Back removal of a rotary skeleton watch

[PatrickP]

Not sure on the exact model, but my rotary skeleton watch's winder suddenly puts up no resistance. I'm pretty sure that it's the large cog next to the winder cog (see image) that has its screw loose but I can't figure out how to open the back. Im guessing it's a snap on back but the lip is very thin so I can't get a firm grip with a thin knife.

Appreciate the advice and help you guys are able to give me.

 

[mikepilk]

25 minutes ago, PatrickP said:

Not sure on the exact model, but my rotary skeleton watch's winder suddenly puts up no resistance. I'm pretty sure that it's the large cog next to the winder cog (see image) that has its screw loose but I can't figure out how to open the back. Im guessing it's a snap on back but the lip is very thin so I can't get a firm grip with a thin knife.

Appreciate the advice and help you guys are able to give me.

 

Pretty sure it's a snap on - but they are quite tight

I repaired one of these for a work colleague and needed a press to get the back on.

They use a Chinese movement (Cousins ref 2888 or similar ). Not the most robust movement- they can flex and  pivots pop out. 

 

 

 

[PatrickP]

36 minutes ago, mikepilk said:

Pretty sure it's a snap on - but they are quite tight

I repaired one of these for a work colleague and needed a press to get the back on.

They use a Chinese movement (Cousins ref 2888 or similar ). Not the most robust movement- they can flex and  pivots pop out. 

 

 

 

The lip is very thin, is there a way to open the back without specialist equipment. I have a small knife but I can't get a firm grip on the thin lip to push it open.

[mikepilk]

12 hours ago, PatrickP said:

The lip is very thin, is there a way to open the back without specialist equipment. I have a small knife but I can't get a firm grip on the thin lip to push it open.

Have a close look as there will be a wider gap somewhere, possibly near the lugs. Hold the movement in a cloth to protect your hand if the knife slips, also it stops you pressing the case closed with your fingers as you try to open it.