If you are interested in making fully stabilized video with your GoPro or other sports cam here is two videos showing the assembly of an AlexMos 3-Axis Gimbal Video Stabilizer. This is by far the cheapest way to take fully stabilized video.
This BGC (Brushless Gimbal Controller) is normally installed under a drone or quad copter but I have constructed a handheld gimbal to take fully stable video anywhere. The steel frame has mounting rings and base for a 3S LiPo battery giving you an extended battery life for those extra long recording sessions. At the end of the hand grips there are a pair of analog joysticks to control the pitch and yaw of the brushless motors giving you full control of your shot. There is a handle along the top to help with those low angle shots.
If you’d like to see more please drop a comment below, email me directly using firstname.lastname@example.org or hit me up at any of my social links with your comments and suggestions.