By now im getting used to spontaneous setbacks and today is no different.
Nevertheless there were some interesting revelations:
1: watertest
The case seems to leak from bezel region (something to keep in mind for every zf bb54 buyer)
2: inner case dimensions
Plan: swap in 29 mm raffles dial
The rehaut opening is 27 mm across and the entire dial print fits comfortably inside. I thought it would be pretty close with the "T swiss T" at 6 o'clock but i got pleasantly surprised by the spacing. This means railroad dials (wich i avoided because of spacial concerns) should work fine aswell.
Everything was going smooth until it was time to reistall the crown stem. The movement sits too high.
This is caused by staggered inner diameters leading up to the rehaut opening in the case. The 29mm dial sits (neatly) inside a 29.2 mm inner diameter.
This is followed by the actual rehaut position with an inner diameter of 28.2 mm.
3: fitting the dial
The dial needs to be 28.2 mm max, this meant that i had to shave off approx. 0.4 mm radius.
I set my calipers to 0.4 mm and fixed the sled with the lock scew. I then draged the calipers around the outer circumference of the dial, engraving the smaller diameter onto the backside of the dial.
Now its time to grind the dial to size. This was a stright forward (although scary) process using a metal file. After a few adjustments i got the dial to roughly 28 mm all around.
The edge obviously wont be pretty but thats where the 27 mm rehaut diameter comes into play. As far as i can tell everything looks clean when installed.
I would not reccomend trying this with a gloss dial. You will have a generous amount of shavings flying around and they will get on the face of the dial. There is no visible damage to my matte dial, but a gloss dial will need some protection.
So the final verdict is that you can make a 29mm dial fit the ZF bb54 with one hour worth of grinding. Sadly there doesnt seem to be a 28 mm plug and play dial available online (let me know if you find something interesting).
Next up is modifying the case to accept the anthaya brevet crowntube...