Need Help with Moon Dial

Zu-Astarti

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This was kindly identified for me by SoaringJoy as a Mauthe from the '20s. It belongs to a local retirement home. Some of you may recognize it from previous posts. Some of the folks at the home have been there for over 20 years and no one remembers this clock ever running. I've spent nearly two months, off and on, restoring the movement. It had just about every problem you can imagine. Rust, mold, missing screws, rating assembly bent, incredibly dirty and dripping with oil. I've gone through this thing piece by piece. Multiple trips through the ultrasonic, pivots polished, holes pegged, every surface that slides or pushes against another surface has been polished with emery buffs until you can see your face. The movement has been running beautifully on the stand for two weeks. The only thing left is to get the moon dial working. When I got it, the moon dial arbor was missing and the dial was held on by a screw and nut tightened down so the dial couldn't turn at all. The cam that makes the dial work was popped off the hour tube and was just loose in the movement. I made a new arbor for it, took all of the other components apart, cleaned them and polished all of the sliding surfaces, including the running edge of the cam. Put it back together, lubricated it and mounted it on the movement. When the hour tube turns around to the point where the cam starts lifting the bar that pushes up the fork, that advances the moon dial, the clock goes out of beat and eventually stops. Everything is moving freely, and it requires incredibly little effort to to turn the dial, but the movement doesn't seem to have enough power to do the job. If I advance the clock by hand, past the point where the cam is lifting, the clock goes back into beat and runs merrily along. This is the first grandfathers I've work on, so I don't know if this contraption is a standard arrangement, or if it's some kind of Rube Goldberg invention. As always, any advice would be appreciated. Sorry this has gotten so long...
 

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The Klock Dok

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Jul 22, 2012
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Oren,, observe the moment you begin to lose power. Where on that lobe does it start to go south on you.that lobe on thde cannon looks to be mighty high, and if it it too high it may be mooving tha transfer bar beyond its lemits, if that is the case it will stall the movement. good work ,,,,,,,,,,,,,,,,,,TKD
 

Zu-Astarti

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Feb 24, 2012
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Oren,, observe the moment you begin to lose power. Where on that lobe does it start to go south on you.that lobe on thde cannon looks to be mighty high, and if it it too high it may be mooving tha transfer bar beyond its lemits, if that is the case it will stall the movement. good work ,,,,,,,,,,,,,,,,,,TKD
Good thought, but that's not it. I've been baby sitting it for a few days, and it has actually gone all the way around a couple of times without stopping, but it goes badly out of beat. It can stall anywhere within about a three-hour period when the cam pushes the bar toward its highest point.
 

Tinker Dwight

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Hi
It doesn't look like any that I've seen. It looks like a helper spring on
the end. Most of these lever types use a counter balance and springs,
only to keep ratcheting parts working.
Check to make sure that the moon disk can spin freely with the springs
held away.
Also check that the spring ratchets don't have more tension that needed.
The just need to lightly touch.
The fact that it is stopping the clock is not that it loads the hour hand,
it is that it is a side load on the minute or center shaft ( possible location
of missed lube ).
Tinker Dwight
 

Tinker Dwight

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Hi
Looking some more convinces me that it is someones idea of what was needed.
If you look at the cam, you'll see quite a bit of lift. It looks like it would
lift the bar more than a single tooth ( that is all it should do in 12 hours ).
That really depends on the pivoted end though.
Tinker Dwight
 

Zu-Astarti

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Feb 24, 2012
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Hi
It doesn't look like any that I've seen. It looks like a helper spring on
the end. Most of these lever types use a counter balance and springs,
only to keep ratcheting parts working.
Check to make sure that the moon disk can spin freely with the springs
held away.
Also check that the spring ratchets don't have more tension that needed.
The just need to lightly touch.
The fact that it is stopping the clock is not that it loads the hour hand,
it is that it is a side load on the minute or center shaft ( possible location
of missed lube ).
Tinker Dwight
Thanks, Tinker. I hadn't thought of it pushing down on the minute shaft. I definitely lubed it when I put it back together. Not sure what else I can do to lighten the load. The dial does spin very freely when the spring is held away, and I have it adjusted so that the spring barely touches the teeth--just enough to prevent it from dropping back down when the fork drops.
 

shutterbug

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I don't particularly like the lift arrangement. If the lift lever is outside the dial posts, it binding against them, and if it's inside it may be getting interference from the chime levers. Is there any chance of getting a pic from the side with the movement mounted with the dial? I think the arrangement is you have home made. Typically, the tension spring is on the other side of the dial, too, or at least not in proximity of the lift.
 

harold bain

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It sounds like the crutch must be too loose for it to go out of beat that easily, Oren. Previous repairmen must have had the same problem with the moondial, and likely gave up. I would try tightening the crutch to the anchor arbor. This movement should be well before the advent of automatic beatsetters.
 

Zu-Astarti

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Feb 24, 2012
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It sounds like the crutch must be too loose for it to go out of beat that easily, Oren. Previous repairmen must have had the same problem with the moondial, and likely gave up. I would try tightening the crutch to the anchor arbor. This movement should be well before the advent of automatic beatsetters.
I had actually considered that, but the crutch is quite snug. It takes some effort to move it.
 

Tinker Dwight

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Be sure to check my second post. I think it is trying to lift too much. It
should only lift on tooth each time the hour hand goes around.
I think you'll find it is moving several.
Tinker Dwight
 

Zu-Astarti

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Feb 24, 2012
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I don't particularly like the lift arrangement. If the lift lever is outside the dial posts, it binding against them, and if it's inside it may be getting interference from the chime levers. Is there any chance of getting a pic from the side with the movement mounted with the dial? I think the arrangement is you have home made. Typically, the tension spring is on the other side of the dial, too, or at least not in proximity of the lift.
Here's a picture...

In_situ.jpg
 

Zu-Astarti

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Be sure to check my second post. I think it is trying to lift too much. It
should only lift on tooth each time the hour hand goes around.
I think you'll find it is moving several.
Tinker Dwight
Yep. You're right. It's lifting two teeth with each revolution. So then, my task, should I choose to accept it is to reshape the cam so that it only lifts enough to move one tooth. There were a lot of file marks on the cam originally (which I polished out), so I kind of suspected it was homemade in the first place.

Even if it doesn't have to lift as far, I'm not sure it won't have the same amount of downward pressure on it from the lifting bar.
 

Tinker Dwight

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Hi
You'll either need to add a long light helper spring or a counter balance
of some type ( I prefer the counter balance ).
If you use a light spring, place it towards the pivot if it is stiff and towards
the end if it is really light.
I'm not sure how you could counter balance but it might need to be clever
with another arm to lift going from left to right, lift, pivot, counter weight.
Anyway, see how it does when you've reshaped the cam.
Most of the cam driven ones that I've seen are just an eccentric circular
shape without any special light or drop.
Tinker Dwight
 

harold bain

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Yep. You're right. It's lifting two teeth with each revolution. So then, my task, should I choose to accept it is to reshape the cam so that it only lifts enough to move one tooth. There were a lot of file marks on the cam originally (which I polished out), so I kind of suspected it was homemade in the first place.

Even if it doesn't have to lift as far, I'm not sure it won't have the same amount of downward pressure on it from the lifting bar.
I would try putting something under the lift bar so that it doesn't start lifting as soon, and doesn't drop as far. With a bit of experimenting, should be easier than cutting down the cam, to get it to where it only takes one tooth at a time. Make sure the cam, and the part that rides on it are smooth, and greased.
 

Zu-Astarti

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I would try putting something under the lift bar so that it doesn't start lifting as soon, and doesn't drop as far. With a bit of experimenting, should be easier than cutting down the cam, to get it to where it only takes one tooth at a time. Make sure the cam, and the part that rides on it are smooth, and greased.
Hey, that's a pretty awsome idea. That's why I love this message board. There's a retaining assembly at the end of the bar. It should be pretty easy to slip something in there to raise up that end. We'll see how that goes. If it's still too heavy, I'll see if I can come up with a helper spring as suggested by Tinker.

Worst case scenario, the Oldies will have a nice chiming clock with a non-functional moon dial instead of just a broken clock. Thanks to all.
 

Zu-Astarti

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Well, I'm just about ready to throw in the towel on the moon dial. I put a small piece of brass flat stock under the lifting bar so that it wouldn't have to lift so far. So far so good--only lifts it one tooth now. Gave it a try and the movement stopped when the cam reached the lifting bar. I rigged up a long, very light helper spring. I got it adjusted so that the fork is just able to drop back down on its own. Gave it a try. Movement stops. If I give the pendulum a push after it stops, the anchor rocks back and forth, but the escape wheel doesn't advance. While the pendulum was still swinging, I took off the minute hand and boom--it starts running again. Put the minute hand back on, and it stops. Seems that when the cam is pushing up on the lifting bar, the hour tube wants to move forward against the back of the minute hand with enough force to stop the movement. The hour wheel is held in place by a washer on the minute wheel arbor in the usual way, so I don't think there is a lot I can do to prevent it from pushing forward. :confused:
 

harold bain

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If you are sure it's the hour cannon, and not the hour hand that is interfering with the minute hand, perhaps you could trim a few thou off the hour cannon.
 

Zu-Astarti

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If you are sure it's the hour cannon, and not the hour hand that is interfering with the minute hand, perhaps you could trim a few thou off the hour cannon.
It would have to be more like 1/16". The hour tube advances well out over the minute hand square. It is definitely not the hour hand; it sits well back on the tube. And I find myself reluctant to modify the movement to accommodate a jury rigged moon dial. I would hate to lop off the tube and have it still not work for some other reason. Maybe I'm just being squeamish. :whistle: Excellent suggestion though. Thanks for the advice.

Actually just saw a very good reason not to shorten the hour tube: the pin on the end of the rack tail that drops onto the snail barely--I mean barely--catches the snail when the hour tube is all the way forward, which is where it would be if I took enough off for the tube not to meet the back of the minute hand. I'm just going to let it sit for today, but I think I'm just going to take the cam off and disable the moon dial. It's still a nice chiming clock even without it.
 
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harold bain

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Here's another suggestion. With the dial on, and just the hour hand, note how much the hour cannon can move. Is the moon dial cam pretty much centered on the activation lever? Could you add a pin behind that lever to limit the travel of the hour cannon by not allowing the cam to go far enough for the hour cannon to contact the minute hand? It would be a simple solder job to put a short pin on the lever, limiting travel. You may need to adjust the cam's position to make this effective.
 

Zu-Astarti

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Feb 24, 2012
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Here's another suggestion. With the dial on, and just the hour hand, note how much the hour cannon can move. Is the moon dial cam pretty much centered on the activation lever? Could you add a pin behind that lever to limit the travel of the hour cannon by not allowing the cam to go far enough for the hour cannon to contact the minute hand? It would be a simple solder job to put a short pin on the lever, limiting travel. You may need to adjust the cam's position to make this effective.
I was busy adding a paragraph to my last post when you posted this. I'm trying to visualize that pin. That might just work. I wonder if it would be too much friction, if it's pushing up and forward against two surfaces. Although the contact surface of a round pin would be pretty insignificant. I would prefer to modify the moon dial apparatus rather than the movement if possible. Thanks.
 

harold bain

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The pin would only need to extend about 1/4 inch or less to be effective. It shouldn't cause much friction, and will keep the hour cannon away from the minute hand. If you wanted to really get creative, you could make a sleeve for it (hollow brass tubing), and put a head on it (like a nail head) so that it can roll with the cam.:whistle: Could even use a brass nail.
 

Tinker Dwight

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I'm thinking you may need to modify the rig on the dial and rebuild another cam.
First the leverage is all wrong. The cam sites close to the fulcrum while the action
is at the end of the lever. This is about a 2:1 disadvantage.
I'm thinking that there should be a fulcrum to the left of the cam and about half
way to the current fulcrum. The advancing arm would go up from about where the
current fulcrum is and reaches up to pull the moon dial down.
The location of the fulcrum and shape of the cam should be such that it take
3 or 4 hours to advance the moon dial. ( maybe longer )
The side thrust could be reduced by a factor of 3 or 4 this way.
Tinker Dwight
 

Zu-Astarti

Registered User
Feb 24, 2012
489
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Anytown USA
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Hi
I'm thinking you may need to modify the rig on the dial and rebuild another cam.
First the leverage is all wrong. The cam sites close to the fulcrum while the action
is at the end of the lever. This is about a 2:1 disadvantage.
I'm thinking that there should be a fulcrum to the left of the cam and about half
way to the current fulcrum. The advancing arm would go up from about where the
current fulcrum is and reaches up to pull the moon dial down.
The location of the fulcrum and shape of the cam should be such that it take
3 or 4 hours to advance the moon dial. ( maybe longer )
The side thrust could be reduced by a factor of 3 or 4 this way.
Tinker Dwight
I like Harold's pin idea, but I think you're right, Tinker. The mechanical disadvantage is just too great for this to work as is. Your idea sounds great, but that's way more than I'm prepared to put into at this point. I hate to be a quitter, but this is a gratis job that's been in my shop for about two months, and I'm ready for it to go away. I think the folks at the retirement home will be thrilled just to have a working clock. It keeps good time and has a nice sounding chime. As an old buddy of mine used to say, "Good enough for government work."
 
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