Stuck screw, and out of ideas.

[ChrisInOz]

10 hours ago, MikeEll said:

I did a lookup in the old Bestfit catalogues based on the setting lever and yoke shapes you posted.

Thank you for bringing the Bestfit catalogues to my attention.  I have downloaded them now and they are a superb reference for a beginner like me. 

[ChrisInOz]

On 11/19/2024 at 5:48 PM, JohnR725 said:

Then you really need a different solution like something designed for screws like something like this. I find that work a drop or two on the screw and wait a little while and I've never had a problem. Then I have a link to the company manufactures This product but I do know there would be other penetrating fluids for screws this just happens to be the one we have at work and it does work really well

https://westernoptical.com/products/screw-loosening-fluid

 

The screw loosening fluid has arrived,and I've applied a drop to the screw head.   I've also given it a couple of taps in the staking set to help it along.   Will try the hot-cold treatment to assist the penetration of the oil too.

 

[JohnR725]

4 hours ago, ChrisInOz said:

Will try the hot-cold treatment to assist the penetration of the oil too.

Sometimes I will place the watch on the heater we have for drying cases. So I do think he'd is good for allowing the penetrate but not sure how hot you're going to get so you do want to make sure you don't burn the substance. I've also found that sometimes I just left it overnight and came back the next day.

[ChrisInOz]

1 hour ago, JohnR725 said:

Sometimes I will place the watch on the heater we have for drying cases. So I do think he'd is good for allowing the penetrate but not sure how hot you're going to get so you do want to make sure you don't burn the substance. I've also found that sometimes I just left it overnight and came back the next day.

It was 35 degrees here today.  I should have just put it in a jar outside in the sun, but I didn't think of it. 

It has occurred to me that the part I should heat is actually the barrel arbor,  since the threads that are stuck are actually inside the arbor.   If I heat that up, expanding the threaded bore,  then hit the screw head with freezer spray,  that might open up a gap to draw the oil in. 

The screw head itself is very wide compared to the threaded part,  so the penetrating fluid has a long way to go before it reaches the threads.

[JohnR725]

28 minutes ago, ChrisInOz said:

35 degrees here today.  I should have just put it in a jar

I think a better use of the a clever way of figuring out how to send the outside temperature into the jar and send it to me so I could release it where I live. As we are heading into our winter months and I would enjoy some warm weather.

[ChrisInOz]

9 minutes ago, JohnR725 said:

I think a better use of the a clever way of figuring out how to send the outside temperature into the jar and send it to me so I could release it where I live. As we are heading into our winter months and I would enjoy some warm weather.

Yes,  we are in late spring here in the southern hemisphere.  Likely to see some hot weather in January and February.  It can reach 45 C sometimes (or 113 F if you prefer.)

[ChrisInOz]

Woohooo!   The screw is out.  It came out completely intact,  nothing left behind in the arbor,  and YES, it is left-hand thread.

The parts are all OK apart from some surface blackening from the coca cola.

I applied screw loosening fluid to the screw head and left it to be absorbed for three days.

The final result came from heating the screw with my soldering iron at 450C for one minute,  then squirting the screw head with a tetrafluoroethane freezer spray.  This was quite spectacular,  with the whole ratchet wheel becoming instantly covered with frost.

I tried the screw both ways as usual,  but this time it came free on the clockwise turn. 

Thank you everyone for your helpful advice.

One more question:

I think the black carbon stain can be removed from the ratchet wheel and the click  with a very light polish on a lapping plate,  but what about the barrel arbor?   Should I try to polish away the black from the bearing surfaces of the arbor,  or is it better to leave it alone?

 

 

 

[Neverenoughwatches]

1 hour ago, ChrisInOz said:

Woohooo!   The screw is out.  It came out completely intact,  nothing left behind in the arbor,  and YES, it is left-hand thread.

The parts are all OK apart from some surface blackening from the coca cola.

I applied screw loosening fluid to the screw head and left it to be absorbed for three days.

The final result came from heating the screw with my soldering iron at 450C for one minute,  then squirting the screw head with a tetrafluoroethane freezer spray.  This was quite spectacular,  with the whole ratchet wheel becoming instantly covered with frost.

I tried the screw both ways as usual,  but this time it came free on the clockwise turn. 

Thank you everyone for your helpful advice.

One more question:

I think the black carbon stain can be removed from the ratchet wheel and the click  with a very light polish on a lapping plate,  but what about the barrel arbor?   Should I try to polish away the black from the bearing surfaces of the arbor,  or is it better to leave it alone?

 

 

 

Congratulations,  how closely can you inspect the arbor's surface ? The pivots should really be polished just like any other train or balance pivot.

[JohnR725]

1 hour ago, ChrisInOz said:

I think the black carbon stain can be removed from the ratchet wheel and the click  with a very light polish on a lapping plate,  but what about the barrel arbor?   Should I try to polish away the black from the bearing surfaces of the arbor,  or is it better to leave it alone?

16 minutes ago, Neverenoughwatches said:

The pivots should really be polished just like any other train or balance pivot.

we end up with a interesting problem here of how much polishing are you going to have to do? Then I have an image I snipped out of a book regarding if you have to go beyond polishing you will end up with a problem of shrinking the parts which is not desired.

 

[Klassiker]

The barrel arbor bearing surfaces need to be smooth and shiny. Has the cola eaten away at the surface, or just left a superficial stain?

Try with some jeweler's rouge or similar first. This won't remove hardened steel, and you might be lucky and get a nice finish. You can get rid of some roughness with a harder abrasive, without removing too much metal. A few 100th mm are not going to be as critical here as they would be on a balance staff. If the surfaces are badly pitted, you probably need a replacement.

[Neverenoughwatches]

19 minutes ago, JohnR725 said:

we end up with a interesting problem here of how much polishing are you going to have to do? Then I have an image I snipped out of a book regarding if you have to go beyond polishing you will end up with a problem of shrinking the parts which is not desired.

 

Hopefully the arbor's surface is not too damaged, pivot to bearing tolerances surely allow a little more here than with something like a balance pivot. Some amount of burnishing woukd be better than none, the OP  would be in a better position to decide once he knows how poorly the arbor is.

13 minutes ago, Klassiker said:

The barrel arbor bearing surfaces need to be smooth and shiny. Has the cola eaten away at the surface, or just left a superficial stain?

Try with some jeweler's rouge or similar first. This won't remove hardened steel, and you might be lucky and get a nice finish. You can get rid of some roughness with a harder abrasive, without removing too much metal. A few 100th mm are not going to be as critical here as they would be on a balance staff. If the surfaces are badly pitted, you probably need a replacement.

 

13 minutes ago, Klassiker said:

Try with some jeweler's rouge or similar first. This won't remove hardened steel

I really like pollinum for polishing or autosol which has a bit more bite to it. I'm sure we discussed this ages ago about what effect an abrasive can have on spinning metal watch parts....the possibility of charging it with compound compared to a pivot file or burnisher. 

7 minutes ago, Neverenoughwatches said:

Hopefully the arbor's surface is not too damaged, pivot to bearing tolerances surely allow a little more here than with something like a balance pivot. Some amount of burnishing woukd be better than none, the OP  would be in a better position to decide once he knows how poorly the arbor is.

The OP does have the option of reducing the arbor bearing size also.......not an ideal situation just an option. 

2 hours ago, ChrisInOz said:

think the black carbon stain can be removed from the ratchet wheel and the click  with a very light polish on a lapping plate,  but what about the barrel arbor?   Should I try to polish away the black from the bearing surfaces of the arbor,  or is it better to leave it alone?

 

For the rat wheel and click I would just try a dab of autosol on a chisel ended piece of pegwood to clean them up.

[ChrisInOz]

2 hours ago, Neverenoughwatches said:

Congratulations,  how closely can you inspect the arbor's surface ? The pivots should really be polished just like any other train or balance pivot.

I'll have a good look with a 10x loupe, and see what condition it's in.   Might try the 20X phone camera lens too.  I don't have a microscope yet.

[DaveL]

WD 40 is not a oil ,it is a water dispersant , Kroil is another penetrating fluid 

[ChrisInOz]

Progress report.

I successfully cleaned the arbor, and reassembled the movement,  and it now runs,  but there is another problem.

After I cleaned the mainspring and barrel in the ultrasonic,  I found a small piece of mainspring in the bottom of the jar.   I'm pretty sure that this was the tab that hooks onto the barrel wall.   Now I can put a couple of winds on the spring and get the movement to run,  but if I wind it any more I can hear the spring slipping in the barrel,  so I can't put on a full wind.  (This is a manual wind movement, not automatic.)

The answer would seem to be to get hold of another mainspring to replace the original.

For those who have just joined us,  the movement has been tentatively identified as a Gruen 240, or something very similar, by using the bestfit catalog.  (thanks @MikeEll.)

Unfortunately,  the Gruen reference sites I have been able to find don't list the 240 movement, so I don't know the official specs for the spring.

I have a micrometer,  so I can get an accurate measure of the height and thickness of the spring.   I presume that I should not unroll the spring to measure its length,   so I should calculate the length mathematically from the barrel size.  I can do that OK.

I then hope to order a generic spring from Cousins UK.

The problem I have is understanding what terminology to use when ordering the part.  The outer end of the spring hooks to the barrel wall by using a very short (~6mm) piece of spring metal that is spot welded to the end of  the mainspring.   This is the same height as the spring itself. There are no holes or projecting tabs.  Is this what Cousins refers to as a "normal bridle?"  It is closest in appearance to the circled image below.

Am I on the right track with this?

Thanks in advance for any advice.

On 11/25/2024 at 6:55 PM, Neverenoughwatches said:

I really like pollinum for polishing or autosol which has a bit more bite to it. I'm sure we discussed this ages ago about what effect an abrasive can have on spinning metal watch parts....the possibility of charging it with compound compared to a pivot file or burnisher. 

The autosol did the trick very nicely,  and the bearing surfaces on the arbor came up smooth and shiny with no pitting.   Thank you.

I cleaned and rinsed the part again afterwards,  to avoid leaving any traces of abrasive.

[HectorLooi]

It is possible to use the old spring by folding over a small length to act as the bridle. You need to heat about 6 mm of the end of the spring and fold it over and flatten it. This will catch the stop on the barrel wall.

 

Edited December 11, 2024 by HectorLooi

[Neverenoughwatches]

I was just about to recommend the same as Hector's suggestion, before I saw it. You can do this with just a lighter, but start at a distance. The thin steel can heat up real fast, and hit cherry red in just a second. Aim for only the tip and draw the heat away slowly. Letting the steel air cool to anneal it, so do not make the mistake of quench hardening  it. When done fold over around quarter of an inch, flatten but retain the spring's end curve shape. You can also rivet the tab back on if you fancy tackling that. Make a short steel pin, drill the two pieces of steel a fraction wider than the pin's diameter. And then hammer the pin both sides on a steel block to form the rivet with a flat punch, or better a concave punch if you have one. You can make a reasonable estimation of the spring's length by placing glass or persplex over it, then use a piece of cotton to follow the shape, pull straight and then measure the cotton's length.  Check the size against the Generale Ressorts data list after you've downloaded it . Always keep in mind what a previous repairer/service guy might have done before you. What is fitted in the movement is not necessarily correct, he/she may have used a different size of spring to the original ! Never assume something is right !!! What is there should only be a guide, a good guide if the movement was performing well before you took it apart. Keep us updated.

Re. the polish up, metals can become abrasively charged ie. embedded adrasive particles. These cannot be washed free, this is how lapping plates are made. The softer the metal the more and easily it can be charged. Arbors are generally pretty hard but there is potential for it to become a rotary lapping tool. Depends how hard you had to work to clean it up. Burnishing is better, technically a filing process but also forms a hard outer layer through compression. 

[Klassiker]

5 hours ago, ChrisInOz said:

Am I on the right track with this?

Yes, that is the end you need.

[AndyGSi]

Here's the details shown on Cousins & Emmy for the Gruen 240. How does this compare to what you've got?

[ChrisInOz]

25 minutes ago, AndyGSi said:

Here's the details shown on Cousins & Emmy for the Gruen 240. How does this compare to what you've got?

Thank you @AndyGSi,  but that appears to be different from the movement I have.   Mine is a two hand movement that looks like it may be from the 1920s perhaps.  Maybe the sweep seconds one is a later version of it.  

I plan to take the mainspring out of the barrel again,  to measure its dimensions,  so I will see how it compares with the one you found.

@MikeEll identified it from the Bestfit catalog using the ligne size,  yoke and setting lever. See pictures below.

 

 

3 hours ago, Neverenoughwatches said:

I was just about to recommend the same as Hector's suggestion, before I saw it. You can do this with just a lighter, but start at a distance. The thin steel can heat up real fast, and hit cherry red in just a second. Aim for only the tip and draw the heat away slowly. Letting the steel air cool to anneal it, so do not make the mistake of quench hardening  it. When done fold over around quarter of an inch, flatten but retain the spring's end curve shape. You can also rivet the tab back on if you fancy tackling that. Make a short steel pin, drill the two pieces of steel a fraction wider than the pin's diameter. And then hammer the pin both sides on a steel block to form the rivet with a flat punch, or better a concave punch if you have one. You can make a reasonable estimation of the spring's length by placing glass or persplex over it, then use a piece of cotton to follow the shape, pull straight and then measure the cotton's length.  Check the size against the Generale Ressorts data list after you've downloaded it . Always keep in mind what a previous repairer/service guy might have done before you. What is fitted in the movement is not necessarily correct, he/she may have used a different size of spring to the original ! Never assume something is right !!! What is there should only be a guide, a good guide if the movement was performing well before you took it apart. Keep us updated.

Re. the polish up, metals can become abrasively charged ie. embedded adrasive particles. These cannot be washed free, this is how lapping plates are made. The softer the metal the more and easily it can be charged. Arbors are generally pretty hard but there is potential for it to become a rotary lapping tool. Depends how hard you had to work to clean it up. Burnishing is better, technically a filing process but also forms a hard outer layer through compression. 

Thank you. Lots of excellent advice and tips there.  I polished the arbor by holding it in a pin vice and rotating it against  a folded piece of watch tissue charged with autosol.  it only took a few turns with very light pressure to make it bright and shiny again,  so hopefully I haven't forced the grit into the metal. 

4 hours ago, HectorLooi said:

It is possible to use the old spring by folding over a small length to act as the bridle. You need to heat about 6 mm of the end of the spring and fold it over and flatten it. This will catch the stop on the barrel wall.

 

Thank you @HectorLooi.   It's great to see an example on video.

 

 

[AndyGSi]

25 minutes ago, ChrisInOz said:

@MikeEll identified it from the Bestfit catalog using the ligne size,  yoke and setting lever. See pictures below.

Not sure how he did this as the Gruen 240 is completely different.

It also looks too small to me for an 11 1/2 lignes?

Edited December 11, 2024 by AndyGSi

[Neverenoughwatches]

20 minutes ago, ChrisInOz said:

I polished the arbor by holding it in a pin vice and rotating it against  a folded piece of watch tissue charged with autosol.  it only took a few turns with very light pressure to make it bright and shiny again,  so hopefully I haven't forced the grit into the metal. 

I think you'll be fine with that, arbors are hard , I'm sure it would take a lot more than that to push abrasive into it. 

6 minutes ago, AndyGSi said:

Not sure how he did this as the Gruen 240 is completely different.

It also looks way too small to me for an 11 1/2 lignes?

I had this just recently,  possibly the one I'm currently working. Gruen 240 was the closest keyless I could find, and yet the rest doesn't match. 

31 minutes ago, ChrisInOz said:

Thank you. Lots of excellent advice and tips there.  I polished the arbor by holding it in a pin vice and rotating it against  a folded piece of watch tissue charged with autosol.  it only took a few turns with very light pressure to make it bright and shiny again,  so hopefully I haven't forced the grit into the metal. 

What's important is looking for any wear, any grooves in the arbor can transfer to the barrel ,bridge and plate, so no amount of polish can improve that. That can potentially drag the amplitude down, so a nice smooth surface is what we want to looking and aiming for. But polishing will quickly remove some stubborn sticky residue and make it all shiny again, wear would still exist and likely be less visible through the shine. 

[AndyGSi]

16 minutes ago, Neverenoughwatches said:

I had this just recently,  possibly the one I'm currently working. Gruen 240 was the closest keyless I could find, and yet the rest doesn't match. 

The keyless doesn't match but think it is some sort of Gruen.

Gruen 240 from eBay.

[ChrisInOz]

42 minutes ago, AndyGSi said:

The keyless doesn't match but think it is some sort of Gruen.

Gruen 240 from eBay.

Here's the keyless from mine.  Mechanically similar,  but different in the fine details.

Actually,  looking at those parts,  I wonder if mine might have been hand made.  The surface grain makes it look like they were both cut from the same piece of metal.  The corresponding parts on the "real" 240 look like they could be a drop in replacement for these,  even though parts of the shape are different,  the important geometry looks like a match.

 

 

[AndyGSi]

9 minutes ago, ChrisInOz said:

Actually,  looking at those parts,  I wonder if mine might have been hand made.  The surface grain makes it look like they were both cut from the same piece of metal.  The corresponding parts on the "real" 240 look like they could be a drop in replacement for these,  even though parts of the shape are different,  the important geometry looks like a match.

Bridges are also different from the Gruen 240 on eBay.

Edit

I would still have expected the mainspring to be very similar though.

Also subtle differences on the dial side.

Edited December 11, 2024 by AndyGSi

[ChrisInOz]

11 minutes ago, AndyGSi said:

Bridges are also different from the Gruen 240 on eBay.

Edit

I would still have expected the mainspring to be very similar though.

Also subtle differences on the dial side.

Well, I actually bought a Gruen 240 from eBay last month.  It doesn't run and I haven't done anything with it yet,  but perhaps I should try its barrel complete in this movement and see if it works.  

Although not identical,  they do look like close cousins.

This is mainly a training exercise for me,  so I will try to repair the broken mainspring too.