Family owned cuckoo clock, disassembly assistance please.

btb67

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I have a vintage cuckoo clock owned by my family since new and just a few months younger than me at 67 years old. My parents bought it in 1953, and now both are no longer with us, its in my ownership now and I've decided to strip it down, clean, and repair as necessary. It hasn't run for about 30 years, but always been on the wall back home.

I've done a lot of reading, learning both in this forum and many instructional videos on YouTube, and feel ready to tackle the job.

Now I've began to open the movement I've come across the first of which will no doubt a few questions as I progress, if I may. One of the chain wheels, has a cog on 'the other side' of the front face plate, and I can't see how to free it from the pivot to remove the wheel. There doesn't seem to be any clips, and I'm wondering how to remove it. I've attached a couple of pics that should show what I'm describing.

The movement has 'Forestall' engraved on it, its German, but not one of the usual makes from what I can tell.

Any guidance would be much appreciated.

20210913_145729.jpg 20210913_150020.jpg
 
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Schatznut

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Without seeing the rest of the movement, I'm assuming the small spur gear drives the count wheel on the strike side. It's pressed onto the arbor and will be very difficult to get off without damaging it or the back plate or both. You may be able to get away without removing it at all if you can get everything clean enough and there's no appreciable wear in the hole. Start by soaking in mineral spirits and scrubbing away all the oil and crud you can. Soak in Evaporust or similar to get rid of the corrosion on the ferrous bits. Then clean and dry carefully. Once everything is shiny and unstuck, you can determine whether it has to come apart or not. If it does, soak it liberally with good penetrating oil and let it sit for a couple of days. Get a couple of paint can openers from your local hardware store and grind down the tips so that they'll fit under the edges of the spur gear. Then very gently apply even upward pressure to the gear. Probably best to cover the whole thing with a cloth while you're prying in case the gear comes off suddenly.
 
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btb67

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Thanks for the guidance.

I've had it soaked in ammonia based clock cleaning solution for a few hours along with all the other parts, and checked for pivot hole wear as you've suggested. There is only minute play, the hole still appears to round and the ratchet works, so I'll leave it in place.

Good tip about using a chemical rust remover, thank you.
 
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RJSoftware

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Typical problems on these clocks are the main wheel aka chain wheel clicks. The clicks create one way action for rewinding/raising weight up. When the click fails the weight falls pulling chain to floor. Some cuckoo clicks are worse than others, one in particular isn't even a click but is simply a spring wire wrapped around arbor that tightens in one direction and slips in other, worse design ever..!

The bushings/pivots hardly ever ware on these. I think it's because most are not 8 day runners but 30 hour (wind up daily). Though easy to wind, simply pull the chain, people get tired of daily winder. So they often just hang unused.

The more problematic are ones with music/animation. The key component that fails on them is in the music box. Many use a tiny plastic gear that drives the worm gear which pushes the fly which catches air to regulate the speed of the pinned cylinder that "twangs" the comb teeth of the music box component.

When the music box fails the clock eventually comes to a binding stop as levers from music box that normally get set up for next sequence fail. This all due to that little plastic pinion that drives the music box worm gear. The gear is pressure fit on arbor and after some years the plastic splits causing a hairline crack. The gear is so high on music box train (train= series of gears) that the tiny split interferes with consistent operation. This intermittent problem fools many a repaired into false victory to find recall. The trained ear hears the tiny click click click.. of the plastic pinion split.

If it is music box best solution is replace, pay attention as different models wont adapt. Also customer might object to different tune, or not.

A lot of cuckoos with mb wind up in limbo land because mb are expensive.

Yours is probably all original. But often weights have been swapped out. The attempt to power through problem components with extra weight makes cuckoo weights the most migratory part of the clock. Doesn't work either.

Chain links stretch as owners tend to yank the chain downward in a hurry. Restoration is one by one squeezing each link back closed. Sometimes a replacement chain is poorly selected and intermittently slides over chain spokes to floor.

The bellows arnt that bad to repair.

Basically give it a good cleaning, skip pulling difficult pinions like the count wheel pinion, oil and test for reliability. If you really needed to there are pinion pullers you can find on ebay.

Lots of little gotchas with lever adjustment. Lifting bellows too high binds movement, too low small chirp. Bird door flaps after each cuckoo chirp or binds. Door is supposed to stay open till all cuckoo chirps are done then rudely slam shut..! All of these are lever adjustment.I

Vinegar used in ultrasonic cleans rust in seconds. Ultrasound is good investment. Get one big enough to do carburetor too.

Good luck
 
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Robert Horneman

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The small gear on the chain wheel is easy to remove. Put the plate in a vice so the wheel is down and is not tight. use a small punch and tap the wheel off the gear.
 
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btb67

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Thanks both for the extra information.

RJSoftware That is so much useful advice. I think this one will OK once put back together. As you say hardly any play in the pivot holes, all are round and appear unworn.. The ratchet mechanism looks good, a sprung wire that puts pressure a cam which locks in the castellations in the other part or or not depending on direction, doesn't seem worn.

Should the ratchet be lubricated with anything?

Also where I've removed the rust and corrosion on the steel parts should I lightly coat them with anything?

The cleaned up chain wheel looks better, photo attached, this is where I'm wondering if I should lightly coat to keep further corrosion from coming back?

The bellows are good, and the lifting levers and gong lever seem to be positioned properly.

If I decide to make a hobby of this an ultrasonic cleaner will be on the shopping list.

Robert Horneman Thanks for the advice, I don't need to do that this time, but good to know how to go about it anyway.

20210914_142149.jpg
 

btb67

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Thomas Sanguigni Looking very closely with a loupe I can't see a wire or peg, but there is evidence that its been 'hit' or 'pressed' just above the cogs to squash it on.

You can just make it out in the photo, there is a matching mark on the opposite side

. 20210914_150238a.jpg
 

Schatznut

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Re rust preventative, I recommend a quick shot of Starrett M1.
 
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RJSoftware

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After I treat rusted with vinegar in u.s., I rinse with water then rinse in amonia bath. The vinegar is acidic and amonia is alkaline/base. They cancel each other out. However, I am of the opinion that the vinegar and u.s. probably causes metal to become more porous. So I dunk parts over night in regular car motor oil. Then u.s. with dish soap & water. Then isopropyl alc bath to absorb residual water, then hair dryer. Then standard clock lube on bushings with dip oiler to minimize oil. Too much oil attracts dirt which eats pivot/bushings.

I want to warn you about the vinegar & u.s. as it can be extremely aggressive. The more delicate the rusted parts the shorter the duration should be. Some watch parts I do only 5 to 10 seconds. The trick is to get two parts connected to move again. Once movement is restored regular water and back and forth action can restore action with minimal damage.

This trick I learned many years ago as electrician. When working some construction jobs required working in rain. Tools like lineman pliers would get soak, rusted and then neglected. The typical solution was to treat with penetrating oils, wd40, etc.. But what I found that worked like a miracle was just using water and working the pliers back and forth. It ia amazing to watch the water penetrate and rust oozes out. The pliers once again swing wide open with no effort. My thinking is the rust probably still retained moisture that creates a barrier in the tighter parts of the joint. That is why the water suceeds shere others lack. Plus it's free.

The alcohol is interesting to me how it cross boundaries between oil, gas and water. I probably will have to put some gas dry in my 93 Miata tank. Went gas shopping now I gots the sputters. I should have known 10 cents cheaper a gallon had a cost.
 
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RJSoftware

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High fructose, hard on the liver. The liver is only organ that converts it to usable sucrose. It causes insulin resistance and fatty liver disease and non alcoholic cirrhosis. It's epidemic in the states. Main contributor to type 2 diabetes. It's nearly in every food. Made illegal in some countries so I hear. In the states they have the right to rename it so consumers have harder time knowing.
 
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btb67

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Many thanks for the replies and tips, I've read and taken all advice.

I have citric acid powder around for various uses and find it good for rust removal, making up a weak solution with a few grams in 200ml of water and an overnight soak, followed by a proper rinse and clean, good tip to neutralise the acid with an alkaline solution though. IPA is good to keep around too, agree with you.

I can see the purpose is to properly clean, remove any rust and not to leave the metal parts compromised, but able to naturally withstand corrosion in a normal home environment..which may be different according to your location of course!

I haven't drank any kind of cola for many years now!

Thanks again for taking the time to help and advise me.
 
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Mike Phelan

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High fructose, hard on the liver. The liver is only organ that converts it to usable sucrose. It causes insulin resistance and fatty liver disease and non alcoholic cirrhosis. It's epidemic in the states. Main contributor to type 2 diabetes. It's nearly in every food. Made illegal in some countries so I hear. In the states they have the right to rename it so consumers have harder time knowing.
RJ, we avoid any of the ready-made meals in supermarkets here - market stalls abound in the north of England, so fruit and veg are good and cheap.
 
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RJSoftware

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A bit more about the ulrasonics fyi.

Utrasonics are great..! Probably one of the best tools for watches and clocks of this erra. But, there are some gotchas.

First, purchasing a genuine ultrasonic. There are improperly named jewelry/gem cleaners that are not ultrasonics. They usually posses an electric solenoid or two. These do not produce waveforms that genuine ultrasonic do. The frequency has to be above a certain threshold to produce the desired effect called cavitation.

Cavitation is the secret workhorse of the ultrasonic. This, to my understanding is microscopic implosion bubbles. I don't really understand it, seems to border on the insanity of.Quantum physics, but I digress hey.! The genuine ultrasonic use ceramic piezoelectric speakers not coiled wire solenoids.

Dials.

Ceramic does fine, of course paper dial does not. But be careful of surprise decals found mostly on watch dials and some clocks. Yep, they magically just float off the dial. There goes maker logo, name, chapter ring, digits and various significant dial indicators. No way to reattach.

Plates.

For most part ok. Most plates are brass and does great in amonia based solution with soap and water. Ammonia effect on brass really shines it up. But beware of shellac on brass plates. This is put on by manufacture to keep brass from tarnishing/oxidation and turning brown. Clocks with exposed movement do this.

The ultrasonic with ammonia does a poor job on shellac plates/parts as the shellac gets comprised but does not fully come off. What you wind up with is a clock that shellac flakes fall off and into the gears. I say shellac, but really uncertain as shellac is supposed to dissolve completely with denatured alcohol. Sometimes for me, even that fails. Persistence seems to work. Maybe another chemical stripper..?

Vinegar.

The vinegar and water solution works wonders but can turn some metals black or discolored. Test alternative parts for reaction if you can.
Vinegar with Q-tip or Iso with Q-tip can do wonders on cleaning metal dials. But be careful on decals. Just avoid them.

Naptha.

I do it but don't recommend. Why? It's an ultimately superior parts cleaner for watch parts especially. I do not fill tank with naptha but use small jar and fill tank partial with water to transmit waves into jar. But could be fire and toxic hazardous.

Immersion.

The best is full tank immersion. But sometimes using a small jar can suffice. Water can be filled in tank to transmit waves into jar and the level of water in tank adjusted so jar rest on tank bottom.

To simulate full immersion the jar can be tilted so part rest on corner of jar bottom to further reduce cleaning fluid required. Ex. using naptha. To angle jar a small wad of toilet paper under one side sitting in tank water holds jar at angle.

The ultrasonic can be a disaster on dials Especially watch dials. Ceramic are no worry, but be careful with metal ones.

RJ
 
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