What I Have Designed And DoneThe Controller Enclosure

Top Shell: I modeled the main controller housing with a hollowed-out internal cavity, a uniform wall thickness, and integrated dual 21 mm circular joystick cutouts.

Bottom Plate: I created a 3 mm solid matching backplate featuring an interlocking, 1.5 mm high alignment lip that keys perfectly into the top shell to prevent twisting.

Mechanical Fasteners: I added four heavy-duty screw pillars inside the top shell corners with an inner diameter of 2.5 mm and an outer diameter of 5 mm. These line up perfectly with matching 3 mm clearance screw holes on the bottom plate.

Internal Component Layout
In my main assembly workspace, I have arranged the physical layouts to ensure everything will fit inside the shell:

Power Hardware: I locked a large dual-AA battery holder directly down the center channel. I also cut out a precise 10 mm by 4 mm slot on the top rim to perfectly seat my physical SS12D00 slide switch.

Left-Pocket Assembly: To keep things organized, I clustered my main electronics on the left side of the battery holder:

The Baby Orangutan B-328 microcontroller.
The nRF24L01 wireless transceiver module for robot communication.

A tiny Pololu 5V Step-Up Voltage Regulator to boost my AA battery power up to a clean 5V.