Workshop Hints
Cuckoo Clock Hints
The British Horological Institute has archived and edited the following from e-mails sent to the Clock/Clockers mailing lists on the Internet. The information here does not necessarily indicate a method approved by the BHI, we are only publishing this digest so that others can decide for themselves whether the methods listed below will suit them.
From
Jim Edwards, Karen Eldred, George Evans, Murray R. Falk, Scott Fuller, John Kuntz, Peter S. Mak, Jeff Major, Ron Morris, Mike Murray, Norm Schreck, Brian E. Shaw, Jack Shows, Douglas K. Stevenson, Michael A. Webb, Chuck Wilkie, Jim Wright,
Index
| Bellows holes Replacing Bellows Recovering Bellows Music Box hints |
Replacing a Movement Replacing Hands Correct Weights |
The body of the bellow almost always has little holes usually made my the either the securing screw or the bottom securing nail. Sometimes these bellow bodies have been shifted and "remounted" so many times that the body is filled with holes. These holes will dramatically change the tone and decrease the volume of sound. Once these holes are "filled" you will notice a distinct increase in volume and a clearer more pleasing tone.
- Insert toothpicks into the holes and cut them off flush. These usually hold well with just friction but you could place a small dab of wood glue if you desire.
- Cover the whole side of the tube adjacent to the inside of the case, with a piece of masking tape. Not only does this cover the holes more quickly, but seems to have the added advantage that it improves the frictional stability of the tube against the case. Notwithstanding this, it is still necessary sometimes to plug the screw hole with a glued toothpick, if the tube has been removed many times previously.
Old cuckoo clocks can often be obtained that have been lying about for a LONG time with both bellows fully extended. While you can pull them closed, they won't stay that way. Hence the clock will not cuckoo.
- The bellows "tops" can be easily replaced today.
- You can re-cover the bellows
- The bellows "tops" can be easily replaced today. Most suppliers have bellows tops. Remove the old top and blow into the pipe to test it first. You may in rare cases have to replace the entire assembly. When you do replace the bellows tops, make sure you allow clearance for the bellow to rise without rubbing on the inside of the case. And carefully transfer all the loops and bird wire to the new bellows too. This makes a nice job. The material they use today is far better than in yesteryear.
- You can re-cover with
TYVEK which is a synthetic material used nowadays for bellows. The original material used was probably thin animal hide-rabbit skin, etc.
Antique white kid gloves which are delightfully thin material and always found around flea markets at reasonable prices particularly if slightly soiled or stained) anyway. Be aware old leather is nothing more than that - old leather. As leather ages, it gets hard and porous. Neither of these attributes are appropriate for pneumatic bellows that operates 180 times per day for weeks, months and years on end.
New leather for maximum authenticity and longevity. The correct leather can be hard to find, but it's not impossible. Two types of leather are particularly appropriate: Cambretta, a sheep/goat skin that measures about .020 inches; and Zephir skin, some kind of intestinal material which is extremely thin and totally airtight. Both are used routinely in player pianos and organs. I get mine from suppliers to these trades.
- The basic steps in recovering them:
1. Make a tracing in pencil on paper of the bellows opening width.
2. Scrape away all the old covering, glue, etc.
3. Glue a new hinge piece on the fixed ends of the two bellow pieces-the top board, and the bottom board.
4. Place a business card or two between the bellows top and bottom as the hinge glue dries. (Note: I use a white craft glue from Michael's art supply)
5. After the hinge is glued, trim off any excess from the sides.
6. Using the template you traced earlier, lay the bellows on it's side on the tracing and open the bellows to the traced size.
7. Lay a piece of TYVEK or animal skin material about 2" by 8" on the side facing up. Position it so that it will wrap around the hinge side, the side facing up, and the bellows opening end. When you have it positioned correctly, glue it down.
8. Do the remaining side, and wrap the material half-way around the hinge side. You can trim the material vee-shaped to make a neat job on the hinge.
9. Using a lolly (popsicle) stick, gently start making the creases that will eventually form the folds that will help close the bellows. Usually I start by poking the stick on the side folds first, then do the front. Gradually close the bellows as you push the stick in deeper in the folds until the bellows closes nicely. You can use a new bellows to compare the folds and creases. some of the 'old school' always moistened the creases and then clamped the bellows (or used rubber bands) overnight. This gives a clean drop. 'One may use a small brush and water'
10. open the bellows half-way and let in dry overnight. The next day, work the bellows open and close a couple of times to insure everything's OK.
11. If you are using leather, when the glue is dry, sprits the leather with plain water (not so much as to soak them or the glue may let go) then do the fold and THEN use a rubber band, leaving it overnight till dry. This works like a charm. The fold is crisp and correct and a little flexing of the bellows will loosen up the hinge to proper working flexibility..
Be careful when forming the creases not to make them too crisp. The creases are the high wear points and this is where the bellows tend to fail. If the creases are too crisp, the leaks at the creases will happen sooner than later.
The leather needs to be formed such that it "knows" which way to fold when the bellow is actuated - - but that's about it!Vola!- you have just replaced the bellows material, and you did it yourself! If it didn't turn out right, do it over. It takes a few times to get it. Do a bunch of the same size at the same time, it will give you good practice.
*TYVEK is a registered trademark by Dupont, Inc. for their synthetic, non-woven material that is used in clean-room garments, surgical wear, floppy-disk sleeves, and Fed-Ex envelopes.
- Never run the music box barrel through the cleaner.
- You can ruin music boxes by turning them backward, which snapped the teeth off of the comb.
Replacing a movement with a new movement
- when replacing a movement; save the wires from the old movement. A small thing, but it ensures that you don't have to do a lot of bending when installing the new movement to make it match the location of your bellows and music.
- With some practice, you can use a jeweller's saw to cut a pair of hands out of the ivory pieces from old piano keys. A piano-repair shop would be a possible source.
- get yourself an old soup bone and start carving! You can cut it out with a hacksaw or jewellers saw. Do it on a day when your allergies are acting up since sawing old bones is a stinky task.
- Try soaking a pair of new plastic hands in tea or coffee. These produce somewhat different tones, depending on the strength of the beverage.
- None of the replies mentioned this solution for "tinting" new plastic cuckoo clock hands:
- Paint with the proper tint of Crafter's acrylic paint. Hobby & craft stores sell it (Delta Ceramcoat) for about a $2 per bottle. It beats the ugly white. Coffee and tea staining doesn't always work for plastic, but it should for bone (or paper dials).
There are a few rules of thumb that should work regarding wights on cuckoos: Some of the earliest cuckoos with wood plates and count wheels use odd-ball weights, try to find currently available weights that will come close to what you need.
A clean and lubricated modern 1-day (30 hour) movement - 275 g; A clean and lubricated modern 8-day movement use 1 kg or larger weights, 1.2 kg (1200 grams, 1.5 kg (1500 grams) up to about 2200 grams.Some modern movements, like the 1- day with quail come with 320 g weights. My personal definition of "modern" is "rack strike system".
The Herrs use 320-420 gram weights.
Antique cuckoos seem to take a lot more weight. I recently inherited one (believed to be 1920's or before) that's a 30-hour but has HUGE weights - about 1950 grams.
Probably the most important thing for you to consider is it's condition. If the movement is dirty, dry, or worn it'll need to be properly cleaned and repaired before you even have to worry about how much weight it needs. That's been my experience with "flea market" or "hand-me-down" cuckoos!
The best way to test the proper weight is to use a small cotton drawstring bag and fill with buckshot (lead-shot). Use a kitchen food scale or small fishing scale to measure the weight of the bag. Start at the low end of the scale, say around 250 grams and try the clock with the bag on the chain hook. If the clock runs, and the strike speed sounds about right, then you have the proper weight. You can add about 10-20% more weight for good measure. On some cuckoos the music box weight is slightly less.
You might also get a copy of Karl Kochmann's book "THE BLACK FOREST CUCKOO CLOCK". The book does devote about five pages to identifying cuckoo movements, with their correct weights. However, one small disclaimer. I have a 1983 printing, which has the plate indentification section, and a newer printing, which does not. I believer the 1993 printing was the last to have it. The earlier version is titled "The Black Forest Cuckoo Clock", while the later is titled "The Black Forest Clockmaker and the Cuckoo Clock".
