My new sure-fire get rich quick scheme

[Steve Voigt]

Like many of you, I regularly browse through the blogs aggregated at Norse Woodsmith. There is a lot of good stuff there, but there's also a lot of drivel.
This morning, I came across this gem, in response to a question about dealing with difficult grain:

Or you can use a high angle plane or my new favorite technology, a high angle chip breaker. As this link will show you:
http://vimeo.com/41372857, Professors Kawai and Kato dialed in the importance of the chip breaker or cap iron in producing good results even against the grain. I replaced my standard cap iron with one ground at 75 degrees and the results were very interesting.

So apparently, it's not about setting the cap iron at the correct distance--what you need is a new cap iron ground at the "correct angle." And you can't just grind your old chipbreaker--you need to get a new one, because…well, just because.

So, on to my business plan. I'm going to buy up all the old Stanley chipbreakers I can get. I'll grind a small secondary bevel, and resell them for oh, about $80 apiece. I'll guarantee that these patented high angle chipbreakers will stop all tearout (provided, of course, that you set them the correct distance from the cutting edge).

OK, I'm off now to start planning the construction of my first yacht and vacation mansion.

- Steve

[David Weaver]

Not a good business plan - I think you should sell standard angle cap irons for the people who bungle theirs by putting them at 75-80 degrees.

Of course, I know you're joking - I wonder what a thin shaving on a 75 degree cap iron would do in a plane that had a long wear - nothing good, I'd bet!

I experimented with all manners of angles (but nothing below 45 degrees) several years ago and found an 80 degree cap iron to have a very narrow working range, and a bad feel (and worse surface than a 50 degree or so stock chipbreaker). Since the video came out, I've seen 80 degrees mentioned several places, but it's better for videos and studies than it is for plane-using woodworkers. Something rounded a little in the 50 degree range seemed the nicest.

So...sell the "patented perfect amount of curve" on the cap iron, too. I'm sure the bunches who take the CS classes would get their phones at and wire the money right to you.

[Steve Voigt]

Yeah, I was obviously being silly, but you're right about the angles. I too have experimented with a wide range of angles, and found the same thing. At 75° or 80°, you move the breaker just a hair too close and the plane is suddenly impossible to push.

It seems to me that someone who was serious about this would start by doing a little research. There is a huge trove of information from SMC, Wood Central (your article, but also some very long threads), Wood Net, and other places. An hour of reading, followed by a few hours of experimenting, should be enough to figure out that (1) the angle isn't that important, but should probably be in the 40°-60° range; (2) the brand of chipbreaker isn't that important--almost anything can work with a little tlc; (3) the crucial thing is the distance, duh.

On the other hand, if someone's research consisted of watching the video that some blogger linked to, followed by 10 minutes of experimenting in the shop, then I guess this is the sort of thing they're likely to come up with…

[Pat Barry]

Thanks for posting the video. It is very enlightening. I suspect this sparked some discussion previously also. Material likely makes a big difference. Have they done further work to show the effect of material? It seems they are telling us that we need to factor the distance from the edge to the cap iron as well as the angle. This makes sense.

Also, does anyone know if they have more recent work with other plane blade angles?

Here was their summary (based on their testing with the 40 deg angle blade to surface)
Summary

1. If the blade is sharp and if the cutting depth is smaller than .05 mm (2 thou), then tear out will not occur even with a single blade
2. The distance of the cap iron to the edge of the blade should be adjusted according to the cutting depth.
3. A cap iron bevel angle of 80 deg prevents tear out more than a bevel angle of 50 deg and so the cap iron can be placed further from the edge of the blade.

[Terry Beadle]

I'm a little disappointed in they showing mostly against the grain cutting. They did show a with the grain segment but I was hoping to see how a with the grain cutting with different cap iron angle settings would affect the surface. I 'assume' from the video they went against the grain because the with the grain cutting was not affected by a high angle cap iron setting.
I 'assume' it would be smooth results and the cap iron could be in the 40 to 80 degree range with out significant affect in results.

I wonder still it that is so.

Right now all my cap irons are set to 45. I adjust my cap iron to cutting edge depending on if it's a jack plane, jointer, or smoother. Smoother is set to very close and depth of cut is set to 2 thou or less. Jack plane has cap iron set to about 1/16th to 3/32 nds. About the same in the jointer. This seems to work.

The other thing is if the grain changes direction mid work piece, I change the direction of the plane too....unless I just really roughing the work piece and not concerned about tearout.

So now that I'm thinking about my thinking, I'm thinking I might be over thinking thinking about my thinking...hoot!

[Greg Ladd]

David,

No need at all to bring CS into this thread that I can see.

There are many that value his perspectives and the fact he has helped many desire to increase their hand tool skills. He has also hand plane thousands of board feet of lumber so it is a fair assumption he has some decent level of skill and therefore, a level of experience which obviously provides a decent basis from which to educate others from.

Those that have an opportunity and choose to attend the CS classes (or training with anyone else) do so of their own free will. Woodworkers as a group should encourage learning of the craft by others, no matter the route an individual chooses. Many times in life, an instructed learning opportunity opens the door to dramatically increased learning later when one practices some newly discovered skills in private, on their own.

Please, give it a rest.

Greg

[David Weaver]

Greg, did I violate the TOS here? I didn't. If I or anyone else was looking for someone to tell them what to post or what not to post outside of the TOS rules, we would ask.

[Steve Voigt]

Terry and Pat,
I didn't actually mean to post that video--I figured most people had seen it--but I'm glad you got something useful out of otherwise snarky post.
I guess I need to remember that not everyone has seen and read the relevant stuff. If you want more info on the video, or cap irons in general, here are the three best sources I know:

Steve Elliott's website. Click on chipbreaking and read everything.

Kees van der Heiden's blog. Especially check out the videos of Kees using his planes with different cb settings.

David Weaver's WoodCentral article. I'm not allowed to link to this, but if you google "setting a cap iron - woodcentral," it's the first link that comes up.

[Warren Mickley]

Tear out can occur when the cutting depth is .001 and less. It depends on the wood. The Kato study worked with only a couple of different timbers and only a few orientations. The study was designed to show how the cap iron worked, not to be a definitive guide for its use. As Peter Nicholson wrote in 1812,

The distance between the cutting edge of the iron, and the edge of the cover, depends altogether on the nature of the stuff.

As to the sales of cap irons, I think the important factor is marketing. As may have shown, good marketing can sell cap irons that are nearly useless.

[Kees Heiden]

I've got a theory why the Japanese might like a steeper bevel angle on their capirons. It isn't quite as easy to set the capiron close to the edge in a Japanese plane. You can't really see what you are doing. I guess they set it, then take a few cuts and look at the surface if tearout is still a problem, then tap it down a little deeper etc. A capiron bevel angle with more effect might be usefull in that process. In a western plane you set the capiron by sight, before inserting it into the plane. I find that it is not difficult to set it at 0.1 mm, so the bevel angle doesn't need to be so steep. With a 45 degree leading angle you can get all the effect you want, even for quite demanding types of wood, if you set it that close.

BTW, in the Kato article on Steve Elliotts webpage you can read that a capiron with a 50 degree bevel, set at 0.15mm from the edge gave the best performance on their piece of wood.

[Warren Mickley]

I've got a theory why the Japanese might like a steeper bevel angle on their capirons. It isn't quite as easy to set the capiron close to the edge in a Japanese plane. You can't really see what you are doing. I guess they set it, then take a few cuts and look at the surface if tearout is still a problem, then tap it down a little deeper etc. A capiron bevel angle with more effect might be usefull in that process. In a western plane you set the capiron by sight, before inserting it into the plane. I find that it is not difficult to set it at 0.1 mm, so the bevel angle doesn't need to be so steep. With a 45 degree leading angle you can get all the effect you want, even for quite demanding types of wood, if you set it that close.

BTW, in the Kato article on Steve Elliotts webpage you can read that a capiron with a 50 degree bevel, set at 0.15mm from the edge gave the best performance on their piece of wood.

The Kato study says (figure 12) that a capiron with 80 degree bevel set 0.3 from the edge gave a good surface also. I have used a capiron with rounded bevel since 1975: this is what Peter Nicholson described in 1812.

[Winton Applegate]

For most all wood, figured, reversing, rowed what have you, through more than ten minutes of experimenting I can assure you, I have found the perfect chip breaker placement and the angle as David said can be left stock.


I take the chip breaker in hand, carefully carry it across the room and wedge it under the door to hold the door open.


Then select a bevel up blade with a 45° sharpening bevel, even an old 40° will do for about everything under the sun. I mindlessly slap it into the bevel up plane,

even an old stock (no filing or fettling) LN BU Jack will do in a pinch

push the plane along the wood while advancing the blade until it starts to bite, change the tilt until the cut is centered on the blade, I push the plane and keep turning the depth further and further until I fart , back off a bit so the effort is a bit less and I have my maximum depth of cut.

I don't even have to walk across the room and change the setting of the chip breaker under the door; it seems perfectly content there and seems in no way to have any effect on the depth of cut. Believe it or not . . . it is true.

Plane until dinner time or the work is finish.

Back off the depth and finish plane. See comments above on CB.
No squinting at thousandths of an inch gap judgments.
Absolutely no freaking throat jamming I had never even paid attention to the word wear until I started watching this bevel down micro setting breaker “stuff” .

It did help me tune the Japanese scraper plane I recently bought for screwing around with but I would have filed it even if I didn’t know what it was called I was filing . . . and reached for the bevel up when I had some serious planing to do.

Funny thing . . . the Japanese scraper plane does not have a chip breaker either and it planed one of my unmentionable, purple colored, chipout prone woods with no tear out with a stock factory sharpened blade that wasn't all that polished.
Hmmmmm
no chip breaker, Japanese bevel down plane, no tearout and a healthy thickish ribbon.
. . . hmmmm
no chip breaker, Japanese bevel down plane, no tearout and a healthy thickish ribbon.
. . . hmmmmm

I'm thinking, I don't have to keep thinking about thinking . . .
Thanks Terry I enjoyed that.

So the best setting for the chip breaker is at least twenty feet from the work bench. In my shop at least. YMMV.


PS:
Ah yesssss
a little silliness
always desirable around such a serious subject.


Of course I couldn’t avoid contributing. I really did try.
I hand cuffed my self to the radiator with the wireless key board well out of reach.


After that all I recall is darkness accompanied by the sound of wild thrashing and clanking . . .
oh and there was another more distant sound . . . like a wild beast howling.


When I came to I found I had made a post on this thread.


Sorry
I did try to stop the beast but he was just too much for me.

[Kees Heiden]

The Kato study says (figure 12) that a capiron with 80 degree bevel set 0.3 from the edge gave a good surface also. I have used a capiron with rounded bevel since 1975: this is what Peter Nicholson described in 1812.

This article: http://planetuning.infillplane.com/h...ron_study.html
I don't see a figure nr. 12?
At the end of the first part, they write in conclusion 9 that the best wear profile resulting in self sharpening was with a 50 degree angle set at 0.1 mm from the edge. At 0.2 mm from the edge the capiron had the least amount of wear.
So in the second part of this study they used a 50 degree bevel at 0.15 mm, because of the wear characteristics of blade and capiron.

[Warren Mickley]

Kees, I was referring to to this study on Steve Elliott's website.
http://planetuning.infillplane.com/h...ker_study.html

This study was widely discussed on the woodworking forums in 2007-2008. People who did not read it carefully came up with the erroneous statement that the cap iron had to be within .004 inches to have an effect. The naysayers long used this error to proclaim the impracticality of the double iron system.

I think the wear study is less significant because it only studies the wear after planing 600 feet of material. A trying plane or a smoothing plane has lost its ability to produce a fine surface long before this point. It is like arguing about the taste of various week-old loaves of bread. For myself, the only plane I would ever use this much without sharpening is a jack plane, in which case I would not care so much about surface quality.

[Pat Barry]

At the end of the first part, they write in conclusion 9 that the best wear profile resulting in self sharpening was with a 50 degree angle set at 0.1 mm from the edge. At 0.2 mm from the edge the capiron had the least amount of wear.

I'm sure that the article is not referring to the wear of the cap iron. They are referring to the wear of the blade itself. The actual statement was:
"The best wear profile, resulting in self sharpening, was found at a cap iron distance of 100 microns (0.004”) and an angle of 50 degrees. The most shallow wear on the blade face was at a cap iron distance of 200 microns and an angle of 50 or 60 degrees."