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ATO Junghans ATO repair - Big Problem??

buck

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Jan 27, 2006
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I think my ATO repair may be dead in the water already:mysad:. I pulled the movement from the clock, at it looks like I have a missing part. Attached are some photos.

Based on photos from the archives, it looks like there should be some type of assembly extending off of the right side of the movement. Is this the mechanical switch assembly? There are two threaded holes on the side of the movement. I don't suppose a replacement is available? Also, it looks like there is a small hairspring on the back. Mine is broken and in rough shape. Is there a replacement for this, maybe form the watch supply houses? Any help would be appreciated :).
 

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eskmill

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Alas....the contact assembly is missing completely. It is only obtainable from salvage of a donor clock. The contact pair are thin brass fingers with gold tips. They make connection with the precious metal bar that articulates from the underside of the ratchet wheel.

The "hairspring" is actually a copper coil needed to assure connectivity of the above mentioned articulating metal bar and the movement frame and clock stand or metal case.

The gold contact fingers when found on a "donor" clock are often found deeply eroded. They can be re-positioned slightly in the bracket so as to cause a clean portion to make with the moving contact bar or rod.

You might be able to "make a deal" with the subscirber looking for a donor coil. :?|
 

buck

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So I have either a clock in search of a donor, or a clock that can be a donor. Yet another failed Ebay purchase :bang:. Back on the shelf it goes. Oh well, at least I have something to look for at the Marts!
 

praezis

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It should be possible to drive your ATO with the same circuit, that the 1-coil Kundo used. Then no contact assembly is needed.

Until now just an idea, not yet built.

Frank
 

alanb

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Nov 26, 2005
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You might be able to "make a deal" with the subscirber looking for a donor coil. :?|
Let us all know if you do decide to break it up for spares... although my Ato is working, it could do with a few replacement pieces (it has a missing decorative nut, and a badly scuffed chapter ring)....
 

alanb

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Nov 26, 2005
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Alas....the contact assembly is missing completely. It is only obtainable from salvage of a donor clock. The contact pair are thin brass fingers with gold tips. They make connection with the precious metal bar that articulates from the underside of the ratchet wheel.

The "hairspring" is actually a copper coil needed to assure connectivity of the above mentioned articulating metal bar and the movement frame and clock stand or metal case.

The gold contact fingers when found on a "donor" clock are often found deeply eroded. They can be re-positioned slightly in the bracket so as to cause a clean portion to make with the moving contact bar or rod.

You might be able to "make a deal" with the subscriber looking for a donor coil. :?|
I'm having problems making my ATO run reliably. Should the little brass fingers only touch the bar for an instant to provide the contact? I can't see any obvious way to adjust either the swing of the rod, nor the position of the finger 'tips'.

When I first bought the clock the fingers were covered with some kind of gungy grease. This caused them to vibrate madly when the rod touched them and stuck to them for an instant. I cleaned all that off, but now the clock runs less well than it did.

On the other side of the fingers from the rod is a thicker piece of springy metal, secured at the base of the fingers, which is bent so that the top almost touches the backs of the fingers. This seems to be adjustable by a single screw at the bottom - turn the screw and the top touches the finger-tips permanently, unscrew it and it moves away altogether. What's the purpose of this, and how should it be set for best results?

Any tips gratefully received! I can provide a photo if my description is too unclear!
 

eskmill

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The moving contact bar that makes with the gold tipped springy stationary contacts should cause the stationary contacts to move no less than 0.001" and no more than 0.010".

The duration of contact closure is really quite long considering the stroke of the pendulum.

What's critical I believe, is the timing of contact closure. It must be as the pendulum approaches the middle of its span if the solenoid is to repel the armature. If late the pendulum has already passed the middle of its travel and would be retarded by the late impulse.

When time permits I will try to post something to illustrate contact adjustment and what controls contact timing.
 
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buck

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Jan 27, 2006
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I was able to find a donor movement at an auction! I am in the process of cleaning the first movement, and will soon take the contacts off of the movement I just bought for the 'transplant'.

With regard to the copper 'hairsping' coil, is this something I can make? If the purpose is to ensure continuity and not motion, it would seem like this could be fabricated. I can turn the collet, but where would I find flat copper stock for the coil itself? Or can the coil be made from wire? Or, since metal is metal, can I use a pocketwatch hairspring?
 
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eskmill

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'Glad you 'scored' on a donor movement. A watch balance spring could be used in place of the copper "hair-spring" continuity enhancer that these Junghans ATO clocks have to have for reliability.

Take a close look with a loope at the surface of the gold contacts. I've seen them badly pitted and turned them over to the opposite side with no problem.

How do they get pitted? Either someone not familiar with "weak current" clocks substituted a 9 volt battery for the single cell or more likely, just abrasion from dust against the steel (stainless steel) contact pin that makes contact with the "gold fingers." Note that the design results in some "wipe" motion to the contacts. Some examples I've seen look like they've run most of their working life without the protective glass cover.
 
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buck

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Jan 27, 2006
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Thanks - I just bought a watch lot on ebay that has a small box of hairsprings, so I'll give one a try.

I was cleaning and reassembling the movement last night, and hope to get it running soon. I noticed that the pivot for the contact lever (for lack of the correct term) that is in the upper right of the movement extends through the plate to what looks like an electrical contact on the front of the plate. When I oil the pivot holes, does this one get oiled, or does it stay dry to maintain electrical contact? It is my recollection that levers generally do not get oil in a clock, but thought I would ask for opinions.
 

eskmill

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The plate covering the pivot hole acts as an "end-stone." Thus the shoulder of the arbor is prevented from riding against the inside of the plate hole or bushing. Hence lower friction.

I do oil the pivots on the Junghans ATO clocks and on the KundO electronic clocks with similar "weak current" battery clocks using watch oil.

That being said, there is at least one message board subscriber who opines that these movements do not need lubrication.

Go figure, I can't. :rolleyes:
 

buck

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Jan 27, 2006
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In a separate email, I asked about what suspension spring could be used in this clock. One of the responses mentioned a #54 spring from Timesavers. I got the spring today, and the brass clip on the suspension spring is too wide for the slot in the suspension spring bracket in the clock. Did I order the right spring, or do I need to file the slot on the bracket wider? I supose I could file the brass clip of the spring down to make it narrower, but it seems quite a bit wider than the slot it is supposed to fit into.

The bracket also has a notch for a pin on the suspension spring. The pin I have only has one pin, for the pendulum. I am assuming I can fashion a pin, is that the correct thing to to? Any tips wouldbe appreciated :).
 

jerry2222

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Oct 15, 2011
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Contact me if you can help me please adjust my ATO " Gold fingers " as mentioned in an above posting...
I don't know which battery to use for this clock to create enough power for the Contact assembly to work ?

Thanks for any help i can Get from someone


Jerry5839@aol.com

March 9 2021
 

jerry2222

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Oct 15, 2011
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In a separate email, I asked about what suspension spring could be used in this clock. One of the responses mentioned a #54 spring from Timesavers. I got the spring today, and the brass clip on the suspension spring is too wide for the slot in the suspension spring bracket in the clock. Did I order the right spring, or do I need to file the slot on the bracket wider? I supose I could file the brass clip of the spring down to make it narrower, but it seems quite a bit wider than the slot it is supposed to fit into.

The bracket also has a notch for a pin on the suspension spring. The pin I have only has one pin, for the pendulum. I am assuming I can fashion a pin, is that the correct thing to to? Any tips wouldbe appreciated :).

Sand down the sides of the Brass suspension spring with Emery cloth...to create a loser fit in the holding slot. ..Spreading open the slot in the hanger is hard .... and Kundo #54 is 25.oo each on the Clock... Clockworks .com sells them... Very eaisley broken or one bend in the spring metal makes it no good too...

I have 20 of these clocks if anyone has broken as many as me let me know...lol (Electro magnetic clocks on E- bay..

The Junghans are the rarest ones too,.. lots of different shape Kundos are on sale... (Obergfell Keiinger movements)

Jerry5839@aol.com
 

jerry2222

Registered User
Oct 15, 2011
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I figured out the Junghans ATO electro magnetic clocks....with the side contact assembly with the 2 gold fingers
if anyone is as crazy as me with these type clocks... or Kundo's.. I have lots of small spare parts too...
I also have the circuit boards for the Electro- magnetic Kundo's- Seth Thomas- Kieninger (all the same clocks). Contact me via private conversation.
 
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Dave T

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Just picked up a Junghans ATO yesterday sold as non running. After studying the forums here and checking the coil, etc. I have it running now with a C battery. Problem is, a C won't fit under the base. This clock originally came with the flat style battery that is sold on Timesavers for about $30. I paid $15 for the clock!

I'll rig up something that fits under the base. Two AA's in parallel? Three AA's in parallel? There's room under it for those. Wonder if this would work? Thoughts?
1633192548814.png

The only other problem is that the brass sleeve that fits over the outside pendulum is cracked in several places. Would like to find a replacement for this too. You can see it here on the left side in the second picture.
Junghans ATO.jpg Junghans ATO sleeve cracked.jpg
 
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jerry2222

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Oct 15, 2011
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2 double A’s work….fine… but the clock might run too fast even after you screw down the pendulum … a C battery is too strong on mine … i buy the battery holders from radio shack or on line e bay..
 

Dave T

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Maybe I should try a single AA? I don't have any way to hold them yet. I'm using a makeshift clamp.
 

Mike Phelan

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2 double A’s work….fine… but the clock might run too fast even after you screw down the pendulum … a C battery is too strong on mine
Any number of single (C, D, AA, AAA) zinc+carbon cells connected in parallel will give the same voltage - typically 1.5 volts so the clock will run just the same. :???:
 

sophiebear0_0

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Nov 5, 2012
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AA batteries will work fine.

The only issue is that the AA battery capacity is a lot lower than the C cell. So you can either use a single AA and accept
that the battery will need changing more frequently, or use 2 or 3 AA batteries wired in parallel to still deliver 1.5 volts.

I use standard single AA battery holders and glue them side-by-side and wire them in parallel. I then house the holders in a Perspex shell with an open back to provide easy access to change the batteries. I use a couple of knurled brass nuts to serve as terminal connectors. You could obviously use wood or thick card if you don't have access to Perspex. You can then download an appropriate label for the clcok.

Regards,

Peter

Olympic battery.JPG
 
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Dave T

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Mike, I understand the difference between parallel and series. I'm just trying to get a combination of batteries that will fit the allowed space. Cs and Ds are too wide to fit the allotted space.

Peter, Thanks for the recommendation. That's more like what I had it mind. Don't know what Prospex is, but I'll either make a container or try to buy one. I'm thinking three AAs might be what I need. And I'll see how long the clock runs. I think the one pictured above in post #17 might still do what I need.
 

Dave T

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I've got this clock running steady, but it's gaining time very fast!
How do you regulate this thing? The pendulum is adjustable, but I doubt I can compensate for a 15 minute gain in a two hour period!
 

sophiebear0_0

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Dave

It sounds like the gathering pawl that sits above the ratchet wheel is picking up more than one tooth per swing. There is a screw adjuster which can be used to adjust the pawl / ratchet wheel interaction. i would try turning in the screw a tad to rise the pawl to se if this helps.

You are right that fine tuning of the regulation is achieved by adjusting the pendulum bob height.

Regards,

Peter
 
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Dave T

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Thanks Peter, After posting here last night I found a comment somewhere in the forums here that the contact point on the vertical bar at the right side of the movement must just barely make contact.
So, I backed off on mine, until it just barely kept running. And this morning it has gained maybe two minutes.
I looked hard at the ratchet wheel thinking also that it might be advancing more than one tooth. But now, I'll just wait to see how it goes and try adjusting the pendulum to get the rest of it.
Here's a video as it is now. Unfortunately, as I look at it there's not much to see.
View attachment VID_20211005_085509934.mp4
 
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Jmeechie

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Hi Dave,
I’ve worked on a lot of these style of movements over the years and you need to raise, the advance pawl or arm so it’s not dragging across the advance wheel like it is. And yes, you are correct in adjusting the contact points to barely touch at full swing. If too much or too soon of contact and a much wilder swing will occur causing 2 teeth to be picked up occasionally.
Cheers,
James
 

Dave T

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James, I'm so glad to see this reply. In my last post I thought sure I had the time regulation issue fixed, or greatly improved.
But after watching it for a few days I see it is gaining a lot! Not sure how much but maybe an hour overnight!
I can tell you that the pendulum ends now don't protrude through the two brass sleeves on each end as it did earlier. ie" less swing
I clearly don't yet understand how this clock is regulated. Right now I'm just guessing. So far the only adjustment I've made is to the side arm contact.

I will attempt to raise the pawl arm as you suggest, but I'm not sure how much or how to measure it. I think what you are saying is that the arm should make contact on each tooth but not dragging on the wheel.
 

Dave T

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Thanks again James, That adjustment to the advance arm pawl as you recommended. Not much, but it has gained about a minute now in 24 hours. Big improvement! I can probably get the rest of it by adjusting the pendulum.
 
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Dave T

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This clock has been running for some time now, on a rigged battery holder. Last week I replaced the rig with a AAA battery holder, and it ran for a couple of days and has now stopped.

Trying to figure out why it stopped and what to look for. I've never had the clock apart for cleaning, for what it's worth.
 

Jmeechie

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Start with the basics, double check what you replaced ( connections, good/new batteries, voltage from new holder correct). Then move to testing voltage at contacts as well as a good return/ground.
These movements are delicate but sturdy. They supposedly never oiled the pivots so servicing is a mere components cleaning!
My suspicion is you may have bumped the switch or tugged a wire and it’s now not making a good contact! How about pictures of the work you did on the battery box install. Also, did you get the voltage connected correctly?
Cheers,
James
 

Dave T

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Thanks James, For whatever reason I had to adjust the electrical contact a little closer, and it's running fine again.

I have the pendulum adjusted as high as it will go, but so far is not gaining, like it did before this last adjustment.
 
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Dave T

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I need to deal with this clock. It's gradually losing time or else the pendulum adjustment is stuck. It's tight and doesn't want to go any higher.

Anyone dealt with this issue?
 

Jmeechie

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I’m wondering if your contacts/switch is occurring at the wrong time, too early which is causing the pendulum to momentarily stall so it’s running slow?
Or they’re dirty and only impulsing every few swings?
 
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Dave T

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Could be on both counts, but I don't know how I'd check it.
Actually, all I've done with this clock so far, is connect a good battery to it and adjust the contacts, to slow it down. Initially it was running too fast and advancing the escape more than one notch occasionally.
 

Jmeechie

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So lower the pendulum bob down to about half way, unscrew. Set the time and run the clock for 24 hours. Now, adjust the contacts 1/4 turn (either way) and note on a sheet of paper what you did. Reset time and run 24 hours and see what effect you had. If it’s slower, reverse direction with contact screw adjustment.
Also, have you tried reversing the battery in the holder to verify correct polarity? These clocks are polarity sensitive.
 
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Dave T

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Thanks a bunch. Had no idea how to approach this.
No, I haven't changed the battery position, but when I started I tried to be sure it was correct, and was concerned that putting it in backward might cause some damage to it.
 

Jmeechie

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No, yours is not an electronic switched movement (newer) so reversing voltage will not cause any damage. The reason I suggest this is these clocks have a magnetic rod in the pendulum tube and are oriented North - South and the coil functions as a magnetic attractant. So if the coils power is reversed it will repel ( North end magnet entering the coil energizing North) but due to motion it will not bounce it out or away but rather slow it until the opposite end nears the coil. So, it will slow or hesitate the pendulum swing causing slow running. I see a lot of people saying on here, there’s only runs on 3 volts or more but not on 1.5 volts as originally designed
So, I’d try reversing the battery and see how it runs, it may stall or stop after 10-20 minutes. If so, go back to the original battery direction and run the adjustment procedure I suggested above.
I hope this makes sense.
 
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