Jump to content

Stuck ratchet wheel screw


Recommended Posts

I'm working on an old AS984 movement from the 1940's and cannot get the ratchet wheel screw loose.  I've soaked it in numerous solutions  and even tried taping it on my staking set to loosen the crud that is binding the screw to no avail.  I'm starting to strip the screw head and don't want to continue  without reaching out to the forum.

What are my other options?

George

Link to comment
Share on other sites

2 hours ago, PostwarO27 said:

I'm working on an old AS984 movement from the 1940's and cannot get the ratchet wheel screw loose.  I've soaked it in numerous solutions  and even tried taping it on my staking set to loosen the crud that is binding the screw to no avail.  I'm starting to strip the screw head and don't want to continue  without reaching out to the forum.

What are my other options?

George

Same issue here a couple of days ago George. As ww  and nickelsilver says, test for the common scenario of a reverse threaded screw. Feel for some movement each way. After a few experiences with them it will become second nature to test and feel for tightening and loosening of a rachet screw regardless of its threaded portion direction of up or down the screw.

  • Like 1
Link to comment
Share on other sites

Yes, checking for LH threads was the first thing I did.  I've yet to come across a movement with LH threads in both the ratchet and crown wheels but I've only been at this a couple years so I;m sure I'll run into one eventually.

I haven't tried the heat but as soon as I'm done typing here, I will be.  I disassembled the movement as far as I could and right now I have the barrel bridged sandwiched  in between the ratchet wheel and barrel arbor and that subassembly is soaking in a ramekin of WD, which as a toolmaker by trade, was our go to solution for loosening corroded nuts and bolts.  The click is still in place to help keep the barrel from spinning when trying to loosen the screw.

 

 

Link to comment
Share on other sites

8 minutes ago, Darthkram said:

AS 984 is definitely a Left Handed ratchet wheel screw.

I made that mistake on the first one I disassembled and wound up with a snapped screw head as a prize!

I just tested a couple other AS 984 movements I have and they were also both LH ratchet screw.

I was starting to think the same thing.  I noticed that the click rotates in a different direction than all the other movmenets I've worked on.  The head of the screw is the same as a RH screw, there is no marking of sorts to alert the mechanic as to the direction of thread.

 

However I still can't budge the thing.  Its like the screw and barrel arbor are one piece.

  • Like 1
Link to comment
Share on other sites

SUCCESS!!

I managed to separate the ratchet screw from the barrel arbor.  I ended up soaking the subassembly in CocaCola overnight and with a couple of taps on my staking set with a punch collinear with the screw axis, it loosened up the crude holding it together.  LH thread.

I'm going to mark that screw head with three lines to indicate to whoever takes it apart in the future that its a lefty.

 

Thanks for the tips y'all !!

  • Like 4
Link to comment
Share on other sites

  • 1 year later...

I'm having the same issue with an AS 1002 movement. However I think the 1002 ratchet screw is RH thread. My conclusion is based on the fact that the click is "standard" not reversed as mentioned above. Also, i can look inside the barrel arbor where the original screw broke off and see right handed threads.

Still i can't get the screw loose on my donor watch. Currently i applied Liquid Wrench, which is similar to Kano Kroil. 

If i want to try heat, can i heat up a "junk" screwdriver with my butane torch and then hold it on the screw?

Link to comment
Share on other sites

You probably haven't given enough time for the oil to penetrate.

Try this.

Remove the balance cock assembly.

Remove balance the jewel on mainplate side.

Remove the fork.

 Drop the rest in Coca Cola for a 48 hrs soak.

Good luck

  • Like 2
Link to comment
Share on other sites

1 hour ago, signcarver said:

I think the 1002 ratchet screw is RH thread.

Be careful. I have just checked on two AS 1002's and in both cases the ratchet wheel arbor screw is LH threaded.

  • Like 2
Link to comment
Share on other sites

Yes, this is common for old AS movenents. The screws, actually, are the same, and can be replaced by each other.  They used only one machine to make the screws, that's for economy.

I can't imagine that the click will work in reverse, that is silly thought. Unless it is on the crown wheel,  not on the ratchet wheel.

Edited by nevenbekriev
  • Like 2
Link to comment
Share on other sites

@Nucejoe Thank you! Soaking now.

@mikepilk Thank you. 

- I have seen the AS 984 and AS 1002 mentioned together as if they are interchangeable but i know the mainplates, ratchet wheels, and crown wheels are different per the pictures below. So, is it possible that the threading on the ratchet wheel screws are different? I'm soaking the donor in Coke so i'll try it again tomorrow.

 - The watch i am working on is marked AS 1002 on the mainplate (see second picture below). Note that both the ratchet wheel and the crown wheel on the original watch are smooth (no circular groove around the screw.)C3141967-88B2-4FBC-8B70-5EE62A5DFE62_1_105_c.thumb.jpeg.21a7136236466e82665e1080fac809f2.jpeg

Mainplate of original watch, clearly marked AS 1002

77E1009F-E0A2-4130-9C32-241E95EBD99D_1_105_c.thumb.jpeg.a2815a802d3b4f3199c1054f20e13dee.jpeg

Donor watch below - The donor watch was advertised as a 1002, but i believe it is a 984 (there are no markings and the mainplate is different from my original watch. 

Note the circular grove around both the ratchet wheel and crown wheel.E75EC251-B3D4-4D7E-98F8-1EB9350C852F_1_105_c.thumb.jpeg.e3f665d05e24d5e26b924c2dc21f3d6e.jpeg

No markings on the mainplate AND the mainplate is different from the original watch.

41C85D85-F6DA-407D-8CFF-64EA62B29BA3_1_105_c.thumb.jpeg.2b341e8283f3f9c60d3195f3c8aae64e.jpeg

 

Link to comment
Share on other sites

Updates:

@Nucejoe Coca Cola soak worked! Got the screw loose. Thank you!

@mikepilk You were right. The ratchet wheel screw and crown screw are both lef handed threads. Also, upon further disassembly of the donor, which i couldn't do until i got the ratchet wheel screw loose, i found a marking on the donor that says AS 1002. It wasn't in the same place as the original, but it was still there. 

  • Like 1
Link to comment
Share on other sites

18 minutes ago, signcarver said:

Updates:

@Nucejoe Coca Cola soak worked! Got the screw loose. Thank you

Popcorn now ?  

Soak balance cock assembly , to loosen two little scrws that hold the upper balance capstone. You be amazed how easy they unscrew.

Edited by Nucejoe
  • Like 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.

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.



  • Recently Browsing

    • No registered users viewing this page.
  • Topics

  • Posts

    • The Chaika 1601A bridge styles look more like something from an earlier time. It is also finished relatively well for the 1980s, as a lot of manufacturers by then had started a race to the bottom in terms of finishing and materials as a result of the quartz crisis. If you compare it with a comparable Swiss movement from the same period, you will find they have much less elaborate bridges, and other cost cutting measures. Straight cut bridges with no bevel on the edges are much cheaper and simpler to produce than the curved bridges of the Chaika 1601A. They even went to the trouble of stamping a serial number on the movement. A practice which only the higher end Swiss manufacturers were bothering with by this point. The Chaika 1601A does have a relatively cheap balance though. The 'timing screws' in the balance are for decoration only. Having said all that, the USSR caliber designs were fairly conservative, and produced for relatively long periods. This was partly as a result of the command economy, which tended to lead to relatively little innovation in design, and partly because they weren't chasing after the fickle flights of fashion that arguably drove some of the changes from other manufacturers. Some of the USSR designs were licensed or even "borrowed" from Swiss and French designs.   For example I have a Sekonda pocket watch (which may be the next one on the bench for a clean and service). It has a Chelyabinsk Watch Factory "Molnija" 3602 caliber in it, which was based on a Cortébert movement used in Swiss watches from around 1940. Here is one of the examples from Ranfft. You can see that it is similar to the Chailka with curved bridges. They even had Breguet over coil hairsprings and "Geneva" striping. Some had shock protection, some did not.   The Sekonda is in its original 1980s plastic presentation box, complete with "manufacturers guarantee" (although Sekonda obviously didn't manufacture it). This same Molnija  movement was produced in the Chelyabinsk Watch Factory with little change, except notably in the level of finishing, from around 1947 until the early 2000s when production ceased. For comparison, here is a Swiss ST96 from around the same period as the Chaika and the Molnija. . Smaller jewels, flat and unrefined finishing, and all in all, a little bit lacklustre. .. and a Rolex 600 from around 1922   The Chaika, despite being from the 1980s, to my eye at least, looks a little closer to the Rolex than the ST96  
    • Elaborate on this statement. What sorts of things define calibers from different decades? The only thing I can think of short of the pocket to wrist watch shift around WWI and quartz is shock settings starting... late-40s, early-50s?
    • I'm not sure who "we" is as I'm not a part of how "we" do it. Most of "us" develop their own method(s). Please re-read what has been said;  
    • Nice one Andy- a very ‘blingy’ 404 with all those jewels…
    • It's a matter of preference really. You should keep the #5 aside and just use them for fine hairspring work though; otherwise they will end up damaged and be useless for that. Some like #1, some #2, some #3 for general work. Some use brass or nickel tweezers for general work- this is good as they are less likely to scratch delicate parts, and are much "grippier". On that note, the finer the tweezer, the more likely it will be to want to launch parts.   I have a bunch of nickel tweezers that have been retouched so many times they are like 30% shorter than new. Those become handy for when you need very strong tweezers- just used a pair to unscrew the bond from inside a floating barrel. My general use tweezers the last few years are a couple of pair of #5 that have been sharpened enough times that the ends are now very strong; useless for hairspring work, great for general work. These are Dumont Dumostar, which is a much more tough alloy than the Dumoxel, and less brittle than their carbon steel ones.
×
×
  • Create New...