Installing an OEM crown to a Panerai...

[V]

Well a friend has send me an OEM crown for my destro and I am trying to figure out a way to install it...

First I have a rep case with a rep case crown tube. I have as well a Jimmy case with a jimmy case crown tube installed on it.

PROBLEMS:

First of all the crown although for Unitas it takes the 1,9mm stem (instead of the 2,1). Easy to fix I guess (with adaptors something)...

Second the crown on the edge has a small extended circle that leads to the following problem:

It CANNOT go through the rep crown tube... That means the hole needs widening (don't know how to do this without destroying the inner rubber seal)

It CAN go through the Jimmy crown tube hole (and I was happy for it ) BUT jimmy's tube diameter is around 0,5mm and the inner circle of the crown accepts less diameter tubes. So although it goes through the hole is does not LOCK.

I guess this is a bigger problem than the hole and it needs a different approach.

So the other problem I don't know if it will exist just yet (because I have not been able to get the crown through the tube) is if the crown will LOCK with the rep tube (it seems it might work -both around 0,4mm- but it will be millimeters if not)

Photos:

CROWN

REP CASE (notice the smaller hole and the smaller diameter tube)

JIMMY CASE (notice the bigger hole but also the bigger diameter tube)

[Jetsons]

V, I'm certainly no expert but you probably need the matching OEM tube (or generic equivalent) and retap the case for the new tube. This is what needs to be done when installing the OEM crown/tube on Subs which I am familiar with. The stem may also need to be trimmed for the revised tolerances.

The rep tubes are usually smaller and not as robust as the gens, at least that's the case with the Subs. If you can source the tube set with seals, it shouldn't be much of a problem to install your crown.

The OEM crown looks sweet!

[V]

If you look the original image of the crown you will notice the following..

It seems there is an inner circle of steel (lighter colour). Don't have any clue why they made it like this. Probably different models had different diameter crown tubes??

If I will manage to take off the material in the red line (lighter coloured) it will fit ok (and leave just the blue).

[Usil]

Interesting project. Keep us posted on how it turns out.

Usil

[Watchmeister]

Well, we will find out. My 2893 GMT is off to Ziggy with an OEM crown and Jimmy Crown guard. I know he has a world class drill press for case manipulation and has good access to innumerable stems, stem adapters, tubes and gaskets. Hope springs eternal.

[V]

Well, we will find out. My 2893 GMT is off to The Zigmeister with an OEM crown and Jimmy Crown guard. I know he has a world class drill press for case manipulation and has good access to innumerable stems, stem adapters, tubes and gaskets. Hope springs eternal.

Good good.. lets see how it will go yours and I will send mine next.

What case and case tube you sent? Rep or Jimmy's?

Btw our crowns are Pre-Vendome

Vendome changed them afterwards.

[Watchmeister]

The crowns are from 5218 201A and B (if you have the PVD as well) to be exact. I am trying to mount them on the 2893 rep cases.

[HauteHippie]

kruzer - this will be an interesting project to watch!

[V]

The crowns are from 5218 201A and B (if you have the PVD as well) to be exact. I am trying to mount them on the 2893 rep cases.

And I am trying to mount it on a Jimmy case.. It will be interesting indeed

[Guest avitt]

Here is the solution to your problem:

First, push out the Jimmy tube. Carefully chuck the tube in a Dremel, or small drill (gripping the area where the tube enters the case). Turn on the Dremel, and shave off the outer diameter of the tube, using a handheld Dremel grinding stone attachment. Test fit with the crown frequently, and be careful not to take off too much material...it is possible to cut through to the internal gasket channel of the tube.

When you've got the outer diameter correct, just polish the ground area, and re-install. I used this technique to fit a Lello crown to a Jimmy case/tube.

[V]

Here is the solution to your problem:

First, push out the Jimmy tube. Carefully chuck the tube in a Dremel, or small drill (gripping the area where the tube enters the case). Turn on the Dremel, and shave off the outer diameter of the tube, using a handheld Dremel grinding stone attachment. Test fit with the crown frequently, and be careful not to take off too much material...it is possible to cut through to the internal gasket channel of the tube.

When you've got the outer diameter correct, just polish the ground area, and re-install. I used this technique to fit a Lello crown to a Jimmy case/tube.

Question: How can you push out the tube? I have asked in another thread and all the people told me that it is almost impossible without damaging the tube. Mark said you need a special tool (that he doesn't have).

But I think I will contact The Zigmeister after his mini vacations because i am not good with the dremel anyways

Is not easier to remove some material from the inside of the crown?

[sssurfer]

Question: How can you push out the tube?

I have been successful in pushing out the tube by using a tool that I found in an inexpensive chinese screwdrivers set. It was like a screwdriver but with a conical end. I discovered that almost all the chinese cheap screwdrivers sets come with that tool.

You put the cone end into the tube, from inside the case, and you simply give one sharp and neat hammer stroke.

Is not easier to remove some material from the inside of the crown?

In case anyone is interested, I recently managed to fit a crown into a different tube with an opposite approach than acting on the tube. I acted on the crown, by replacing its stem tube.

The crown was a Davidsen's one. You all know that the stem tube of a Davidsen crown is quite large, it doesn't fit on a standard rep tube.

I verified that most crowns (with the possible exception of palpatine's crowns) are made of two parts.

One part is the outer one, the one that we touch with our fingers when we wind the watch, and that gets in touch with the lever.

The other part is the inner one with the stem tube, the part that in the pic by V is inside the blue or red circle.

Keeping the stem tube with pliers and rotating the outer part makes the two parts separate quite easily and without damaging the outer part.

So I removed the inner part (with the stem tube) from the Davidsen crown. It left a socket 5.8mm diameter.

Then I filed a standard rep crown down to remove its outer part and leave just a 5.8mm central part with the stem tube.

Then I placed this inner part within the socket left in the Davidsen crown, glued them together and --voil