Sharpening a Router Plane

I rarely drop things and when I do, 25 years of soccer gave me the ability to catch an item with my foot before it hits the floor.  But on this day, my foot was hurting so I wore slippers in the shop.

After sharpening my router plane's 1/2" iron, it slipped out of my hand.  Normally I'd try to arrest the fall with a sneaker-clad foot.  But wearing slippers, I had no choice but to let it hit the concrete floor.  Arrgh!!!

Showing the corner of the iron that hit the concrete

This post is not so much about how to sharpen the iron - it's a Lee Valley router plane with detachable iron that gets screwed onto a sharpening aid.  Rather, it's about how to get the iron's leading edge perfectly parallel to the sole of the plane.

Marked a line to grind back to

Ground to the line

Sharpened as normally done on the diamond stones

Tested the cutting action on a flat piece of wood

Looking from above, you see the iron is cutting more on the right side

I had to take the iron back to the stones two more times, focusing on removing material from that right side before getting the cut I wanted.

A nice even cut left to right

I might never notice a problem if the bottom of a dado was about 0.002" out of parallel with the board's surface.  But it's still worth it to get the iron's edge just right.  I don't need any small issues like this magnifying an out-of-square problem in a project.