702 / 7020 Countersink?

[bkwbkw]

Managed to get my hands on a gen 702 crown and aftermarket tube and I'm having a bit of difficulty as to what to do next.

I had countersunk / chamfered my MBW 1665 case to fit a gen 703 and the crown sat nice and flush against the case. However, with the 7020 tube fitted, the crown sits about a half mm away from the case.

I pulled out my drill bit and countersunk the case some more, but noticed (under loupe) that in order to achieve what I wanted, I would need to remove quite a bit of material around the base of the tube, and not go any deeper. The angle for the tube fits fine within the hole I've opened, but the outer threads (where the crown screws onto) needs to be sunk into the case a hair.

I believe this is due to the tube not being a gen 7020 - Perhaps it's 1mm too tall? And if this is indeed the problem, I fear that once I fit the rubber gasket inside the crown, it'll compound the issue more.

So anyways, I looked at some pictures of gen 1665 and have noticed that some have their 702 crowns perfectly flush with the case, while others are off by a half mm.

Suggestions and guidance needed please! Should I shave off .5mm off the top of the tube? Should I get a larger bit and make the hole larger so the tube sits lower in the case? Leave it alone?

Unfortunately I do not have a picture of my watch with me (forgot to upload before coming to work), but here are two gen examples of 1665's.

Flush with case:

Here's a gen that looks like it's having the same issue mine is having:

[Nanuq]

My initial thought would be to alter the things that can be fixed if you don't like the results. Drilling out the case further is irreversible. But taking .5mm off the tube can be salvaged, if you can find another tube. That's the way I'd go.

Here's some food for thought: what looks like a 0.5mm offset from the case may not, in reality, be so.

[FxrAndy]

if you are going to mod any thing then the tube is what i would do. Like bob says above

[freddy333]

I guess 1 man's trash is another's collectible.

Often, after Rolex replaces a tube, there is a slight, but noticeable, gap between the case & bottom of the crown (when fully-seated). Therefore, I always (specifically) try to replicate that gap on my gens & frankens

[bkwbkw]

Here's some food for thought: what looks like a 0.5mm offset from the case may not, in reality, be so.

Agreed. Due to the bevelled inside edge of the 702, it looks like it's further away from the case than it really is. So I grabbed my loupe and saw that there were exposed threads. Also, it's this bevel that actually accentuates the flaw.

I'll take a stab at reworking the tube tonight, but.. Anyone have a source for 7020 tubes? There was someone here before that had sourced some. I PM'd him and never heard a response.

Can 7030 tubes be modified to fit?

Thanks guys!

[bkwbkw]

Freddy, Good points mate.

I'll take some macro shots of my watch and share.

[alligoat]

I would think sanding a little off the top of the 7020 tube would be the easiest route.

Marsupilami did a run of 7020 tubes about 1-1/2 yrs ago, don't know if he has anymore at this point.

I also thought the chinese had duplicated the 7020 tube, but I don't know where I saw them.