The Veritas Custom Planes - more than a review

[Derek Cohen]

Patrick, if you can get your setting to work - and I will accept that you do because you say so - then what are you doing that is so different from everyone else. As far as I am aware, no one would agree with your recommendations. Explain you mean by "0.25mm face". What is the angle here?

Regards from Perth

Derek

[Patrick Chase]

Patrick, if you can get your setting to work - and I will accept that you do because you say so - then what are you doing that is so different from everyone else. As far as I am aware, no one would agree with your recommendations. Explain you mean by "0.25mm face". What is the angle here?

Regards from Perth

Derek

Let's use the Veritas custom plane chipbreaker as a starting point, since we both used that for our respective experiments.

The chipbreaker ships with a primary bevel of about 27 deg. I modify that by honing a 45-70 deg secondary bevel at the tip (where the angle depends on the plane's bed angle and intended use). 0.25 mm is the height of that secondary bevel. If I grind the secondary bevel taller than that I find that I don't get any additional reduction in tear-out, but do get huge jamming problems, and that forces me to set the chipbreaker further back along the blade. If I don't grind such a secondary bevel at all then I don't get much tearout reduction, presumably because the chipbreaker just bends the chip a few more degrees (still a "type 1" chip) instead of folding it back ("type 2").

I'm not the only one running such a configuration. I believe that David Charlesworth did roughly the same thing when he experimented with close-set chipbreakers, and I've seen recommendations to "create the secondary bevel with a few strokes over a finishing stone" in discussions of Japanese plane setup. I know there have been others (perhaps even David Weaver but I'm not positive), but those are the 2 I remember clearly.

[Derek Cohen]

Interesting Patrick.

I hone a secondary bevel on the chipbreaker at 45-50 degrees. I place the chipbreaker about 0.4 - 0.5mm back from the leading edge for smoothing interlocked grain. Typically, I am using either a LV Custom #4 (42 degree bed), LN #3 (45 degree bed), or Stanley #3 (45 degree bed - PM-V11 blade and chipbreaker). The symptom of being a tad too far forward is that the shaving becomes crinkly and starts to accordion. When it is too far back, the shaving is curly. Just right and the shaving straightens up. You say that you get straight shavings with a similar angled leading edge but with a 0.25mm wide secondary bevel. However, you need to get 0.1mm from the edge to make this work.

Setting a chipbreaker at 0.4mm is hard enough. Many report that they inadvertently push the chipbreaker a tad too far forward and pop it over the edge of the blade. I've done this as well. I really cannot imagine setting the chipbreaker at 0.1mm! I am not doubting that it could work - I've never tried as I cannot see why one would need to make the whole process harder. The results I get are good with the set up I described.

For reference, I have been participating in a thread on the UK woodworking forum, where David Weaver commented:

The reason that I don't like 80 degrees on a cap iron is that it narrows the distance the cap iron can be set. The range between too close and not close enough is shorter, and the chance of getting an affected surface is greater. That's not a problem on a super surfacer, apparently. I don't know if other people agree with me on that, but I checked bed angles with a cap iron from 38-50, and cap iron bevel angles from 45-80 (I didn't get enough effect at 45 to get a perfect surface, and I didn't like the abruptness of 80. Coincidentally, the best working chipbreakers that I've found are stock stanley cleaned up and polished - no steeper angle than what's already there.

Then ...

... don't think too hard about measurements. Set it close as you did, and then back it off a smidge and try the plane again. If not enough, back it off a smidge again. The distance depends on the thickness of the largest shaving you want to take ...

I will let others comment. They may agree with you and disagree with me. Or have another opinion. Discussion is always good.

Regards from Perth

Derek

[Patrick Chase]

Interesting Patrick.

I hone a secondary bevel on the chipbreaker at 45-50 degrees. I place the chipbreaker about 0.4 - 0.5mm back from the leading edge for smoothing interlocked grain. Typically, I am using either a LV Custom #4 (42 degree bed), LN #3 (45 degree bed), or Stanley #3 (45 degree bed - PM-V11 blade and chipbreaker). The symptom of being a tad too far forward is that the shaving becomes crinkly and starts to accordion. When it is too far back, the shaving is curly. Just right and the shaving straightens up. You say that you get straight shavings with a similar angled leading edge but with a 0.25mm wide secondary bevel. However, you need to get 0.1mm from the edge to make this work.

As I said in a previous message, I aim for more like 0.2 mm (and yes, it requires magnification, controlled lighting, and a bit of tweaking to achieve that). I typically gauge it by comparing the exposed blade to a ruler with 1/64" divisions, and aim for half a division.

I don't think you need to be within 0.1 mm for a 0.25 mm high bevel to be effective - once again the video shows us that the geometries don't work that way, and my own results are consistent. The contact point of the shaving was within the first 0.25 mm of the chipbreaker face even at 0.3 mm of setback (albeit with an 80 deg bevel). I don't get accordion shavings - in my experience that's the symptom of having too tall of a secondary bevel.

[Derek Cohen]

Out of interest, what wood do you work, what planes do you use like this, and how thick are the shavings?

Regards from Perth

Derek

[Patrick Chase]

Out of interest, what wood do you work, what planes do you use like this, and how thick are the shavings?

Regards from Perth

Derek

I'll start with the easy questions: I use close-set chipbreakers on WoodRiver #3, Veritas "classic" #4, custom #4 (with 55 deg frog), custom #4-1/2 and to a lesser degree on an LN #8 and a Veritas Custom #7. I use fairly shallow cuts on difficult woods, typically 4 mils or less (but seldom below 2 mils - ultra-thin shavings are for bragging rights, not woodworking). On easy woods I often swap in blades with the chipbreakers set further back and take deeper cuts.

The biggest variable is probably wood - I work mostly with North American hardwoods, including a lot of striped and curly varieties. While the grain can be quite difficult, they're not as tough as a lot of the stuff you plane so that may be partially what drives us to different optima.

More broadly, I think there are a couple things we know (i.e. are well supported by evidence at this point) and a couple more that seem likely.

We know that tearout happens when the shaving exerts enough leverage to separate the wood fibers ahead of the blade (I'm intentionally using informal terms here instead of the more precise ones that an engineer would ordinarily choose). Whether that happens depends on several variables, where the key ones include the stiffness of the shaving (which in turn is a function of its thickness and the stiffness of the wood), and the resistance of the wood fibers to separation.

We know from the Kato/Kawai video and other experiments that a close-set chipbreaker works at least in part by reducing the structural integrity of the shaving and thereby reducing its stiffness and therefore its ability to lever fibers out ahead of the blade. You can see this reduction easily by comparing the bending stiffness of type I (curly) and type II (straight) shavings with all else held constant. A lot of people seem to think that it works by "pushing the shaving back down", and that may happen to some degree with very high chipbreaker tip bevels, but if you compare the "no-chipbreaker" and "50-deg" configurations in Kato/Kawai you'll see that the shaving is actually lifting at least as far above the back of the blade in the 50 deg case - if anything it's being lifted up rather than pushed down. Also, the force applied by the chipbreaker will be ~normal to the contact point, so there simply cannot be a significant downward component with a 50 deg chipbreaker on a 42-45 deg blade.

Leverage is simply force times distance, so the key question to consider when determining the setback (distance from leading edge to chipbreaker) is therefore: Is the setback long enough that the shaving exerts enough leverage to tear fibers out ahead of the blade before it reaches the chipbreaker? If it is then it doesn't matter what the chipbreaker does to the wood, because you're already doomed by that point.

That brings me to the topic of wood species: I suspect (but do not know) that the "tough" woods you work have more strongly bound fibers and that actually increases the amount of leverage that is required to cause tearout. That works in your favor here, since it means that you can set the chipbreaker further back but still be able to weaken the shaving before it causes tearout. It would also explain the difference between your results and Kato/Kawai (they showed significant tearout with a 50-deg chipbreaker set 0.3 mm back. 0.4 would be worse).

[Stewie Simpson]

" If you are still in analysis paralysis mode, you simply have extra energy that’s not being channeled into more meaningful areas! "

[Brian Holcombe]

I set based on the chip, feedback is the determining factor. However, that being said I don't find Patrick's settings to be unusual, they're within the normal range for me on both a Kanna (38 degree bed, and something like 60~ degree leading edge to the breaker) and also my LN 4 with a 45 degree angle.

I used to set with a feeler gauge, though I no longer find that to be necessary. The baseline feeler gauge, for me, was .010".

[Jim Koepke]

I just set it where it works. Never thought measuring everything would make a difference.

ultra-thin shavings are for bragging rights, not woodworking

Not only do "ultra-thin" shavings help to avoid tear out when working against the grain, they give information on the condition of the edge of the blade. They are not useful for hogging of extra wood, but they do have a place in the world of woodworking.

jtk

[Patrick Chase]

Not only do "ultra-thin" shavings help to avoid tear out when working against the grain, they give information on the condition of the edge of the blade. They are not useful for hogging of extra wood, but they do have a place in the world of woodworking.

jtk

Yeah, I was partially kidding there. I think too much is made of shaving thickness, though. Even smoothing can be tedious when you do it a mil at a time.

The big selling point of close-set cap irons is that you don't have to settle for ultra-thin shavings when planing against the grain. Recall that the people who advocated most vocally here (notably David Weaver) were hand-tool-only woodworkers that were looking for a way to *not* have to do that.

[Steve Voigt]

0.25 mm is the height of that secondary bevel. If I grind the secondary bevel taller than that I find that I don't get any additional reduction in tear-out, but do get huge jamming problems, and that forces me to set the chipbreaker further back along the blade.

The most interesting thing about this claim is how it relates to the difference between traditional cap iron design (woodies and Stanley/Bailey) and the single-bevel design used by all the makers of premium metal planes. Traditional cap irons have curving, convex bevels, so the bevel is at its steepest right at the tip. They were made this way for at least a hundred years before Stanley/Bailey, who nonetheless used the same convex shape. In this configuration, the height of the secondary bevel is essentially infinitesimal, a point.
Modern makers have largely ditched this design in favor of a flat single bevel, but it's clear that their chipbreakers weren't designed with an ultra-close setting in mind, since as Patrick mentioned the bevel angle (around 30*) is too shallow to take advantage of the chipbreaker effect. In contrast, old woodie cap irons and Stanleys terminate at around 45* right at the tip.
FWIW, I make my cap irons with a smooth convex radius that terminates around 45*, then I put a very small secondary bevel on the edge, slightly steeper, around 50*. I've never measured the height of this bevel but I'd guess it's between 1/64 - 1/32.
Warren has said for years that the convex shape is important, but this figure of .025 is the first hard claim I've seen suggesting that the size of a secondary bevel matters. Lots of people have done (mostly informal) testing on the distance between cutting edge and cap iron, but AFAIK no testing has been done on the size of a secondary bevel. It's an issue that definitely deserves further study.

[Derek Cohen]

Steve, I rounded the front section of my LN #3's chipbreaker. The leading edge secondary bevel is around 50 degrees and about 1/16" high. I can't say that I have noticed a difference, however.

Regards from Perth

Derek

[Patrick Chase]

The most interesting thing about this claim is how it relates to the difference between traditional cap iron design (woodies and Stanley/Bailey) and the single-bevel design used by all the makers of premium metal planes. Traditional cap irons have curving, convex bevels, so the bevel is at its steepest right at the tip. They were made this way for at least a hundred years before Stanley/Bailey, who nonetheless used the same convex shape. In this configuration, the height of the secondary bevel is essentially infinitesimal, a point.
Modern makers have largely ditched this design in favor of a flat single bevel, but it's clear that their chipbreakers weren't designed with an ultra-close setting in mind, since as Patrick mentioned the bevel angle (around 30*) is too shallow to take advantage of the chipbreaker effect. In contrast, old woodie cap irons and Stanleys terminate at around 45* right at the tip.
FWIW, I make my cap irons with a smooth convex radius that terminates around 45*, then I put a very small secondary bevel on the edge, slightly steeper, around 50*. I've never measured the height of this bevel but I'd guess it's between 1/64 - 1/32.
Warren has said for years that the convex shape is important, but this figure of .025 is the first hard claim I've seen suggesting that the size of a secondary bevel matters. Lots of people have done (mostly informal) testing on the distance between cutting edge and cap iron, but AFAIK no testing has been done on the size of a secondary bevel. It's an issue that definitely deserves further study.

To be clear, I don't claim to have been tremendously rigorous. After reading a bunch of sources I put a pretty high secondary on a couple cap irons, and got jamming. I went back to the Kato/Kawai video and measured (in the ruler-on-screen sense) the height of the contact point along the face, using the known projections as a reference. That's how I came up with 0.25 mm. I imagine you could go somewhat higher than that without trouble, but I decided to stop tinkering and spend my time making stuff once I had something that worked.

[Patrick Chase]

Steve, I rounded the front section of my LN #3's chipbreaker. The leading edge secondary bevel is around 50 degrees and about 1/16" high. I can't say that I have noticed a difference, however.

Regards from Perth

Derek

1/16th (~1.6 mm) is absolutely monstrous compared to the distances we're talking about here. Even with your 0.4 mm setback you're not accomplishing anything but causing clogging with that. I acknowledge that my 0.25 mm is probably close to the bare workable minimum and might not work at all at 0.4 mm setback, but a back-of-the-envelope analysis of the mechanics would suggest that you're high by at least 2X and probably more like 3X.

[Kees Heiden]

Let me add something to this discussion too.

Derek, when I look at that picture you posted on the previous page of this discussion, I would say that you have a distance set of less then 0.5 a mm, more like 0.3 mm or even a little less. It is of course very hard to take a measurement from a picture on a computer screen, but that is what it looked like to me when I zoomed in a lot. It is very hard to make these measurements on the workbench too. I tried several methods, and the only one that really worked was a digital microscope with measuring software. (For everyone, this is NOT what I recommend for daily practice, it was only for research!)

In my experiments with capirons beveled between 40 to 50 degrees, I found that a 60 degree cutting angle was more or less equivalent with a 0.1 mm setting of the capiron. A 55 degree cutting angle equivalent to a 0.2 mm setting. Combine these findings with the Kato video, and I think that 0.4 mm is a bit too much, unless the wood is cooperative.

Patrick, I have also thought hard about what makes the capiron tick. How does it really work? When I meassured the forces on the iron, I saw that the vertical force is decidedly negative for a 45 degree cutting angle. In other words, the shaving pushes the iron downwards, or better to say, the iron pushes the shaving upwards. This leads to tearout, the shaving is pushed out of the wood. When you increase the cutting angle, this negative force is strongly reduced and I even got positive values in my test wood at a cutting angle of 60 degrees. In other words, the iron doesn't lift the shaving up anymore, thus the reduction in tearout.

With the capiron a different effect could be seen. The negative vertical force was only reduced a very little bit. But this setup is equally capable of reducing tearout, so the mechanism must be something else. I also don't think the capiron is "breaking" the shaving. A broken shaving has lost its integrity and can't push on the iron anymore. That would also lead to a reduced negative vertical force.

What I think, but can't really proove, is this theory: The shaving slides up the cutting iron and then meets the capiron which bends it a little further. This creates a resistance in the path of the shaving, it rubs and it rubs harder because of the extra bend. This resistance is a force directed back in the direction where the shaving comes from. And I think this is the force that supports the shaving and reduces the tearout. This rubbing theory is supported by the Kato video (you can see how the shaving is compressed by the capiron, while you don't see anything breaking in the shaving) and the measurements they did on the wear pattern on the front of the capiron.

BTW, when you have troubles with a clogging mouth, then there is a simple cure. Open up the mouth. Wooden smoothing planes always had a relatively wide mouth, much wider then it should have been to prevent tearout.

Links to my articles:
http://planetuning.infillplane.com/h...s_van_der.html

http://planetuning.infillplane.com/h...pbreakers.html

The Kato article:

http://planetuning.infillplane.com/h...ron_study.html

A study from the Walker and Goodchild was done in 1960 (Experiments at rectilinear cutting) and they looked at various cutting angles. They also saw that reduction of vertical force with increasing cutting angle.