Kawai and Kato microscopic video on planing, with subtitles

[Wilbur Pan]

A while back, mention of a video showing what happens on a microscopic level when planing was made here. One barrier to watching this video was that it is Japanese. Or at least it's a barrier to me, since I don't know Japanese.

Using a translation of the audio and titles from this video by Mia Iwasaki, I added subtitles to the Kawai and Kato video. The subtitles I added were based on Mia's translation. I did revise her translation a bit taking into account terminology that woodworkers (American woodworkers, at least) would use. I tried to match the translation to the audio as best as I could. If anyone who actually knows Japanese catches any mistakes, please let me know. I can make edits and reupload the video.

But at least there's a subtitled version of the video now.

Thanks to Mia, Bill Tindall, and Professors Kawai and Kato for their generosity and work.

You can watch the video here.

Enjoy!

[jerry nazard]

Wilbur,

Fascinating and informative video. I have been following the discussion on another forum and checked over here to view comments. I especially wanted David's take on it as he was posting about chipbreaker placement just the other day. We shall see.....

Best to you!

-Jerry

[Curt Putnam]

Sir Wilbur - What a wonderful effort! That video should be a source of much pondering and you've made it accessible to all of us! Thank you!

[Matthew N. Masail]

Thank you very much !

[David Weaver]

Same video, same stuff I was referring to.

When I got irritated enough about thinking there was something I didn't know (that probably wasn't difficult), I bought a cheap Millers Falls #9 (i'd sold off all of my common bench plane smoothers), and played with it for a couple of weeks until I figured out how to use the cap iron to:
* get a better surface than I could get out of my high angle plane
* be immune to any tearout no matter what the wood is and no matter whether or not the plane had enough passes on so that it wasn't "freshly sharp", and do so at least as well as my infill smoothers

And I said something to Warren M on woodcentral and Bill Tindall saw it and sent me an email and said "I have something for you to look at". It was the text version of this study, and not surprisingly it was lots of detail on some exact circumstances that go right along with this. Bill, and I think Steve Elliot had been going back and forth with this stuff and Bill did a lot of work to find out who to get to so that we could even get this information, and then to converse back and forth with people who don't speak english.

The study goes into details that aren't as important for us, like blade wear patterns, etc because I think it was done with the intention to commercially apply the results to the super surfacer planer that gets used in japan (ever wonder how they don't tear something out on some part of a board when they zip it through and take a very long and fairly thick shaving those?.

Anyway, a bit later, Bill sent us another email and said that he thought he'd found the video, which is the one that I posted (same as this one without translation). I might've been a bit too esoteric about it, I was fascinated to see how much wood moves below the cut line with different chipbreaker settings.

Playing around with a cheap plane and seeing the video (you never know if the video is just one circumstance and you can still find circumstances where the "trick" doesn't work, but so far I haven't found any) is why I said several times in posts where someone was asking about a high frog that they didn't need it. I'm convinced that if there is a situation where a high angle plane outperforms a common pitch plane with a proper cap iron, then it's just that the cap iron isn't set or tuned correctly.

I bugged Chris Griggs with it a little bit the first week or two that I was doing it, too. I don't know what his conclusion is now, hopefully the same.

There's another "problem" that this solves with stanley planes. A thin iron will be perfectly stable, it will be impossible to get it to chatter in the heaviest of smoothing cuts, like bordering on being deep enough to be too coarse to be called smoothing cuts. Which is good because there are some bench plane irons that only come in thin versions (most notably, the tsunesaburo blue steel iron, which I think is the best iron that exists for smoothing if the surface quality matters).

Once you can completely mitigate tearout, then you can figure out how far you can back off the cap iron in less demanding wood, because it does make a plane harder to push when it's bending the chip like that, and in some situations, the surface is better if you back off a little (warren listed some things, but quartered pine is definitely one of them from experience). But, even if it's only set close and the surface isn't optimal, it's still been better than my 55 degree plane every time, by a pretty significant amount.

The original intent of making a big deal about it on here shortly before this study information came about was just to respond to people who said they needed something for figured wood, but with the stipulation that money is tight. Turns out, nobody really needs anything other than a cap iron of decent fitness.

You just have to have in the back of your head seeing all of the old becoming new again, if high angle single iron planes were a need, why did they just about disappear from the market, except in mostly lower cost planes. Not to mention, as george will often point out, that craftsmen who do use common pitch single iron planes have been steepening the angle of attack for years with a back bevel, and even Toshio Odate mentions that in his book (though he mentions it solves various other things).

Bottom line, we have video of what's going on now, scientific testing to prove it in a set of given circumstances, and other interesting information. And I won't sound like I rounded the bend like I would've if this stuff never showed up in this detail and I followed every "what should I buy" post with "you already have everything you need".

Everybody knows the GI Joe slogan, right?

[David Weaver]

All of this bantering isn't meant to deter anyone from getting or trying infill planes, they still are the cats rear end. More weight means they're still going to be smoother in harder wood, and be easier to push.

But it may be enough to convince some folks that they'll want to order an infill plane with a double iron instead. It's turned my shepherd panel kit into a killer plane, though I did have to do a lot of work to their second iron. Still, a plane that bulled through stuff and left only a "little" tearout now bulls through with no tearout.

Now we can argue about whether or not the difference in level of finish between a 55 degree iron (in a single iron plane) and a 45 degree iron matters, that's the next step in the arguing, and whether or not every person who uses hand tools wants to bother with learning to set the double iron. There are some circumstances that japanese wood is used (unfinished, even in architectural work) where they care more about the unfinished surface than we do.

[David Weaver]

This is stuff (again, courtesy of Mia, Steve and Bill) that came from a translation of the planing information that was geared toward people hand planing. Their conclusions were (paraphrased):

* using the chipbreaker effectively where it's needed will on average double the planing force needed
* If it's set right, a good consistent long shaving should result (if it's set too close, the shaving will probably not be a nice smooth long shaving). i.e., look at what is going on with the shaving, it changes when the cap iron is working properly, and it's different even than it would be if you were using a single iron plane and with no tearout. It will be continuous and a little bit straighter.
* It's a matter of iteration, you may not get the set you want on on the first try (my thoughts are this isn't always true, i guess it depends on how critical the cut, and how thick the shaving. The tougher the wood/grain direction and the thicker the shaving, the bigger the advantage of the second iron is).

And my thoughts about setting it, since few of the experts want to expand (because they probably don't want to entertain those of us who are hacks)
1) you need raking light to be able to see a very short edge protruding from under the second iron. If you don't have a light source to use where the edge is glinting light back at you, you probably will be left guessing
2) set the chipbreaker close to start. If the shaving comes out straightened out without bunching, the cap iron is probably getting a chance to work the chip and you should get excellent results with no risk of anything bad happening anywhere on the wood. If it's bunching up and not feeding, and bulling you around, and the fit is good, it's too close to the edge. If the shaving isn't straightening out at all or is otherwise no different than it would be with the chipbreaker set at 1/16th, it's probably not doing anything.
3) if you have a setting that is working well, but you don't quite like the surface (especially in soft woods), you can then back it off some and still take a heavy cut without risk
4) if you have wood where you can plane entirely downhill with the grain, then it doesn't matter where it's set, any plane at any pitch will work well. You might want to start with it set off (i.e., not being used effectively) by default and only set it close when you have trouble.


Someone else on WC said that they set the chipbreaker progressively tighter (in a japanese plane where you can do that a little more easily) until the shaving shoots straight up out of the plane. that's not a bad tip, either, but maybe not that practical for a bench plane where you want to be close right away.

[Chris Griggs]

I bugged Chris Griggs with it a little bit the first week or two that I was doing it, too. I don't know what his conclusion is now, hopefully the same.

Yep, my Stanley no. 4 will plane anything I have both with and against the grain with a stock blade and a closely set CB. Before Dave started talking to me about this stuff I really thought CBs were pointless. Since then, I actually pulled my Hock blade out of it and am going to camber it and put it in my jack plane where I've started to feel a thicker blade matters more. So pretty much same conclusion as Dave the CB not only support a thin blade but seems to mitigate tearout. BUT, all I can say is that a closely set CB seems to work - I don't have any high angle planes and the gnaryliest wood I have around is curly cherry and curly soft maple, so I can't speak with any amount of authority as to how a closely set CB would compare to a single iron HA blade on really gnarly stuff. Derek needs to give this a go on some of his crazy aussie wood and report back.

[Kees Heiden]

An extra tip. Make sure there is plenty pressure of the capiron on the blade. The shavings are pushing pretty strong against the capiron. On my Stanley #7 the shavings were pushed under the capiron, despite it being well fitted, because it lacked it's youthfull spring. I've bent it a bit in a vice and the problem is now gone. Also make sure the levercap is possitively clamping down, maybe turn the screw a bit further down.

Another benefit of the close capiron setting is the added support to the edge. No chatter anymore. Because you can now pull the frog back (no tiny mouth neccessary) the sole of the plane will add extra support to the blade too.

[Van Huskey]

Very interesting information. Thanks

[Bob Strawn]

It is such a joy to be able to read a forum thread on chip breakers where actual chip breaker discussion is going on!!

Here are two failures of mine and a theory as to why they failed.

I made a plane, using two plane blades, one on top of the other with a wooden shim at the back between the blades. The bevels faced away from each other. It was stable, but really did not have the chip breaker advantage. It was also a pita to adjust. There was not a soft iron on top to deaden vibration, and it still seemed stable. Perhaps the wood shim sandwiched between the blades absorbed the shock.

I also ground a flat surface on the 'edge' of a chip breaker when tuning one. This plane was one of those that wanted to jam chips no matter what I did to adjust it. It was ground to a 45 degree angle. Added to the 45 degree angle the blade was bedded, the angle was straight up and down. I did this to try and reduce jamming. It did not. I discovered a hair line fracture that required considerable stress to reveal, epoxy resolved the jamming issue. While testing the newly stable plane with a 45 degree edge on the chip breaker, I found it worked but never found the sweet spot for dealing with rough wood.

I am now convinced the the mostly rounded edge at the front of a chip breaker allows us to more easily alter the alter the angle of the chip breaker as we adjust it. Close up the angle of lift is higher than further back. This is done to a certain degree by a flat edged chip breaker, but a curved chip breaker may end up being more versatile and allow for higher angles. In the video the chip breaker is in effect an 80 degree wall where the chip never touches the top of the chip breaker. Most of the time, when I am planing the the chip touches the chip breaker in such a way that the closer the chip breaker is set, the higher the chip breakers functional angle is.

My 45 degree chip breaker was never going to produce a chip deflection greater than 45 degrees. My use of a 30 degree blade with perhaps a 2 degree shim lifting it, had a maximum deflection that was even lower.

As far as chip breaker distance from the blade goes, apart from chatter I don't see how the wood surface would 'know' the difference. I suspect the real issue is the angle that the chip is wedged open as the blade starts to sever a layer from the surface of the board.

Bob

[David Weaver]

Just a thought here, it's late. I think the action that occurs is actually the chip being pushed back into the surface of the work piece so that it's not allowed to lift itself. Once there is too much distance, the chip doesn't have enough structure to be forced back town toward the surface of the wood to be cut by the plane iron before it's allowed to meet the actual point of cutting.

I think I read that somewhere in the study, but I don't remember. It's in keeping with the additional planing force being required (because you do the work to cut, and you do the work the smash the chip downwards back into the wood to hold it down before it's cut (of course the whole assembly is moving). It also is evidenced by the surface left on softwoods (where the grain looks crushed if you look closely).

If the action were wedging, I suppose the same could be true, though I don't know why a wedged piece wouldn't just tear out ahead of the iron from getting popped up if the mouth were wide open.

Here is an interesting bit that JWW says about chipbreakers:

http://www.japanwoodworker.com/newsw...ntent_id=11505

To fit the chip breaker, place it in position on the iron. Be sure it does not rock on the iron. Any adjustment is made by tapping down one tab (found at the top of the chip breaker) or the other until the chip breaker sits evenly on the iron . Now hone the chip breaker hollow side down on a coarse grit water stone until a flat area is established directly behind the edge. Next polish this area on a finish stone. Turn the chip breaker over and sharpen at an angle of 20° on a coarse water stone until the edge is sharp, then polish the bevel and hollow side on a finish stone. Finally, hold the chip breaker at an 85° angle to the finish stone and make a dozen or so strokes. This will add a secondary or "micro bevel" on the chip breaker. The ideal chip breaker breaks the shaving without offering any further resistance.

A very shallow primary bevel and a tiny bevel of 85 degrees. The last sentence is interesting.

Because of a mouth problem on my panel plane (courtesy of yours truly not filing the mouth away toward the bun at the top in the front), I had to employ this on my panel plane to have room for feeding (of course, I could just file as much clearance as I have now with the bun permanently installed, but modifying the front of the cap iron was a bit easier).

I put a bit more than a dozen strokes on a finish stone, but not too much. It works great.

[jerry nazard]

It works. Test plane was a type 11 #4. I set the frog flush with the back of the mouth to support the iron completely. Cap iron honed and set VERY close on a Hock blade sharpened at 30°. My shavings are tight continuous rolls.

It didn't cost anything close to $300..................

-Jerry

[Derek Cohen]

David, I think that you need to post photos of the chip breaker set up on the blade, and the blade set up in a Stanley. Also photos of the leading edge of your chip breaker.

Here's what happened to me today ..

I used a Stanley #3, initially set up with a Mujngfang HSS blade. It is a little thicker than the original Stanley. I also used an original Stanley. Wood was a nasty piece of Jarrah.

What I found was that the mouth would jam with shavings if I closed the chip breaker down. Pulling the chip breaker back alleviated the problem. Of course that does not help with the experiment. So I swapped the Mujingfang for a Stanley blade. But same thing all over again.

I redid the experiment, this time with the front of the chip breaker ground and honed to 80 degrees (as per the research). This made it worse as the thickness of the chip breaker was forced even further forward than before (I calculated that the Stanley chip breaker angle was 50 degrees out of the factory), and blocked up the mouth even more. The only thing I did not do was open the mouth wide ... since I could not do this on a Stanley.

Now I was serious about this experiment. I have photos of everything and happy to post them. I was going to compare the Stanley #3 with a LN #5 (double iron with 55 degree frog), Veritas SBUS (single iron, 62 degree cutting angle), and Marcou BU smoother (single iron, 60 degree cutting angle).

All the blades were freshly sharpened. Out of interest, in addition to the HSS Mujingfang in the Stanley #3, I had an A2 blade in the LN, a 3V blade in the Marcou, and a PM-Vll blade in the SBUS (not that any of this is relevant to to outcome). All the planes took excellent shaving (with the Stanley set up with the chip breaker 1/8" back), but the surface finish is where the results count: it was pretty much in order of the cutting angle, with both the Marcou and the SBUS leaving a better finish that the LN. The finish of the Stanley was a little clearly rough.

So, I just could not pull it off with the chip breaker. Since others are claiming positive results, clearly i am doing something wrong. Clear this up for me.

Regards from Perth

Derek

[David Weaver]

Derek - it's just a matter of mouth opening. If shavings aren't getting caught under the chipbreaker (between it and the iron), then the restriction has to be happening between the top of the mouth in front (which is what my problem was with my panel plane, but self created because of the geometry I left).

If you can move the frog back just so that the iron is supported all the way back and almost touching the casting at the mouth, there should be enough room.

The only plane I've had trouble with so far is a type 11 #5 1/2 that has a replacement iron (I do not have the original iron at all) and the mouth just can't open enough to remove the restriction without mangling the chipbreaker to a very low primary angle with a high secondary angle.

If the mouth of your #3 is too tight to function properly (and it very well may be) then I think that's a casting flaw that the mouth wasn't opened enough to use the plane properly. You can, of course, mitigate it with a file. But maybe just pull out another bailey style plane ( you have a 4 1/2, right? )

I don't know if I'll get pictures this weekend, I might be able to, but if I don't, keep at it. The behavior of the entire plane will change completely if you get it set close enough, as will the shaving.