this is a step by step guide of how to build a one axis camera gimbal although it would be easy enough to add a second asis.for paning.

Step 1: What You Need.

2 bearings-
pvc pipe-600mm
servo-9gram
wood-balsa-any
glue-hot glue or anything
wire-any
weights-stuff thats heavy
metal pipe-0.7mm

TOOLS
dremel tool
hot glue gun

Step 2: Lets Start

get you pvc pipe and cut it to 100mm
get your pipe and cut a hole in the side the same size as you camera. for a gopro hero it will be 60/40mm

Step 3: Step 2

now cut a piece of balsa wood to the width of the pipe and lengh of the pipe and glue in place
you can now start to create the two end caps you can use pipe end caps or make some with balsa like i did to save weight.
just cut some wood to the diameter of the pipe and sand down with the dremel to flush with end and glue in place

Step 4: Step 3

now you can insert the bearings find the center of each end cap and draw around the bearing now cut out the circle and fit bearing in place and glue in place the center should revolve freely

Step 5: Step 4

you can now insert the metal tube into the bearing and glue in place my tube was cut to 80mm but you can always cut off the excess,
once done you can glue in place.

Step 6: Step 5 Balancing the Gimabl

balancing the gimabl- insert your camera into the gap and slowly attach weight to the back with bluetack untill it sits balanced once balanced cut a hole into the inside wooden back plate just big enough to fit your weights inside and glue them in place onece glued check the balance again and and adjust till balanced.