Need help with a crystal for a chronograph

[rogart63]

Have a Dugena chrono that needs a new crystal? But today when  i removed the old one i discovered that the tachy scale is the tension ring: Can i use a normal ATC tension ring crystal and just replace the tension ring?  Would like to use the old tachy meter ring . Or should i use a crystal with a wide ATCB  tension ring? Discovered the the wide ring only goes up to 34 mm so that is out?

Edited December 26, 2016 by rogart63

[Geo]

I would re-finish the original crystal Roger.  

Use the well established wet or dry paper technique, finishing off with Solvol Autosol and a micro-fibre cloth.   Do not touch the inside when doing this.  I usually go one stage further by polishing both inside and out with a cloth made for polishing silver.  Doing this you can re-use the tension ring and the watch will look perfect.

[rogart63]

21 minutes ago, Geo said:

I would re-finish the original crystal Roger.  

Use the well established wet or dry paper technique, finishing off with Solvol Autosol and a micro-fibre cloth.   Do not touch the inside when doing this.  I usually go one stage further by polishing both inside and out with a cloth made for polishing silver.  Doing this you can re-use the tension ring and the watch will look perfect.

Unfortunately full of cracks? So  a replacement is a must? Otherwise i would have done that? Looking okay on the picture but it's not  

Anywhere i can find a sizes for the different crystals?  Tried Cousinsuk but only found the catalog for the special crystal and there sizes? 

A well no harm in trying one? They aren't that expensive? 

Long shot but anyone have a 35.6 mm ATC crystal to measure the tension ring on? 33,8- 33 ,9  mm  is the tension ring and 1 mm high

[clockboy]

I would have thought the ring just sits on top of the dial much the same as the Seiko set up.. If so then there should be a small clearance between the crystal and the ring.

[rogart63]

Seen a few watches with the same kind of crystals? So somewhere there must be a manufacture for them? Or are they  brand specific? 

[rogart63]

12 hours ago, clockboy said:

I would have thought the ring just sits on top of the dial much the same as the Seiko set up.. If so then there should be a small clearance between the crystal and the ring.

The tachy ring  sit inside the crystal like the tension ring?

I ordered a Sternkreuz ACT crystal from cousisnuk today. With a chrome ring. Hopping i can replace it with the tachy ring? Fingers crossed. 

Edited December 27, 2016 by rogart63

[rogart63]

This is promising if the sternkreuz doesn't work? They have a chronograph with similar crystal om the homepage?  http://www.gssupplies.com/plastic_watch.html

Edited December 27, 2016 by rogart63