Jump to content

Let's talk Mainsprings

Fraczish
 Share

Recommended Posts

Fraczish Watch Enthusiast

Fraczish

Posted
Posted

As a hobbiest (currently) I've take a movement apart and reassembled it a couple of times now. I've always stopped short of removing the mainspring as I don't have a winder. 

So I have a couple of questions...

1, how would I go about ordering a new mainspring? Assuming originals for many of my vintage pieces will not be available.

2, in respect of a Winder, as a hobbiest what might suit my needs? I've seen a set on cousins that go for around £175. Do I need all these?

Many thanks always guys :-)

rodabod Distinguished Member

rodabod

Posted
Posted

1. Look up a genrale ressorts catalogue for a size reference. Failing that, measure the old one.

2. I'd keep hand winding in the meantime. You have to be really ham-fisted to distorted them. Used sets turn up on eBay occasionally.

Fraczish Watch Enthusiast

Fraczish

Posted
  • Author
Posted

Thank you Rodabod. When measuring for a mainspring is it just the uncoiled length and width to consider? One site I looked at talked about a strength value and a diameter?

rodabod Distinguished Member

rodabod

Posted
Posted

The "strength" sometimes an older term refers to the thickness. It is critical, whereas length is not absolutely critical. The reason is because the force developed follows a cube rule relative to the thickness. Ideally you'd use a micrometer, but a decent vernier caliper may suffice.

  • Thanks 1
Fraczish Watch Enthusiast

Fraczish

Posted
  • Author
Posted

Thanks again that's really useful to know going forward.

I've looked through the GR book and found the mainspring for my watch. Where would I actually source one from? Either genuine or generic?

Fraczish Watch Enthusiast

Fraczish

Posted
  • Author
Posted

Got a few from Cousins. 

Is there anything specific I should know/do during installation? My Intention was to use Molykote DX on the barrel wall. I believe the spring will be pre-lubricated is that right?

I have read somewhere on here about often  having to manipulate the hook end of the MS, not sure Mark covered this in the chapter, could be wrong though. And advice would be great as always. 

watchweasol Distinguished Member

watchweasol

Posted
Posted

The hook end of the mainspring, the outer end has attached a small tongue which will auto locate in the anchor position by means of a stop on the barrel wall,     automatics have a bridle spring attached which locates against the barrel wall and slips when under max tension so as not to break the spring, hence the breaking grease on the wall. The details given by Rodabod  are spot on  usually    Height X  Thickness  X  Length X   Barrel diameter. 

  • Thanks 1
Fraczish Watch Enthusiast

Fraczish

Posted
  • Author
Posted (edited)

Thanks watchweasol. The course has not covered Automatics yet, not sure if it does in Level 3. I was aware of the the slipping action as a basic concept from reading threads on here, haven't had one apart yet. 

Edited by Fraczish
rodabod Distinguished Member

rodabod

Posted
Posted
3 hours ago, Fraczish said:

Got a few from Cousins. 

Is there anything specific I should know/do during installation? My Intention was to use Molykote DX on the barrel wall. I believe the spring will be pre-lubricated is that right?

I have read somewhere on here about often  having to manipulate the hook end of the MS, not sure Mark covered this in the chapter, could be wrong though. And advice would be great as always. 

Usually you can just push the empty barrel cover over the new spring and it will slip in with a little coaxing. Remember to get the orientation correct. 
 

Lubrication - depends if it’s an auto like WW says. New springs are sold with a lubricant film on them, but I also add more anyway as I don’t see the harm, plus some stock is quite old. 

JohnR725 Distinguished Member

JohnR725

Posted
Posted
3 hours ago, Fraczish said:

My Intention was to use Molykote DX on the barrel wall

Generic conversations on mainsprings can be an issue? Like using the term Vintage is interesting like what kind of vintage? So typically on mainsprings you need the with, thickness or strength and length. Then it depends on whether We are talking about a Swiss or American mainspring as mainsprings are interesting they can be measured in inches, metric and Dennison and conceivably the package will have all three. Then if it's vintage the end of the spring is important because the ends may be different depends on what were looking at.

Then mainspring lubrication if the mainspring is the normal new either prelubricated or made out of a material a proper steel that doesn't need lubrication no lubrication is required including on the barrel wall. Unless of course it's an automatic mainspring Then your lubrication choice would be very very bad for that. So typically all you'd need to do is lubricate the arbor. Unless It is an automatic then Some form of breaking grease will be required and of course lubrication of the arbor.

Then if we want to be generic about this if you know what the watch is you can look up what mainspring supposed to be in their. If it's a vintage watch there may be no listing  then you have to take it out and measure it. If it's a standard Swiss mainspring usually can just push it in you don't need a Winder.

  • Thanks 1
Fraczish Watch Enthusiast

Fraczish

Posted
  • Author
Posted (edited)

Thanks John,

I have managed to look up the correct MS for the watch I'm working on (peseux 180) manual. Apologies for the confusion, when I said I ordered a few, I ment I've ordered a couple for watches I intend to service in the coming weeks. So I'm fairly sure I've got the right one. 

Thanks for the tips about not greasing the barrel wall. I for some reason thought Marks lesson advised to, I've likely got that mistaken. 

The end I believe is "normal" type

Edited by Fraczish
Fraczish Watch Enthusiast

Fraczish

Posted
  • Author
Posted
8 minutes ago, mooseface said:

Mark Lovick has posted an excellent video on mainspring choosing on Youtube. Worth a watch if you'll excuse the pun.

 

Brilliant thanks, I will definitely watch that one:thumbsu:

AdamC WRT Addict

AdamC

Posted
Posted

One website I use regularly to find suitable mainsprings for the vintage watches I service is https://www.vintagewatchstraps.com/mainsprings.php. Very useful explanations and calculators that I use so either when you can’t identify a movement to look up a mainspring or when one isn’t available from the materials house. I can work out a suitable size by measuring the internal diameter of the barrel and external diameter of the arbor. Ideally you’ll have the old spring to measure the thickness (strength) but even without one, one of the calculators can estimate the correct thickness. It also helps as a way to verify if the old spring was in fact the appropriate one as past servicers have been known to fit a “near match”. The Ranfft website also has mainspring data for most vintage watches. Hope that helps for future reference.

 

 

Sent from my iPad using Tapatalk

  • Like 1

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

    • watchweasol
      Hello from the Netherlands

      By watchweasol · Posted

      Hello and welcome to the fo4um. Enjoy
    • clockboy
      Hello from the Netherlands

      By clockboy · Posted

      Welcome to the forum, enjoy.
    • JohnR725
      A lathe with indexing that won't break the bank?

      By JohnR725 · Posted

      You're asking a pretty broad question and you didn't specify the machine but yes it's simple especially if you have the right machine. The question has problems but I'll take it as it is. Is it really that simple yes especially if you have the right machine. So in the video below he's making a screw and yes it really is that simple but pay attention to the machine it is not simple at all probably wasn't cheap but it is small it will probably fit in your garage. Unfortunately wouldn't fit in my garage as it's far too cluttered up with things. In the video he talks about making a screw and pay attention to the machine. The machine has lots and lots and lots of cutters and lots of things to do lots of machining all-in-one machine conceivably one step after another all programmable. If you look at his channel lots of CNC's stuff and there are several other videos related to this machine. He goes to the factory where they talk about it and show all the other machines they make in Switzerland.  I did look up the specifications the machine I don't recall the price it's not going to cut wheels I think it has a maximum diameter around 11 mm basically it's really good for making small diameter watch parts. Then in one of the other videos he goes to a factory that used to make parts with waterpowered machinery been in business for 100 years and everything they now make is made with CNC machines including this one. What was interesting with the factory photo was that when they make some parts they can put them on a optical comparator comparator compares with whatever the reference is and the machine can be programmed to adjust its cutting to make sure everything is actually being made to specifications. Oh and then somewhere in all of this there was at least one picture of a balance staff can't have a CNC Swiss machine without making balance staffs.   It would be really nice if we had pictures of the machine. Then yes if you look at the page for wheel cutting you can enter parameters and it will generate a G code but he left out things? Notice he has a picture of a complete wheel but the G code isn't making a complete wheel it's only cutting the gear teeth I don't see whereas the program for crossing out the spokes? Typically when you see people cutting gears once the teeth are cut most the time the spokes are cut by hand. Occasionally someone will mill them out but typically not with the program which seems strange if you have CNC capability for instance one of my friends fill it used to design assembly line equipment or things to make things. So his hobby was to continue to make tools to make things like clocks. Very interesting and clever clocks but his true fund was making the machines to make the clocks. Then machine is not controlled by G code like we would typically find today as the stepping motor controller he has was made a long time ago and the individual controllers used a textbased program. So the company had a editor you could write a program to cause each the stepping motors to do something. So basically once you figure out how to cut a gear he would just change the parameters for different size gears so here's an example of a gear as you can see we have the teeth and the spokes. Then we have a picture the machine which sucks because it would've been so much nicer if I could've taken a picture when it was cutting a gears so we can see things better. Then yes there is a worm gear stepping motor indexing this is a mini lathe and the indexing is at the end of the lathe head hiding. The basic operation of this machine would be brass sheet not cut to a specific diameter size not even round mounted on the machine. Then it turns and a milling cutter will cut the diameter. Then the gear would be cut with a gear cutter. The same mill cutter for the diameter although conceivably change the size I don't know but basically the same milling for cutting the outer diameter would be used to cut the spokes. I really can't remember how he did the center hole but whatever it was was very precise.          
    • JerseyMo
      Does a lighter fluid trick actually work on vintage mechanical Timex watches?

      By JerseyMo · Posted

      Yeah I know the site and the creator of it.  the two video clips are good examples of the quicker method and a full tear down.  the quick method will work in many cases. But not always and not for all the different movements.  I strongly suggest to not bend the four tabs as was done in the first clip.  Instead there are three tabs that insert into the top plate, Much saver way as to not break a tab.
    • JseTay
      Lathe motor advice

      By JseTay · Posted

      I found a motor that is 3/4 hp and another that is 1.2hp. They come with speed controller. So I don’t think I would need a wiring diagram. But I sure appreciate you offering your help! Do you think 1.2 hp would be too much for a watchmaker’s lathe?
×
×
  • Create New...