Jump to content
Deggsie

Help with Amplitude Please

Recommended Posts

Hello all, I hope you’re keeping safe and well?

 

Can someone please confirm where amplitude is measured from please? Is it : -

 

A: the angle travelled from the balance wheel’s rest position (ie roller jewel between bank pins) to maximum swing, or

 

B: angle travelled from max arc swing in one direction to max arc swing in the other direction, or

 

C: something different

 

I hope that makes sense, if not let me know and I’ll draw a sketch ... I usually prefer sketches but being lazy just now. .

 

This question has come about because today I video recorded a movement in slow motion and was astounded. The balance wheel swing was 460 degrees max swing to max swing. I thought a condition called ‘over banking’ occurred way before that angle was achieved?

 

Kind regards

Deggsie

 

 

Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

It's A.

See my responses here and here.

You have an amplitude of 230 degrees, giving a total swing from one extreme to the other of 460 degrees.

If you think about it, from the balance sitting at rest, it can rotate through something like 345 degrees in either direction before the impulse pin makes contact with the wrong side of the pallet fork, so it should be possible to see a total (extreme clockwise to extreme anticlockwise) swing of about 690 degrees without over-banking.

 

Edited by Marc
additional link

Share this post


Link to post
Share on other sites

Hello Marc,

Thank you for taking the time to clarify that, although I was really hoping the definition of amplitude would be B (full swing to full swing). Sitting here now, I have a sinking feeling of failure and inadequacy! Usually I struggle to get 180 degrees amplitude (360 degree on the slow motion video). I think I might take up darts instead

Keep safe all

Regards
Deggsie


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

Don't be too downhearted @Deggsie, 230 degrees isn't too bad, it all depends on the movement, its age, new/old main spring, etc...   If it's a newly serviced 1980's ETA with a new main spring on full wind then 230 is on the low side. A similar aged Seiko with its original m/s 230 is ok, something from the 1930's with its original blue steel m/s 230 is pretty good. It's all a matter of perspective. You need to let it run at least 24 hours after servicing it for things to settle down, amplitude often goes up in that time.

Share this post


Link to post
Share on other sites

Hi Degssie. You would want the oscillator reach max speed as impulse jewel gets to delivering energy to the fork and you have zero speed at " max arc swing" at end of path in each direcrion. So your electrical engineering glasses are showing things correct. Article B is correct. Marc simply shows where velocity hits zero. Now if you understand what I just said, I am glad one of us dose.

Share this post


Link to post
Share on other sites

Thank you for the attachment Marc, and also for clearing up what had again confused me. I’m now certain I know what amplitude is. At least until I forget

The good news is I made progress today. I stripped the whole movement, cleaned, rinsed and reassembled.

I watched a very interesting video made by a gentleman called Christian (the watch guy) who demonstrated how he lubricates the escapement. Basically, assemble dry then apply tiny dot of 9145 to a tooth. Advance 5 teeth by manually moving the pallet lever, apply tiny dot, and repeat a third time. Unfortunately I don’t have 9145 so used 8000. This method definitely improved my amplitude, and using 9145 may improve it more.

I now have 220 degrees of amplitude which I’m happier with.

Stay well and keep occupied
Kind regards
Deggsie


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

Thank you Marc for taking the time to help clarify this. Hopefully it helps me decide weather dart or fresbie. Good to hear Degssie back to keeping busy. Regards Joe

Share this post


Link to post
Share on other sites
On 4/19/2020 at 6:03 PM, Nucejoe said:

Hi Degssie. You would want the oscillator reach max speed as impulse jewel gets to delivering energy to the fork and you have zero speed at " max arc swing" at end of path in each direcrion. So your electrical engineering glasses are showing things correct. Article B is correct. Marc simply shows where velocity hits zero. Now if you understand what I just said, I am glad one of us dose.

I should apologize for having wrongly entered choice B as correct. The rest of my post clearly points out to the interval between the two zero amplitude the midpoint of which amplitude is highest

.Regards Joe

Share this post


Link to post
Share on other sites
I should apologize for having wrongly entered choice B as correct. The rest of my post clearly points out to the interval between the two zero amplitude the midpoint of which amplitude is highest

.Regards Joe

Hey , no need to apologise. I understood what you meant. I think I was being lazy and should have created a sketch to eliminate ambiguity. No harm done. I actually stripped, the movement, cleaned and relubed. The movement has good amplitude now for its age.... however the root cause was due to the escapement pivot being too long. As soon as I tighten down the end jewel the amplitude reduces. I need to safely shorten the pivot by micron at a time

 

 

Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites
39 minutes ago, Deggsie said:

however the root cause was due to the escapement pivot being too long. As soon as I tighten down the end jewel the amplitude reduces. I need to safely shorten the pivot by micron at a time

So, the jewel is capped, like a balance staff? May I ask what calibre? I have serviced two movements having capped escape wheel pivots; an ETA 1080 and an ORIENT 46E40 (Diafix jewels).

I'd say about a third of the watches I have serviced have increased their amplitude. The rest have either maintained their amplitude or lost amplitude. In one case (and one case only) losing amplitude was a positive thing (a HAMILTON Khaki housing an ETA 2824-2) as it was re-banking in one position. After servicing the amplitude was surprisingly even in all positions. Dial up/down 330 degrees and in all other positions about 280 degrees. BTW, that is the best result I ever achieved after a service, but I was basically just lucky as the topic is complex not to mention often difficult to do anything about. I've made the following notes which I try to check when I have amplitude problems:

o    Too much pallet stone locking. The amount of lock is generally considered to be one sixth of the width of the impulse face.
o    Over-oiling in general, for example, the pallet stones, the seconds hand pivot.
o    Jewel settings not sitting flat under the anti-shock spring creating friction on the balance staff pivots.
o    Too little end-shake (remember the Seagull having a hump under the balance cock to compensate for this).
o    Pivots and jewel holes not cleaned and polished well enough!
o    Cracked jewels (friction).
o    Too weak mainspring.
o    Hairspring problems (magnetism, dirt, debris, asymmetrical)
o    The hairspring index pin being bent.
o    The hairspring not moving evenly between the boot and the index pin.
o    Train of wheels not running smoothly (friction problems).

The Moebius 9415 Pallet stone oil seems to be what everyone is using but I've had some very good (better!?) results with "Dr. Tillwich Type 1-3". Anyway, WRT is full of threads on this topic so I'm not trying to start another debate about it here. Just thought I'd mention it.

Edited by VWatchie

Share this post


Link to post
Share on other sites

Lots of good stuff there @VWatchie you been really busy.
And to confuse Deggsie even more I found a compilation I made not to long ago with some pictures which maby can bring some enlightment in your hunt for more amplitude. 

In my books most of the times one gain the most Amplitude when one concentrate in cleaning and lubricating the balance and escapement area since it is after all here the action takes place. Regulating the watch correctly also will give you a boost.

A fresh mainspring will just add some more icing on the cake.

So here is a small compendium I made just for you ;) .

Watch Theory Escape-Regulator.pdf

Share this post


Link to post
Share on other sites
1 hour ago, HSL said:

So here is a small compendium I made just for you ;) .

Well, that looks just fantastic and the illustrations are just brilliant! :Bravo:

Haven't yet had the time to read it through but you can be sure I'll read it through carefully. Thank you!

Share this post


Link to post
Share on other sites

Ditto. Thank you very much. The graphics are super clear and beautifully support the text. Is it your profession also to prepare this sort of documentation?

Kind regards Deggsie


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites
So, the jewel is capped, like a balance staff? May I ask what calibre?

Hello, the calibre is AS1194, and yes escapement has a capped jewel. If I tighten this the balance almost stops! Remove the end stone and reasonable amplitude is restored. The escapement is too long and I need to shorten one of the pivots. Of course, the issue may be the bridge is locally depressed.
7d8d7e1fde131b9f19d6ba9e7379b845.jpg


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites
8 hours ago, Deggsie said:

The escapement is too long and I need to shorten one of the pivots. Of course, the issue may be the bridge is locally depressed.

Looks exactly the same as the ETA 1080 that I serviced:

018.thumb.JPG.a09f0edb80ad643b67ee448cbb0c329e.JPG

Well, that's a tricky situation and one that I never would have anticipated and I suppose the cap jewel can't be adjusted a bit using a jeweling tool? Too little end shake on non capped jewel is of course an easy fix if you have a jeweling tool, but in this case, hmm... If anyone has experience of handling this situation it would be interesting to hear. If you need to shorten the pivot my guess is that a jacot tool (haven't got one of those, yet...) would do the job!?

Share this post


Link to post
Share on other sites
8 hours ago, Deggsie said:

Ditto. Thank you very much. The graphics are super clear and beautifully support the text. Is it your profession also to prepare this sort of documentation?

No, I'm in the reaserch area. Just  writing repports day out and day in when not conducting  tests.
But I been following Andy Hulls inspiering post and thought I would try to learn how the big boys do it, so I got on it and fetched even more inspiration from well known sources... One have to have a go at everything before on die or. Next objects will be from the louvre..
5453261_SomeDrawings.thumb.jpg.0876cefadcf39713e3dbfcdc20fdf5e6.jpg

Share this post


Link to post
Share on other sites
4 hours ago, VWatchie said:

Looks exactly the same as the ETA 1080 that I serviced:

018.thumb.JPG.a09f0edb80ad643b67ee448cbb0c329e.JPG

Well, that's a tricky situation and one that I never would have anticipated and I suppose the cap jewel can't be adjusted a bit using a jeweling tool? Too little end shake on non capped jewel is of course an easy fix if you have a jeweling tool, but in this case, hmm... If anyone has experience of handling this situation it would be interesting to hear. If you need to shorten the pivot my guess is that a jacot tool (haven't got one of those, yet...) would do the job!?

It appears that the jewel is "rubbed in", although in a more modern way, i.e. it looks like the steel was crimped around the jewel likely in a very automated process. That would mean the hole at the top side of the jewel is smaller than the jewel diameter- thus no chance of adjustment, although a good chance of cracking the jewel.

 

This method if securing jewels in steel parts persisted quite some time after friction jewels became the norm, as the interference fit between steel and a jewel needs to be something like 0.002-3mm, rather than ~0.01mm for brass. With this method the opening for the jewel is made for a free fit, then the metal moved to hold the jewel, less chance of breaking the jewel and less precision needed in manufacturing.

Share this post


Link to post
Share on other sites
It appears that the jewel is "rubbed in", although in a more modern way, i.e. it looks like the steel was crimped around the jewel likely in a very automated process. That would mean the hole at the top side of the jewel is smaller than the jewel diameter- thus no chance of adjustment, although a good chance of cracking the jewel.
 
This method if securing jewels in steel parts persisted quite some time after friction jewels became the norm, as the interference fit between steel and a jewel needs to be something like 0.002-3mm, rather than ~0.01mm for brass. With this method the opening for the jewel is made for a free fit, then the metal moved to hold the jewel, less chance of breaking the jewel and less precision needed in manufacturing.

I’ve swapped the cap jewel / keeper plate with two other identical assembles from an eta and es. It seems they are bog standard in geometry. Neither rectified the darn problem. I’m 100% certain I need to shorten the dial side pivot, or ... try another escapement for this movement. However, for now, I’m in no hurry to do anything irrational- it will have to wear itself down before wears me down


Sent from my iPhone using Tapatalk

Share this post


Link to post
Share on other sites

Arriving late to the party would you refresh my memory? So I always like to know what was the condition of the watch in before? Then what have you done to it?

Then looking at this discussion one of the things that's really helpful for diagnosing problems is a timing machine. I know hobbyists are operating under a budget but the Chinese timing machines are very affordable work really well and they let you see things that you really can't see any other way. Then if you're having a problem they are even more helpful.  Or basically I think you're insane to repair watches without a decent timing machine which is now affordable versus what it used to be.

On 4/26/2020 at 4:52 AM, Deggsie said:

however the root cause was due to the escapement pivot being too long. As soon as I tighten down the end jewel the amplitude reduces. I need to safely shorten the pivot by micron at a time

I just find it interesting that the pivot is too long and wondering how that has occurred? Especially if this was a running watch before. Also if the place is ben what is the end shake issue like for the other wheels? Also if you shortened the pivot remember to restore it to its original shape otherwise you're going to have issues because you change the shape of the pivot. Also did you look carefully at the pivots themselves to make sure that there not bent.

 

http://www.ranfft.de/cgi-bin/bidfun-db.cgi?10&ranfft&0&2uswk&AS_1194

https://watchguy.co.uk/cgi-bin/lift_angles

Share this post


Link to post
Share on other sites

You need to look at the pivot and cap 5 times before you decide to shorten the pivot. If after much examination and a good night sleep, you still feel a need to shorten the pivot, then use a Jacot tool with the right lantern and hole size on the end.  Or a lathe and measure, measure, measure.

Share this post


Link to post
Share on other sites
On 4/30/2020 at 9:15 PM, Deggsie said:

How would you shorten the pivot VWatchie? I’m thinking a very fine slip stone

I don't know, but I agree with @jdrichard that a jacot tool is the way to go. I haven't got a jacot tool (yet ) so I can't say for sure but as I understand it, it can be used to reduce the diameter of pivots (increase side shake), polish pivots, and shorten the length of pivots. Of course, I would expect the top of the pivot to be rounded (as a balance staff pivot) but have no idea how this would be accomplished and if the jacot tool somehow can assist with this too? Perhaps @jdrichard can enlighten us some more?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...