Level of difficulty is Medium.
Cost (not including TV and articulating wall mount) is Low (under $10).
Note: Have a helper when removing your TV or hanging it on the wall.
Parts I used (your list may vary depending on mount):
(1) flat panel TV with standard 75mm x 75mm or 100mm x 100mm VESA mounting pattern
(1) articulating wall mount with 75mm x 75mm or 100mm x 100mm VESA mounting pattern
(2) 4-3/4" square x 1/16" thick steel plates
(1) 9/16" x 1-1/2" long bolt (9/16" hex head, 3/8" shaft, 16 threads per inch)
(3) 9/16" x 16 nuts
(7) 3/8" flat washers
(2) 7/16" x 1-1/2" long bolts (7/16" hex head, 1/4" shaft, 16 threads per inch)
(2) 7/16" x 16 nuts
(20) 1/4" flat washers
(2) 1/4" wing nuts
(4) #8 x 1/2" long philips head machine screws
(4) 1/4" x 18 nylon thread lock nuts
Tools I used:
safety glasses (recommended)
3/8" drill bit
1/4" drill bit
file to smooth out snags from drilling
Rotary tool with cut-off wheels
hammer and punch to mark drill points (keeps drill bit from walking before starting into material)
clamps for holding parts while drilling (recommended)
Step 1: Drill Corner and Center Holes in Steel Plates
Note: The steel plates I used were electrical box covers that already had one corner slot and one key-hole. Don't do like I did! Move your bracket more than 1/4" away from any existing holes in the steel plate in order to not compromise its strength. After making my mistake, I decided to place the hole I drilled that's too close to the key-hole at the bottom of the finished product so it won't have weight trying to pull on it. Hind-sight shows me I should have used the existing key-hole or moved my holes farther away from the existing key-hole.
Step 2: Drill Holes in Plates to Make the Adjustment Mechanism
Step 3: Bolt It All Together
Using a helper, I hung the articulating bracket on its wall mount. I positioned the articulating mount the way I wanted it, then tightened all its joints and set-screw.
Finally, I loosened the wing nuts on my adapter to rotate the TV to a perfectly level position and re-tightened the wing nuts.