Heuer 7700 Stopwatch

[Kappa505]

I just finished this service and since there isn't really any written documentation on how to fully assemble this movement from what I could find (there was stuff for the dial side but not mainspring side or keyless works). I'm not a seasoned professional but think some photographs that I took and some explanations could be helpful for others. 

To remove the pressed on case back I had to sharpen and polish the case back removal tool as the indentation for it in the case back was super narrow. I used this same tool to remove the glass and pressed on glass bezel. The original acrylic was chipped and wasn't very tight so I ended up replacing it with size 54 crystal from Esslinger. 

(GS PKH Pocket Watch Crystal

(GS = MM Size: GS 54 = 47.0mm)

20534

To install it I placed the bezel over the lower die of a crystal press then raised the bezel up around the compressed crystal. 

When you remove the case back this is what you find. I bought is watch as a non runner and didn't realize at the time how to remove power from the mainspring at this point so I just went full send and removed the balance first followed by the barrel bridge. It was at this point that things flew out everywhere so I couldn't take pictures of how it was supposed to be put back together; a problem to be solved at some other time. 

With the barrel bridge removed and having now figured out how to assemble this section the ratchet wheel, click, click spring, crown wheel and crown wheel spring should look like this. All held in place by the barrel bridge. If you zoom in you can see how the crown wheel spring should be oriented. On a side note with some finesse it looks possible to power down the mainspring with the barrel bridge still on by moving the click out of the way from the side of the movement. 

The following photos are of the disassembly of the train of wheels. 

The balance cock/bridge has three screws. The balance cock safety screw and the end shake regulating screw (the one with the cross on top) can be seen below. The hole in the balance bridge that the regulating screw goes into is through and through so when it's tightened it lifts up on that side of the balance cock changing the end shake.  

I try and take good pictures of what the screws look like and where they go. 

Ratchet wheel, crown wheel, and crown wheel spring are removed showing the crown wheel core. 

Click spring and crown core removed. 

Case screws removed. 

Removing the train wheel bridge. With pictures of their location and a closeup of what they look like.  

Train of wheels. The center wheel/seconds wheel and the minute wheel are connected on the dial side to the seconds heart and the minute heart so will take some pressure to remove from this side. I removed everything but the seconds wheel and the minute wheel so I could get at the seconds heart and minutes heart from the dial side. 

Removal of the pallet cock with picture of the screw. 

The winding pinion, winding stem guard as they should be seated. The winding stem brace and the winding stem screw are also shown. The stem cock screws are also shown removed. It should be noted that the winding stem brace has an upward bend so it will raise when the winding stem screw is loosened.

1 hour ago, Kappa505 said:

 

Edited March 14 by Kappa505
Too many repeat pictures

[Kappa505]

With the bezel and glass removed your first job is to remove the hands. These bad boys are on there insanely tight. Removing them without special tools is a problem. 

I used these to take the hands off. Made pretty easy work of it. 

With the dial and hands off you are rewarded with this view. It becomes apparent why this was a non runner. Someone poured melted hard candy inside and there was a broken retention spring on the seconds heart. If you zoom in to the middle you can see it the piece laying inside. 

The hands are hard pressed onto the posts of the hearts and the hearts are held onto the seconds and minute hand by a small spring that engaged the respective arbors. The seconds and minute wheel will now come out. 

I recommend removing the springs before you remove the dial rest plate. This will prevent stuff from shooting everywhere if things aren't properly seated. I also recommend waiting to replace these on assembly so that you don't struggle to get the winding pinion and winding stem guard as they relate to a tab on the hammer lever. This also shows the dial plate screws and their locations. 

You can see how much corrosion and dried hard candy was inside this with the dial support plate removed. Obviously my spring removal recommendations were based on personal experiences. Lucky enough everything was super stuck together that nothing flew out. 

Positions of the springs. 

Chronograph levers being removed

The pillar wheel was stuck solid. This photo also shows that the screw retaining the pillar wheel jumper does not seat flush. It's the screw that's located right by my index finger. 

This shows the two screws retaining the pillar wheel jumper and the operating lever bridge. The operating lever has the tab that extends through the main plate and interacts with the winding pinion and winding stem guard on the other side of the main plate. The operating lever is the super long lever that extends from the pillar wheel to the keyless works anatomy. After a thorough cleaning I essentially assembled this in reverse. I began with the train of wheels first, installing the train bridge. Then back to the chronograph side so that I could install the minute and seconds hearts and finishing the dial side (without springs) then installing the winding pinion and winding stem guard and winding stem so that everything lined up. Then the springs followed by the dial support plate, dial, and hands. Then finished off with the winding works ( crown wheel, ratchet wheel, ect.

[JohnR725]

9 hours ago, Kappa505 said:

service and since there isn't really any written documentation

You would think with the company as large as this and with the quantity a stopwatches they made that servicing information would be out there but typically it has not existed. Equally as unhelpful the last one I serviced when you pop the outer back off the Intra back had a nice note. The note stated that if you needed servicing they gave you an address to send your watch to.

Then the hands are on really really tight because they take a heck of a lot of force when they return to zero. Providing you don't have something like a split-second were hands are on top of hands typically the hands do not have to be removed. Normal procedure would be to remove the two screws gently lift up the dial and the heart-shaped cams will come off with the hands still attached. Although in your particular case with the one heart-shaped camp and it's broken spring that one would have to come off but otherwise typically the heart-shaped cam's hands and dial all come off as one unit.

 

[Kappa505]

17 hours ago, JohnR725 said:

but otherwise typically the heart-shaped cam's hands and dial all come off as one unit.

 

How do you get the hands/dial/heart cams reinstalled as a unit and engage the two cam hammers at the same time? I had to move the two hammers out of the way in order for each heart to seat all the way. 

[JohnR725]

when the watches in running mode the hammers should be out of the way and then the heart-shaped cams can go on..

[Kappa505]

That makes perfect sense. Wish I knew that before I started. It wouldn't have changed the situation with the broken spring. 

[JohnR725]

3 hours ago, Kappa505 said:

Wish I knew that before I started.

I was trying to remember where I found out about this? It might've been when I was in school because we took in a variety of things and one of the first things I did as a student was I was handed a bag of stopwatches to deal with. yes in the school they took in watches and I get a whole bag of stopwatches. So this is where I probably learned.

But just because I knew that the last one I worked on a 736 I didn't have it in running mode. Because I forgot about that and removing when it's returned to zero makes it a little bit harder to remove things.

Then for anyone else that comes here. Snipped out an image from the pictures up above Springs that are nicely color-coded. Plus a photograph so you know where they go. The last one I worked on a 736 the two spring is appeared to be almost identical. There are about the same color they both looked may be the same. The parts list indicated different part numbers which might imply there different and. The really important not the mixup the spring is if they're not color-coded.

 

 

[Kappa505]

I really appreciate the input.