Rotary case back

[chrisdt]

Can someone help with this please....Is this a screw back? If it is the pins would be very thin. If snap on

no prize points for case knife visible. Thanks

[RichardHarris123]

I think snap back, if screw on, very difficult to make the holes line up. Are they screw holes. 

[chrisdt]

No...They would line up for a double pin opener but the pins would have to be .5mm or less

[Neverenoughwatches]

I do not see the purpose of the holes extending into case. Pins from a screwback opener will catch the edge of the holes.

[Kalanag]

I‘d say it is screwed on.

 

[chrisdt]

Thanks guys for your input ...Tried various ways but Kalanag gets first prize. It is screw back so I have removed with minimal damage. For anyone else who comes across this type of case back I've added a picture of the removal tool. Mind you it doesn't do the compass much good.

[ColChibani]

Could a "blue ball" have done the trick?

Maybe you could use one to close the case, without risk of damage.

[watchweasol]

Quite often in such cases when a screw back gives problems one way out is to superglue on a large nut and use a wrench, then dissolve off the superglue with acetone . Usually removes the tightest backs.

[Neverenoughwatches]

Did the effort twist the compass arms and bend the pins ? A soft rubber ball is the recommended thing to use, I mostly use a rubber bung fitted to a handle. But these from AliExpress look useful, and are cheap.

[chrisdt]

I have the rubber ball and the 3 finger dish type of remover but it wouldn't budge. I did hold the compass legs right down near the points so they are ok. Never come across this type of caseback before. Also never come across a Rotary with an automatic movement which doesn't say so on the dial....