Whenever I sharpen my plane blades, I end up with only the center portion sharpened.
For my setup, I use a veritas side-clamling honing guide, and 1,000 grit diamond stone, 5,000 grit ceramic stone, and 12,000 grit ceramic stone. I set the blade in the guide, get the knob finger tight, then give it about 1/8 turn with the alan key to lock it in. I sharpen on the 1,000 grit stone until I feel a burr along the whole length of the blade, then progress up in my grits. No mater how long I spend, only the middle part gets sharpened at the higher grits. the center portion takes on a nice mirror shine, but the edges do not.
I appreciate any feedback and help!