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Issues getting watch to unwind


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Hi everyone, hoping I might be able to get some advice on re-assembling my watch movement.

Working on a Bfg-866 movement from an older watch I got as something to practice and attempt to fix. I disassembled it and managed to get the arbour back in it's rightful place in the mainspring, which fixed the winding issue I had had with it. However, on putting the movement back together I got the train wheels all in place and made sure they could all move smoothly after fitting the wheel bridge back into place, however when I try to test wind it without the crown it would wind up and add tension, but nothing would move and the spring wouldn't unwind. I don't have the pallet fork or anything else in while testing this, and double checking everything seems to move smoothly, and the mainspring wheel had a tiny bit of play side to side, seeming to imply it isn't caught on anything either. Am I missing an obvious issue here? Feel so close to having it working and any advice to get it going is much appreciated :) (Apologies for any part naming mistakes, still pretty new here. If I can get this watch to run, as it so nearly did before these issues, it will be my first successful repair, hence my eagerness!)

Thanks in advance

 Callum

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That thought did cross my mind, so I got the keyless mechanism and the crown back in and wound it with that to the same result. I also didn't actually remove the mainspring from the barrel as it seemed to be absolutely fine other than the loose arbour. I also don't have the proper tools yet to get it rewound without a long night with a lot of cursing, so I just left it in and reassembled it.

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Hi  You have assembled the watch minus the fork/pallet and tensioned the main spring and there is no movement through the train yes. Right take the tension of the mainspring and remove the ratchet wheel and with a piece of peg wood apply a little pressure to the barrel teeth and see if the train moves if so the ratchet wheel is jamming the barrel check its fit is correct. If all is still locked up dismantle the watch again and fit the barrel and it immediate wheel and try again, If ok fit the next wheel and check again untill all is fitted back again.

I have enclosed the tech sheet for the BFG 866.

2529_BFG 866,866.31.7.pdf

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These bfg866 movements can be a pig to realign the plate on. Much patience and test push the barrel before winding as mentioned above, it sounds like you have some misalignment with the barrel, be sure to relieve the tension in the mainspring before taking the click/spring off.

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14 hours ago, Nucejoe said:

Bfg 866 MS is a weapon and a pain,   eye protection is a must. I clean the tube which  the arbor goes through. Lube. If no luck repeat until it decides to work.   

 

I have done the same thing on problem child movements.

 

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Well damn. In taking it apart and putting it back together, testing it repeatedly to make sure everything spun, I wound it up to the same result. I also think I've managed to break the smallest part of the escape wheel pivot off, which is the second time I've done this on this watch. I could get another and try again, but at what point is it not worth it? I feel like I'm more likely to end up either with it still not winding, or another broken pivot :( As a follow up question then, how do you guys keep yourself motivated while working on projects? I've tried two watch repairs, and so far neither have succeeded. I know it's a matter of practice and patience to eventually succeed, but its still demoralising each time

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Somehow when putting it back together for the last time without the broken escape wheel, it runs fine when the spring is wound, all the gears spinning gently and winding it down. Also managed to get the balance wheel sat perfectly, gently moving back and forth for ages. Just when I lose hope I get it again xD I'll give it a bit and then I think I'll try, hopefully for the final time, and fix this thing once and for all

 

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If the escape wheel pivot is snapped or not correctly seated it can give the appearance of jamming the train looking like it won't release power as the wheel is tilted.

The only suggestion I can make is patience and if you feel like you're beginning to get frustrated. Cover it and walk away for a bit then return later, I've broken pivots more times through frustration and a desire to hurry up than carelessness or otherwise.

Pin pallet movements are both good for practise in that they're plentiful and cheap but bad in that they're incredibly fiddly to get the barrel and train plate aligned.

For good cheap practice movements I heartily recommend a couple of cheap HMT watches from eBay Indian sellers, you can get them for less than a tenner in auction and 10 to 15 on bin listings, they're based on a citizen, (miyota) and are quite nice to work on for practise.

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:thumbsu:Hi over the years I have done many BFG866 watch movements, They were a work horse unit years back, Yes the are a P.I.A. when re assembling the top plate and getting the pivots to line up. My method was to fit every thing in place put on the plate and hold with two screws tightened sufficient to hold every thing but still allow you to manipulate the wheels, I also made some tools,  poor quailty sewing needles bent into various shapes to allow you to push or pull the wheels into line, similar to the ones we use when rebuilding clocks they were to me easier than tweezers. They can be made from wire and then hardened fitted to a dowel handle. poor quailty needles bend easy good quality one are hard an snap un less you soften them up.  As M1KS says cover it up and walk away if frustration creeps in. We all make a balls up now and then perseverance and paitence are the key words here, Just keep trying, The BFG 866 although simple construction is probably not the easiest one to start on, Tame M!KS's advice or pick up some cheap Russian jobs and crack on.

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I agree with the Pain in the ? , not great movements. But last 2 i did the plate went on straight away! Must have been pure luck, as usually a struggle. Mine were scrappies for practising, one has a broken pinion on the Balance, but not having the tools to sort it got put back in scrap, just not worth spending on.

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I also go for placing the gears, then lightly placing the top bridge, putting in a couple of screws, but do not under any circumstances tighten them more then maybe 1 to  1 1/2 turns or so, just enough to catch the threads and no more. This allows you to rock things about till those annoying pinions all pop back in place.

Gravity should bring down the top plate, not finger pressure. If you are pressing down in frustration, then something is going to give, and that almost certainly is going to be one of the pinions that isn't lined up. Your fingers should be pressing just lightly enough to stop the bridge from lifting, but gently enough so that you can maneuver the gears in to place. This requires a very light touch.

The use of soft needles and sewing pins to guide things around is good advice. Again, you are moving things gently, not jamming them into the holes. Initially it feels like you are trying to balance half a dozen marbles on a plate, but with practice, it gets easier.

Once you are certain all of the pinions are in place, lightly tighten the screws down, and check to see if the bridge rocks at all, if so, check again, as something is almost certainly no aligned correctly. As you screw down the screws, keep checking that the bridge is going down evenly, and that things haven't jammed up. Only once you are certain that the train is moving and the bridge is flat, would you snug them down completely.

I also agree with getting hold of an HMT or two. They are cheap as chips. You can often pick up some of those hideous Chinese skeleton automatic watches for a couple of quid too, but their build quality is pretty variable.

I like the HMTs better, as they are actually fairly well constructed, since they are licensed copies of Citizen movements, produced to similar quality standards or at least they were when they left the factory. Some of the people servicing them over the years may have added a few "apprentice marks", and one or two I have picked up were barely able to limp along, despite the seller claiming they were "recently serviced".

They almost invariably respond well to cleaning, servicing, and adjusting, and since they have a more traditional multiple bridge construction with jeweled bearings, they are easier to tear down and put back together than some of the all eggs in the same basket, single bridge pin lever mechanisms. Finally, since you can pick them up for a few quid, it is less painful when some pico-scopic part, pings into a parallel universe, or over exuberance breaks something. We have all done both of these things. I have launched small parts, and accidentally mangled hairsprings,  more often than I care to mention. 

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Hi I forgot to mention that once he plate has dropped into position or so you think just run the screws in to hold the plate and no more then with the tool / needle try lifting each wheel, if they all lift up and drop It means that all the wheels now are in place and got end shake any that do not lift and drop are still held, so back off the screws half a turn and shuffle the errant wheel into place . when they lift and drop you are home but continue to check as you tighten the screws down. It all takes practise.

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1 hour ago, watchweasol said:

Hi I forgot to mention that once he plate has dropped into position or so you think

At this point, look all around the bridge to see no space to the plate. Final check, one stick on top of bridge, another turns the barrel, observe the escape wheel spin. Now you have all pinions in 100%. What can happen now is that while you screw in you dislodge, to prevent that keep the stick on top and drive in two opposite screws. For the rest you can relax.
This is one operation where is important to have the work as high as possible.

 

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If you want to see how this process looks, take a look at Mark's latest video, you can see him aligning the various pivots and checking them, on a Seiko movement at the point I have linked in the video below. Note that he is exercising only very gentle pressure with those tweezers. Just enough of a feather light touch to keep things from moving and no more.

Furthermore, don't just watch this section of the video, it is well worth watching the whole thing, as you can also pick up tips on oiling, mainspring maintenance and a bunch of other stuff.

Edited by AndyHull
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Thanks to everyone for the responses, with a bit of perseverance and some oiling I got it to wind and unwind perfectly, and got the escape wheel fitted good :) The only I have now is the hairspring being slightly twisted, so it runs but slowly stops over a minute or so. How exactly do you go about removing it from the balance staff, as from what I can see there are no screws to allow it to come off?

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You carefully lever it off, minding not to damage the hairspring. They are not particularly tight. Levers like for removing watch hands. I have used stanley knife blades before, just go under the hairspring and gently prise it off. Remember to mark where the end of the hairspring sits for alignment refitting it, or it will be out of beat. 

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3 hours ago, stevew said:

You carefully lever it off, minding not to damage the hairspring. They are not particularly tight. Levers like for removing watch hands. I have used stanley knife blades before, just go under the hairspring and gently prise it off. Remember to mark where the end of the hairspring sits for alignment refitting it, or it will be out of beat. 

Thanks for the advice, does this also work for the stud at the end of the spring? In marks video he seems to unscrew it allowing it to come off whereas mine appears to be friction fitted 

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