Hermle clock problems with chime train

[LittleWatchShop]

I posted this issue on that other forum but nothing satisfactory results.

Here is a ST branded movement but it is a Hermle 340 I believe. 

The problem is this: with just the chime train installed (no levers), I get a hiccup at the fly.  I believe that the warning wheel interface to the fly is such that the wheel tooth sometimes hits the top of the fly pinion tooth and it jerks or hiccups and then moves on.  It appears to be a depthing issue, or worn pinion...neither are very satisfying to me.  I have downloaded the Hermle 340 exploded view from Cousins and am convinced I am using the proper fly.  Moreover, I have watch some videos an looked at images that confirm this as well.

At first blush, one would think "bushings."  Indeed, I have already rebushed the second wheel--it was BAD! However, there is almost no play in the warning wheel and fly.  In fact, If I manually push the two together for maximum engagement, I can still slip the warning wheel past the fly pinion.

It feels like a design flaw or manufacturing flaw.

Where to go from here?

I will follow up with pictures and video

Here is a video

https://youtube.com/shorts/1c_utsrSHjw?feature=shared

[HectorLooi]

Try filming it in slo mo or super slo mo. I believe that the fly is hitting something when it gathers speed.

[LittleWatchShop]

  On 3/21/2025 at 1:54 PM, HectorLooi said:

Try filming it in slo mo or super slo mo. I believe that the fly is hitting something when it gathers speed.

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Problem is it might take 10 seconds or so before it happens...let me give it a try.

Start watching at 28 seconds

 

[watchweasol]

Does it happen at the same place every time, try marking the wheel . When watching it ,it gives the impression of not running at a constant speed, might just be the video. .One assume# that all the wheel teeth are ok and cut evenly.

[LittleWatchShop]

  On 3/21/2025 at 3:20 PM, watchweasol said:

Does it happen at the same place every time, try marking the wheel . When watching it ,it gives the impression of not running at a constant speed, might just be the video. .One assume# that all the wheel teeth are ok and cut evenly.

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Happens at different locations.  There is some aliasing due to the sample rate of the video.

I can detect no wear on the teeth of gear or pinion.

[watchweasol]

It is possible that the problem is further back in the train and exhibits only at the fly and warning wheel. In such cases I usually dismantle the clock and re build ths strike side wheel by wheel , without the barrel and checking as each wheel is fitted back out to the fly. Laborious I know but whan chasing rainbows some times necessary.

[HectorLooi]

Couldn't see anything in the slo mo.

I agree with @watchweasol, check each wheel individually for freedom of motion and endshake. Then 2 wheels at a time, checking for interference and depthing.

[LittleWatchShop]

These are certainly valid troubleshooting techniques, but I already know that the depthing of the warning and fly is inadequate, yet there is no evidence of enough pivot wear to support the depthing issue.  It is a mystery.

[RichardHarris123]

You all know, I know very little about clocks, not even sure that I understand the problem, so please feel free to laugh at my suggestion. 

Is it possible that the highlighted area has been bent, just enough to affect the depthing?  

As said feel free to laugh, it does us good. 

[LittleWatchShop]

  On 3/21/2025 at 5:03 PM, RichardHarris123 said:

You all know, I know very little about clocks, not even sure that I understand the problem, so please feel free to laugh at my suggestion. 

Is it possible that the highlighted area has been bent, just enough to affect the depthing?  

As said feel free to laugh, it does us good. 

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No, this is not a dumb question.  It is something I have checked and it appears OK.  During my research, I saw where someone suggested heating that pensula where the fly is, and then bending it to the left a tad.  This seems drastic to me. 

[AndyGSi]

Can you post another slowmo video looking down from the top.

[LittleWatchShop]

Here in super slow motion.  Hiccup right at the beginning.

 

[nevenbekriev]

  On 3/21/2025 at 5:15 PM, LittleWatchShop said:

No, this is not a dumb question.  It is something I have checked and it appears OK.  During my research, I saw where someone suggested heating that pensula where the fly is, and then bending it to the left a tad.  This seems drastic to me. 

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Actually, this 'peninsula' is made exactly for depthing regulation, simply by bending it. Only one correction - no heating is needed. This is silly idea. Guys, have You never worker on alarm clocks? This is traditional way for depthing the escapement there and the verge for the bell hammer too. Be brave and bend it a little. The main idea of this regulation here is to obtain depthing where the noise is smallest, but use it to obtain correct interaction without hesitation

[LittleWatchShop]

  On 3/21/2025 at 7:02 PM, nevenbekriev said:

Actually, this 'peninsula' is made exactly for depthing regulation, simply by bending it. Only one correction - no heating is needed. This is silly idea. Guys, have You never worker on alarm clocks? This is traditional way for depthing the escapement there and the verge for the bell hammer too. Be brave and bend it a little. The main idea of this regulation here is to obtain depthing where the noise is smallest, but use it to obtain correct interaction without hesitation

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Not sure how to grab the peninsula to bend it, but otherwise, I think I agree.

"Be brave and bend it a little."

[watchweasol]

Hi L.w.s. Agree with Neven, be brave   Attached some pages from the manual FIY.  Cheers

[rjenkinsgb]

It looks (and sounds) like the depth of engagement between that last wheel and the vane shaft pinion is wrong, with then not meshing correctly.

I agree with the other posts - adjust the mesh depth!

I get the impression they are almost completely out of mesh, to the the point the tooth ends are very near jamming against each other rather than meshing and turning smoothly & that's causing the noise and occasional jams.

 

[LittleWatchShop]

  On 3/21/2025 at 8:07 PM, rjenkinsgb said:

It looks (and sounds) like the depth of engagement between that last wheel and the vane shaft pinion is wrong, with then not meshing correctly.

I agree with the other posts - adjust the mesh depth!

I get the impression they are almost completely out of mesh, to the the point the tooth ends are very near jamming against each other rather than meshing and turning smoothly & that's causing the noise and occasional jams.

 

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Yup...definitely a meshing issue.  What a poor design.  I will build up the courage to do some bending. Fortunately, it is my clock and I have $3 invested so far.

[LittleWatchShop]

I think I am going to hit it with a little heat unless someone objects

[HectorLooi]

  On 3/21/2025 at 7:02 PM, nevenbekriev said:

Actually, this 'peninsula' is made exactly for depthing regulation, simply by bending it.

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I've always wondered why there was this little finger.

But shouldn't the meshing distances been pre-determined before locating the holes on the plates? And why only the fly has this adjustment and not every wheel?

[Dell]

Do you have a depthing gauge if you have then check with it first before moving because that will not only tell you if depthing is correct & if not it will tell you how far & what direction.

[MikeEll]

  On 3/21/2025 at 7:02 PM, nevenbekriev said:

Actually, this 'peninsula' is made exactly for depthing regulation, simply by bending it.

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Exactly, that’s what its there for.

[oldhippy]

Do not bend anything you can cause more trouble. Remove the fly and check that it is tight and not able to move unless the whole thing rotates. Run the strike without the fly. Did you check to make sure all the wheels run true and no bent pivots or teeth and the pivot holes ar all good. Let me know how this goes.

 

 

 

 

 

[HectorLooi]

  On 3/21/2025 at 8:15 PM, LittleWatchShop said:

What a poor design.

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So far I've only worked on 2 Hermle clocks, 1 anniversary clock and 1 Westminster chime clock.

The movements appeared to be well made and above average quality. I don't think this is a design problem. Hermle 340 movements have been around for some time and are used by many clock manufacturers. If it were a design problem, I'm sure we would have heard a lot more complaints. 

[LittleWatchShop]

  On 3/22/2025 at 11:37 AM, HectorLooi said:

So far I've only worked on 2 Hermle clocks, 1 anniversary clock and 1 Westminster chime clock.

The movements appeared to be well made and above average quality. I don't think this is a design problem. Hermle 340 movements have been around for some time and are used by many clock manufacturers. If it were a design problem, I'm sure we would have heard a lot more complaints. 

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You make a good point. Maybe it is a manufacturing issue. There is no way this clock ever worked right.

When I return to my other shop tomorrow,  I will check to see of someone switched the brass fly wings of the two arbor (chime and strike). It's a long shot!

[oldhippy]

The early movement were fairly well made. These modern ones are expensive rubbish, the so called brass is soft you can tell that when you need to re-bush, the steel is also soft again you can tell that when you need to do work on the pivots or replace one. The springs are way to powerful for the so called brass and steel causing exc=sesif wear throughout the movement.  Give me a Smiths chiming movement any day or better still an Elliott which I collect.