Smartphone Stand #5 (Δ-shaped)

I've made several smartphone stands, but this model is probably the most practical keychain-type smartphone stand.

[feature]
folding compactly
stable carrying with lock function
stable standing with delta shape
no support printing

[size]
height:21.5mm, thickness:9mm, length:73mm

[screws to use]
M3 CAP 18mm x2
It is recommended to use glue to prevent the screws from loosening.
No nuts needed.

[print conditions]
-printing type: FDM
-printer: Original Prusa i3 MKS
-filament: PLA, PETG
-support: no
-brim: no
-raft: doesn't matter
-print directions: Please refer to the photo

[revisions]
2022/03/29
In order to widen the opening angle, the design near the hinge was slightly changed.
With this change, the corners now hit my fingers, so I added a fillet.