Jump to content

More info about truing calipers please!

VWatchie

By VWatchie
in Tools & Equipment

 Share

Recommended Posts

VWatchie Distinguished Member

VWatchie

Posted
Posted

BergeonNo5896.thumb.jpg.50965b1a6b71dc9e705bf1b6b1e9ca9c.jpg

I just learned that the above tool is called a truing caliper, and from what I gather or conclude by searching the Internet it can be used to determine if a balance wheel and/or a train wheel is in good condition. That is, that the wheel does not wobble vertically or horizontally. I also believe I read somewhere that a truing caliper can be used to rectify a faulty wheel, but I may have misunderstood?

Anyway, I always wanted a method to at least be able to determine that all train wheels and the balance wheel are in good condition, that they don’t wobble, that the pivots are perfectly straight, and so on. Would a truing caliper like the one in the picture help me achieve this, or would there be a better option? I guess as the balance is freely visible it’s pretty easy to determine if it wobbles in any direction, but what about the train wheels?

If someone can shed some more light on this tool and its use I’m sure more than I would appreciate it!
 

  • Like 1
  • Thanks 1
Link to comment
Share on other sites
VWatchie Distinguished Member

VWatchie

Posted
  • Author
Posted (edited)
17 minutes ago, Nucejoe said:

I don't see any use of this with an escape wheel. 

Thanks joe! So, that brings me back to my major question about what would be a the best or a good way to determine that all train wheels and the balance wheel are in good condition, that they don’t wobble, that the pivots are perfectly straight and so on.

Based on your reply I would assume that a truing caliper is the best option for a balance wheel, but what about the train wheels, for example, an escape wheel? How can we best determine that it is perfectly straight when it comes to how the wheel rotates between its jewel bearings, that the arbor and the pivots aren't bent, etc.? I guess eyesight goes a long way, but in the realm of micro mechanics a few hundreds of a millimetre do count and I would assume aren't always visible?

Edited by VWatchie
  • Like 1
Link to comment
Share on other sites
Nucejoe Distinguished Member

Nucejoe

Posted
Posted

Hi, 

Three are following your thread and the only response( mine) didn't really address your questions, that means bunch of us are waiting to learn from answers given by knowlegable folks here  @oldhippy & @nickelsilver  and more.

I had a watch that ran accurate FU & FD but inaccurate in pendent up or down , took me couple of months to find the cause was out of round balance wheel. 

I am self though you know and this was several years prior to start of this forum.

Regards    Joe

 

  • Like 1
Link to comment
Share on other sites
watchweasol Distinguished Member

watchweasol

Posted
Posted

Hi  These poising calipers come in various design like the one attached below and all do the same job. That is to say determining whether a balance rim is running flat and also not out of round. Never having had to use on  train wheels as yet does not mean to say that the same principal can not be used to determine the same. If and when you have to change a train wheel arbour you have to set it up as was (flat and parallel to the arbour) and in the round so as not to cause depthing problems and intermittent stoppages of the watch/Clock.  I have used a home made device for checking clock wheels  after pivoting and checking after mainspring breakages spinning the wheels in the lathe and monitoring its flatness and round.

(964) Pinterest.html

  • Like 1
Link to comment
Share on other sites
nickelsilver Distinguished Member

nickelsilver

Posted
Posted

The Bergeons above are specifically for checking balances for flatness, and in the case of split balances for trueness in the round (a solid balance that isn't round or is eccentric is a bigger problem than what these can handle). The pivots are held by the conical portion, and quite a bit of force can be exerted on the rim to bring it true. The adjustable "finger" is for a visual reference while truing. The truing itself is done simply by finger or with non marking stout tweezers.

 

The one below is a typical caliper for checking and truing train wheels. It holds by the end of the pivot, in V shaped cups. The little tool with the dovetail filed in is the traditional visual reference, it is simply slid around until a point is near the wheel rim, the wheel turned by hand, and checked for flatness. That little dovetail tool is usually one of the first projects a student makes in school, I don't think they sell them (I think my daughter made this one a couple of years ago as a project, hahah). Adjustment is carried out with stout tweezers, with one tip pressing in the center by the pinion, the other side of the tweezer is lifting on the rim at an arm. If a bend is discovered between two arms then the correction is at both arms. Bending between arms is a good way to kill the wheel. Obviously a bit of feel is developed to not strain the pivots.

 

To check pivots for straightness the best is to run them in a lantern in either a Jacot tool or in the turns. If you have a good lathe with good collets that can be used too, I regularly check and straighten balance pivots in my lathe.

 

20201015_075753 (Large).jpg

20201015_075817 (Large).jpg

20201015_075829 (Large).jpg

  • Like 3
  • Thanks 2
Link to comment
Share on other sites
VWatchie Distinguished Member

VWatchie

Posted
  • Author
Posted

Thank you very much @nickelsilver! For an enthusiast like me this kind of info is really priceless. Despite being explained in a clear and detailed language with illustrations I still need to struggle to fully understand and create a clear image of the procedure.

One of the things that I struggle to get my head around is the thing about using a "lantern" in a Jacot tool. I got myself a Jacot tool some time ago but having no prior experience of micro mechanics or education in this field I can't figure out what a lantern is. My native language is Swedish but trying to translate "lantern" just doesn't make any sense to me.

Oh well, I realize that I must look like a hungry chick that demands you to feed me, but to don't worry, I realize your time is limited and I'll will of course eventually figure it out if you haven't got the time (or interest, which I'd fully respect) to elaborate.

Anyway, again, thanks a ton for the input!

Link to comment
Share on other sites
KarlvonKoln Distinguished Member

KarlvonKoln

Posted
Posted

A little while back, I made this set of trueing calipers.  It was originally meant to tide me over until I could buy a pretty, vintage, German pair I had my eye on.  It's just a billet of brass which I cut to shape, and where I drilled a single hole through both arms for the pivots, then holes for the set screws which I tapped for threads, then a threaded hole for the reference arm.  The pivots are just thin  steel bar stock with highly polished divots in the ends.  

I keep not getting around to snatching up a nice vintage set.  Mine works well, despite lacking any real aesthetics, so I just keep using it when I need to.  But I swear, one day I WILL pick up a nice German pair.  One day.

20201016_213254.jpg

  • Like 4
  • Thanks 1
Link to comment
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.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  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.

×
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • ChrisInOz
      No images showing

      By ChrisInOz · Posted

      The post below contains the link. If you don't already have a discord account it will take you to the registration screen.  Registration is free.   https://www.watchrepairtalk.com/topic/31653-mark/?do=findComment&comment=279066
    • luiazazrambo
      WWW Eterna sucked me in.

      By luiazazrambo · Posted

      HWGIKE#57 Valex FEF 190 15 jewels Swiss lever full service and repair This one was waiting for a balance staff replacement in my cabinet parts and case cleaned up with a new balance staff and a 4th wheel as the original 4th wheel had a broken pivot for the off center second hand. I never attempted a balance staff replacement before however I received a Bergeon Molfres (i was hunting it for about 2 years) and with the help of it I managed to remove the old staff and riveted the new one in. It also received a new MS, crystal and the hole for the MS arbor was also tightened. With the new MS now it has an acceptable performance meaning that the amplitude goes up to 280 fully wound, has an acceptable beat error and I have the two nice lines but only dial up, dial down is not as nice and I could not figure out as why. I have the two lines but the amplitude is dropping to around 230 and the lines are a bit hairy. Both dial up and dial down the lines just go up and down without seemingly any pattern. I cleaned the movement two times, and then a 3rd time pegged out the main plate and train bridge holes but made no change. Both the HS collet and the roller table was too lose on the new staff... I did not count how many times I took the balance cock off to sort out the HS collet, the roller table and the beat error, somebody before me also shortened the HS by pushing it out a bit and it seems every time somebody is messing with the end of the HS the protruding bit is most of the time twisted bent etc. This one was probably one of the most challenging repair and service. I might take the new MS out and clean it lubricate it as I just pushed the new one in to the barrel from the retaining ring. Plus started to re-read the theory of the escapement and how to analyse the graph on the timing machine: Greiner Chronografic Record manual. I am also thinking to put the watch on a 24 hour long run with the eTimer SW it once helped me to figure out what was wrong with a watch. There is an interesting part of the Greiner record manual talking about the pallets and the end shake of the balance and pallet staff. Maybe this is my issue? Who could that possibly identify? After a few years now I am still without a clue how could watchmakers make parts I can only see with my microscope or how could/can they carry out complicated services impossible to do.. real magic..... .... ..... before I sent this post while the pics were uploading I had an idea, i was browsing the possible outcomes on the timing machine I had one for magnetism..... so I demagnetized the movement and it is not hairy now.... two really nice lines 0.2 ms beat error still a bit wavy, but a lot lot better..... argh....  
    • Nucejoe
      Hello from Cypress, CA

      By Nucejoe · Posted

      Hi there, welcome here.  
    • JohnR725
      No images showing

      By JohnR725 · Posted

      yes the advertising revenue should generate money. The question is how much money? Then as far as the cost of the website goes that's relatively easy to determine? all you would have to do to grasp costs and profitability would be to go to the link below and you can actually get a website for free try it out for free I believe you get no advertising initially. They also talk about that they'll help you out they have marketing tools and some sort of paid subscription or something. So I guess were shopping for a whatever just ask them what would a maybe could use this one as an example in other words it's going to look basically identical to this is going to have advertising a paid subscriptions what's it going to cost? After all they want to sell or give us a message board like this they should bill answer the questions as they're the people who did the software for this. Yes they really said you can have a free discussion group at least to start. https://invisioncommunity.com/ I was curious about the monthly supporter thing where exactly do we find that on this message board? A quick search I'm not finding it so obviously I'm not looking in the right place?
    • Curare
      No images showing

      By Curare · Posted

      Help me out here, but with all the advertising on this site (which I don't mind) wouldn't it pay for itself or even make money for the owner ???
×
×
  • Create New...