Junghans Clock question

[Randy]

Not a clock repair guy ( yet) but working on one for a friend.
A 30's-40's mantle style, w/ westminster chimes.

Crafted a new suspension spring, filed the escapement teeth that were in need of cleaning up.
Got it in beat again,..and it ran quite well for about a 4-6 hr stretch.
Mainspring's OK, and lubed.
Lubed the cams, pivots, etc....
The gear train runs freely with the escapement removed.

But,.......it now stops about 5 minutes short of each hour, and I'm thinking that it has to do with one of the cams that start the chime sequence ???
it runs for another hour if I nudge the minute hand forward of the 12 o'clock position.
I'm open to any suggestions

Thanks

Randy

[Arutha]

Hi Randy, this could be caused by a few problems. Is the chiming mainspring powerful enough? If it is the original spring it could need replacing. Try just putting the chiming wheels between the plates and check for binding or stiffness which can be caused by a bent pivot or not enough end-shake on an arbor. There are so many of these westminster chime movements its a bit of a tricky one to answer without seeing the movement. Tension springs if bent out of shape can also cause problems because they put too much pressure on the parts they are retaining.
Sorry I cant be more help but please post a picture up of the movement and I might be able to help a little more.
Paul.

[Randy]

Thanks Paul.
The chime sequence always seems to work.
And I've actually had it run for 4-8 hours stretches before it goes into this pattern of stopping just before the hour.
I did have to adjust the tension spring that regulates the ratcheted arm that moves up as the hours are counted off.
Before I did, it would continue to chime until it wound down.
Maybe I over did it ???


The mainsprings ( this has three ), are old, and one or more could be hanging up at full wind due to corrosion.
I have a let down tool,..but not a winder, so I've not taken them apart and replaced them.

Ill double check for binding, and I'll try hard to get a shot of the movement on here in a day or so.

Really appreciate the suggestions !!

All my best,

Randy

[Arutha]

Hi Randy,
You can remove the springs by hand, its always better to use a mainspring tool if possible as it reduces the risk of distortion but if you go carefully you should be ok. I am guessing if the springs are original they will need to be replaced anyway. I seem to remember Bob showing in his video how to remove a spring by hand (He is going to murder me if I got that that wrong! )
If you do have a go please make sure you wear eye protection and gloves. I have done a few by hand and the idea of doing it is more frightening than actualy doing it. If the spring doesnt open out to at least two and a half times the diameter of the barrel it will need to be replaced.
Thats the problem with Westminster chimes, it could be a combination of very minor problems that add up to stop it working.
Keep us updated Randy and good luck.

[Bob Tascione]

Hi Randy,
I would suspect loss of power in the time train. It seems like it just doesn't have enough umph to activate the chime. If you have the time to wait, you can try disengaging the strike and chime train from the time train and let the time train run to see if it makes it a full 8 days. My guess is that it will fall short of that mark. Would then check springs as Paul suggests and bushings, pivots etc. for wear.
Please let us know how things work out!
Bob

[Randy]

Thanks Bob,..I'll give that a try.

[Bob Tascione]

You bet Randy!
Please let us know how it works out.
Good luck,
Bob

[willofiam]

Hi guys, Randy if I can I will throw my 2 cents in on this, I have dealt with the mainspring not being strong enough but I also have dealt with like you said, a cam and pin or leaver binding thru the lifting period, what I am training myself to do is turn the minute hand (somehow) thru all the chime sequence, watching for anything that might be out of time or just not right. when you said that you could nudge it past the hour and it would run thru the next hour then my guess would be that a cam is binding with a pin or "lever" if that's what it is called. (do you hear anything when you do that????) sometimes it can be one or two teeth away from setting up properly and binding on the cam before getting out of the way. Hey, pictures are always nice and if you still have issues they would help us. if you do take pics then try to get the rack and snail mechanism at the point where you are having it stop. keep on keepin on Randy. Please tell Bob and Paul to behave themselves.
P.s. my computer is in the shop and I am having Bobs forum withdraws , had to fight my wife for some time on hers. She won of coarse but I was able to negotiate a couple a minutes. see yall when I get my energy back for another round. William

[Arutha]

Good to see you are still with us William, I was wondering where you had got to
How are you getting on Randy, any news?
Paul.

[Bob Tascione]

Hey William,
Hope you get that computer up and running soon. I had the same problem the past few days. My laptop (I only use laptops as we travel quite a bit) had been busy rendering some projects for a few days so I've needed to use Phyllis' laptop. Very dangerous territory!! I have a bad habit of messing up computers fast and having been together for 40 years now she knows me far too well, so had to be on best behavior. Came through with no cuts or bruises...her computer came through fine too!
Bob

[Randy]

Thanks for the input William ( and others ).
I have watched it cycle,and everything seems to work well.
I'm convinced at this point, that I'm dealing with a set mainspring.
I found that I can give it 6-7 winds, and it works fine.
Go one more, and it stops shortly thereafter.
Everytime.....


I'll have to go the next step on this one, and try my hand at replacing LARGE mainsprings.
I'm pretty shop savvy,..so I should be able to get this done without losing and eye...


All my best you guys !!


Randy

[Arutha]

Good luck Randy and if you dont have a mainspring winder make sure you have thick leather gloves and eye protection, I have a winder and I still use these.
Paul.

[willofiam]

[Bob Tascione]

Good to hear you got the computer up and running Bill!

I agree. I think you could be on the right track Things do sometimes jam when more power is applied.

I'm still waiting though to hear about the condition of the springs. It does sound like the springs are just dry and dirty. When they get like that the coils will often tend to stick together when enough pressure is put on them. If the springs are badly set then it seems to me that even less power would be available to overcome stuck together coils. It's fairly common to see a clock run ok as Randy mentions with a few winds and then stop all together when more power is applied. Until the springs are cleaned or replaced it would be hard to tell how much effect worn bushings, pivots etc. are having on the clocks performance.

At this point though it sounds like sticky springs to me.

Welcome back Bill!
Bob

[willofiam]

Thanks Bob, you always put my mind at ease, now I can get started on the next one, old new haven shelf clock with really small mainsprings, and guess what..... mainspring issues . William