Jump to content

Tissot 794 day disc fixing


Recommended Posts

Hi all,

I managed to get my hands on a vintage 1972 Tissot Seastar Automatic with a 794 movement. It's given me a few challenges along the way with the calendar mechanism and no technical sheet to refer to but I seem to have overcome everything until the last part of the assembly. The date wheel is advancing fine now, as does the day disc when light pressure is given with pegwood when I rotate the crown. However, my question is, what holds the day disc centralised and in place? I've worked on an ETA 2836-2 date/day mechanism, and on this, a circlip held the day wheel on. The design suggests with this one that the dial alone will provide enough pressure to hold it in place though I'm not convinced. I've invested in a new date ring and day disc due to the originals being badly damaged.

Has anyone worked on one of these old Tissot movements before who could kindly offer some advice on fixing the day disc please? Photos of the job added.

Many thanks,
Adam

20200613_002612401_iOS.jpg

20200615_225149464_iOS.jpg

20200615_225513939_iOS.jpg

Link to comment
Share on other sites

4 hours ago, AdamC said:

However, my question is, what holds the day disc centralised and in place? I've worked on an ETA 2836-2 date/day mechanism, and on this, a circlip held the day wheel on. The design suggests with this one that the dial alone will provide enough pressure to hold it in place though I'm not convinced.

Yes that is very common with Swiss mov.ts, a thin brass washer goes between the hours wheel and dial, otherwise the day disc takes its place. 

  • Like 2
Link to comment
Share on other sites

Do you have the dial support ring. 

Yes, I have the plastic dial support ring and (I think - see photo before disassembly)2c5f36697ee2cdc5e8632c0441fc813c.jpg&key=92754e33815abce315385fd210a14cf699700a430830210a653059b2b60128b8everything else , thanks Nucejoe. Unfortunately no dial feet so am fitting dial sticky pads https://www.cousinsuk.com/product/dial-spots-strips secure as recommended by someone. Then just the auto rotor to fit and hopefully I’m done.

 

 

Sent from my iPad using Tapatalk

Link to comment
Share on other sites

Dial ring looks good. 
Don't pads raise the dial plate higher?   

That’s my fear now. The pads are 0.4mm thick so I won’t know till I try


Sent from my iPhone using Tapatalk
Link to comment
Share on other sites

Pads are always an agly hack, I try would find someone to resolder the feet. 

I agree jdm. I do have a soldering iron for electronics but fearful of damaging the dial. Looked on eBay without luck for a flat one with diameter 29.5mm without success :(


Sent from my iPhone using Tapatalk
Link to comment
Share on other sites

7 minutes ago, AdamC said:


I agree jdm. I do have a soldering iron for electronics but fearful of damaging the dial. 

It's a valid fear. Watchweasol has the plans for a machine, maybe he will post the details. You can try a dial washer too.

  • Like 1
Link to comment
Share on other sites

You could use JDweld to glue some dialfeet on. I guess Cousins has these, I bought mine at Boley.

Do you mean J-B Weld epoxy? If so, I can obtain it from Amazon. Sounds feasible.


Sent from my iPhone using Tapatalk
Link to comment
Share on other sites

Its quite difficult to glue feet back on but heres a tip.

I usually do it first  before assembling. What I do is fit the feet back in a bare movement so that they stick out a bit equally, then dress the tips so that they are flat, Next Apply some JB weld to the dial where you want the feet to go .. sighting thru the hole in the middle of the dial to ensure you get it really centred. Use blobs of rodico on the edges to ensure the dial stays level. If you like you can reattach the centre wheels, canon pinion/minute wheel to ensure that the dial is really centred. Leave it overnight or longer and then remove dial from movement .

Good luck

Anilv

  • Like 1
Link to comment
Share on other sites

Hi  Adam  http://www.dirkfassbender.de/dial-feet-soldering-machine.html      Information found on this link is what I based my machine on only that it uses a separate power supply ( a car battery charger) as it has an over current detect and cut off all other details are virtualy the same.  I will get the other information for you soon..

  • Like 1
Link to comment
Share on other sites

Hi Adam  If you search on the site in "watch repair tools and equipment there is all the details I posted in Oct 4th 2019.    and  google      "dialfoot soldering machines" i t will give you lots  of the Including the original Wesley R Door drawings.   cheers

  • Like 1
Link to comment
Share on other sites

On 6/16/2020 at 10:44 AM, AdamC said:


Do you mean J-B Weld epoxy? If so, I can obtain it from Amazon. Sounds feasible.


Sent from my iPhone using Tapatalk

correct, I used it for some dialfeet, make sure you sand the dail at the position of the dialfeet

Link to comment
Share on other sites



×
×
  • Create New...