Jump to content

Tissot 28,5-621 mainspring question

rogart63

By rogart63
in Watch Repairs Help & Advice

 Share

Recommended Posts

rogart63 Distinguished Member

rogart63

Posted
Posted

I am about to change the mainspring in a Tissot 28,5-621 - But as i took out the old one i found an extra spring inside. Should that be there? Can see that the new has that slipping spring. Movement is a automatic. 

Look att the first picture and you see tha spring  attached. Second picture is the old spring. Third is new DSC09206.thumb.JPG.b1d6a0b96179427951a7e66bea2850e1.JPGDSC09205.thumb.JPG.6bab39e6f90b1404fa3ec5e9eda6f0ec.JPGDSC09204.thumb.JPG.d9c06961484809c1641fede775503f19.JPG

Link to comment
Share on other sites
oldhippy Distinguished Member

oldhippy

Posted
Posted

That first picture is a bodge up and its not needed. Is that a post that someone has added to the barrel? If so it needs to be removed. The new correct spring will have the slip spring attached. You might need to replace the barrel, check it for wear on the inside.   

  • Like 1
Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
  • Author
Posted
1 hour ago, oldhippy said:

That first picture is a bodge up and its not needed. Is that a post that someone has added to the barrel? If so it needs to be removed. The new correct spring will have the slip spring attached. You might need to replace the barrel, check it for wear on the inside.   

 

That small spring was special made and was sitting inside the barrel. I removed it and replaced it with a new automatic mainspring. The automatic winding didn't work properly before and i think the reason was this special spring. The barrel looks okay. Now properly oiled. 

Link to comment
Share on other sites
JohnR725 Distinguished Member

JohnR725

Posted
Posted

On some early automatic watches the mainspring was two pieces. The spring itself that would look like conventional spring and a shorter spring that was on the outside provided the slipping and some place for the mainspring to attach.  Your shorter Slipping spring looks something homemade or basically it just doesn't look right? Fortunately today when you get your mainspring it's one spring and you don't have to deal with that outer peace that's hard to find and a pain to get into the barrel.

  • Like 1
Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
  • Author
Posted
1 hour ago, JohnR725 said:

On some early automatic watches the mainspring was two pieces. The spring itself that would look like conventional spring and a shorter spring that was on the outside provided the slipping and some place for the mainspring to attach.  Your shorter Slipping spring looks something homemade or basically it just doesn't look right? Fortunately today when you get your mainspring it's one spring and you don't have to deal with that outer peace that's hard to find and a pain to get into the barrel.

The homemade spring was slipping badly. So in an hour the winding was gone.  

Link to comment
Share on other sites
rodabod Distinguished Member

rodabod

Posted
Posted

That looks like an early automatic bridle. I think Eterna or Movado invented it possibly. Omega used them on the bumper watches. They can be adjusted. See page 5:

http://watchguy.co.uk/wp-content/uploads/2012/12/Repairing-Omega-self-winding-watches-bumper.pdf

De Carle quotes Omega in his Complicated Watches book about adjusting the slippage.

 

 

Link to comment
Share on other sites
  • 3 months later...
oldhippy Distinguished Member

oldhippy

Posted
Posted
42 minutes ago, rogart63 said:

Got this back yesterday. For some reason the mainspring is slipping and there is no tension in the mainspring. 

Did you send it away if so what repairs did the watchmaker undertake?

Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
  • Author
Posted (edited)

Wonder if the spring isn't to short. What happens if i go up a little? Anyone has some info on how long the mainspring should be? 

Says 280 mm on cousinsuk . But it doesn't fill up more then half of the barrel. Wonder if i go up to 300? 

8 minutes ago, oldhippy said:

Did you send it away if so what repairs did the watchmaker undertake?

It's me that is the so called watchmaker ;) I have done a service and changed the old mainspring as the old one was broken. I put the autowinding bridge back as that was sent along outside the watch. Sent it to the owner that in his turn sold it to an other guy. But he says it doesn't run okay.  It has a low amplitud. Around 160 degree.  Something i can agree on. When i wind the barrel with the screw it feels like it never got any tension.  Checked the hook on the barrel arbor and it looks fine. 

Edited by rogart63
Link to comment
Share on other sites
oldhippy Distinguished Member

oldhippy

Posted
Posted

It could be that the auto is not winding. As the barrel was in a bit of a mess, a replacement of the whole unit might have been best. If the person is active in his working day wearing the watch and takes it off at night it should still be going in the morning providing it fits on his wrist properly and doesn't flop around.

Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
  • Author
Posted
4 minutes ago, oldhippy said:

It could be that the auto is not winding. As the barrel was in a bit of a mess, a replacement of the whole unit might have been best. If the person is active in his working day wearing the watch and takes it off at night it should still be going in the morning providing it fits on his wrist properly and doesn't flop around.

 

It works but has a low amplitude. When i wind the barrel screw i can keep turning million of turns. Feels like the mainspring is slipping inside the barrel. The auto is working fine and the rotor is doing it's thing. Wonder if i should give the NOS mainspring a go. Or maybe remove the new one as it can be broken? How knows even it it was new when i put it in. I will check that before i order a new one. 

Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
  • Author
Posted (edited)

Can't figure this out?  When i look at the Tissot 28,5R-621 family. Ranfft says all the same mainspring. But cousinsuk have different mainsprings for each movement. cousinsuk says 260 mainspring and jules borel says 360 . Wonder if cousinsuk has the right mainspring? 

http://cgi.julesborel.com/cgi-bin/matcgi2?ref=TIS_28.5R-621

Edited by rogart63
Link to comment
Share on other sites
rogart63 Distinguished Member

rogart63

Posted
  • Author
Posted (edited)

And ranfft doesn't says how long it should be? Last time i switch a mainspring on a 28,5 i think i used a 360 mm . Think i wrote about it? 

Anyone has a bestfit catalog or something to verefy my teori? 

Looks like i have been there before? At least now i know the problem. Will order the correct mainspring. Why does cousinsuk says 260mm ? 

 

Edited by rogart63
Link to comment
Share on other sites
JohnR725 Distinguished Member

JohnR725

Posted
Posted

So I found a parts list at least it confirms that it's a newer spring with bridal attached. Then bestfit online doesn't have a mainspring at all? It does have other parts like the barrel listed but not with the mainspring. Then it does confirm and agree with the tech sheet that the TIS 28.5R-21 Is the base model for the TIS 28.5R-621. Then the physical bestfit book gives the mainspring as a WA80 3 1/2 x 11 x 10 1/2. So if I do the calculations for length comes out to 266.70 mm to add to your mystery.   

Tissot 28.5R-21 Part Sheet.pdf

  • Like 1
Link to comment
Share on other sites
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • Zedster
      Movement inserted from crytal side

      By Zedster · Posted

      Hi, guys I have a bit of a predicament and hopefully, somebody can advise. I'm working on a Roamer MST 521 where the movement is extracted from the crystal side. I'm now at the final hurdle where I need to replace the movement back into its case but I'm not sure of the correct procedure. I still need to fit the hands but that's where the problem lies. If I insert the winding stem to test the hands for correct alignment I will need to turn the movement over to release the stem again it's the spring-loaded type and needs a small bit of force to push down but with the hands fitted, I don't think I can do this on a cushion without causing some damage to the hands and that's the last thing I want to do, this watch has already been a love-hate relationship and I'm so close to boxing this one off which I'm counting as my first major project.  The other option is to case the movement then fit the hands and hope everything is okay. I've already broken the original winding stem but managed to find a replacement, the last one in stock, so I'm a bit reluctant to keep removing it. Any suggestions would be appreciated. 
    • Jon
      Main spring

      By Jon · Posted

      I would go for the dearer spring. You won't need to remove the spring from the carrier ring and then use a mainspring winder to get it into the barrel, for a start. Also that spring is closer to the needed dimensions, especially the length. The length plays a part in the mainsprings strength. If you double the length you will half the force (strength) of the spring and vice-versa. A spring with 20 mm less length would be about 7% shorter, so technically would be 7% more strength, but I find halving this number is closer to real-world findings, so the spring would be about 3 to 4% more strength/force. On a mainspring that ideally kicks out 300 degrees of amplitude, a 3% increase in amplitude would be 309 degrees. Increasing or decreasing the length of the mainspring will affect the power reserve to a greater or lesser degree. It depends how much shorter or longer it is.
    • Malocchio
      What tools does ebay have to offer this week.

      By Malocchio · Posted

      I recently bought this but not on ebay. I figured if I want something Japanese I better check Japanese auction sites since these don't seem to pop up on ebay. I paid 83 € plus shipping & taxes. I think it was pretty reasonable for a complete set in good condition.
    • GuyMontag
      1972 Bulova President "E" Sea King 11ACACB movement

      By GuyMontag · Posted

      Did you take the friction pinion off the large driving wheel and grease it? Although, now that I think about it, that shouldn't have any effect on the free running of the train if the friction pinion isn't interacting withe minute wheel/setting wheel...
    • DDean
      Incabloc Lyre Spring & Low Earth Orbit

      By DDean · Posted

      I did in fact use Rodico to get the spring into general position and "hold" it there while I used a fine oiler to make subtle positional adjustments.
×
×
  • Create New...