Eta 28xx DWO tips...

[automatico]

There are three main problems with date wheel overlays (DWO) on eta 28xx movements:

 

1...Date wheel overlay rubs the underside of the dial because it is mounted on top of the original date wheel.  This causes the date to change half way, not at all, or at random times during the day...random times because it sticks for a while, then comes loose.

2...Trouble installing the date wheel with overlay installed.

3...Hands too close to the dial.

 

1...Easy fix for problem one is to put a series of dimples in the calendar spacer ring so the dimples will hold the dial a fraction of a mm higher above the DWO.  Use a small screwdriver or punch to make the dimples and try to make them all as close to the same as possible.  Not much is needed, just enough to keep the DWO from rubbing the dial. 

Reminder:  taller dimples = less space between dial and hands, less purchase for hands on CP/hour wheel.

 

2...There is no easy way to install a date wheel with the DWO installed but it is easier if you remove the date jumper plate (and spring) when removing the date wheel and install them after the dw with overlay is put back in place to prevent damage to the dw and overlay.  Look at a parts pic to find the date jumper plate (p/n 2595), the date jumper aka 'index spring' (p/n 2784) is under it.  Most of the hassle is caused by the index spring (with slight tension on it) being mounted under the date jumper plate, but with a little practice it becomes easier.  Take care not to dislodge the DWO from the date wheel with a screwdriver or the screw when r/r the screw holding the jumper plate because there is very little space between the screw and DWO. 

You might get by with removing the other part that holds the calendar wheel in place...minute train bridge (p/n 462), but it has two little wings that have to be slid into slots in the plate plus the screw that holds it in place is partially covered by the DWO so it is easier to r/r the date jumper plate and spring.

 

3...The not so easy fix for problem three is a taller canon pinion, hour wheel, and sweep second pinion but they are not very expensive and are easy to get.  You could also raise the hands on the original tubes a little bit but this will not help very much.

 

[TickleShoes]

I've seen some extra tall dial spacers but haven't found them to purchase separately. Likely the rep makers include them in certain builds. I wish they were available on the open market.

Another consideration is that any additional height added to the dial will start to offset the stem placement. I'm currently experiencing that with an SD4k. Used an extra tall dial spacer thinking "why not" and now the stem won't insert. Just gotta find time to rip it apart and start over :/

[automatico]

"I've seen some extra tall dial spacers but haven't found them to purchase separately. Likely the rep makers include them in certain builds."

 

So far, I have been able to get by with punching dimples in the original spacers when needed...the dimples only amount to .2mm or .3mm so the stems still line up Ok.  I have also made brass spacers that are tall enough to mount the dial on for a few projects that had dials with no feet...the distance above the movement needed for the date disc can be figured in when making the spacer.  A friend with a machine shop turned a stack of 2.3mm thick brass flat washers down to 32mm od with 24mm centers for spacer blanks.  The washers were originally about 20mm id x 50mm od iirc.  It usually takes an couple hours to make a spacer using one of the rough blanks on my small Sherline lathe.