2006 Eberhard & Co Navy Master Triple Calendar Service Cal 7751

hello young and old friends old new welcome back to the channel today we're going to look at this lovely aber heart go with a 7751 movement it's a buckle up eberhard is one of those manufacturers that are a little bit anonymous to a lot of people but they produce some beautiful watches and they're especially known for chronographs this one has the 7751 movement so a derivative of the 7750 easily the most used chronograph movement ever and we see that it doesn't actually run we can set the time and you might have already seen that the weekday quick set pusher at 10 o'clock works let's see at midnight yeah so the weekday and date and gmt function work as they should and the date quick set also works as it should but it doesn't run the 7750 family has a hack so when you pull the crown out all the way to time setting mode then you do stop the watch but that's not the case here i see the chronograph doesn't run either so something is wrong in the kingdom of denmark so open sesame let's see what you're hiding this watch has a screw down case back as is fairly common nowadays it's a good way to secure the case back it means you do not damage any gaskets there's also much less chance of scratching the case back a lot which commonly happens with the screw on case packs when people are curious what's inside and try to use whatever they have to open and then it slips and scratches and there we have it a very ubiquitous 7750 family honestly not a beautiful movement but very functional and we see that for some reason the watch started running so let's put it on the time grapher and see what we can see and it looks pretty good to be honest yes high beat there and the watch is running way too fast but the lights are straight that's what we want we'll check the play on the rotor this is a ball bearing rotor there's a special little thing with this screw for the rotor and has this little dimple in the center that's to accommodate the chronograph seconds hand very important to use that screw there it's a bit odd that the watch started running when we took the case back off doesn't seem to be anything pressing on the movement we'll take the hands off much as we can we want to use big hand levers small ones will be sharper and they are more easily slip as well there are a few tiny marks on the dial around the hands and that goes especially for the sub dial hands now there are no dial screws on this movement it's a typical movement in that sense uses this dial clamps dial fasteners which have their benefits and their disadvantages now when working on the 7750 it is actually quite important that you have support in the movement holder so if you do this a few times it's well worth having a specific movement holder for the movement family as you can see i put in a generic crown and stem actually because the original crown stem for this watch is too short for the movement holder now there's a lot of parts in this watch that want to jump out literally there are a lot of jumpers and springs everywhere so for instance under those discs we took off for the week day and the month that's why we keep an eye out for that now speaking of the 7750 family so the chronograph part is identical all the differences are on the dial side so they're all calendar related differences so if you worked on a 7750 you probably know it has a standard date disk this triple calendar version as we saw has a hand for the date and two discs for the week day and the month and it's also got a moon face and for some reason amberheart took the moon face disk out you can see that all the other components are actually still there including the jumpers and the quick set but no moon phase disk and of course no cutout in the dial either so we disassembled the calendar part so we can take off this calendar plate as well underneath that plate we have the 24 hour wheel and then we have the weekday setting wheel and the hour and minute wheel the hour hammer and the brake and the hour counting wheel now this is the actual canon pinion it's called a driving canon pinion and this construction is also why the hands move so let's say slowly or little by return of the crown there's a lot of gearing taking place now we're over on the chronograph side of the watch we just started the chronograph just want to check that everything runs as it should the chronograph wheel in the center here showing the seconds has a little finger on it and that little finger then moves the intermediate minute counter wheel one tooth ahead per minute so with each revolution of the chronograph wheel just inspecting to see that that goes as it should and yeah that looks all right and of course that intermediate minute counter wheel then it pushes the minute counter wheel one to the head also now anything more than showing the time on the watch is termed a complication so even a date is a complication of course the chronograph is a slightly more complicated complication and it's also one of the most popular ones it takes a little bit more space to make a chronograph so our chronograph watches are typically bigger and the eberhard actually had the 42 millimeter chronographs back in the 1940s so they were sort of a little bit ahead in that sense and there are a lot of beautiful chronograph movements and in my opinion 7750 is not one of them there's a lot of floating pieces as you might see as we pick things apart here and it's very much born out of focus on streamlining costs making easy to manufacture parts much more than creating something that was beautiful nowadays the 7750 is an etta movement it was developed by a valjoux so you often hear vol joule 7750 was one of the three main manufacturers of chronographs in switzerland together with the venus who they actually acquired and land rom or london especially a land run was known for their column wheel chronographs this one is a cam shifted chronograph that's the cam that we're taking off there cams are much easier to manufacture than column wheels and the 7750 was made with this specifically in mind and really was a child of the quartz crisis so compared to its predecessor the 7733 which was basically a little bit less refined version of the venus 188 the 7750 is of course automatic it has a higher bitrate and perhaps most crucially it has an oscillating pinion instead of the traditional horizontal clutch as most chronographs before this one had and i think it's quite equivocal that the horizontal clutch is the most beautiful solution but it has its drawbacks as well and nowadays quite a few chronographs also have vertical clutches we will be looking at some other chronographs very soon so we can have a look at the different types as well and back in 1973 when the 7750 was introduced it wasn't really celebrated it was really seen as more of a low-cost less refined version of course nowadays it's very ubiquitous if you walk into watch store or if you browse chrome 24 you can bet your uh something that most of the chronographs will be 7750 driven and that also has a lot of benefits of course for people working with watches like us a lot of people on this channel it means that there are a lot of spare parts it means that you will get used to the movement you'll know a little bit more about the quirks the things to watch out for and so forth of course nowadays it doesn't sell spare parts anymore but the salita sw 500 is basically the same movement and selita has now actually in that time movement production anyway all right well we've been talking a lot we've managed to strip the watch down last thing we need to do is take off the shock setting in balance the shock settings on the balance and on the underside are different the one on the balance is a little bit wider and we're also going to take out the mainspring given the high repeat rate that we saw away i think it's probably perfect and it looks good indeed just need to clean the barrel a little bit and then we can head off to the cleaning machine and 33 minutes later we'll get a shiny new watch or about 150 pieces of one that we have to glue together with super glue and duct tape but we're up for the challenge let's start with getting the mainspring back into the barrel it's a very long mainspring what you might have noticed is that the lid of the barrel has a little pinion if you can guess what that is then comment below we're going to put some cleaver on the bare wall sort of goes nicely this sticky black thing with those uh super villain finger cuts from my version i think those black super villain finger cuts also sort of contribute to the whole image of the watchmaker i mean it's like nowadays all the kids want to become watchmakers right it's like my eight-year-old son he wants to be a watchmaker and i told him no no no no get on like a good job like a influencer or youtuber and now that he knows that his dad is both the youtuber and the watchmaker he's like whoa that fascination will probably last maybe two weeks anyway i'm going to put some 1910 on the capsules as noted before when there's a thicker jewel it should go on the top on the balance and the same thing when it's a bigger jewel it's typically also on the balance side as is the case here and i'm going to see the balance i'll select nicely with the higher bit movements like this one we can easily turn the balance so that's a benefit the hair spring is much stiffer for some reason this is the 17 joule version typically you would find the 25 drill versions this is a 17 dual version which means that there are let's say a few missing jewels nothing to call interpol about but it is a bit uncommon to find that some of the wheels in the wheel trend for instance are not jeweled you might ask what's the reason for having 17 jewel versions and the main answer is archaic customs rules for instance the us and also other customs they separate between the watches with the 17 or fewer jewels and more than 17 and of course in today's production one joule is probably worth i don't know five cents so it makes no sense whatsoever not that we would really think customs is based on common sense anyway but there you go and of course joules in the movement will reduce friction reduce wear improve accuracy etc so most likely this watch was produced for export to the us all right we got into the keyless works and you might remember this which has a hack and the hack has a little lever that fits into the groove on the sliding pinion so we need to make sure the sliding pinion is positioned properly otherwise the keyless works is pretty uh undramatic and that sort of sums up the overall movement as well i would say it's very much functional reform much more in line with the psycho philosophy than swiss typically i think if the el primero and the seven fifty and to the beauty contest and the el primero would be the unanimous winner and the seven seven fifty would be the ugly stepbrother of the janitor and cleaning the puke off the floor after the el primero's victory party and if you think that's an unfair analogy yes absolutely it isn't a beauty contest and success slides in numbers 7750 is easily the most successful chronograph movement ever so as mentioned before it makes it a very important movement to uh to know for us watchmakers we will come across it a lot and it's a movement that is okay to work on we're almost done with the keyless works we oiled and greased the various parts the sitting lever spring and cover plate is best assembled together with this intermediate setting wheel and then simply placed on top like this unless we do we screw the screws holding it down just a little bit and then we can put the setting lever spring onto that little knob on the setting lever speaking of the oils and greases one of the good things about let's say a modern movement like this even though it is actually almost 50 years old is that you can still find the technical communication or the tech guides if you will that show what you should do when you take it apart and reassemble and part of that is of course also a lubrication chart i'll post a link to the technical communication below but for the lubrication the tech guide used to say that you should use molecule dx for the grease but given that swatch bought out mobius a few years back it now recommends that you use mobius 9504 which is very similar to be honest to moloko dx but i think that's much more commercial recommendation than an actual benefit-based one unless you think of the financial benefits to swatch group which is what they do so we put on the ratchet wheel the crown wheel we fix or dropped the pellet fork and for those of you with sharp eyes yes it's the wrong screw in the ratchet wheel i'll replace that later the ratchet wheel in the 7750 has this uncommonly small screw for the barrel arbor that's my excuse anyway so with the heart beating we can wind the watch a bit and then we're gonna see if we can make it run a little bit nicer so we see that it runs very fast and there's a big beat there so the first thing we're going to do is take out the beater non-modern movements that's quite easy you just move this stud holder a little bit you probably have to do that in several iterations back and forth a little bit and of course we have to be very careful we don't uh mash the screwdriver into the balance tiny little adjustments itsy bitsy teeny weeny adjustments polka polkadot bikini and i'm getting too old for this or actually i'm just getting the right edge for this but anyway so with those adjustments we see that the beater can be taken out and for adjusting the bit rate how fast the watch runs we adjust the index the index spans the hairspring it shouldn't hold the hairspring tight but the hairspring should just be allowed to breathe in between the two pins or similar and in essence means that the hair spring is made shorter or longer if we move the index a shorter spring is stiffer and thus oscillates faster vice versa for the longer spring so that's how we make the watch run faster or slower you might have seen that the amplitude was not that high which wasn't fully wound so that's the reason fully wound it's around 300 so that's fine we started disassembling parts of the automatic works and we're going to put on the cam put a little bit of d5 on the post and also at the underside of the cab you might remember had a thick layer of grease probably multicultix when we took it off with the cam jumper in place and with a proper ratchet wheel screw you can put on the chronograph bridge if the chronograph bridge doesn't seem to want to fit then there are a couple of things to look out for one is the proper ratchet wheel screw the other is the cam jumper spring and the third is that little detent that goes through the movement to help with the hour counter reset by the way one thing that can be very useful when working with chronograph movements is to leave the screws in place that way you won't mix them up for this movement that's less of an issue since we have a very clear technical communication available so we started putting together the chronograph parts right here we're doing the oscillating pinion and this friction spring here with that little plastic donut on top it's probably the most pingable part ever made in the watch industry so be very careful when you handle that one it fits underneath the chronograph wheel then here we have the clutch and this is uh probably the main difference between an oscillating pinion type chronograph and a horizontal clutch dot chronograph the bottom of the oscillating pinion is in constant mesh with the fourth wheel and when the clutch tilts the top over in a little bit it comes into contact with the chronograph wheel it's a pretty nifty way of doing it if that's the most elegant looking but it's quite efficient doesn't really steal a lot of amplitude from the movement and it's actually not a new invention it was invented almost 100 years before the 7750 was first made by the way what we're doing here is to increase the hardship camps of the counter wheels i'm in the counter and the chronograph wheel we're using a 9504 you could use some molecule dx you could also grease the end of the hammer instead but i was taught to do it this way so that's what i'm doing this operating lever spring can also be a little bit tricky to get in it has two different ends and you need to make sure you put the proper end into the proper place it's also very functional type design and then we can put the operating lever in put a little bit oil on the operating lever spring also just a tiny little blob of d5 so i have a window in my workshop looking out over the jura mountains in switzerland and sometimes it's sunny actually relatively often it's a nice climate here but that's what creating a little bit of shadows right now in the picture so when you're filming this you're kind of praying for the sun to go away here's another cyclist kind of thing plastic components this is the brake or the lock as it's called in this movement there are versions of the 7750 with metal components instead of plastic there and here we have the hammer and the hammer is the piece that hits the hardship camps and then forces them to return to zero it has highly polished ends to also reduce friction and with all that in place we can put on the automatic bridge can also be very tricky to get in place there's a little post at the end of it it fits down into the reduction wheel next to the reverser wheel and since a lot of these components basically just float on top of the chronograph bridge it's quite easy to move things around when you try to fit that post in but if at first you don't succeed then try try again and again and again and again again serenity now you really do have to keep a zen mindset when you're working on watches because if you get frustrated by little parts pinging away or not fitting have to redo things then yeah you probably aren't going to be happy with watchmaking we're getting the hammer spring into place it's a very strong spring it has this little eye towards the end of it and it's very useful in putting it back in place or for taking it out and the last thing we're going to put in before the chronograph part is assembled is this clutch spring can also be a little bit tricky by the way when you have a movement with a hack it's quite uh helpful to be able to stop the movement whenever you're working close to the balance especially if you're putting in tiny screws so they like reduces the chance of damaging the hairspring so we're checking to see that the clutch works as it should that the oscillating pinion engages and disengages properly we're going to let the chronograph run for a minute just to double check that the minute counter slips over as it should we're going to speed this up a little bit so we don't have to wait for a whole minute and obviously completely unrelated to that if you've never tried the inhaling helium as for instance from a balloon and a children's birthday party you really missed something all right that looks good then we can turn the movement over start working on the calendar side we mentioned this when we took the watch apart this is the actual canon pinion has to be very well oiled on this friction spring on the underside and when i say oiled obviously i mean greased with the molecule dx or 9504 if it's not well lubricated then you risk a chance of stripping some of the wheels when you turn the crown one of these dial fasteners was broken so we replaced it i tried using uh duct tape on it but just didn't work this is the weekday quick set jumper activated by the pusher in the case a few of these springs have different ends that look very similar so absolutely worth downloading the communication before you start working on these movements the minute wheel has a little bit different construction than normal the pinion is sort of a lantern pinion kind so it's got a cover on top of it so the best way to put it in is together with the hour wheel as i just did there and the 24 hour wheel that you see we're putting in here there's a reason for that little cover on the top of the minute the wheel pinion so that the 24 hour wheel doesn't mesh and jam up the whole movement then we can put in the hour counter together with its corresponding brake and hammer the hammer goes on top of that detent that comes from the other side of the case and it's of course activated by the cam which is in turn activated by the operating lever putting a little bit more 9504 on the contact points of this steel parts and this says spring is also quite tricky absolutely to be recommended that you hold the spring and the parts down and hurry hurry hurry to put on the calendar plate the calendar plate is secured with three small screws two of those screws are still exposed after all the components for the calendar works are in place one is hidden under the month disk and the reason i'm mentioning this is because it might be necessary to take the calendar plate off if you need to adjust the sequencing of the weekday and the date jumping let's just first put the date wheel in place there's a cutout and it's a calendar driving wheel next to it that you have to align to get the date wheel in place now that calendar driving wheel is aptly named since it actually flips both the date wheel and the weekday disc so if we zoom in we can see this little finger at the bottom here that finger flips the weekday disc over but at the underside of that wheel we can see another pin that pin goes through to the other side and flips the date wheel over now most of these kinds of wheel are friction fit the two different parts that goes for star wheels for the date discs weekday discs that kind of thing so if you ever need to adjust those things you simply use your tweezers like i did there moving on we're going to put in the date corrector with its cover plate when there is some moon face at this in place this one would also quick set the moon face all the parts are actually in place except for the moonfest disk itself that's the moon face corrector there and there's the jumper for the moon face but where's the moon face where did the moon face go yeah i'm sorry i'm sure what that was so after correcting the sequencing of the weekday and the date change we realigned the calendar driving wheel with the deck wheel and then we can put on the jumpers on the other side of the movement for the weekday disc and while we oil this last few pieces i mentioned without going into detail that eberhardt is viewed as a chronograph expert and you might then wonder why they use stock movement like this one well the answer is that they do like basically everyone else but this is not what they're famous for eberhard's main claims to fame and lie in a few different watch series like the extra four or extra fort uh nowadays especially the chrono four the chrono 4 is quite unique in that all the different counters and the subdials are lined up four in a row mostly horizontal but they also made the vertical ones so that you can more easily read the timing of your chronograph and that is a module that they built on top of the 2894 which is again built on top of 2892 eberhard was the first to introduce an hour counter in a chronograph that was back in 1938 so really a while ago and they really competed with the likes of breitling and longines and being first to fly by chronographs and very highly regarded in that space as mentioned today they are probably best known for the chrono 4 but in general i think the different models that eberhard makes are really well designed very classic very stylish so worth looking at we've got all the candle parts in place i'm going to start putting on the hands on my chronograph like this one with an hour counter and the gmt hand there are enough hands to choose from so we need to plan a little bit as you can see we're starting with a minute counter and the reason is that when the chronograph is reset to zero it's going to point straight up towards midnight and that's where a lot of the hands will point so we cannot press it down if we try to reset it to zero the other hands will be in the way and next we're going to put on the hour counter hand we started the chronograph almost a minute ago already so we're just gonna check at the same time that minute counter goes back to zero there you see it flipped to one it goes nicely back you can also see that we're using a swiss play though to put the hands in place the thing is these sunken subdials the hands are very close to the dial so we really want to avoid as much as possible having sharp metal objects close to the dial all right now for the date and the weekday we know there's a quick set for the date so if we change the date enough to have the month disk flip over to the next month then we know that's the first of the month so we can place the date hand correspondingly for a chronograph and especially one with a central date hand like this you will easily find that the diameter of the collet is just too wide for your hand setting tools so you might have to make your own ones with a little bit bigger diameter for the hour and minute hands it's a standard procedure first forward the hands or the time setting mode till the date flips at midnight and then we put the hands at midnight and gmt hand also needs to be aligned of course the same procedure find midnight place the hand test the biggest issue in placing hands on the chronograph is the chronograph seconds hand that's for a few reasons chief among them is that if you mess up the alignment you'll probably have to take all hands off again and do a lot of extra work second is that the in some movements and 7750 being one of them the chronograph seconds hand can be very very tight so you might even have to sort of stake it on or hammer it on especially when it's a new movement so that's also a very good reason to have this kind of movement holder where you have support for the other side of the pivot now the watch isn't running fast where you just put it up a little bit just going to see that everything works together so in the meantime i actually put on the new crystal on the case so here we see that the movement has been running the chronograph for half an hour and then we try to reset and just make sure that the hands are well aligned so with all that looking good we can encase the movement again we polish the case a little bit put in the new crystal as i mentioned i'm gonna put the actual crown and stem back in you might remember that when i took the rotor off initially i mentioned that the screw for the rotor is a special one with this little dimple in the middle that actually supports the chronograph seconds hand so we need to make sure we have that same screw here otherwise we're going to break that pivot for the ball bearing we're going to put some le beta v 106 to make sure it runs smoothly of course 7750 has this characteristic wobbly for the rotor it's an easy way to tell if watch has a 7750 family movement just put the watch flat in your hand and raise your hand fast and take it down again just as fast if you feel and maybe even hear the rotor spinning like you know it's a 7750 all right with the case pack back on i'm gonna put on the nice strap test things one last time basically never do enough testing for a watch especially complicated watches like this and it looks quite good on the wrist i think we'll let the chronograph run even a bit longer it's a pretty handsome watch i think chronographs are typically a little bit bigger and perhaps more impulsing on the wrist we covered a lot of ground in this long video i hope you enjoyed it thanks for staying with us if you like our videos then clicking like and subscribe will help us a lot you'll also be notified when new videos come we'll be back shortly until then tata

Channel: Vintage Watch Services

Views: 48,179

Rating: 4.9174194 out of 5

Keywords: vintage watches, watch repair, watch servicing, mechanical watch, old watch, vintage watch, horology, watchmaker, watch services, watch restoration, watchmaking, old watches, 7750, 7751, Eberhard, Eberhard & Co, Valjoux, Chronograph

Id: 7WufdEccM1g

Length: 55min 37sec (3337 seconds)

Published: Wed Mar 24 2021