Fitting a 2893-2 in a DSN 6154 case

[mastergod]

Hi guys,

For my "Kosmos Radium" custom project I must install a 2893-2 movement in a DSN 6154 case.

(Picture from DSN site for reference)

He actually sells two types of these cases: One fits a 6497 movt; The other fits a MOLINJA movt. I

[sssurfer]

The most relevant constraint is the movement thickness, cannon pinion excluded.

The 2893-2 is very thin, 3.81mm thick.

The 6497 is 4.50mm thick.

I doubt that DSN uses true molnija movement, most likely he uses its china replica i.e. the CH190X movement, that is about 6mm thick.

In the end, the case for the 6497 should be a better fit for your 2893-2.

Still, you are left with a 0.69mm difference, that might make your stem misaligned.

[mastergod]

The most relevant constraint is the movement thickness, cannon pinion excluded.

The 2893-2 is very thin, 3.81mm thick.

The 6497 is 4.50mm thick.

I doubt that DSN uses true molnija movement, most likely he uses its china replica i.e. the CH190X movement, that is about 6mm thick.

In the end, the case for the 6497 should be a better fit for your 2893-2.

Still, you are left with a 0.69mm difference, that might make your stem misaligned.

Thanks. I hope it can be done - time will show.,

MG

[stilty]

The difference in movement thickness between the two movements is not an issue. The problem is stem alignment.

The measurement from dial support seat (bottom of dial) to center of stem on the 2893-2 is 2.00mm.

The measurement from dial support seat (bottom of dial) to center of stem on the 6497 is 1.85mm.

This is a difference of 0.15mm. Not a lot, but if you use the 2893-2, your stem will be out of alignment with the case tube and may bind or snap.

Do you have to use a 2893-2? Why not a 2892-A2? The measurement on the 2892-A2 is 1.50mm. Now you have a difference of 0.15mm the other way. That is an easy fix as you can make a spacer of 0.15mm to fit between the dial and movement in order to align the stem.

Your other option if you must use a 2893-2, is to sand the back of the dial so it is thinner, but then you will end up with a very thin dial... 0.40 - 0.15 = 0.25mm thick dial... probably not a good idea.

Now, if you solve the stem alignment problem. what are you going to do about hands? The Hour hand size for 6497 is 2.00mm vs 1.50mm on the 2893-2, and the minute hand is 1.15mm vs 0.90.

[mastergod]

The difference in movement thickness between the two movements is not an issue. The problem is stem alignment.

The measurement from dial support seat (bottom of dial) to center of stem on the 2893-2 is 2.00mm.

The measurement from dial support seat (bottom of dial) to center of stem on the 6497 is 1.85mm.

This is a difference of 0.15mm. Not a lot, but if you use the 2893-2, your stem will be out of alignment with the case tube and may bind or snap.

Do you have to use a 2893-2? Why not a 2892-A2? The measurement on the 2892-A2 is 1.50mm. Now you have a difference of 0.15mm the other way. That is an easy fix as you can make a spacer of 0.15mm to fit between the dial and movement in order to align the stem.

Your other option if you must use a 2893-2, is to sand the back of the dial so it is thinner, but then you will end up with a very thin dial... 0.40 - 0.15 = 0.25mm thick dial... probably not a good idea.

Now, if you solve the stem alignment problem. what are you going to do about hands? The Hour hand size for 6497 is 2.00mm vs 1.50mm on the 2893-2, and the minute hand is 1.15mm vs 0.90.

Hi & thanks

I just received a 2893-2 movt and would like to go with that, but if it