sharpening problem with a camber

[Patrick Baney]

Something tells me there is more trick taking place at the center of the blade than at the edges.

This is one of my reasons for suggesting people not try every trick there is.

Step one: Get a good bevel

Step two: Do a couple passes for a camber. It really doesn't take much to keep the edges from cutting.

After you get that working, then try adding a trick if you like.

Here is an old post with thoughts about cambering > https://sawmillcreek.org/showthread.php?158373

jtk

This!

In particular, this -

Something tells me there is more trick taking place at the center of the blade than at the edges.

I struggled with this issue on and off for literal years. I spent untold hours and good money trying to sort out exactly the issue you are describing. I chewed through an entire LN blade trying to figure out what was causing "uneven" honing of *some* of my blades. I finally traced it back to haphazard application of the ruler trick, which was creating an inconsistent bevel on the back of my irons. I'm not against the ruler trick, and I continue to use it, but it absolutely has a dark side. This dark side seems to be relatively uncommon, as posts describing the issue you're describing are quite rare (i've seen them all), but when the issue pops up, it's a bear to diagnose.

[Jim Koepke]

When I took the iron out of the guide and checked it it was perfectly flat across after using the 1000 stone. Then I went back and did the cambering, using 15 strokes on the two outsides, then 10 in the two middles, then 5 in the center. I did this on the 1000 and then the 8000. Then I checked the cutting edge against the machinist square. It wasn't square anymore, but I couldn't really see much of a camber either, which leads me to the next thought...

It all comes down to how much camber you are trying to create. The amount of camber should be in relation to the thickness of shaving one wants to achieve.

If you want to take final smoother shavings of ~0.001", there is no need to have a total camber of 0.01" out to the edge. That would be more in line with a try/scrub plane taking a shaving in the 0.005 - 0.008" range.

jtk