This is a interesting project of me. Project number-03. This is the wrist watch casing design(bazle) project. This casing will be used for the skeleton watch movement below, https://www.alibaba.com/product-detail/ENLOONG-Real-Luxury-Skeleton-Tourbillon-Movement_62429616610.html?spm=a2700.wholesale.deiletai6.17.15361a4dDaX7Yw&bypass=true

You can use other movements also. But you have to edit the casing to accomodate the movement perfectly. If you need any help, I will help you.

You can't make threads on the crystal sapphire, So I used bush nut for the casing mounting screw. Here is the link for the bush nut, https://aliexpress.ru/item/33047616164.html?spm=a2g0o.productlist.0.0.512364a3l0aNnQ&algo_pvid=3bd5e13c-7404-47bd-952a-cd44781be5d8&algo_expid=3bd5e13c-7404-47bd-952a-cd44781be5d8-40&btsid=0ab6f83a15890658333188443e6463&ws_ab_test=searchweb0_0

Bush nut diameter is 2.5mm and length is 4mm.

This casing dsigned for cnc milling. Material of the casing will be the crystal sapphire. You can 3d print it also. For 3d printing you should keep in mind tolerance and shrinkage of the plastic, so you need to edit the STEP file before 3d printig.Here I used 4XM1 screw to attach top with bottom part. I also used special pin for the belt. Here is the link of the belt pin, https://www.esslinger.com/watch-band-parts-tube-screw-head-and-friction-end-head-style-bars-for-band-to-case-refills-in-large-sizes/

This is the belt pin model Number- 81.6038.1825. Belt size is 24 mm. You can use any types of belt.

Custom size and design possible for any movement skeleton. You have to contact with me for more details.

3d editable STEP file format attached. You can use STEP file format for CNC milling machine to produce G-Code.

Thanks, Mahbub