Hermle 340-020 floating balance adjustment

[Bill Lawson]

We have a Hamilton mantle clock with Hermle 340-020 works that used to belong to my wife's grandmother. It has a lot of sentimental value to my wife. It runs pretty well but.... I adjusted the floating balance to the maximum on the plus side and it loses about a minute a day. It has the older style floating balance. I cleaned and lubricated the pivot points on rest of the works, with clock oil, but that didn't seem to help speed it up. So, now I'm looking at removing a pair of weights from the floating balance. I adjusted it all the way to the minus and it lost around two and a half minutes a day. I did that to try to figure out which pair of the weights to remove. I'm hoping to land, with it keeping good time, somewhere left of center on the adjustment. I have a diagram that shows me which pair to remove to speed it up 2 minutes a day. So that is where I thought I'd start.

Those are a lot of words to get to the question. My question is this: do I have to let down the tension on the main timekeeping spring before I remove the floating balance?

Thanks in advance.

Also, if my logic is wrong on which pair of weights to remove, or if you have any other tips or suggestions I'd appreciate you sharing your thoughts. Thanks again.

Without this forum I wouldn't have known a floating balance from a mainspring. I feel good to have at least cleaned and lubricated the clockworks and to have gained the knowledge of how to adjust the floating balance to regulate the clock. I even saw how that adjustment moved the first level weights in and out, simple but effective. What precious little clock knowledge I have I owe to this forum. You all are awesome to me.

 

[dickstorer]

Mr. Lawson,
You do not have to let the power down to remove the balance. With the bal whl out, the mechanism will not run. May I ask how much rotation you are getting on the balance wheel? With the clock fully wound the bal. should rotate at least 270 degrees. If not, you are probably chasing your tail. You stated that you cleaned and oiled the movement, did you take it apart to clean?

Before you do anything, a minute a day is not bad.

 

[Bill Lawson]

Thank you for your reply,
I didn't totally take the works apart. I know I'd be in over my head if I tried to take it all apart. I did remove the works from the case. I cleaned the dirt, that I could see from the outside, off each pivot point. I applied the clock oil after that. But only enough to fill the little wells, being careful not to let it run over the sides of each well. That was tricky for me. I ended up using a small sewing needle backwards to apply it with. I know that the gold standard is to take the works apart. But as the famous clockmaker Dirty Harry said, "A man's got to know his limitations." To answer your question on the balance wheel rotation, I've now studied it's movement the best I can. For me that is to watch it at the very bottom. If I watch the big ring, it moves so fast that I can't tell what part I've seen before. But, from what I can see it is over 180 degrees but not 360 degrees. Thanks again.

 

[wow]

These movements usually require bushings in every train. A total tear down is almost always necessary. It’s probably about 50 years old? If it is that sentimental to your wife and you do not have the tools and knowledge to do a total rebuild, you should take it to a good repair person or replace the movement with a new one. Butterworths sells replacement movements at reasonable prices.

 

[R. Croswell]

If you don't already have this, download it here: hermle_floating_bal_summary.pdf (davesclocks.net) there is almost never a need to remove any of the weights in the floating balance. At one time the balance was adjusted for the proper weight to keep time. If it no longer keeps time, and nothing is broken, either the balance pivot jewels are dirty or the balance is not getting enough power from the going train of the movement because of wear and/or accumulated dirt. If you remove weights to speed up the clock and do nothing else, the "fix" will be short lived and eventually the clock will stop running. When you find and fix the problem, it will run too fast, and you will be faced with the task of replacing the weights (if you are able to find them).

The first step is to determine whether the problem is with the balance or the going train. Follow the instruction in the above document and remove the balance assembly. Clamp it in a vise (gently) and turn the balance wheel 270 degrees in one direction and release it. If it is ok it will rotate on its own for close to 5 minutes (3 minutes minimum). If it passes, don't mess with it and DO NOT attempt to oil it.

With the clock running, 180 degrees rotation is insufficient. You should be getting 360 degrees (270 minimum). If disassembling and cleaning and checking the pivots and pivot holes for wear is beyond your pay grade, best to set it aside until you have more experience, or farm out out to someone who can solve the problem. Your continued efforts to resolve the timekeeping issue by altering the balance will only make it more difficult in the long run. I know this isn't what you want to hear, but it is what it is. Good luck.

RC

 

[Willie X]

If the balance shaft is touching the frame (at the bottom) it will loose time. If someone has cleaned the balance in a ultrasonic cleaner it will loose time. And if there is anything dragging in the escapement (often the little dart that moves in and out of the rotation limiter or binding on it's wire pivot) that will cause a clock to loose time. That's about it on the loosing time.

A worn out train is usually the culprit for gaining time. Look up 'checking for wear'.

Test the rotation by placing a large sharpie pen mark on top of the balance rim, in line with the double rollers (drive pins). You can easily see the mark when it stops.

You can clean the balance when it's off the clock. Occasionally there is a cumulated oil in the holes, this can cause cause a clock to run slow. Soak it in Coleman Lantern Fuel for about 10 minutes and carefully brush off any residue. I will post before and after photos, if I can find them ... Willie X

 

[Bill Lawson]

R. Croswell,
I appreciate your guidance and the floating balance pdf. I'd prefer to know "what it is" than to make a mistake that I'd regret later. Thank you.

Willie X,
I appreciate you chiming in (see what I did there LOL). I had actually considered putting a mark on the balance rim to aid in trying to discern how many degrees it is rotating. That will be my next step. Along with testing it by following the steps in the .pdf that R. Croswell provided. If you could post those photos it would be a big help to me. Thank you.

Thanks to both of you, I'm going to study that floating balance more. It seems like the next best place to focus on.

 

[Bill Lawson]

So, with the clock running, the floating balance does go past 180 but definitely not 270 degrees. Also, when I removed it and tested it according to the instructions in the pdf it stopped way before three minutes. I see no visible oil or residue on it anywhere. So I'm thinking it may need to be replaced. Where is a good place to buy a replacement?

 

[Elliott Wolin]

Two things worked for me (n.b. I'm a beginner). First, I took a cell phone video of the balance in action and everything was completely clear when playing it back at reduced speed. I.e. I could tell exactly how much rotation I was getting in both directions (eventually over 400 degrees total).

Second, after soaking in Coleman fuel (as noted above), it wouldn't run well. I put the tiniest dab of synthetic watch oil on the upper and lower bushings using a watch oiler, and it's been running great ever since. Indeed it's hard to stop it as, if you do, the slightest vibration gets it going again.

 

[Bill Lawson]

Two things worked for me (n.b. I'm a beginner). First, I took a cell phone video of the balance in action and everything was completely clear when playing it back at reduced speed. I.e. I could tell exactly how much rotation I was getting in both directions (eventually over 400 degrees total).

Second, after soaking in Coleman fuel (as noted above), it wouldn't run well. I put the tiniest dab of synthetic watch oil on the upper and lower bushings using a watch oiler, and it's been running great ever since. Indeed it's hard to stop it as, if you do, the slightest vibration gets it going again.

Thank you! I think I'll give it a shot. I'm guessing clock oil is probably too thick?

 

[Elliott Wolin]

Yes, watch oil is typically very thin. I don't recall what I used, but there are many brands. The thinner the better for this application in my opinion. A synthetic oil is probably best as it's less likely to thicken with age

But note that many people say not to use any oil at all in these floating balances. Mine just wouldn't work well dry.

 

[dickstorer]

To Elliott Wolin--appreciate you coming forth about oiling the floating balance. I, too, always use a good grade of synthetic watch oil on them.. And I usually put them in my US cleaner. If the US cleaner does not harm a watch hairspring I think a floating bal spring would survive.

 

[R. Croswell]

These things have a small tube through the center with a tiny jewel bushing in either end and a thin wire through the tube about which the balance rotates. The problem I see with the US is that a water based solvent is usually used (unsafe to use Coleman fuel or combustible petroleum solvents). If you get that tube filled with solvent you may have trouble getting in out. When the cleaner eventually dries up you will have a bigger mess. Soaking in Coleman fuel or “OneDip” while rotating the balance and shifting it back and forth along the wire should flush the trash out of the jewels nicely. Hopefully you complete the process quickly and not too much gets inside the tube.

Regarding oil, opinion seems divided between no oil and just a thin film. If going with oil, do use thin watch oil, apply the tiniest amount to the wire at both ends. Work the balance along the wire and blow off any excess. There is really no loading as the balance is suspended and the wire is more like a guide to keep it in place. I tend go with the no oil group.. if there is no oil there will be no dust attraction and no oil to dry up and get sticky.

I hope it goes without saying, NO WD-40!

RC

 

[Willie X]

Note, there is no need to give rate/ regulation any thought until you get the balance rotating at about 360°. Willie X

 

[Bill Lawson]

Note, there is no need to give rate/ regulation any thought until you get the balance rotating at about 360°. Willie X

Understood, I gave up on that idea for now. Thanks!

 

[R. Croswell]

Note, there is no need to give rate/ regulation any thought until you get the balance rotating at about 360°. Willie X

Note, there is no need to give rate/ regulation any thought until you get the balance rotating at about 360° - that needed to be said again! And I'll add to that until it free rotates (unpowered in the described test) for better than 3 minutes.

RC

 

[Bill Lawson]

Note, there is no need to give rate/ regulation any thought until you get the balance rotating at about 360° - that needed to be said again! And I'll add to that until it free rotates (unpowered in the described test) for better than 3 minutes.

RC

Got it, I don't intend to do anything more than get the floating balance working properly from this point on. After that happens I will reassess. Thank you for taking the time to reach out to me again. Are you sure on the WD-40? Just kidding, I may be a clock neophyte but I actually know a little bit about oils. And I don't usually just go off doing things I don't know much about without first seeking expert advice. That's why I joined this forum, laid out my plan, and asked for input. Also, in the instant gratification world we live in I can be pretty patient. I know it has to go against the grain of any good horologist that I cleaned and oiled the movement the way I did. But I didn't do it without weighing things out. I think I'd just replace the movement before I'd send it out to be reconditioned. So my thinking was by doing some basic maintenance, that I feel comfortable doing, we could enjoy it as it is for as long as possible before replacing the whole movement. As a test, I put a tiny film of that clock oil on the floating balance wire and things improved a little. But as soon as I can get my hands on some white gas I will remove it and clean it. Then try it without oil first and see If I can get the 360° running rotation and then have it rotate for better than three minutes out of the clock as described. As a last resort I will get some watch oil and try a light film of that on the cleaned wire by the jewels at the ends of the tube and then slide them over it to see that they get a little lubrication. Thank you again. Your input has been very valuable to me.

 

[Willie X]

I would recommend you lay off on the oil. The factory that made them recommends no oil. Willie X

 

[Bill Lawson]

I would recommend you lay off on the oil. The factory that made them recommends no oil. Willie X

Thank you Willie. I didn't have white gas handy but I fully intend to clean it as you recommended. My thinking was since I was going to be cleaning it up soon anyway, why not try a tiny film of oil on that wire right near the jewels. It might give me some indication if the floating balance, that we have, can be resurrected (improved.) It did that. It's not perfect now but the time lost over 24 hours was more than cut in half. It is still, however adjusted to the max on the plus side. But that test actually encouraged me more to try your method for cleaning it. I also have my eye on a replacement floating balance if I'm not able to get this one up to spec.

Those images you provided were amazing. I don't know how anyone could think that laying on the oil like that could in any way be good for a delicate thing like a clock movement. Mine shows no outward sign of having ever been oiled. I know now that ours has a slight amount of oil on/in it, because I used it for testing. I fully intend to clean it and try to rehabilitate it without using oil at all as you suggested. But, if after cleaning it thoroughly it's still not up to the specs Mr. Croswell provided., I'll be honest I will probably try that tiny amount of oil again I just tried for testing.

Willie, I truly appreciate your advice. It has helped me see the importance of less is more and to understand how it was designed in the first place. I'll report back in this thread how it goes.

I want to thank you ALL for your insight, patience, and time. And for genuinely trying to help me. It has been very encouraging to this stranger who is playing in your playground.

 

[Willie X]

The problem comes when a foreign substance gets past the jewels and into the brass tube. There is no way to remove it and there was no reason to put it there in the first place

The reason for that 'before' photo was to see the end result of oiling. People, in general, just love to oil and bend stuff! Did you notice the splayed out banking tabs. They are supposed to be parallel, or very close to parallel.

Just more job security for us clock people I guess ... Willie X

 

[Bill Lawson]

The problem comes when a foreign substance gets past the jewels and into the brass tube. There is no way to remove it and there was no reason to put it there in the first place

The reason for that 'before' photo was to see the end result of oiling. People, in general, just love to oil and bend stuff! Did you notice the splayed out banking tabs. They are supposed to be parallel, or very close to parallel.

Just more job security for us clock people I guess ... Willie X

I did see the splayed out banking tabs right away. Although I had no idea that they were called banking tabs. But that name makes sense now that you say it. At first I thought that the before image wasn't of the same unit as the after. Then I realized you are not only a clock guy but also a magician. I hope that I wouldn't ever get that far off track. I learned a long time ago not to force a mechanical thing. And I'm sure that applies to a clock movement more than many other things. I know that I crossed a line by adding that little bit of oil in my "experiment." I now have the white gas and am on my way to cleaning the whole mechanism. I'll let you know how it goes. Thanks for the thinly disguised reprimand. I appreciate it all Willie. I mean that sincerely.

 

[Willie X]

The main (and first) thing to do on these clocks is to isolate the problem.

A good 'run down' time on the free balance wheel test will give you a green flag on that.

With the balance out and the time spring wound up and let back down about one turn, test the train for power. Simply move the little balance fork left and then right, using a toothpick or similar. You should hear and see a nice sharp movement from one side to the other. This should be accompanied by a nice metallic click. Do this twenty or thirty times and this will give you some idea of the power available. If you see and hear a soft tick or a thud here and there. Your movement gets a red flag. Look up 'checking for wear'. This is done with the springs let completely down.

In short, if you have a 'good to go' in both just mentioned departments, your problem will be in the escapement itself.

That will take a lot more study on your part. On this MB there are hundreds, maybe a thousand, post and articles on this movement.

Willie X

 

[Bill Lawson]

The main (and first) thing to do on these clocks is to isolate the problem.

A good 'run down' time on the free balance wheel test will give you a green flag on that.

With the balance out and the time spring wound up and let back down about one turn, test the train for power. Simply move the little balance fork left and then right, using a toothpick or similar. You should hear and see a nice sharp movement from one side to the other. This should be accompanied by a nice metallic click. Do this twenty or thirty times and this will give you some idea of the power available. If you see and hear a soft tick or a thud here and there. Your movement gets a red flag. Look up 'checking for wear'. This is done with the springs let completely down.

In short, if you have a 'good to go' in both just mentioned departments, your problem will be in the escapement itself.

That will take a lot more study on your part. On this MB there are hundreds, maybe a thousand, post and articles on this movement.

Willie X

Thank you, Willie, for hanging in here with me. Your first priority of isolating the problem makes perfect sense. It is how I troubleshoot most things and it makes sense here as well. My problem is not knowing the proper sequence or even how to do the tests. I think I blew it on my original testing of the floating balance. I am now confident in having done it correctly. And green flag on the floating balance. I redid the tests before doing the dip. It went just over five minutes on the bench test and very close to 360° while the clock is running. Your suggestion of marking the wheel with a sharpie was money. I made the mistake of trying to watch the mark from the front. But if I look to the back I can watch the mark come into view and briefly slow to a stop before going around to the other side. It really is a great way to check for 360° while running. So on to other tests for now. I will do the fork test probably tomorrow. I see how to let the springs down but would feel a lot more comfortable letting them go down on their own. I know for the next test the one to let down a turn is the time spring and that is the center one. I don't have a great way to secure the movement while holding the "click thing" back and using my driver to let it down. So I'll wait. I do have a driver that fits the square post nicely though. I have a question about oil. Should I put a tiny amount of clock oil on the pivot point of that little balance fork? Right now it moves with seemingly the slightest touch. I know I keep repeating this, but I thank you again and again. I don't think I can thank you enough.

 

[Willie X]

Just lay the movement on its back, on a folded bath towel and have at it. If the balance is attached to the movement, you have to be carefull with that. Maybe doubling the towel a second time, if it seems necessary. Willie X

 

[Bill Lawson]

Two things worked for me (n.b. I'm a beginner). First, I took a cell phone video of the balance in action and everything was completely clear when playing it back at reduced speed. I.e. I could tell exactly how much rotation I was getting in both directions (eventually over 400 degrees total).

Second, after soaking in Coleman fuel (as noted above), it wouldn't run well. I put the tiniest dab of synthetic watch oil on the upper and lower bushings using a watch oiler, and it's been running great ever since. Indeed it's hard to stop it as, if you do, the slightest vibration gets it going again.

Taking a video really did the trick. I thought I was seeing the sharpie mark I made slow and stop at the back, which would put it at 360°. It turns out the floating balance mark is quicker than the eye. Tonight I took a video and saw that it was actually close to 450°. So that part isn't the culprit unless 450° is too much. Thanks for the great tip!

 

[Bill Lawson]

I tried everything I was comfortable doing. So I ended up moving two weights. There were two that were removed like the ones in the picture Willie X provided. You can see one is removed from the arm that connects to the outer ring. I moved the ones that were closer to that outer ring to the hole left from the original ones that were removed. The clock now gains approximately 5 seconds a week. And the adjuster is close to the middle instead of being adjusted all of the way to max gain. I know this is not how most if not all of you would have done this. But it's what I felt comfortable with after having done the other things you all suggested. The good news is that the floating balance performs to the top of the specifications. The clock pivot points have been cleaned from the outside (not perfect I know) and each pivot point has been lightly oiled with clock oil. I never dreamed it would be that accurate and it's been consistent for 11 days now. Also, I let it run for 8 days before fully winding it and it never lost a beat. I'm very happy with that result. If we can get a year or more out of it that would be awesome. When the time comes I'll buy a new movement. But for now there is no need. Thank you all again.

 

[Bill Lawson]

It's been almost 2 months since my last update. The clock is still going strong. We have placed it on an end table in our living room. And we love hearing its soft chimes going off every quarter hour. They're so soft and gentle and I'm so used to it now that I don't even notice the chimes every time they go off any more. All I do is wind it once every seven or eight days. It loses just slightly less than 2 seconds a week. I consider that to be very good. I'm thinking it may change once we get into warmer weather here in Michigan. But for now it's been very consistent. All I will do now to adjust it is nudge the minute hand a tiny bit forward every month or so. I've done that once so far. I'm afraid that if I even touched the adjuster it may only end up making it off more than 2 seconds a week no matter how hard I may try. Thank you all again for all of your thoughtful and considerate advice. Is there anyone here who would try to adjust it to make it even more accurate than it is now if it was their own personal family heirloom? Or am I correct in thinking that's a fool's errand?

 

[Willie X]

If you really said "2 seconds" in a week. Odds of that ever happening would be like winning the lottery and getting struck by lightning on the same day!

A rate inside one minute per week would be very good. Two minutes would be about average and acceptable.

Willie X

 

[Bill Lawson]

If you really said "2 seconds" in a week. Odds of that ever happening would be like winning the lottery and getting struck by lightning on the same day!

A rate inside one minute per week would be very good. Two minutes would be about average and acceptable.

Willie X

Yes, I really said just a tick or two under 2 seconds in a week for the last almost two months. Your description of the odds of that happening brought a smile to my face and is pretty much what I was thinking since it's a mechanical movement. But I wasn't 100% sure. Maybe you clock guys did some clockmaker magic on clocks that were special to you. I guess I'm the one who had the magic happen. And this clock is definitely special to us. Thank you for the confirmation Willie. And thank you again for all of your other helpful input.
.

 

[Willie X]

Thanks for reporting back. Willie X

 

[shutterbug]

So if you win the lottery and are struck by lightning on the same day .... would you be considered lucky? Hmmm.....

 

[Willie X]

You would be 'conflicted' in many ways.
Willie X

 

[Bill Lawson]

So if you win the lottery and are struck by lightning on the same day .... would you be considered lucky? Hmmm.....

Good point! If the winning lottery amount was ≥1 Mil, and the lightning strike was guaranteed to be mild, I'd be willing to take one for the team.