Video of a cap iron at work..and discussion about the cap [Archive]

David Weaver

05-01-2012, 10:00 AM

Bill Tindall, over at wood central has gone to great lengths recently to find information about the planing test that was done around 1980 at Yamagata University by two professors that none of us have probably ever heard of, professors Kawai and Kato.

I suspect this video is going to be popping up all over the place as a result of Bill's efforts in general, and you may have seen a link already at wood central to the video posted elsewhere.

What it describes in motion is what is going on below the cut line based on different cutting conditions and different combinations of cap iron projection and effective angles of attack (as well as without them). You have probably seen some pictures from this video, but to see the wood fibers moving in video is a lot more instructive. What it describes in general is that with the cap iron set properly, we're probably not ever going to need anything other than a basic bench plane to plane anything at all. The settings in the video, I think range from .004" from the edge to .012" to the edge (perhaps only .004" and .008" are included).

This is the direct video link to the video at Yamagata University, and if it changes, I will post a link from elsewhere, but this is the best quality of the video I've seen (it's large). Start around 3:00 if you don't want to watch particulars about the machine. This is a direct link, and it will pop up a video screen.

Original Cap Iron Video (http://kegaki.kj.yamagata-u.ac.jp/shiryou/0025.mp4)

And the credit that goes with the video (please do not repost the link to anyone without providing this credit - the video is not public domain):
Educational Video on "Influence of the Cap-iron on Hand Plane."　
Created by Professor Yasunori Kawai and Honorary Professor Chutaro
Kato, Faculty of Education, Art and Science, Yamagata University.
Video taken in Yamagata Prefecture, Japan.

There are other ways to control tearout, like
* steeper pitch
* very tight mouth (note the video is done totally without a simulated mouth ahead of the iron, the cutting effect is entirely due to the cap iron and the iron itself)
* sharper iron and thinner shaving
* discretion in picking wood, skewing a plane in a cut across quartered grain,
* planing with the grain regardless of what it takes to do that

But to do what is shown in the video is probably free, and it can be done with very inexpensive planes as well as expensive planes will do anything. No 55 degree frogs are needed, no 3 or 4 thousandth mouths.

Bill's excellent detective work to track this stuff down came with perfect timing, right along with when I was drawing conclusions from playing with an $11 common smoothing plane ($14 if you include the spare iron) vs. one that cost me $300 in materials to make. I still have more to learn from using the cap iron, like when I can back off of it some to improve the surface, but needless to say that when it is set tight, it has still given a better brighter finish than my 55 degree infill smoother on everything that I've tried. It does not have the same cadillac feel in all wood (that's a weight issue), but for sure the surface is a bit better.

It's worth the trouble to learn to use the cap iron properly, even though it doesn't make us feel as warm and fuzzy as buying more planes (and if I'm not chief indian in the pack of plane buyers, I'm first assistant to the chief).

Maybe we can get a productive discussion going, and save a few people some bucks. It only takes a couple of weeks of use to learn to set the chipbreaker as tight as these videos without accidentally running it past the edge and over it (dinging up the edge in the process).

Chris Griggs

05-01-2012, 10:13 AM

Thanks a lot Dave. Geez, I've spent several years convincing myself that my Stanley No. 4 is inadequate, and that I need a premium smoother, and you had to go throw a wrench in my logic. I've had it with you ;)

Actually, I'm glad you posted this Dave. I finally saw the video, not just the pics last week (I've been lurking at WC lately and saw the link). It really does show sooooooooo much more than just the pics alone.

I've been messing with this too, and it does seem to work. What I like about it is on a standard BD plane its easier to adjust the cap iron than the frog/mouth. I don't always need the cap iron to be that close, but if I do, its quite easy to move it up.

As you said, there are a lot of ways to reduce tearout, and while I still don't think cap irons are essential they are a good option. And they cost you no extra money.

The other funny thing I'll mention is, that since I started setting the cap iron really close, I've come to prefer the old style better. Becasue they have a relatively fine edge, and they are made of soft metal, the modern ones will chip and crumble if you hit knots/hardened sap when they are finely set. As, I mentioned to you in a previous discussion, I went back and actually blunted/rounded over the leading edges on my modern CBs. The old style ones have a steeper rounded over edge on them already.

(I am still going to buy at least one premium smoother one of these days)

David Weaver

05-01-2012, 10:22 AM

I think I like the older ones better, too. I don't know what the angle of attack is on an old stock chipbreaker, but it works well.

There is another very big side benefit of setting the chipbreaker close, and that is that a stock or stock thickness iron is completely stable, even in very hard wood. No chatter on anything, no need for a super thick iron, no need to file the mouth bigger, etc.

I'm almost embarrassed that I was such a big pusher of everyone should go out and make a 55 degree infill and file the mouth to 4 thousandths of an inch so they could disregard planing direction (still can, but it's expensive for the materials and takes time to do it). It's still a good pleasant to use option, but it's definitely no smoother for white pine to set one up like that, either.

I have a cap iron that I set up just like you're talking about (it's unavoidable for me to use it, since it's on a spiers reproduction panel smoother), except that I gave it a primary bevel of 25 degrees and made a tiny secondary bevel of 80 degrees or so. It works pretty well and feeds in a plane that otherwise wouldn't feed because of an oversight I made.

The benefit of all of this is obviously we can smooth anything without getting into any real trouble, regardless of what we guess on grain direction. No more flattening a panel and finding tearout in the final smoother pass, finagling the plane in all different directions, etc. Just straight through strokes to get a good surface.

The original stanley design with a frog that goes all the way to the casting is genius design, more than we probably have ever given it credit for. It provides a bright finish on softwoods, and with the stock hardware, can smooth anything that back bevels and steep irons have been recommended for.

Chris Griggs

05-01-2012, 10:46 AM

There is another very big side benefit of setting the chipbreaker close, and that is that a stock or stock thickness iron is completely stable, even in very hard wood. No chatter on anything, no need for a super thick iron, no need to file the mouth bigger, etc.

Yep. I actually pulled the Hock iron out of my no. 4 a couple weeks ago and put stock blade in just to test this. The stock blade is still in my smoother and working wonderfully. The hock is waiting to be reground with a jack plane camber, and will be used for rougher work, where I've come to find blade mass matters more, and where the CB cannot be placed as close to compensate for a lack of blade mass.

Jonathan McCullough

05-01-2012, 10:54 AM

Interesting. So how can we ensure that the chipbreaker is set back .1 mm along the length of the iron in a shop environment? A jig that lets you run the CB to the blade against a flat surface, then some sort of stop along the back edge of the iron with a .1 mm shim, then remove the shim and move the CB back against the stop again so the CB is set back exactly .1 mm? What about eased corners so you don't get streaks in the work? I guess you'd have to ease the CB at the same time you ease the corners on the iron, then sharpen the iron and put the roundover on the CB. I'm not sure the video indicates that a higher bedding angle for the iron wouldn't reduce tearout. It seems like the fibers lift off the surface, but the CB curls them up before they get a chance to move vertically. Seems like a higher iron bedding angle would also promote the shearing of the fibers before they got a chance to lift up vertically, slightly more so than at the 40º angle.

Chris Griggs

05-01-2012, 11:00 AM

Yes. A higher bedding angle wood also do that. The CB is just another option (an option that until very recently I thought was completely absurd and finicky to the point of being a waste of time). Daves point in bringing all this up lately isn't too say that higher bedding angles/tight mouths don't work, or that single iron planes don't work. Rather he is ponting out something that anyone with a reasonably well tuned bailey style can try without going out and buying anything new.

As far as setting it, its not something you want to or need to be scientific about. You just get it as close as you can and still see a gleam off reflection of the blade. No loop, no microscope, or other crazy gentleman woodworker esotera. It's quite easy once you've done it a couple times. On my smoothers the corners are so slightly eased that it has zero impact on setting the cap iron. I guess if you clip the corners heavily with a file, than this method probably would't be the thing for you.

David Weaver

05-01-2012, 11:06 AM

The video definitely doesn't indicate a higher bed angle doesn't work, because it does work. It indicates that it's not the only way to mitigate tearout.

Setting the chipbreaker close to the edge is actually pretty easy, and the corners on a smoother, regardless of how they're rounded off or cambered doesn't really make a difference as long as you're setting the chipbreaker based on the depth of cut at the middle of the iron. If the corners are really relieved abruptly, they'll not ever touch the wood, anyway, and if you are bottoming out the chipbreaker and getting bulled around, either the cut is already too heavy or the chipbreaker set too close.

It is surprisingly easy to set the iron closer, actually, than .004, and you'll be able to tell you did that by the fact that the plane will bull you all over the place if you do it, even on a 2 thousandth thiick shaving, while still cutting a shaving (plus, the shaving will look bunched up to some extent). The surface will be fine when you do that, though, it's a no harm foul.

It takes a week or two to get used to setting it close for a smoother shaving depth, but not too close. You can just see a strip of bright metal off the back of an iron when it's set right for a light smoother shaving. There's no need for a jig, etc, just look for a uniform reflection from the iron.

Anyway, you definitely don't want to ease the edges on the chipbreaker. There's no need to worry about where the chipbreaker is over a part of the edge that's not cutting.

This is one of those things where cleaning up the front edge of the chipbreaker and trying it relieves a lot of questions. Once you're at "tearout proof", then you can back it off some to find out what works. But everyone who works with hand tools should have a go-to for smoothing that will remove no more material than you need to and at the same time make no threat of tearout and extra work.

Jonathan McCullough

05-01-2012, 12:29 PM

Ah okay I see. Could you elaborate on the adjustment? I've been doing it by eye, and have found that moving the CB too close gives odd chips and suboptimal performance, so I've backed off the CB to about 1/32", maybe a little less? and have found that to be a sweet spot that gives consistent results. I've also found that going over the edge of the CB with a buffing wheel makes for better chips. Also have been known to put the CB in a vise and bend it just a little to close up any gap between the edge of the CB and the iron.

Chris, although sarcasm is my second language, I was being earnest. I'm familiar with machining tolerances and usually find them to be incompatible with most woodworking. But the video demonstrated different adjustments between .1 and .3 mm, so I was seriously asking--how does the average bear recreate those nice lab results in a shop setting without screwing around too much with micrometers? I've been making those adjustments by eye, but maybe I'm missing something or could be doing it better, so if adjusting a CB calls for repeatable results with .1 mm resolution every time you sharpen, why not a jig?

Jim Koepke

05-01-2012, 12:30 PM

David,

Thanks for doing the work of finding and sharing this video.

I'm almost embarrassed that I was such a big pusher of everyone should go out and make a 55 degree infill and file the mouth to 4 thousandths of an inch so they could disregard planing direction (still can, but it's expensive for the materials and takes time to do it).

At least you are still open to learning things that may not agree with what you previously felt was the way to go. It has happened to many of us. I know it happens to me.

I like my old Stanley/Bailey bench planes. They can do great work. They are not as nice as a brand new LN bench plane, but they can do the same work when set up properly.

That is why my position is that someone with more time than money should look for older planes. The other side of the coin is some folks do not have much time, but the paycheck is fat enough to buy a new premium plane. In that case, a premium plane will allow them to get to work as soon as it arrives.

jtk

Chris Griggs

05-01-2012, 12:34 PM

Chris, although sarcasm is my second language, I was being earnest. I'm familiar with machining tolerances and usually find them to be incompatible with most woodworking. But the video demonstrated different adjustments between .1 and .3 mm, so I was seriously asking--how does the average bear recreate those nice lab results in a shop setting without screwing around too much with micrometers? I've been making those adjustments by eye, but maybe I'm missing something or could be doing it better, so if adjusting a CB calls for repeatable results with .1 mm resolution every time you sharpen, why not a jig?

My bad! Sorry, I shouldn't have assumed. I speak the language of sarcasm quite fluently as well, and I thought you were being goofy (as I often am). Original post edited.

I actually tried at one point to use a sheet of paper to offset the CB about .004", but it didn't work, though admittedly I didn't mess with it for very long. I would say just keep playing by eye. I think you'll pretty quickly be able set it where you want it with just some practice. You can tell when it's set right, because 1) the surface is tearout free against the grain 2) the shaving changes... it holds together more (less gauzy but equally thin)... it sometimes has little wrinkles where I think it's breaking (type II chip?) 3) BUT the plane doesn't as Dave said "bull you around" and the shaving still ejects nicely

I'll add, that while learning to set the CB has in some ways made me feel less of a need to buy new stuff, it has really made me want a clifton stay-set chipbreaker (and by extension a clifton plane :)). It makes a lot of sense if you are using a very closely set chipbreaker. And yes, I realize I can get a Clifton CB without purchasing the whole plane....

David Weaver

05-01-2012, 12:35 PM

I guess if you could come up with a jig that was easy to use, it wouldn't be a bad idea. But a week or two of setting the iron should under half tension and then moving it to where you want it and tensioning it the rest of the way should take care of things, and it might become a jig that you wouldn't use much.

If you have a light source (even just looking toward a window or whatever), you'll be able to get it as close as you want it. If a polished edge on the chipbreaker makes it hard to see, blue (if you have any blue around) the edge of the chipbreaker or marker it. A couple of years ago, it seemed like tedium to me (after seeing the pictures somewhere on the web - from that video), I ran the chipbreaker over the edge a couple of times and swore it off until not that long ago and decided I'd do it for a couple of weeks no matter what. That sort of solved the problem.

Setting it partial tension and then moving it where you want it and then hitting full tension helps to set it close and tight (without setting it right on the edge or going over). If someone has trouble with that, they can set it partial tension and then lightly tap it into position.

Jim Koepke

05-01-2012, 12:35 PM

David Weaver

05-01-2012, 12:44 PM

If it's used properly, the shaving will change because it's noticeably being worked by the cap iron. Like straighten out some and come straight up out of the plane.

Someone mentioned accordion shavings being an indication that it's too close, but I don't think I've seen anything like that though I've definitely moved the iron close enough that it provides significant resistance, but still cuts. Too much resisitance is probably too close, and in soft woods is almost definitely too close (straight soft woods probably don't require the cap iron at all unless poor orientation of the boards forces planing seam where wood goes opposite directions).

Chris Griggs

05-01-2012, 12:50 PM

I find the hard core accordion shavings (that clog the plane and bull you around) result if the the CB is too close, like all the way at the edge... but also result when you combine a really tight mouth with a close, but otherwise not too close, CB.

To some extent you need to pick your poison.

I do still get some amount of "crinkle" when things seem to be flowing right (though the plane is harder to push), but I still need to play with this some more. Perhaps I am setting the CB closer than is needed at times - I'm still not 100% consistent on finding my sweet spot.

Darren Brewster

05-02-2012, 6:49 AM

I have been following the Woodcentral posts, and it is great to finally see this video. Thanks David.

george wilson

05-02-2012, 9:59 AM

A very instructive video,David. I think what most guys are going to be concerned about are the obstacles of getting the chip breaker's edge and the blade's edge to mate up closely enough for these very fine settings. Also,both the chip breaker(CB) and the blade have to have very flat surfaces to keep chips from getting between them. The cutting edge of the plane blade will also have to be quite straight,as well as the edge of the chip breaker,in order for them to mate up that closely.

As usual,it will take the development of some decent amount of skill to make this CB/blade relationship work out properly.

I know from my own experience that using a polished blade and seeing that fine "line of light" is an important device in this as in other applications. Some may not be able to see the small edge of the blade protruding,but with that line of light shining out beyond the CB,it will be more possible. I use 4X drugstore glasses to help my old eyes to see small things.

I am not sure if the idea of using a Clifton chip breaker would work out. When you sharpen the blade,you are shortening the blade,and the chip breaker may be too close,or even go over the cutting edge next time it is clicked in place,so caution on that part when using cb/blade edge tolerances that close.

It seemed in one part of the video,that taking a fine enough cut with no CB,but still against the grain still produced good results,though some of us already knew that from experience. Planing across the grain is also useful in dealing with figured woods. Curly maple is featured on many of the musical instruments,especially bowed instruments. Use of a toothed iron and scrapers,too,is a good technique. Honing a steeper angle on the front edge of the plane iron is an old trick that must have been regularly practiced in the past centuries,judging from the presence of so many original,"dubbed over" plane blades that we have in the museum's collection.

This "dubbing over" technique has also worked quite well in thickness planers with regular style knives. Grinding a blunter leading edge on the blades makes the machine scrape as much as cut,and it does work well on figured woods. These insert cutters employ the same technique,really,a much blunter cutting angle. The machines have the horse power to handle it.

Chris Griggs

05-02-2012, 10:19 AM

I am not sure if the idea of using a Clifton chip breaker would work out. When you sharpen the blade,you are shortening the blade,and the chip breaker may be too close,or even go over the cutting edge next time it is clicked in place,so caution on that part when using cb/blade edge tolerances that close.

I wondering that actually. I guess I was thinking that it would probably need to be adjusted every few honings, but given how close we are talking perhaps you're correct that it would need to be reset moire often anyway.

David Weaver

05-02-2012, 10:28 AM

Yeah, one thing about the video is that it is just one type of wood (not sure what) and it's the simplified scenario of with and against the grain.

What it does show is that if you can plane with the grain, anything works.

If you can plane into the grain and you can thin the shaving, that also works well.

You're also right that there is a bit of skill involved in preparing a chipbreaker (I haven't used the clifton stay set, maybe it could be used a time or two, but their idea of price on a replacement blade and chipbreaker has kept me far away from using any of their goods). On a stock stanley, a user has to set it each time they sharpen, hopefully once they do it enough, they get quick at it, and hopefully if they have problems because of lack of fitness of the chipbreaker edge, they can figure out how to correct it.

When I wanted to build infill smothers, my biggest motivation was 1) that my stock that I can get at the local yard isn't as straight as you'd believe it would be, so making glue-up stuff with all downhill planing isn't always possible and 2) I wanted to be able to smooth something with straight through strokes, fairly quickly no matter what it is.

The infill works for that. I thought more people would build there own, but there have only been a few (maybe people go to sanding or scraping when things don't work out, but that's not a very fast way to fix the problem).

I was pretty pleased to find out that you can still leave the shaving pretty blunt (like 2 thousandths) and pretty much plane anything with a regular common bench plane, which most people abandon as soon as the wood isn't nice. Either that, or they go to super-fine sharpening and super thin slices, which isn't very nice to deal with when you have a lot of large surfaces for furniture (I still don't like to build furniture).

I'm not done building single iron planes, though. I'd like to have a single iron panel plane that looks nice and is scratch made, something in the 50 degree bed range with a 2 1/4" to 2 1/2" range.

Raney mentioned to me on another forum that he's only met two people who control planes with the second iron. I thought that was pretty surprising. I may yet go back to using mostly single iron planes (because it's easy when you have a plane that is made finely and already controls tearout with the mouth).

I think Bill's idea was a little different when he took this on. He mentioned that he uses planes for joinery, but he doesn't like to smooth with them because it's a skill set that is too filled with failure and difficulty. Some of my friends are in the same boat, they get set up to use planes, and it's a novelty, but they go right back to their sander when they actually do anything that isn't just a board to make play shavings on their bench.

Who knows where all of this discussion will go, it might go nowhere and everyone may go straight to buying a high angle plane, or building one (building is always more satisfying, I think), or maybe folks who put the plane down for fear of tearout and due to preference for a sander will decide they can give the smooth plane another whack. Those types could probably use a plane without a set chipbreaker fine, though, because they'll be planing a surface that's already flat and not removing evidence of strokes from a jointer.

Sam Takeuchi

05-02-2012, 11:09 AM

I've read somewhere before that Clifton stay set cap iron has some play in it and while it's not great, it's enough to make it annoying. I haven't played with Clifton ones, so I can't verify it myself. If it does have a bit of wiggle, I'm thinking it could be a problem when you are talking about setting it 0.1mm to 0.2mm away from the edge. I have vintage Record (pre-1960's) stay sets (one for No.3 and one for No.4), both are quite well machined and has no wiggle whatsoever. But while installing it onto a blade, toe piece has to be held by one finger to keep it in place, it can be a bit fidgety trying to get it real close and try to keep the piece from falling. After a while, you hold the toe piece without thinking, so it's not a problem, but as far as setting cap iron goes, stay set doesn't make it easier than a regular one piece.

First picture is how I hold the toe piece while adjusting cap iron. It's not difficult, but it is not as care free as one piece cap iron.
Last picture shows cap iron set to 0.2mm from the edge. Cap iron edge is honed and polished at 35 degrees. No particular reason. Originally it was ground at 34 degrees.

So from my experience, I don't think stay set will contribute any to making things easier...at all.

jamie shard

05-02-2012, 11:19 AM

So that's about .2mm? That seems pretty do-able by eye.

Sam Takeuchi

05-02-2012, 11:21 AM

Yep. It's doable by eye. It is shot in super macro mode though.

Chris Griggs

05-02-2012, 11:31 AM

So I currently have John Coloccia's LV BU smoother in my shop (set to have an included angle of 45 degrees) and I've been using it side by side with my Stanley No.4 (setting the CB at various distances). Last night I played around some more and what I concluded was, believe it or not, that none of the woods I work or have on hand are gnarly enough for it to matter all that much. The worst stuff I have on hand is curly soft maple and a piece of very hard curly cherry that came from an area right by where a big branch had been. Thing is, and I guess this may seem kinda "duh" to many, I can go with or against the grain with either plane, and not get tearout. Works on either plane even if the mouth isn't crazy tight (though it not wide open), and works whether or not the CB is .004" from the edge or 1/32 from the edge. Don't get me wrong, I've now seen the value that a closely set CB can make on the stanley and certainly the LV BU smoother is much nicer feeling to use (once I got used to the girth and 4 fingered grip - disliked it when i first picked it up), but last night more then anything I was reminded of just how far a really sharp blade and light cut can take you. The end result was the same with both planes at various mouth and CB settings.... I decided I need to get my hands on some tougher wood before I continue to form conclusions about the effect of the CB... Then again, I'm perfectly happy working cherry, walnut, and soft maple, so maybe a lot of this is moot for me at the present time anyway.

On another note, I see now why Derek and others who work super hard wood like the BU smoother so much. I really didn't think I would like it (and didn't at first), but it just plows through the wood like its not even there. If I were working that kind of wood, and was doing most my prep with machines, this plane would definitely be the bees knees. I'm growing quite fond of it (its hard not to like any well designed well made tool), but given the woods I work and the fact the I do all my stock prep by hand, I'll probably stick with a narrower No. 4 sized BD plane, even if I do decide to upgrade from my Stanley in the near future.

Chris Griggs

05-02-2012, 11:33 AM

Thanks for the info Sam. And nice pics. I don't think I'd be able to get such a great shot of the CB and miniscule protruding edge.

george wilson

05-02-2012, 1:18 PM

I am thinking that just blunting the top edge of the single iron will accomplish as much as having a separate chip breaker. Blunting the single iron acts as its OWN built in,one piece chip breaker. It has the same effect as raising the pitch angle of the plane iron.

Mr. Lee sent me his book on sharpening,and he advocates this approach. A friend used to blunt the front angle of his thickness planer blades by hitting them on a 20" disc sander. It made the planer plane difficult woods more smoothly. I've known about the blunting for many years by now. I haven't done it to my own planer as I went to the Dispoz-a-Blade system(which Grizzly also sells),and the knives are only .040" thick,or so. Too thin to go and blunt. Blade changing is remarkably fast,though,so I use it. Short of buying a Byrd helical head,I am using the present system. I'm thinking of buying a bigger planer,so don't want to waste the money on an insert head for this one(the dispoz-a-blade was bad enough on entry cost!,cheaper on blade changes in the long run,though).

Generally,I've used other dodges for difficult wood than blunting the blade.

Any arguments???

David Weaver

05-02-2012, 1:29 PM

It definitely works, I'm sure people have done it for a long time.

I saw a patent somewhere in one of the encyclopedias of knowledge or something along that line of someone touting a large single iron with a back bevel, somewhere around the 1830s. I'll bet that long before that, craftsmen stoned the backs of their irons to

My new-found fascination with the second iron is that it keeps you out of trouble without putting a back bevel on an iron, and it preserves the bright finish you get with a common pitch plane. You can just back it off if you don't need it (which is the case most of the time, espec. if smooth planing is a matter of improving the surface over a power planer). the nice thing about using it in a heavier cut is you can speed up removing what the jointer left behind, without the threat of tearing something out when you start to develop bigger flats but still don't want to wait to get everything uniform with a super thin shaving.

Jack Curtis

05-02-2012, 1:29 PM

I am thinking that just blunting the top edge of the single iron will accomplish as much as having a separate chip breaker....

Seems that if blunting works, as logically it should, so should something like grinding a hollow.

Chris Griggs

05-02-2012, 1:31 PM

Just to clarify, because I'm not sure if I follow or not...

By blunting, do you mean putting a slight convex bevel on the back of the blade? Essentially, the same thing as using a back bevel, but a little more quick and dirty?

george wilson

05-02-2012, 1:32 PM

I don't understand what you mean by grinding a hollow,Jack.

Chris,I mean that by grinding or honing a blunter angle on the leading edge of the iron,you are causing the iron to bend the chip tighter,just as the chip breaker did,but without the trouble and skill of setting the chip breaker very close. Also,you don't need to get the cutting edge of the blade and the edge of the chip breaker dead parallel to achieve setting the cb so close to the edge of the blade.

Jack Curtis

05-02-2012, 6:31 PM

I don't understand what you mean by grinding a hollow,Jack....

If the idea is to create an obstruction on the bevel, perhaps the change in direction caused by a hollow would serve the same purpose.

John Coloccia

05-02-2012, 7:47 PM

I just wanted to note, because I don't think anyone else has, just how similar an iron with a large, closely set chip breaker it to a scraper.

Jessica Pierce-LaRose

05-02-2012, 8:14 PM

I just wanted to note, because I don't think anyone else has, just how similar an iron with a large, closely set chip breaker it to a scraper.

Finally got around to watching the video. I was just thinking the same thing.

Bob Strawn

05-02-2012, 8:46 PM

Just in case someone doesn't have this figured out, here is the easy way to tune and set a cap iron. The first thing that must be done, is a flattening of the backs that will contact each other, so that they contact each other. and polishing the bevels so that they merge into one edge that is split between the irons.

Setting the gap, is easy. Put the edges straight down into some nice smooth flat wood. I usually use a bench hook for this. Loosen the screw and then lean the plane blades toward the cap iron. Examine from the side and it should be easy to see when the gap is right. When the gap is what you want, tighten the screw.

Now you can put it in your plane again and go to work.

Bob

Chris Griggs

05-02-2012, 8:56 PM

I was wondering when you'd chime in Bob - you've been the lone voice of the chipbreaker around here for a while now. Last time this was brought up (I think a month or so ago), I was in utter disagreement with you - I've had a change of heart lately.

Anyway, I've tried that method of leaning the blade, but haven't gotten it to work. I've found its just easier to eyeball - perhaps I'll try your thing again though.

Bob Strawn

05-02-2012, 9:13 PM

No problem there, I started out against chip breakers and was honest enough with myself to test my convictions. I proved myself wrong. ;)

If leaning the blade doesn't work try this method; strike a line in the wood, put the bottom iron blade into the line in the wood. If it does not come out even, straight or deep enough, correct the cut channel by tapping the bottom iron into it with of a light hammer. :) Neither of these methods will work well if your cap iron has too sharp an angle. Eyeballing works fine if you can coordinate the fine hand adjustments. You can also adjust by tapping the bottom iron with the screw somewhat tight. No great way to push the cap iron closer using this method, but you can do it.

Bob

Chris Griggs

05-02-2012, 9:19 PM

No problem there, I started out against chip breakers and was honest enough with myself to test my convictions. I proved myself wrong. ;)

If leaning the blade doesn't work try this method; strike a line in the wood, put the cap iron blade into the line in the wood. If it does not come out even, straight or deep enough, correct the cut channel by tapping the cap iron into it with of a light hammer. :) Neither of these methods will work well if your cap iron has too sharp an angle.

Bob

That's a really good idea! I guess that would be the jig John M was looking for his above post. I'm pretty comfortable with eyeballing at this point, but I think I'll still try that.

This is a good thread - lots of useful discussion and ideas!

Bob Strawn

05-02-2012, 9:25 PM

I knew this would happen. :) I have been quoted before I got my post correct! I fumbled the term cap iron and bottom iron in the original version.

Doh!

Bob

Stuart Tierney

05-03-2012, 1:23 AM

I just wanted to note, because I don't think anyone else has, just how similar an iron with a large, closely set chip breaker it to a scraper.

You're right, without question.

I've also decided to give chip breakers a second shot, and my feelings are still mixed somewhat. No doubt they work, but at the same time I don't usually have much in the way of tearout problems with the chip breaker completely out of the picture. Maybe I'm not using wood that's figured enough, maybe I'm getting (and maintaining) my blades at a level of sharpness where the chip breaker isn't asked to do so much. Maybe it's having enough time clocked up actually planing stuff that I naturally manage to avoid tearing out most woods I plane.

I don't know for certain, but I have seen it improve the surface of the wood being planed when it's dialed in properly at the expense of added cutting effort. Not always of course, but where a surface is obviously not 100%, getting the chip breaker to do it's thing certainly helps.

Very interesting.

Also, 'blunting' the blade doesn't give the same effect. If you think it does, you must have been watching a different video to what I saw. Blunting will of course also reduce tearing out, but in that case it's very rapidly lifting the shaving away from the surface, breaking it up instantly. But as the edge itself is 'blunt', you're more scraping the wood fibres than cutting them, which is quite obvious with increased planing effort and in the less 'bright' finished surface. Not an ideal solution, but yet another arrow in the quiver. Even a higher angle of attack of a sharp blade is, I think, more desirable to use if you can manage it.

You do what works. Whatever that is.

Stu.

David Weaver

05-03-2012, 7:51 AM

Primarily, where I will get tearout is on panels where the grain running on direction isn't running the same direction at the other end of the board (so when you glue up, stuff is going all over the place). I would prefer better stock, but I am too cheap, I guess. $5 a board foot for rough cherry is enough - which is what my no-thought yard charges (by that I mean I don't have to plan ahead to get it, I can just go any time).

Anyway, where I get into trouble is at the end of flattening a panel when I have a smoother on a very aggressive cut. If it will take a good finish at that cut, then I'm done. If not, then I'll back it off.

But mitigating tearout (and getting a good surface) on grain that turns right back into you when you're working on a board that has scallops from a jointer is a bit different than taking a board out of a power planer. In my mind, you want to be able to run a fairly coarse shaving and get the marks from the prior plane out with no extra work at all, the board should already be just a couple of smoother strokes above finished thickness. And it might be one in 10 boards that causes a problem if stock is better.

Taking a board right off a power planer, you can use whatever you want unless you have to remove a lot of material.

If the desire goes to getting the absolute brightest finish you can, then backing off of the smoother after the coarse smoothing work is done is fine, too, but not much fun to remove jointer tracks when you can get them out in one or two quick passes with a coarsely set smoother.

David Weaver

05-03-2012, 7:53 AM

I just wanted to note, because I don't think anyone else has, just how similar an iron with a large, closely set chip breaker it to a scraper.

Well, sort of, except that you're not rubbing the chip off, you're shearing it, and the force being applied to stand the chip up occurs longer after the cut is made.

Scrapers don't provide a good option to someone building furniture with a lot of soft maple, pine and cherry.

John Coloccia

05-03-2012, 9:35 AM

Well, sort of, except that you're not rubbing the chip off, you're shearing it, and the force being applied to stand the chip up occurs longer after the cut is made.

Scrapers don't provide a good option to someone building furniture with a lot of soft maple, pine and cherry.

If the scraper is rubbing something off then it's not sharpened properly. The burr on a scraper should shear wood just like a blade. The closer the chip breaker gets to the edge of the iron, the more closely it approximates the geometry of a scraper. I use scrapers on soft woods all the time. It's one of my main smoothing tools for spruce guitar tops. It really sounds like you've never used a properly sharpened scraper. I think you're leaving a lot of performance on the table. You should be taking off nice, big shavings. If you're just getting dust, then there's something wrong.

george wilson

05-03-2012, 9:39 AM

"Blunting" the plane = using a higher angle blade.

Jack Curtis

05-03-2012, 9:50 AM

"Blunting" the plane = using a higher angle blade.

Well, that's kind of what a hollow gives, at least between peaks.

David Weaver

05-03-2012, 9:53 AM

If the scraper is rubbing something off then it's not sharpened properly. The burr on a scraper should shear wood just like a blade. The closer the chip breaker gets to the edge of the iron, the more closely it approximates the geometry of a scraper. I use scrapers on soft woods all the time. It's one of my main smoothing tools for spruce guitar tops. It really sounds like you've never used a properly sharpened scraper. I think you're leaving a lot of performance on the table. You should be taking off nice, big shavings. If you're just getting dust, then there's something wrong.

I have used a properly set scraper, the surface is just not as good, even when the burr is rolled from an edge polished on a shapton 15000. It may not make a difference on a guitar, where it's going to be under lacquer, but it is very evident on bare wood, and if you look closely on something like quartered spruce, you'll see a difference in the surface vs. a common pitch plane.

On very hard wood, there is a lot less difference because the wood isn't subject to crushing as easily at the surface as softwood is.

I may have used a poor choice of words by saying the scraper is rubbing off a shaving, I've never seriously used a scraper that doesn't turn a shaving off the surface just like a plane. I just don't like the finish as much, and I don't think they're practical for furniture work where a heavier shaving to start is a much nicer (and faster) way to go.

Sam Takeuchi

05-03-2012, 12:41 PM

Just to provide some info, the material used in this study is Magnolia obovata (http://en.wikipedia.org/wiki/Magnolia_obovata).

John A. Callaway

05-03-2012, 4:27 PM

This video was absolutely eye opening..... even in Japanese.... This demonstration says so much that a book can never put into words... then maybe, I am one of those guys that has to see it to understand it.

I am currently working on some curly maple panels that have given me a flat out FIT.... read : tear out , even after the LN low angle jack/toothed blade set up went over it, and the LN 5.5 with the 55 degree frog ( although, from reading this thread, maybe I didn't have the mouth set as tight as I should have ) ... I was almost to the point of being one of those guys David mentioned ( going to the sandpaper drawer in a fit of 'being aggravated/frustrated ) .

this video however, has me wanting to do a little work and see what I can achieve.

A couple of questions though :

I noticed near the end of the video the chip breaker was ground at what looked like a ten degree angle ? Should we be grinding down the leading edge to something close to this to help ? It looked like they got the best results with this higher angle CB , but is it going to be something that will prove any more beneficial all the time every time ? The CB before that seemed , to me, to do a job almost indistinguishable from the second one.... but until we get a translation, I am not sure what they were trying to show exactly.

Should we run to the Tormek and start changing the attack angle on the edge of our chip breakers? I m thinking no, but no one has mentioned the difference in the two set ups towards the end of the video....

Thank you for linking this up. The creek will always be home, but I havent even ran across that site since I googled handplanes a few years ago....

David Weaver

05-03-2012, 4:39 PM

A 50 degree front edge works fine. There seems to be different thoughts (that are based on the practice shown here, there are tons of thoughts to be ignored, like places that tell you to set the cap iron at a fat 32nd or something). Anyway, the two schools seem to be:

* setting a shallow bevel and a very blunt secondary bevel on the chipbreaker (not something you can do with a standard stanley chipbreaker, but on the old woodies and on japanese planes you can do this). The idea is that you present a blunt 80º sliver of cap iron to the chip, but then make the primary bevel shallow so that there isn't any additional obstruction in the way of the shaving

* setting somewhere around 50 degrees at the front, which seems closer to where the stanley design is, but maybe it's steeper, I don't know, either curved or just one flat bevel.

Either one works. A full thick bevel of 80 degrees seems like it creates more extra work than is needed, and in some planes it'll cause feeding problems (well, poorly designed planes might have feeding problems no matter what.. I have some old woodies that absolutely won't feed with the chipbreaker set close).

If you have a stock stanley type chipbreaker, I would leave the profile alone and just make sure it has a nice clean face.

If you still get tearout after the plane is feeding fine, then the iron should be closer to the edge. The only tearout you'll get is if you go across the grain (end grain and cross grain cuts are for low angle or skewed planes), though you can skew the plane and still make those cuts.

george wilson

05-03-2012, 5:10 PM

The ultimate solution is a micrometer adjustable cap iron.:)

Bob Strawn

05-03-2012, 6:47 PM

The ultimate solution is a micrometer adjustable cap iron.:)

Those are for sale, George. But the plane is not what we call a hand tool. (http://www.solidwoodmachinery.com/supersurfacers.htm) ;)

Bob

John Walkowiak

05-03-2012, 7:18 PM

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The ultimate solution is a micrometer adjustable cap iron.:) As the saying goes: everything old is new again. I have seen adjustable cap irons at Mid West meetings. Don't remember if they were Dutch or German. The cap iron laid on the iron, no srcew, the wedge held it tight. Threre is a round adjuster with 4 holes in the disk. Looked like you used an ice pick to adjust it. Here are some pictures of a plane I have. The adjuster works in the same way. It was made by the Sandusky Tool Co. It was patented in 1870 by Z. Phillips. It is quite flimzy and I doubt if it worked. There are only a few known. But, it shows that between this and the other I mentioned "mechanics" in the 19th C. were trying to get a more precise way of adjusting the cap iron on the blade.

george wilson

05-03-2012, 8:01 PM

This has been an unusually interesting thread!! The thread on that screw is pretty coarse for a precise adjustment,but someone tried.

I have seen one of those planers that use a stationary blade at Federal surplus. Not a machine I would have wanted to resurrect,myself. They came out in the 70's,I think. Never got popular.

The wood was run through them very rapidly by a powerful feed belt. I don't know how they worked with unusual or downhill grain.

John Coloccia

05-03-2012, 9:55 PM

David Weaver

05-03-2012, 10:18 PM

Thanks to mark hennebury (who is probably the origin of that video), we know the answer to that question, they use a jig to set what they refer to as a "back iron" (or chipbreaker):

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I always wondered how they bruted those things across a board without getting tearout somewhere on it, and now we know the answer. I think they have control for mouth size, back iron and skew.

george wilson

05-04-2012, 8:37 AM

Must have been a bear to keep the blade sharp! Just 1 blade to do all the cutting=3 or 4X the wear on the cutting edge. Probably today you couldn't get the blade resharpened-if you ever could.

There actually was a thickness planer of similar concept in the 18th.C.. A wooden block mounted overhead of the platen,on 4 wooden corner posts. Height adjustable by wedges or some such. Wide blade in the top mounted block. You had to SHOVE the wood through,though!! A crude attempt to plane lumber to the same thickness all over. I never saw one in person.

This is from a VERY OLD recollection.

David Weaver

05-04-2012, 8:45 AM

I wonder if they make a jig for it - to sharpen. Mark made the comment on wood central that they make that jig (with micrometer type adjustments) because they found out that the setting on the second iron is critical.

I have no idea how the irons are set in the planer, but if they're set in square, then everything would have to be extremely accurately ground and honed.

It's fascinating that they went to the trouble they did to make a planer that would plane a board quickly, but leave it looking like a shiny hand planed surface (since traditional building in japan apparently has unfinished show surfaces in the house). But doubly interesting that they have made the second iron a vital part of the machine since it will never do anything other than a straight through shaving, or perhaps with the blade turned askew. they could've probably gone with a steeper pitch (and had a much less complicated setup), but the finish wouldn't have been as good.

Based on the fact that a lot of my trim work in my house still has planer chatter on it (and it's from the '50s), I'd say we're not quite so particular over here. Cover it with stain and varnish back then, nobody will notice.