Hand Tools Archive

Re: Concavity at Edge
Response To:
Concavity at Edge *LINK* ()

david weaver
I know i've read through all of your stuff at least twice. In the event that I end up repeating some of your experiments without recalling that i am, my apologies for that. I'm resisting going to your page (and haven't for a couple of years) because I'm afraid it will taint what I see and my interpretation of it (as in, if you come to a conclusion, then I am going to view things through a lens of expecting to see the same and people often find what they expect to find).

That said, I remember those pictures and I remember seeing them when i first started setting the cap, thinking "oh no, I'm going to cut a big divot in the back of my iron that's really hard to sharpen out". Fortunately, it doesn't seem to have happened that way - the wear on the back is still easy to remove at the edge.

But these pictures themselves made me think (when I took them), oh....the concavity...I can't believe i'm seeing in person what's on the K&K documentation from the planing machine. For lack of a better way to put it, it's one of those kind of "it looks the same as it does on TV!" kind of moments. Whether it's lack of confidence in my methods, consistency or ability to see things from a vertical viewpoint in an inexpensive microscope (relatively, still $425, but not the much more expensive scopes that seem to do better focusing on a wider range of distances from the lens at the same time)...I just didn't expect such a good match.

I'm at the edge of my luddite seat waiting to see if the wear patterns on the other irons will match.

This is definitely not the case of varying irons getting different cap iron sets. I took pictures through the scope and all are 8 thousandths to .01". The constant rotation of the plane should eliminate most of the arguments about whether or not I just planed wood with varying characteristics (I'm still on my first test board, but boards 2 and 3 are from the same load of lumber and none of a distinguishable grain direction, so if the irons all had identical characteristics, we should get the same results. It would've been a smart thing to add a second identical iron of high quality - like the A2 or the V11 so that we could see that two versions of the same iron experience the same results with both placed halfway apart in the test rotation. Oh well, maybe in another decade, i'll do this again).

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