Casio fx-991 Calculator Battery Cover

Casio FX-991 Series Battery Cover

This is a custom 3D-printed battery cover designed for the Casio FX-991 series calculators — including models like the FX-991EX, FX-991ES, and possibly other Casio models with the same back cover size.
It’s a simple, sturdy replacement for a missing or broken original lid.

The part is slightly curved to match the calculator’s shape.
To get the perfect fit, you’ll need to gently heat it up (with a lighter or heat gun for a few seconds) and press it into shape while it’s warm. Once it cools down, it’ll hold the curve nicely.

How to adjust shape:
 

Works great with PLA or PETG, printed at 0.2 mm layer height, 100% infill, and designed for an M2–M2.5 screw. Support must be used.

I wish it fits perfectly. I would thanks if you send me a like, and a comment. :)