Clutch Mechanism on G.K. Movement, Cuckoo Clock Minute Hand

[Mick Mickle]

I joined the NAWCC and forum just to post this question for advice from very talented and experienced folks here: Is there any way that I can fix or replace this particular gear on my cuckoo clock that's supposed to allow the minute hand to be manually set by slipping its engagement with the train?





I can set the minute hand now by removing the outer nut and pulling the minute hand cannon out just enough to disengage the gear, but that is a lot more complicated for making time adjustments than it should be.

As I hope you can see from the attached photos, the gear in my clock's movement has been repaired with a soldered or brazed curved piece of metal with a square hole to interface with a square base on the pivot. Unfortunately, it doesn't ever slip on the square connection, or if it does because it's not pressed in far enough, it simply doesn't connect at all. Also, the pivot isn't long enough to have a way to clip the gear in place to provide pressure against the movement frame like most photos of other similar movements I've seen (not to mention that, as described above, there's no spring or other clutch mechanism that I can ascertain).





The retrofitted gear that came with the clock and is pictured here also has some odd grooves cut into the back. I'm thinking they may have been detents for an earlier tension spring. BTW, when I first removed the clutch gear, it had a very small tubular section that fit on the shaft between the brass gear and soldered metal piece with the square hole. I thought it was brass until it basically disintegrated like paste or 90-year old plastic. I don't know what it's purpose would have been except perhaps to hold the gear tight on the pivot shaft.

Also, if you look carefully, you can see that there was a desiccated large spider and web on the backside of that gear from sometime after WWII.


This clock was from my mother's family, made in 1905, and it has two repair dates of 1927 and 1946 penciled inside the case. As far as I can tell from my research, it's a George Kuehl clock with the G.K. movement. It was in rather sad shape, but I carved new bone hands, temporarily patched the bellows, and otherwise restored it to condition in the attached photo. Except for the clutch problem, it works very well, keeping pretty good time. I've yet to see a picture or a description of how the back of that specific G.K. wheel is supposed to look and work with the square base of the pivot.




Photos I've seen of some Regula movements look like the clutch gear "could" be interchangeable with the G.K. part. However, I haven't seen that particular gear for sale, and I don't know about the gear size matchup. (Sorry that I'm not sure of the proper name for that gear. I believe I've seen it in one book referred to as a reverse minute wheel.)

As I mentioned, I've done a lot of research on the Internet, and the majority of my best search hits come back to this forum. So I'm hoping some of you have some good answers. Thanks for reading, and thanks for your assistance!

Mick

 

[FatrCat]

Season's Greetings, Mick-
Wish I could say I was about to be a big help to you, unfortunately I'm not very familiar with the cuckoo family and how they operate. But in passing and taking a look at your post I just couldn't walk on out the door without stopping to say how nice it is to see the U.S. Dollar does still have some value, lol. A bellows patch. . . . now there's one you don't see every day! Wasn't there a sign on the oval office desk once that read "The duck quacks here" ? Great minds. . . .

Best of luck with your project

 

[howtorepairpendulumclocks]

It looks like you have what to repair the friction work. The "boat" or "bow" (oval) spring and the wheel (its called the minute wheel confusingly even though it doesn't carry the minute hand...) should be seperate components. First step is to remove the solder. Hopefully it is soft solder and not braze... Soak a natural bristle in water, a clockmakers Glasgow brush is good but paintbrush will do (must be natural and not plastic bristles), GENTLY heat the assembly with a spirit lamp or very low flame until the solder just melts, brush away the solder. You will need heat-resistant safety goggles and safety gloves for this operation. An alternative if you know someone who does electronics is to use solder removing wick. Once the components are separated, you are nearly there! Remove as much solder as possible. Next step is the arbor on which the assembly fits. Do you think the end has broken off? If it has you will either have to cross drill a small hole for a taper pin. Maybe the hole is already there The 'clutch' or friction work works by the spring being compressed slightly. Friction between the tips of the spring and the face of the back of the wheel is all that is necessary. For now, ignore the grooves cut in the back of the wheel. Hope this helps. Have a look for that small cross-drilled hole. I can do a drawing if it helps. Let me know.

 

[shutterbug]

Yes, unfortunately you won't find any parts for your movement unless you can find a used movement on Ebay or similar site.
As mentioned by howto, the clutch needs to slip. Whoever soldered it tight did not know a thing about clocks, and was guessing at best. Get that solder cleaned off and lets hope the spring has not been annealed. But if it is now too weak to provide good tension to the minute hand, you can make a new one out of a piece of mainspring.

 

[new2clocks]

Welcome to the forum.

As far as I can tell from my research, it's a George Kuehl clock with the G.K. movement.

You are correct.

Photos I've seen of some Regula movements look like the clutch gear "could" be interchangeable with the G.K. part.

George Kuehl, of Chicago, was a large importer of clocks, many of which were cuckoos. Although we have seen advertisements from Kuehl that they were "importers and manufacturers", I do not believe it has been established that Kuehl had a manufacturing facility. The common term used for clockmaker in Germany, Austria and Switzerland was Uhrmacher - but this term encompasses the whole supply chain for clocks, such as manufacturers, retailers, wholesalers, etc. Kuehl may have utilized this German definition of clockmaker in declaring himself a manufacturer, but this only conjecture on my part. Therefore, it is quite possible that the movement could have been manufactured by one of the large cuckoo movement makers, of which Regula (the tradename of J. Burger & Söhne) was one.

Regards.

 

[Mick Mickle]

Season's Greetings, Mick-
Wish I could say I was about to be a big help to you, unfortunately I'm not very familiar with the cuckoo family and how they operate. But in passing and taking a look at your post I just couldn't walk on out the door without stopping to say how nice it is to see the U.S. Dollar does still have some value, lol. A bellows patch. . . . now there's one you don't see every day! Wasn't there a sign on the oval office desk once that read "The duck quacks here" ? Great minds. . . .

Best of luck with your project

Haha, thanks for the comment! I used a fresh one dollar bill with Elmer's white glue to get back the "coo" in cuckoo. (I did have to dab a little rubber cement in one stubborn tiny cease on the front side.) I credit other threads and users on this forum for the idea. Among suggestions of Tyvek, burger wrappers, and well worn $ bills, I decided on a new $ -- it is just a patch, after all. (I've been carrying the remainder of the dollar bill in my wallet since I cut the corner out. I never see it's there because of the missing corner.) I ordered new leather for recovering the bellows, but I'll wait until it's "broke" again.

Yeah, I think I remember a saying similar to that: Truman in bygone days.

 

[Mick Mickle]

It looks like you have what to repair the friction work. The "boat" or "bow" (oval) spring and the wheel (its called the minute wheel confusingly even though it doesn't carry the minute hand...) should be seperate components. First step is to remove the solder. Hopefully it is soft solder and not braze... Soak a natural bristle in water, a clockmakers Glasgow brush is good but paintbrush will do (must be natural and not plastic bristles), GENTLY heat the assembly with a spirit lamp or very low flame until the solder just melts, brush away the solder. You will need heat-resistant safety goggles and safety gloves for this operation. An alternative if you know someone who does electronics is to use solder removing wick. Once the components are separated, you are nearly there! Remove as much solder as possible. Next step is the arbor on which the assembly fits. Do you think the end has broken off? If it has you will either have to cross drill a small hole for a taper pin. Maybe the hole is already there The 'clutch' or friction work works by the spring being compressed slightly. Friction between the tips of the spring and the face of the back of the wheel is all that is necessary. For now, ignore the grooves cut in the back of the wheel. Hope this helps. Have a look for that small cross-drilled hole. I can do a drawing if it helps. Let me know.

Great information -- thank you! I'm so enjoying gettng used to the sounds of tick-tock and cuckoos while watching Christmas movies that I guess I'll wait till next week to take the clock of the wall and dig in.

I will remove the solder as you recommended. Even if the friction spring doesn't work or I can't find a replacement, I guess the worst case is that I can epoxy the spring back to the wheel to get back to where I am now. So we expect this soldered steel piece is perhaps the spring-steel friction part designed for this minute wheel? When or if it is working properly, the square hole and square base of the arbor are always connected, but the two ends - or tabs - of the steel strip (bow spring) allow slippage against the brass wheel when the minute hand is moved manually, correct?

I looked earlier for a hole in the arbor but didn't see one. The end of the arbor doesn't look broken. But I'll examine all of it more closely soon. Assuming it's not broken, it seems too short now, but do you think maybe when the spring is released from the solder, the wheel will be able to be pushed down enough to clip a pin to keep pressure on the spring?

Thanks, again. I'll let you know how it goes.

 

[howtorepairpendulumclocks]

Yes it looks fine. Yes correct. There are two systems, one with a Rond hole at the centre of the spring and like your with a square hole. the latter provides "more friction" because it is operating at a greater radius. Yes, once the two components are separated, the spring can be compressed revealing more of the arbor. If the arbor is not broken off, the hole will be there! I think the spring will be fine. As another contributor says, you can make one from mainspring or in my experience, work-hardened brass is easier and works well. Oil the tips of the spring where it touches the back of the wheel. If you need a bit more friction to drive the hands, put a thin washer on top of the minute pinion head to increase the compression of the spring.

 

[Mick Mickle]

Yes it looks fine. Yes correct. There are two systems, one with a Rond hole at the centre of the spring and like your with a square hole. the latter provides "more friction" because it is operating at a greater radius. Yes, once the two components are separated, the spring can be compressed revealing more of the arbor. If the arbor is not broken off, the hole will be there! I think the spring will be fine. As another contributor says, you can make one from mainspring or in my experience, work-hardened brass is easier and works well. Oil the tips of the spring where it touches the back of the wheel. If you need a bit more friction to drive the hands, put a thin washer on top of the minute pinion head to increase the compression of the spring.

It sounds like my problem might have a promising outcome. Thanks, I appreciate the help! I'll post feedback next week or soon afterward.

(So many things are becoming more clear to me now as I better understand the terminology of the parts. For example, I found it difficult to see how increasing friction on the "minute wheel" - in advice in other threads - would help when I erroneously thought the minute wheel was the arbor/gear that the minute hand was actually attached to.)

 

[Mick Mickle]

Yes, unfortunately you won't find any parts for your movement unless you can find a used movement on Ebay or similar site.
As mentioned by howto, the clutch needs to slip. Whoever soldered it tight did not know a thing about clocks, and was guessing at best. Get that solder cleaned off and lets hope the spring has not been annealed. But if it is now too weak to provide good tension to the minute hand, you can make a new one out of a piece of mainspring.

Thanks for the tips! I have recently seen movements on eBay being auctioned by the lot for somewhat reasonable price range, and some appear to have a minute wheel that's similar to mine. But, no dimensions were indicated, so I was leery to consider acquiring any for parts. I know that cuckoo clocks come in smaller and larger sizes than what I have. Do you think the majority of old cuckoo clocks scrapped for parts would be around the size I have? I'm just trying to weigh the odds of getting anything I can use.

BTW, I have you to thank in part for the dollar bill patch. It's not only effective so far, but also a novelty.

 

[Mick Mickle]

Welcome to the forum.



You are correct.



George Kuehl, of Chicago, was a large importer of clocks, many of which were cuckoos. Although we have seen advertisements from Kuehl that they were "importers and manufacturers", I do not believe it has been established that Kuehl had a manufacturing facility. The common term used for clockmaker in Germany, Austria and Switzerland was Uhrmacher - but this term encompasses the whole supply chain for clocks, such as manufacturers, retailers, wholesalers, etc. Kuehl may have utilized this German definition of clockmaker in declaring himself a manufacturer, but this only conjecture on my part. Therefore, it is quite possible that the movement could have been manufactured by one of the large cuckoo movement makers, of which Regula (the tradename of J. Burger & Söhne) was one.

Regards.

Thanks for the information. It gives me a bit of optimism that I can explore on speculation whether some other movement parts might fit.

 

[howtorepairpendulumclocks]

If you can, stick to parts that are with your clock. Not only from an originality perspective, but parts that appear similar are often not and will just cause you more problems.

 

[Mick Mickle]

If you can, stick to parts that are with your clock. Not only from an originality perspective, but parts that appear similar are often not and will just cause you more problems.

Got it. Also now that I understand how the friction spring and minute wheel were supposed to function together, I'm thinking that the grooves cut into the back of the wheel (which you said to ignore for now) were an attempt to get better friction connection to the train before taking the nuclear option of soldering. That must have been a big problem for this individual clock in the day. Hopefully, increasing compression with a washer shim, if needed, will be enough to have it work properly.

 

[howtorepairpendulumclocks]

Yes indeed re nuclear. The notches are unnecessary but hopefully the hand setting will not be too lumpy with them there. If they cause a problem you could cut a disc of brass shim material to go between the back of the wheel and the tips of the spring. All good fun!

 

[Mick Mickle]

Have a look for that small cross-drilled hole. I can do a drawing if it helps. Let me know.

Sure enough, the hole is in the arbor. It was completely filled and covered with waxy residue until I poked through it with a fine needle.

First step is to remove the solder. Hopefully it is soft solder and not braze.

Yep, it was just solder. And the spring is still "springy." Question: Should I file the spring tips to a more even roundness or other shape? The tips look a bit sharp and jagged now, and with a very slight twist. I don't know what it looked like originally, but I would expect the current condition to wear the wheel more than it should. (Of course, I understand friction is necessary.)

I'll clean it up better. Also, I got a small sheet of .01" (.25mm) thick brass, so I thought I would start with a layer on the back of the wheel for smoothness.




BTW, totally separate question. How much radial play is normal for the minute hand when tight on the arbor and fully engaged with the movement train? I get about 2-3 minutes of play on the dial when I touch the minute hand.

Happy New Year!

 

[howtorepairpendulumclocks]

It is looking great!!! Personally, I would see how it goes and leave the spring as it is for now. The brass shim should do a good job between the tips of the spring and the back of the wheel. You will need a bit of oil on each spring tip. I think what you are describing with the hand is ‘backlash’?, free play between the gears? If I have that right? Dont worry about it. It is either there from new and or wear. When you set the clock running, first set it slightly ahead of time then set it back to the right time. This will “remove” the back-lash. All gears like this have it to some degree. If i’ve gotten the wrong end of the stick, let me know. Looks like you are winning!!! Well done.

 

[Mick Mickle]

Yes, backlash is what I meant. Thanks for that info and advice.

I'll try the spring like it is, as you suggest, and go ahead and put it together in the next few days. (I pressed a little too hard on the minute wheel and popped a couple of screws holding the movement -- well-used holes + shallow-threaded old screws. While I was thinking about whether to fill the holes with a matchstick wedge or other means, I realized this movement has adjustable mounting points, so the same holes don't have to be used.)

 

[howtorepairpendulumclocks]

...true, the same holes done HAVE to be used but nice if they could be. as you say, plug-up the holes with a piece of wood and some hide glue if you have it. You may then need a fine drill to form a pilot hole but at least the components don't end up looking like colanders... ) Sounds like you are making brilliant progress!

 

[shutterbug]

If the spring got too hot, it may be annealed now. Test if for springiness before you trust it. To rejuvenate a spring, heat it to red hot and quench it. Then drop in into enough motor oil to cover it, light the oil and let it burn out and cool. Should be back to normal then. Do that last part outside please

 

[Mick Mickle]

at least the components don't end up looking like colanders...

Well, since you put it that way, I'll avoid the sloppiness of making Swiss cheese out of the inside of the case.

 

[Mick Mickle]

Test it for springiness before you trust it.

If I press the spring with my thumb against the back of the wheel, I can see it compress and the ends spread a little against the brass. (It takes significant pressure to to that.) When released it regains its previous state. But maybe while I've got it out, I should rejuvenate so there's no doubt. Thanks for those instructions.

 

[shutterbug]

Just to clarify, the oil bit at the end of my post is to anneal it back to the proper hardness - not too hard and not too soft. It turns out that motor oil burns at just the right temperature to achieve that. It could be done by eyesight, but that's not as much fun

 

[JimmyOz]

I can see it compress and the ends spread a little against the brass. (It takes significant pressure to to that.)

Just a note, the spring only needs to be compressed about 2 mm to achieve what you want, it is only to stop the minute cannon from dropping when the hand is on. If you put the spring on the post, then the wheel, then the washer, you want to see just the top of the taper pin hole, this will give enough tension to hold the cannon/hand.

 

[Mick Mickle]

it is only to stop the minute cannon from dropping when the hand is on

Thanks for the info about the degree of compression.

I'm sorry I don't quite understand the terminology of "dropping" in this context. Does that relate to backlash and the minute hand dropping from gravity if the spring tension isn't enough? And if the compression is too much, I've read that the high amount of friction would cause the minute hand to be hard to manually set, possibly leading to a broken hand.

 

[JimmyOz]

Yes, it does not need to have to much tension, it only needs to hold the the cannon/hand from dropping under its own weight. Just put it together and see where the top of the washes is, if you see no taper pin hole it may need the spring flattened slightly, if you see all the hole it will need bent. Then just put the hand on and feel the tension it has, like the saying, Not to little-Not to much-Just Right.

 

[TEACLOCKS]

The convexed spring drives the gear, subsequently giving you a clutch to adjust the minuet hand, not direct gearing.

 

[Mick Mickle]

The convexed spring drives the gear, subsequently giving you a clutch to adjust the minuet hand, not direct gearing.

Thanks! That's what I understand and what I'm in the process of getting to. As you can see by one of the first photos I posted, the soldered spring that I started with was definitely direct connected to the gear train. It will be a pleasure to get the clutch working correctly.

For a while, I was thinking that I would need to insert an instruction card in the box that explained that the minute hand could only be set by removing the outer hand nut and pulling the minute hand out enough to disengage the gear. Then setting the number of cuckoo's and gongs with the vertical side wire.

Hopefully, I'm on a path to standard manual minute hand setting with a working friction clutch minute wheel.

 

[Mick Mickle]

motor oil

Well, apparently synthetic (Mobile 1) doesn't work as well. Although its burning temperature is a little higher than regular motor oil, it looks like it burns a lot longer because it's not as volatile. Maybe that makes a difference. Anyway, the end result was malleable steel. Rather than try again with regular motor oil, which I purchased later, I think I'll use this method that I think you alluded to:

First, I need to put the appropriate bend into the spring. As you can see from these photos, I can barely fit a washer on the pin without covering the hole. And that's with the spring almost flat. You can see space on the arbor between the gear and the square shoulder. I think the minute wheel should be able to ride freely into that space -- that only the spring should be preventing that. So I'm also thinking that I should use some emory cloth or some other technique to get that wheel to ride freely down to the square shoulder so there's room for clip washer and brass shim on wheel backside.

Secondly, I plan to create bow spring curvature by tapping lightly around a large diameter screwdriver or other such tool before tempering.

Am I on right track?

 

[JimmyOz]

You are on the right track, the wheel should be able to get to the square at the bottom of the post and spin freely, however do not take to much off as you don't want it to wobble. When you put the spring on the post it should lift the wheel off the bottom of the post to about where it is in the photo above, then put the washer on top, that is thinner than the gap between the underside of the wheel and the bottom of the post, put in the taper pin, test to see if it holds the hand without it dropping, turn the hand to see if it rotates without too much resistance.

 

[shutterbug]

Remember two steps. First temper it, then anneal it back with the oil. I've never tried synthetic oil for this, so can't offer an opinion.
You can make all kinds of different springs this way.

 

[Mick Mickle]

Thanks to to all who helped me fix the problem I had with this minute wheel friction clutch: howtorepairpendulumclocks, shutterbug, JimmyOz, TEACLOCKS, and others who took the time to chip in. I'll give a little closure with this post.

I don't know that I would have been able to change the minute wheel from its direct connection to the gear train without your guidance. It's working great now, and I can set the minute hand manually smoothly like a charm!

shutterbug, I tempered and annealed the spring again using your oil burning method but with the correct conventional oil. However, I discovered that there was a small crack or two at the corners of the square hole in the middle. I believe that caused it to not hold its shape when depressed. So . . . . scrounging around for material to make a new spring, I found a large binder clip in my desk drawer: Blinding Flash of the Obvious. I cut a new spring out of one side of it, shaping it cold. It's already a spring and about the same steel thickness as the original spring.





howtorepairpendulumclocks, I cut a brass shim disk to cover up the notches in the back of the minute wheel. It seems to be just the right thing for smoothness Since the spring tips significantly press against the shim, slightly denting it, I considered gluing the shim to the wheel so they would move together against the spring tips. But when I tested by rotating the assembled minute wheel with my fingers, I found that the shim and spring stayed together instead, with the friction slippage between the shim and the wheel. Although I didn't expect that, I think it works well. There's more surface area in contact during slippage, making a very smooth action which might reduce wear over time.

I ground down the outer diameter of the smallest brass washer I could find at a hardware store and used a cutoff piece of paperclip to pin the arbor hole. I flattened half of the wire piece with vise-grips to create taper.

As you suggested, I also filled in the stripped screw holes for holding the movement (and the overused nail holes in the front for attaching the loose dial), then drilled pilot holes. It's much sturdier now. Also, the screw holes in both bellows to attach to the case were stripped, so I reinforced them with cut tiny strips of perforated steel made for loose screw holes.





JimmyOz, I polished the section of the arbor just above the square shoulders with a strip of fine sandpaper and got the minute wheel to easily fit all the way. I also manually tested the spring tension by turning the minute wheel with my fingers then reduced the tension by slightly straightening the bend of the new spring. I wanted to be sure there'd be no danger to breaking a minute hand had taken me forever to carve out of bone. My gauge was, if I could turn the minute wheel fairly easy with two fingers, manually turning the minute hand should be even easier. And it was.

FatrCat, I still need to recover bellows with leather I got from Timesavers. But the $ bill works for now, and I'm not in a hurry Maybe "Cuckoo" will sound stronger when recovered correctly.

This might not be the right place to post it, but I've seen numerous posts on this forum on how clock hands and nuts are to be assembled. Maybe this will help someone searching in the future. On this G.K. George Kuehl clock (thanks new2clocks), I found that it worked well to put the minute hand on the square arbor, screw the larger nut on tightly, making sure it doesn't extend in front past the square threads, then screw on the end nut until it bottoms out snuggly. (Of course, the hour hand is pressed on first, pointing at the appropriate hour.) Photos below. In my case, there is end play for the both the hour hand and the minute hand arbors, and the end nut doesn't touch the minute Arbor.

 

[Jonas]

this has been a very interesting discussion to read. Clock repair aside, you have some excellent photography skills, Mick!

 

[shutterbug]

Good job on the repair! Sometimes it takes a village

 

[howtorepairpendulumclocks]

Thanks for the report... appreciated. If you gotten stuck for spring material in future you can always hammer harden a piece of brass, easier to find and easier to work. Good work!

 

[dperry428]

Remember two steps. First temper it, then anneal it back with the oil. I've never tried synthetic oil for this, so can't offer an opinion.
You can make all kinds of different springs this way.

First harden, then temper.