the eventually going back or winding. This is similar to a pocket watch where one direction actually winds the watch and the opposite direction allows you to go back to the previous position to wind it again. The reason I like to use the above method is because the combination of the coil spring and the bridled mainspring does NOT allow for over winding. So once you have compressed the coil spring and it does not "recoil" back to the original position, the clock is fully wound. A fully wound clock should run for about 14 months, with about 7 or 8 of those months having enough power to run accurately. After that the time keeping tends to deteriorate. If the Atmos still does not run after manual winding, please be sure to tell the person you are going to hire to overhaul the clock. The reason is that a marginal bellows will probably not be replaced if the repair person counts a "healthy" wind on the mainspring. If wound properly, either by the bellows or by hand (removing the bellows and pushing the coil spring), which was described above, then the amount of running time totally depends on the caliber. All of these will vary by as much as 4 months but a caliber 540 will run anywhere from 10 months to 14 months. A caliber 528/526 will run anywhere from 14 to 16 months and a caliber 519 and the Atmos II will run anywhere from 15 months to 2 years. All of this has to do with the quality and length of the mainspring. And of course the actual condition of the movement and frame will change these numbers. Some choose to wind by turning the chain and spring pulley (part # 3486). That method is not controllable and you can wind it too little or too much. Too little will not hurt anything but too much and then the clock can have too much power and the balance may over swing causing the clock to run fast because the roller will hit the fork on the opposite side and that will limit the "natural" swing. The general clock terms this is called over swing. Another danger of winding this way is that the "stopping pin" that secures the chain to the "chain stopper", which is the cap of the coil spring, may become dislodged and the chain will eventually lose its tension and if the bellows still has some gas left, then there is no way it will wind the clock. So please don't be lazy and try to wind by pushing the chain and spring pulley. Return to Index Refilling Atmos Bellows Many times a dead or marginal bellows can be refilled. I have a contact that I have used and I'm very pleased with the results. Jeffrey Kitz 531 N. Main Street Oshkosh, WI 54901 920-233-1757 E-mail address: kitztech@vbe.com Web address: http://www.kitztech.com/bellows.htm Purchasing Spent Bellows for Refilling You can order a "spent" bellows that will date within a year of your original bellows. For just an old bellows without refilling, the charge is $60.00 including shipping. This may come up when Jeffrey cannot refill your original bellows and you want to have bellows that closely match the original date of manufacture as close as possible. You must be aware that there is a 20% failure on refilling used bellows. Therefore, I cannot guarantee that your bellows refill will be successful. If you prefer, I can send the spent bellows directly to Jeffrey or ship to anywhere in the U.S.. This breaks down to $50.00 for the bellows and $10.00 for the shipping. Shipping out of the U.S. will be higher. You may use Pay Pal by clicking on the link below:
17000 S. Western Avenue # 7 Gardena, CA 90247-5262
Phone: 310-225-5645, or 877-286-6762
My Web site is located at http://www.atmos-man.com/
Main FTP site is located at http://home.earthlink.net/~atmosman/earthftp.html
Memberships: AWCI ; Clocksmiths; NAWCC
N.A.W.C.C. Chapter # 75 "The San Fernando Valley"
N.A.W.C.C. International 400-day Clock Chapter # 168
Published in Chapter 168's "Torsion Times"
Published in AWCI's "Horological Times"
AWCI's 400-day (Anniversary) clock Bench Course Instructor!