Hand Tools Archive

Thoughts after 600 feet

david weaver
The O1 iron is about to give up. The thinner irons bed OK but not perfectly on the LN plane, so they will be going back to the stanley plane to finish the test. (HSS, tsunesaburo and the O1 iron). Any less than perfect bedding seems to get exposed with an iron that runs out or clearance.

The tsunesaburo has a feel like it is also running out of clearance, but it's ahead of the O1 some. No clue if the gouges on the top of the wear bevel adversely affect the edge, too (not they can reach over, but is the same thing occurring right at the edge?)

The loss of quality suddenly in the LN edge is strange, but I saw this before with A2 - they can continue to cut for a little bit even after the quality goes on a steep decline. Terrible surface, though. One that you could still scrape and sand, but someone not paying attention may leave a flaw on a surface if they didn't do significant work.

3V feels unchanged. The V11 looks like it has a drastic hollow, but you wouldn't notice it planing, and I think the HSS is fine (it doesn't bed as well in the LN plane. All three of them have lost some brightness, but after having minor surface quality issues at first, none of shown the sudden decline (yet) that the A2 has.

So, what's wrong with the bedding in the LN plane? The top part of the iron doesn't quite bed solidly on the top of the frog, but it is bedding on something. Whether that's the dog sticking up from the adjuster or the lateral adjustment wheel at the end of the lateral adjuster, I don't know. I thought it might be the cap iron screw, but it's not as far as I can tell.

I have two choices - move those thin irons back to the stanley plane now that they have some wear, or figure out what the problem is with the LN and address it. The lever cap screw sticking out of the frog will need some trimming if the irons are able to bed down the whole way.

As this test has been run, the bedding of the iron down at the mouth has been solid and planing has been smooth. There is no oscillation or noise. The issue has only shown up as the O1 iron has almost run out of clearance. It doesn't functionally plane in the LN plane and only just does in the stanley. I would be extremely surprised if it completed another 50 shavings.

Shaving thickness at this point in determining the failure point is critical. Shavings vary while you're planing, at least slightly. I've been weighing them and if a plane gets slightly behind in shaving cumulative weight, I set the shaving slightly thicker. Everything plane has traveled the same number of feet, and all are within 10% of total shaving weight planed. The lighter irons in lighter planes tend to cause me to take a thinner shaving as you can feel more with them, so a thinner shaving feels the same as a slightly thicker one in the 5 1/2 or the LN smoother. Without weighing shavings, the total wood volume planed over the same distance would've varied.

Since failure is largely determined by shaving thickness (how much difference, I don't know), it's important that the failure point due to loss of clearance is done with care to set the cap iron just the same and the shaving thickness at failure just the same.

I don't think the slight variation in thicknesses to make up for weight has really amounted to much variation. Just a hunch.

A useful test later for curiosity would be to plane shavings until the plane stops picking up 1 1/2 thousandths, chart that, then plane until it stops picking up 2 1/2, then 3 1/2 up to 5 thousandths or so. IT really doesn't matter, but I've always assumed that pushing shaving thickness when planing accomplishes several goals (as long as the shaving doesn't result in poor quality or lack of control), one of them being that you're less sensitive to clearance. I should be able to document that.

Now that the O1 iron is close to failing, when it (presumably) comes out of the test first, I am going to see how many feet it will plane in cherry. It and one of the other irons will then come back to maple after being sharpened by a washita stone, and at bill's request, the next one that comes out will be sharpened with 5 micron diamond (something that literally could be a one step sharpening process, like a washita) to see how much feet planed is affected by the lower quality starting edge.

We are lucky so far to have results that seem to either match prior experience (I wasn't hoping to see the LN iron falling apart, but I've seen it before in the same wood from the same brand of iron - and the LN was the best in the last test I had, so there's not a quality issue that I'm aware of, more a characteristic behavior).

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