I'm Stymied

Posted: Wed Feb 11, 2009 11:57 pm     Post subject: I'm Stymied

I have 2 Hermle 340-020 clock mechanisms that are virtually identical except one employs a helical style balance spring and the other uses the flat spring type. Both units have the same problem in that the balance wheels are sluggish. I took the balance wheel assemblies out of both units and spun them and they seem very healthy and run a long time on there own. I oiled all the pivots (bearings) with clock oil but that didn't seem to help. Both units look nice and clean and look like new. I can't even come close to figuring this one out!!

If you have an answer for this one, you are a genious!

Thanks, Jim

Posted: Sat Feb 14, 2009 9:05 pm     Post subject:

Your problem may not be in the balances at all. You may have worn bushings causing the power to be affected. Check each bushing by releasing the springs so the wheels will turn back and forth freely. Rotate the largest wheel back and forth on each train of the movement and watch each bushing on both sides of the movement. If you see slack (slop) in any of them, you need bushing work to solve your problem. The other possibility is a dirty movement. Bushings must be clean!

Posted: Mon Feb 16, 2009 11:50 pm     Post subject:

as wow said it may look clean but on these Hermle it must be really clean to work properly and that's after you've checked the pivot holes arn't worn too much and the mainsprings haven't gone weak too.

the barrels on these Hermle wear quicker on the newer mechanisms than the older ones. what letter and or numbers do you have on the rear plate? if the barrels are worn (common problem) you will lose power thro the train.

Posted: Thu Feb 19, 2009 12:33 am     Post subject:

Thanks so much for your replies! first of all the only numbers are 340-020. It also says it has 2 jewels and is made in Germany & not West Germany, so I have to assume it's a newer unit. I'm only talking about the movement that has the flat spring for right now. I bought this clock used in 1993 and the movement was supposed to have been replaced with a new one. I believed him because I truly believe he was a quality person! I've read that these movements can be cleaned ultra sonically. What are your thoughts on that? I will do what WOW said and release the spring tension and check for slop.

I find it discouraging what clokfxr said about the new springs not holding up as well as the old ones. With today’s advancements in technology, specifically metallurgy, things should get better not worse! Dogonit the thing is made in Germany and I always thought that quality always came first!
Thanks again, Jim

Posted: Fri Feb 20, 2009 1:36 am     Post subject:

I did what you said. I released the tension on the clock spring only and not the chime springs because that's where my issue is. I moved the gear and I did see some slop in the bearings especially in the 1st and 2nd gears after the spring gear in the train. How much slop is acceptible?? I would say from just eyeballing it, there is probably several thousanths of an inch of slop. Is that actually enough to cause this problem?? How close are the tolerances on a new movement? I'm actually surprised that there is this much wear because I do keep them oiled. How much of a problem would it be to bush it and is it worth it? I really appreciate your help with this!
Thanks, Jim

Posted: Fri Feb 20, 2009 11:48 pm     Post subject:

i'm surprised you cannot find a letter on the movement. Howevr, hermle have a 'little' slop when they are made. even for a repairer it not always clear whether to bush or not and its even harder not looking at your clock myself.

unfortunatly a lot of it is down to experience. where one repairer might bush a hole , another may not.
probably up to 20 thou would be max before bushing. how would you measure it? if you have an hairspring you could measure the thickness and put it into the hole to gauge it?

the quality of modern clocks is down to price as usual. Hermle had to shave their two factories into one to keep going a few years ago.
i've seen many of their clock movements from 30 years ago which lasted 20+ years before getting worn out.
nowadays i have to clean and oil half the brand new movements i get from suppliers BEFORE putting them into the case because they are dirty!

you say you oil the mechanism on a regular basis but do you clean it then oil it? the dirt your adding oil to only makes grinding paste which then wears the clock out faster. so just oiling a clock frees the wheels to turn but creates another problem.
a lot of people think we estimate a clock because we want their business but as you explain to them why it needs cleaning first they realise you are right!
lets take another example - would you take out a dirty wheel bearing from your car, re-grease it and stick back in without cleaning it?

Posted: Sat Feb 21, 2009 2:20 pm     Post subject:

Thanks Clokfxr. Actually I did find the letter "F" above the Hermle logo. I guess I thought that the letter was supposed to be a part of the clock number so I didn't notice it.

I guess I never thought of it that way. How do you clean one of these? Ultrasonically?

Jim

Posted: Sun Feb 22, 2009 11:37 pm     Post subject:

probably made about 1994 then.

yes you can clean with an ultrasonic. either with specific clock cleaner and rinse or a mix of clock cleaning ammonia and water, then rinse it and dry it.

Posted: Sun Mar 01, 2009 8:26 pm     Post subject:

Okay, I got my ultrasonic cleaner. Now is there a home recipe I can put together for this? I read some websites on the subject and they actually confused me more than they helped. Some say that ammoniated cleaners can remove the lacquer on 'modern" movements. What about the mixture that gets into the spring barrels? How would I dry that? Would rinsing with distilled water be a good thing and then gently blow it off with compressed air and then let it air dry the rest of the way? I was thinking of removing the balance wheel assembly before doing any of this because I'm afraid I might mess up the spring. I'm sorry I'm asking so many questions, but I just want some guidance from folks that have more experience than I do. I hate messing things up!

Thanks again,
Jim

Posted: Sun Mar 01, 2009 9:20 pm     Post subject:

sorry i would recommend stripping the clock COMPLETELY before cleaning.

However if you are cleaning a hermle then the least you have to do is remove the barrels, which are detachable, then take the mainspring out of each one and clean individually.

rinse everything and dry immediately.