Insta360 X3 to GoPro finger mount adapter
The Insta360 X3 and X4 use a 1/4-20 tripod thread on the base, while bike, helmet and chest mounts use the GoPro three-finger interface. This adapter is a 20 mm square block with a captive 1/4-20 bolt or a heat-set 1/4-20 insert on top and a two-finger GoPro fork below (3 mm fingers, 3.2 mm gap, 5.2 mm hole), letting the camera clip onto any GoPro handlebar or seatpost mount. Total height is 22 mm to keep the camera low, walls are 4 mm around the insert and it prints fork-up in PETG.
A measured adapter keeps the heavy 180 g camera from rocking, which shows up as jitter in stabilised 360 footage. Describe the thread type and how far you want the camera offset in SpeakCAD, preview the adapter free in the browser, adjust it in the chat, then download the STL.
Create a camera adapter 20 x 20 x 22 mm with a 6.4 mm through hole and a 12 mm hex recess on top for a captive 1/4-20 bolt, and a two-finger GoPro fork on the bottom with 3 mm fingers, a 3.2 mm gap and a 5.2 mm hole.