Why No Low Angle Wooden Jack Planes?

[Robby Tacheny]

I have been thinking about it and did some researching, and I can't seem to find any mention of low angle wooden smoothing planes. Are they really a 20th Century creation?

It seems like the forces on the plane iron would be mostly the same as on a standard angle plane, except I would think it would be less stress on the wedge, since the downward angle would be less. However, the iron would probably have to be longer to accommodate the more shallow angle.

So to me this suggests that one could make a low angle wooden smoothing plane and just use a longer iron. The only reasoning against the notion seems to be that there may be less body mass (which may be less desirable) and that a low angle plane may not be any better than a regular smooth plane at the normal angle.

Any thoughts?

-R

[Sam Takeuchi]

I do know there are some old woodie with something like 33 degree cutting angle, I can't name who made it or how it's like. I remember reading about it when I was mindlessly reading about planes a few weeks ago.

I think there are low angle wooden planes out there, but the question is whether you are talking about bevel up or down low angle plane. There are quite a lot of bevel down 'low' angle planes. A lot of Japanese carpenters who specialize in temple and shrine building utilize bevel down 37.5 degree planes, which is in fact a low angle in modern Western convention. I'm pretty sure there were and perhaps still are plane makers out there who make low angle bevel down planes.

When it comes to low angle bevel up planes, maybe there's too much force trying to push the blade out to hold iron firm in the position. I don't know, but just guessing from the design, I can kind of imagine blade getting dislodged quite easily.

Another thing is if there's a low angle bevel up jack plane of wooden construction, most of the body from the mouth to heel have to be gutted out to make room for the blade. Or make body height shorter. Either approach may weaken the body quite a bit. It'll be like a making a plane out of a board, not a block. If you make a blade longer, then there's a issue with grip. You might have to actually grip the plane over the blade. In the end, half gutted plane will be connected together with a very thin walls on either side of the plane iron, I really don't think they'll have the rigidity to withstand the normal woodworking abuse.

I'm just guessing here, so maybe there are wooden low angle jack of better design or construction.

[Robert Rozaieski]

Low angle wooden planes exist but are not very common. They were historically called strike blocks, straight blocks or miter planes. Low angle wooden planes are also typically bedded bevel down, not bevel up.

To make a bevel up plane out of wood would require a blade almost the same length as the stock and the wedge and mortise would need to be really long unless the plane was really short. I also think the cheeks would end up being very fragile being so long and thin and would likely split when the wedge was driven. In addition, the wedging forces would be directed across the long grain in a bevel up version as opposed to along the grain in a bevel up version, which would be almost gauranteed to split the stock, especially if the wedge was overdriven. The stock would also likely have a lot of flex along it's length, which would not be desireable.

Here's a bevel down low angle wooden plane that I own.
http://logancabinetshoppe.weebly.com/uploads/9/4/7/5/947508/826708_orig.jpg

The iron is bedded at 35 degrees, bevel down. This gives an effective cutting angle the same as a bevel up plane bedded at 10 degrees with a 25 degree bevel.

The bevel up concept I think was likely introduced in the 19th century with iron, infill miter planes. The steel could handle the very low bedding angles required for a bevel up plane but the wood infill still provided the bedding surface. Some consider the infill bevel up miter planes the best style of miter plane ever made.

[Bob Strawn]

I have made a few, most have been total failures. You need a thick stiff blade as the wooden bed is quite thin. Chatter and 'dolphining' are quite common unless you get the configuration right. The forces that pull the blade downward are not well resisted by the thin bed.

Since usually the blade is attached to the bed and the bed is more flexible, stability is a big issue. Mesquite works fairly well for this since it is stable and less flexible. Ash, one of my favorites for planes, is not so good.

Here is a method (http://toolmakingart.com/2009/02/22/experimental-rabbet-plane/) that I think will overcome the problems. I took the concept a bit to far here (http://toolmakingart.com/2009/03/09/a-lovely-failure/).

The thought is to reverse the normal holding method, and make the top of the bed the actual bed that the blade is held to. Doing this lets the blade be secured to a more solid and stable section of wood. This way the rear sole area is used entirely as a guide against the wood and not as a ridged support for the blade.

Bob

[george wilson]

They had low angle planes in the 18th.C.,but they have to be iron stuffed with wood.As said,the wood isn't strong enough to hold the iron at a low angle.

I put up a picture of a copy of such a plane-probably back about page 20 by now,except it was sterling silver instead of iron for a presentation piece.

[Stephen Shepherd]

and I think the term clad was much more common than 'infill'.

Roubo (MDCCLXIX) Plate 281, figures 4,5,6 & 7 show a wooden low angle plane.

Stephen

[Larry Williams]

I have been thinking about it and did some researching, and I can't seem to find any mention of low angle wooden smoothing planes. Are they really a 20th Century creation?...

...The only reasoning against the notion seems to be that there may be less body mass (which may be less desirable) and that a low angle plane may not be any better than a regular smooth plane at the normal angle....

-R

Robby,

Why would you want a wooden low angle smooth plane?

For end grain? As has been posted, there were both strike block planes (40º (+/-) bed and bevel down) and miter planes (20º (+/-) bed and bevel up for shooting end grain. End grain is where you want these low angles. Well, end grain and soft punky wood.

These planes have clearance angle problems for all but the lightest of cuts when using acute bevel angles of around 25º. Stanley knew what they were doing when they offered both 20º and 12º bedded block planes. The 12º was intended for the lightest of cuts in end grain or very soft woods while using acute bevel angles.

Wooden planes at low angles have structural problems. I can level equipment that weighs more than a thousand pounds easily with wedges because they can exert tremendous force with relatively light force moving them. The closer you get to the natural cleavage lines of a wooden plane body the more likely you are to split a wedge set plane. In fact the problem is common. Here's a commercially made boxwood shoulder plane that's been split just this way. You can see the crack coming off the back of the bed.

http://www.planemaker.com/photos/shldr.jpg

Please ignore the brass sole on this plane. It's one of my early mistakes and I know better than that now. Duct tape probably has better wear properties than brass and duct tape would have been easy to undo.

The miter plane and the strike block make an interesting comparison. The strike block is the early version and the miter plane came along later and relatively quickly replaced the strike block. The miter plane, though, has a much lower bed angle and is a lot more prone to structural failure.

Here's a photo from the September 1997, 30th David Stanley Auction Catalog. It shows the two types of planes next to each other. on edit:The miter plane is bevel up and the strike block is bevel down.

http://www.planemaker.com/photos/dstanley.jpg

As you can see, the lower angle miter plane (top) with its mouth stop is a more complicate plane to make. An early 19th Century British catalog list both planes shows the miter plane sold for three times the cost of a strike block plane. So why did the structurally weaker and significantly more expensive plane replace the strike block?

Our experience with developing a strike block makes us believe the reason is all about the clearance angle. Trade practice back then was to free-hand grind, guessing at angles with no tool rest and then to free-hand hone. You just can't be that casual with the strike block plane. Even taking relatively light shavings with an iron ground near 30º or slightly more the plane balks, requires a lot of force to use and generally acts as if it's dull when it's not. With a good tool rest on a modern grinder it's easy to accurately grind a bevel of 25º and to maintain that even with free-hand honing. With a 25º bevel angle on the strike block it settles down and performs exactly like one would want. It's really easy to use that way but the plane, even though it's intended for light cuts, requires something close to a 15º clearance angle.

Most of the modern low angle bench planes are bedded at 12º. Wood fibers deflect ahead of a cutting edge and need room to spring back or you have to force the plane. I'm sure the frequently reported short edge life and accelerated wear to the flat bottom face of the irons of these planes is a direct result of inadequate clearance. Using obtusely honed irons in these planes only increases the deflection of the wood and increases the need for greater clearance angles. Some of the contemporary low angle bench planes out there are bedded at 20º or a little more and don't seem to suffer from reduced edge life at normal sharpening angles.

So I go back to my original question, why would you want a low angle wooden plane? What angle do you want?

[Robert Rozaieski]

These planes have clearance angle problems for all but the lightest of cuts when using acute bevel angles of around 25º.

Our experience with developing a strike block makes us believe the reason is all about the clearance angle.

You just can't be that casual with the strike block plane. Even taking relatively light shavings with an iron ground near 30º or slightly more the plane balks, requires a lot of force to use and generally acts as if it's dull when it's not. With a good tool rest on a modern grinder it's easy to accurately grind a bevel of 25º and to maintain that even with free-hand honing. With a 25º bevel angle on the strike block it settles down and performs exactly like one would want. It's really easy to use that way but the plane, even though it's intended for light cuts, requires something close to a 15º clearance angle.

Excellent point Larry! In my experience with the plane I pictured above, this has indeed been a major problem. I typically grind my tools at around 30° (I don't measure but about there). However, because my strike block is bedded at 35°, I found using the plane with this bevel angle problematic for all of the reasons you described. The iron was exceptionally sharp, however, even taking light cuts, all it produced in end grain was dust. If felt as though I was using a dull tool and scraping instead of slicing. The clearance angle was the problem since it was only about 5°. I have since reground to about 24° to 25° (based on rise/run calculations using a bevel square). This offered some improvement but I still think it needs more clearance. Problem is, at this low bevel angle, the edge of the iron tends to fold after just a few strokes in end grain. I compensate by moving to a different part of the iron but it still dulls very quickly. I suppose I could try to have the iron rehardened & retempered (it's not original to the plane anyway) but I don't have the ability to heat treat such a large, thick piece of steel. I find myself instead trying to avoid planing end grain if at all possible, or using my common pitch jointer on a shooting board instead.

[Robby Tacheny]

Its mostly just for theorizing. I can say that there is any reason, other than the fact that in researching I haven't come across them so much in modern designs. Also, I am thinking about trying my hand at building a wooden plane soon and thought that it might be neat to try a lower angle since all I currently have are metal Stanleys.

In Larry Williams 1st examples, what if you turned the grain to a vertical orientation rather than a horizontal and put a cap on the bottom with grain turned horizontally. This way you get a sole that should stay more true and a body that would be stronger to the forces applied by the iron.

-R

[Robert Rozaieski]

In Larry Williams 1st examples, what if you turned the grain to a vertical orientation rather than a horizontal and put a cap on the bottom with grain turned horizontally. This way you get a sole that should stay more true and a body that would be stronger to the forces applied by the iron.
-R
You would end up with a very weak area where the escapement/mouth was cut in and the stock would likely snap in half at that point on your first couple of strokes, if it even lasted that long.

[Bob Strawn]

I am thinking about trying my hand at building a wooden plane soon and thought that it might be neat to try a lower angle since all I currently have are metal Stanleys.

-R

My starting plane advice is to avoid expensive/rare woods to start. It does not take a lot of wood to make a plane so the wood and/or glue needed to make a plane does not need to cost much. It also does not take that long to make a plane, and you can use the iron in another plane if a given plane does not work as well as you would like.


If you are looking for low angle, the flush cut plane is one of the most overlooked planes and one of the most useful. A flush cut plane is very easy to make, and one of those tools that you will be regularly reaching for.

Bob

[Robby Tacheny]

Bob Strawn,

Do you happen to have any links to where someone has made their own flushcut plane? Thanks for the advice and thanks for the excellent examples in you previous post.

BTW, I think that first design you posted is wondeful. I wonder if the same results would happen on a Quartersawn and tighter grained wood or with several thinner pieces glued together with vertically oriented grain and possibly with a brass plate on the bottom or a very hard wood?

-R



Originally Posted by Robert Rozaieski
You would end up with a very weak area where the escapement/mouth was cut in and the stock would likely snap in half at that point on your first couple of strokes, if it even lasted that long.

I am sorry, I meant Bob Strawn's first post. However, looking closer at his plane it looks like it did split accross the grain. Also

-R

[Bob Strawn]

Bob Strawn,

Do you happen to have any links to where someone has made their own flushcut plane? Thanks for the advice and thanks for the excellent examples in you previous post.

BTW, I think that first design you posted is wondeful. I wonder if the same results would happen on a Quartersawn and tighter grained wood or with several thinner pieces glued together with vertically oriented grain and possibly with a brass plate on the bottom or a very hard wood?

-R




I am sorry, I meant Bob Strawn's first post. However, looking closer at his plane it looks like it did split accross the grain. Also

-R

The split oddly has no effect on the plane. Probably if I dropped it, it would break there, it really is the wrong wood for the job. Almost punky. I just grabbed a block that was the right size that I had already rejected for any serious work. It was purely an experiment. The funny part is that even though it is a throw away plane, (not the blade however, the blade is a Hock!) I am still using it in preference to a lot of other planes, one of which is a Clifford.

Here is an example of a flush cut plane. (http://toolmakingart.com/2008/07/01/flush-cut-plane/) I marked a thin slice of osage, cut the base shape out and epoxied it to a roughed out block. You need a hard tough wood for the bottom in this design, since it will be taking the brunt of the work.

http://battlering.com/woodworking/images/Flush%20Cut/Lowest%20Angle%20plane4.jpg

Bob

[Robby Tacheny]

Bob, that is an interesting plane for sure! Its more like a scraper though right?

I adapted the design in Bob's first post, please take a look.

I have done drawing of what I think could be a viable design for a Bevel Up Low Angle Wooden Smoother. Keep in mind that the mechanisms aren't completely realized, but I am thinking this might be strong enough for smoothing.

The drawing is done to a scale of one square inch per sqaure on the drawing. I show the blade going through the body only to show that a blade that is 4.25 inches (Hock block plane blade length) would be too long. I am thinking the blade length needs to be more around 3.5 inches or less which happens to be the length of the Hock Krenov style irons. Either way, in this case a shorter length iron should be better.

http://http://www.sawmillcreek.org/attachment.php?attachmentid=118949&stc=1&d=1242932878Does this seem like it could be a viable design with a screw creating the pressure instead of a wedge? Also I think the hole for shavings might be too large.

-R

[Bob Strawn]

I tend to think of a scraper as very high angle, but yes, the flush cut can be like a chisel, or a float sort of. Most folk, me included, that have them tend to mess up the edge by using it to remove glue or paint however. Hard to resist since it does such a good job. I tend to use one of these instead of a bullnose unless the grain is wrong. Then I use a York or higher pitch.

I like your design. If you epoxy the bolt head into a wooden knob, it will look better and be more convenient. The one problem with this design that I see, is that you will lose some sole to work surface reference as you approach the edge of your work. If you put sides on it like a Krenov, then you might still have full stability. When I remake mine, I will put sides on it like a Krenov and have the bottom go all the way up close to the mouth. I will probably use white oak for the body, for it's cross link and hardness. For a smoother, you want good side to side stability, so a thick wall on the sides is not amiss.

Western planes tend to put the blade edge close to the center of the plane, the Japanese tend to put it about 5/8 of the total length back from the front. From my experience, I am now fond of the further back, Japanese blade position, as long as it works out in my plane design.

Bob

[Sam Takeuchi]

You'll need something under the blade to support it, otherwise it'll flex and chatter. Without it, if you run it over a knot or unusual grain, the blade edge get snugged and probably dig in while blade is slightly bent. You can adapt Bob's design and put cap iron underneath, which will add quite a bit of resistance to flexing.

Another thing is the gap under the blade. On a flat surface, it should plane ok, but at the end of the board, when you reach the very end of the board, the blade will slightly dig in once front part of the sole leaves the board. It'll be like slightly chamfered edge. More you plane over that part, bigger this gets. It happens because you plane past the front part of the sole, the only points supporting the plane is the blade edge and the heel. Blade naturally tries to cut downward once there is no sole to keep it steady. To over come that, you need more sole on the back part of the sole where you can exert enough pressure to keep plane level without the front part of the sole, so that the blade leaves the end of the board straight.

[Robby Tacheny]

Bob Strawn said
If you put sides on it like a Krenov, then you might still have full stability.I think that's a good idea. It would add a lot of rigidity. How would you adjust laterally though? Maybe two smallish holes toward the very back of the iron on the sides?


Sam Takeuchi said
You'll need something under the blade to support it, otherwise it'll flex and chatterI tried to illustrate that under the blade. I am thinking something like a table saw arbor nut. It is round and slightly convex with a hollow center and snugs the outside portion as you tighten the center. I am also considering trying design this with only a 2" blade so it would be less likely to flex. I think as mentioned above, adding sides could really strengthen this design.

[Aaron Kline]

Larry, could you post a drawing showing in detail whats happening with a low angle versus a standard angle plane? I don't quite understand the clearance angle issue. Do you mean the fibers of the board spring up directly behind the cutting edge and with a bevel down plane the small open area at the bevel is the clearance angle compared to a bevel up plane which has no area for the fibers to do so since the cutting edge is bedded flat?

[Larry Williams]

Larry, could you post a drawing showing in detail whats happening with a low angle versus a standard angle plane? I don't quite understand the clearance angle issue. Do you mean the fibers of the board spring up directly behind the cutting edge and with a bevel down plane the small open area at the bevel is the clearance angle compared to a bevel up plane which has no area for the fibers to do so since the cutting edge is bedded flat?

I've been trying to think of a way to draw this but I'd need a lot of images to show what's happening. If you think of slicing bread, you can probably remember seeing this. The fibers in the bread resist being cut and deflect ahead of the edge but, after they're severed, they spring back. Wood and other materials, even metals, do the same thing. When the fibers are displaced, the area actually cut is at a slightly higher level than the cutting edge. Wood fibers return with more force than bread and need to have space for their return.

There are a lot of variables involved--effective cutting angle, how acute the cutting edge is, the depth of cut, the species of wood being cut, how sharp the edge is and others. A 12º bedded block plane has barely enough room for the spring-back if the iron is sharpened at 25º, very sharp and the cut is light. My middle pitch (55º) smooth plane cause, sharpened at 30º has 25º of clearance which is barely enough. I free hand sharpen and, when I get in a hurry sometimes I hone when I should regrind. I just pick the iron up a little more to avoid a lot of honing. When I get the angle more than a couple degrees above 30º, my plane doesn't work well. It balks, acts dull, is prone to chatter and worst of all leaves behind a burnished surface. Burnishing inhibits good penetration of adhesives, stains and finishes. I've never measured the exact angle where this happens but I sure know it when I get to that point.

I think clearance angle may be one of the most important factors in plane performance and it's almost always ignored. The necessity of adequate clearance and the ramifications of not enough is hard to describe and there are so many variables.

[Wilbur Pan]

Hi Larry,

Do you think that the "best" clearance angle depends on the angle that the wood fibers are at relative to the edge of the blade when they are being cut? That is, the ideal clearance angle when you are trying to plane end grain with a low angle block plane might not be the same as if you use the same block plane to work on an area of face grain. That makes some sense to me -- it seems that the amount of spring back would be different if the fibers are more perpendicular or more in line with the surface of the board.

That might also be another factor why curly woods are so hard to deal with -- those fibers are at constantly changing angles relative to the plane blade, which would make the ideal clearance angle constantly changing as well.

[Robby Tacheny]

Larry thanks for that excellent explanation. The bread slicing analogy is really vivid in explaining, at least for me.

So in your explanation, you'd say that the low angle may increase tear out since we'd essentially be ripping the wood or would you say that its not going to get a good cut because there is a lack of springing back? Also, do think this could be corrected by adjusting the mouth opening or maybe by just slowing down the stroke?

-R

[Larry Williams]

Wilbur,

Grain orientation certainly plays a roll in how much spring-back happens when the fibers are severed. It's just one of a number of variables. I don't know of any real scientific data on this. The study and examples from the study quoted in Leonard Lee's sharpening book basically ignores viscoelastic deflection, clearance angles and spring-back. I'm not a physicist and don't have the means to do any actual scientific testing, I only know about what I experience and see.

I do have a question for you. Wiley tells me those who use Japanese planes are, by necessity, versed in clearance angles. I've wondered if Japanese planes aren't intentionally set up to burnish the wood as they cut? With the low bed angles and critical attention to iron bevel angles, this may be possible.

I have serious reservations about the practice if that's the case but I can see where some might consider burnished surfaces better. It took me a while to figure out the planed surface I want is a uniform dull surface with all the pores of the wood standing open and as little damage to the walls of the pores as possible. Early on I thought the shiny burnished surface was what I wanted. On the Internet, I often read descriptions of planed surfaces and it sounds as if some people think like I did before I realized all the problems a burnished surface will create in finishing and joint strength.

[Larry Williams]

Robby,

A tight mouth can help reduce tear out but tear out isn't necessarily related to spring back.

I think tear out happens when the resistance to the cut is greater than the strength of the fibers or when the lifting action of the cutting geometry is greater than the strength of the fibers. I still have a lot to learn. One thing I have learned is that planes, especially 18th Century British wooden planes, are highly evolved and incredibly sophisticated. The tools have to be as sophisticated as the products they produce; Chippendale, Sheraton and others didn't make the masterpieces they did with stone axes.

Another important thing I've learned is not to try to redesign or change the traditional designs with out really studying purpose of the features I'm attempting to improve and the ramifications. Leonard Bailey, Justus Traut and the other 19th Century design contractors for Stanley were pretty bright and talented guys. Still, when they translated wooden plane designs to metal they missed a lot. They had a lot of years and money to improve and refine those iron planes but in so many cases they never got it right. I think a lot was lost in the translation.

I know I'm not nearly as smart as collective knowledge of all those that worked before me. I'm still trying to figure out what all they knew. The idea that I might make some big improvement has vanished. At this point, I think it would be arrogant to think I'll improve anything. I just want to figure out all I can from the evidence the early plane makers left behind.

[David Keller NC]

"I do have a question for you. Wiley tells me those who use Japanese planes are, by necessity, versed in clearance angles. I've wondered if Japanese planes aren't intentionally set up to burnish the wood as they cut?"

Larry - that may well be the case. From the little I know of Japanese woodworking, much of it is soft-wood coniferous species, and are left as bare wood (i.e., no finish), so a burnished finish might be highly desirable - such a surface would probably stay a lot cleaner on a door, for example, and japanese culture is obsessed with cleanliness. The examples in cabinetry books that I have on antique Japanese work seems to fall into two classes - either left au naturale or finished with about 30 to 40 coats of urushi laquer, usually tinted.

[Sam Takeuchi]

I know it's little off topic here, but let me share a commonly quoted wisdom among the miyadaiku - carpenters who specialize in temple and shrine building and restoration, that the ancient wooden temples and shrines are build with wood surface so polished that they resist moisture and exposure. I don't have any scientific evidence to back that up, but seeing original structural parts of 1000+ year old building still stubbornly resisting rain, sun and snow to keep supporting those structure, maybe there is some truth to that. I live in Yokohama and Kamakura (ancient capital of Japan, like 800 or some years ago) is right next door. They got temples and shrines left and right between the age of 400 and 1000 years old. Of course they do go through occasional touch up every couple of hundred years (no I wasn't around when they did it the last time), but if they take them apart, they build it back with the original parts unless original parts need to be replaced.

That's been one of major interests for me. What is it about them that's so different. But then I prefer to spend time working on wood than coming up with hypothesis and experiments. I shall wait until someone figure it out. :D

[Wilbur Pan]

I do have a question for you. Wiley tells me those who use Japanese planes are, by necessity, versed in clearance angles. I've wondered if Japanese planes aren't intentionally set up to burnish the wood as they cut? With the low bed angles and critical attention to iron bevel angles, this may be possible.

Hi Larry,

Well, I must be the exception that proves the rule because out of all the things there is to know about planes, Japanese or otherwise, I can easily say that clearance angle is the thing that I know the least about. ;)

As far as the burnishing thing goes, I'm going to stay away from the word "burnishing", and just go through what happens with a Japanese plane in use compared to a western plane. There is a key difference here, and whether you think the final surface is burnished kind of depends on what you think burnished means.

Here's a schematic diagram of the sole of a Japanese plane, greatly exaggerated, compared to the sole of a western style wooden plane:

http://farm4.static.flickr.com/3648/3560683461_2f5bfa7357.jpg

The key here is that the Japanese plane has a relief along the entire sole of the plane in back of the blade. There's also a relief between a small area at the very front of the plane, and a small area immediately in front of the blade. On a western plane, in contrast, the entire sole is flat.

There are two things that I can think of that could make the planed surface be different with Japanese planes. First, with a Japanese plane, because of the relief on the back part of the sole of the plane, the last thing to touch the wood is the blade. What you are left with is a surface fresh off the blade, and the blade only. With a western plane, the sole of the back of the plane does rub over the planed surface after the blade cuts the wood. So you could say that a western plane "burnishes" the surface of the wood more than a Japanese plane does.

On the other hand, the sole of a Japanese plane only touches the surface of the wood in two spots: the very front of the plane, and the area just in front of the blade. Compare this to a western plane, where more of the sole is in contact with the board. Because of this, it may be that the two touch points on a Japanese plane puts more pressure on the board because of the reduced area of contact, causing more compression of the wood fibers just prior to being cut by the blade. In this sense, you could say that the Japanese plane does more "burnishing" than a western plane.

I'll add in a third factor just to confuse things. Although this is definitely not going to be a universally true statement, it seems to me that for the final planed surface, typical Japanese woodworkers may get their plane irons sharper and take a finer final shaving than a typical woodworker using a western plane. This difference may also account for the "burnished" appearance of woods planed with Japanese planes.

Hopefully you can see why I wanted to avoid the word "burnished", since the appearance of a planed surface done with a Japanese plane, with its slightly shiny appearance, may not be due to burnishing at all. I can see why it might appear to be that way based on what boards look like after being planed with a Japanese plane, at least in my hands.

Also, I don't think that this is a softwood vs. hardwood issue. I see similar things when I've planed hardwoods, including cherry, white oak, walnut, and a few South American species, with Japanese planes.

[Robby Tacheny]

Briefly back to the original topic,

I tried the design I posted. It did exactly as people mentioned; Chatter and digging in at the ends. Two good things happened though:

1. The design of having the bolt go through the block and going to a nut held the blade very firmly. I couldn't even do fine adjustments, which kind of stunk, but the blade barely moved even when struck with "objects".

2. I found out that the blade bedded at 12* took very smooth cuts, even though that design never produced thin shavings.

Even though that design ultimately stunk, I had fun and was surprised how just cutting the scale drawing out (paper pasted directly on the board) on the bandsaw yielded a plane in about 5 minutes.

I definitely need to try making another plane soon. Maybe I'll take a shot at that 30* bevel down plane.

Can anyone give me a formula for calculating the actual cutting angle from the blade's bevel and the angle that the blade is bedded?

P.S. I didn't realize Larry Williams actually has a company making wooden planes! No wonder he is a wealth of information on this stuff. He is a pro! Larry, do you teach and if so are you teaching any classes near Maryland this year?

Now hopefully back to some really interesting and informative hand plane design theory. Thanks again everyone for the great advice.

-R

[Sam Takeuchi]

30 degree bevel down plane may have some problems as well. For the sake of discussion, ignoring the plane's body rigidity, 30 degree bevel down blade with 25 degree bevel will have only 5 degree clearance, which is quite insufficient for practical purposes. If you decrease the bevel angle to less, blade edge will be very very weak.

For bevel down planes, cutting angle is the blade's bedding angle, if the blade is flat and not tapered type (wedge shaped), and there is no back bevel.

In practical sense, 30 degree bevel down plane has many problems. First, like it was discussed earlier, a lot of 'meat' from the plane's body have to be removed to accommodate the blade, and weakens the body. Worse, a tapping a wedge in is enough to deform the body, worst, split the body. Second, a 30 degree cutting angle doesn't yield any special result a plane with cutting angle between 35 and 40 degree won't do. Third, bevel and clearance angle issue. You can grind the bevel to 20 degrees to make room for clearance, and add 5 degree back bevel, but then that would make your plane 35 degree cutting angle with a 25 degree bevel, totally making a 30 degree angle plane pointless.

Basically it comes down to all the things that have been discussed thus far. Back to the very first question as to why no low angle wooden planes sort of came to the answer by itself, didn't it? Plane is a very simple tool with long history (a couple thousand years at least), I'm quite certain what can be done with a wooden plane has been all tried regards to cutting angle and bevel up or down, what we see is the designs that didn't fail at some point in the history.

[Bob Strawn]

Another brave soul who learns by making failed tools! The knowledge that you glean is all the better understood for the failures!


Bob

[Bob Strawn]

Robby,

A tight mouth can help reduce tear out but tear out isn't necessarily related to spring back.

I think tear out happens when the resistance to the cut is greater than the strength of the fibers or when the lifting action of the cutting geometry is greater than the strength of the fibers. I still have a lot to learn. One thing I have learned is that planes, especially 18th Century British wooden planes, are highly evolved and incredibly sophisticated. The tools have to be as sophisticated as the products they produce; Chippendale, Sheraton and others didn't make the masterpieces they did with stone axes.

Another important thing I've learned is not to try to redesign or change the traditional designs with out really studying purpose of the features I'm attempting to improve and the ramifications. Leonard Bailey, Justus Traut and the other 19th Century design contractors for Stanley were pretty bright and talented guys. Still, when they translated wooden plane designs to metal they missed a lot. They had a lot of years and money to improve and refine those iron planes but in so many cases they never got it right. I think a lot was lost in the translation.

I know I'm not nearly as smart as collective knowledge of all those that worked before me. I'm still trying to figure out what all they knew. The idea that I might make some big improvement has vanished. At this point, I think it would be arrogant to think I'll improve anything. I just want to figure out all I can from the evidence the early plane makers left behind.

I think one can improve within the bounds of ancient collective knowledge. Every now and then someone rediscovers a method that was mostly lost or passed over. Every now and then someone combines elements from separate traditions and makes something extraordinary. For example, the low angle bed, high angle plane works brilliantly with really hard wood and difficult grain, but seems to be fairly recent. That said, without examining and returning to the body of work that has been evolved, innovated and even revolutionized by great craftsmen and thinkers who worked with and maintained these tools on a daily basis, reinventing the wheel is inevitable.

I have found in my experimentation, that often I have to reinvent the wheel, to even know why the wheel is there. The chip breaker was an innovation that spread quickly and almost universally. Yet many modern woodworkers see little value in it except as a cap iron. I personally set out to prove to myself it was a waste of time, and in doing so discovered how marvelous an innovation it is. With a sharp chip breaker just a couple of thousandths of an inch behind the blade, some of the most uncooperative wood starts to become a pleasure to work.

Planes are I think a good place to learn and innovate. You can make one in a day or less, and they don't cost that much to make. I can make a superb wooden plane faster and cheaper than I can tune up an old Stanley. The old Stanley may have the advantage in stability, but it will never communicate back to my hands the grain and cut information that a good wooden plane does. I will never be able to adjust the Stanley to the precision that I can adjust a wooden plane.

What I am aiming for, is the plane equivalent of perfect woodturning. Sometimes, when woodturning, everything comes together, Rake angle, clearance angle and blade angle line up and my approach to the wood is perfect. Then the blade feels like it is being pulled into the work and a perfect surface, not crushed, barely burnished, is left behind. The blade does not dull and long clean shavings fly.

When the angles are perfect, the cutting edge only touches wood at the start of the cut. So the blade really does not dull at all. My goal is to achieve that in the flat with a plane. It seems like it would be easy, since when turning you usually face grain wrong twice per rotation.

In chaper 4 of Mike Darlow's Fundamentals of Woodturning (http://books.google.com/books?id=51_32RO1dCUC&pg=PA33&lpg=PA33&dq=woodturning+clearance+angle&source=bl&ots=NmNQ0mFyA-&sig=y3XXe_wXftT5w9WzSgH4UeykfeY&hl=en&ei=HbkaSvqoONmJtgf724D7DA&sa=X&oi=book_result&ct=result&resnum=1#PPA32,M1), is one of the best discussions of clearance and rake angles that I have found. His ideal clearance angle is somewhere between 5 and 1 degree depending on how much wood you want to remove, and how smooth a cut you want.

To achive these low angles a bevel down blade seems to be the choice however, so low angle beds, despite the stability that they impart are going to cause more instablility at these angles.

The thought of a flush cut plane with a concave relief near the blade seems tempting, but it would not survive many sharpenings before it needed to be seriously reground. I think that a spear plane or even the right slick, would give much the same result and more stability.

I think it is worthwhile to try and innovate, even if it only helps you to appreciate the already existing body of work. My failures have taught me to be able to see many of the details on older planes that I would have otherwise ignored.

Bob

[Larry Williams]

I think one can improve within the bounds of ancient collective knowledge. Every now and then someone rediscovers a method that was mostly lost or passed over. Every now and then someone combines elements from separate traditions and makes something extraordinary. For example, the low angle bed, high angle plane works brilliantly with really hard wood and difficult grain, but seems to be fairly recent....

...What I am aiming for, is the plane equivalent of perfect woodturning. Sometimes, when woodturning, everything comes together, Rake angle, clearance angle and blade angle line up and my approach to the wood is perfect. Then the blade feels like it is being pulled into the work and a perfect surface, not crushed, barely burnished, is left behind. The blade does not dull and long clean shavings fly. ...

Bob

In a World where every plane is a smooth plane, I can see where one might feel the low bed angle/obtuse bevel angle might seem an improvement. The reality is that you've given up a lot of the function of a plane. Control of depth of cut goes away, it takes more effort and work to push an obtuse iron through the wood and to force the plane into the fibers to overcome spring-back, and edge life suffers dramatically. You end up with what's essentially a scraper plane. You've taken a specialty plane designed for end grain and soft woods and turned it into an even more specialized and limited capability scraper. Some people call this versatility but I see the usefulness of both as very limited.

I also understand what you're saying about turning but we're talking apples and oranges. The spring-back of the wood is also what allows you to take those long over the shoulder type of shavings on a lathe. The motor provides the force to overcome the spring-back and you use a lot of leverage on long tools to get into where the spring-back is what controls the depth of cut and eliminates the necessity to micro adjust the tool in thousandths at each revolution. I've only been able to get this kind of cut when turning wet wood but I suppose it's possible on dry wood as well. This also generates a lot of heat at the cutting edge and it's why turning tools are usually made of high speed steel rather than just normal high carbon steel. Another tool type that uses spring-back to control depth of cut is a spoke shave--the low angle ones like the wooden ones or the Millers Falls cigar shave. There are times this spring-back can be quite useful.

[Larry Williams]

Larry, do you teach and if so are you teaching any classes near Maryland this year?

-R

Robby,

We do teach and just got back from Kelly Mehler's school a couple weeks ago. We're also doing a couple workshops at Marc Adams School in July. That's all that's scheduled now and it's unlikely we'll add anything else. We have a lot of work we need to get done here.

[Chris Friesen]

In chaper 4 of Mike Darlow's Fundamentals of Woodturning (http://books.google.com/books?id=51_32RO1dCUC&pg=PA33&lpg=PA33&dq=woodturning+clearance+angle&source=bl&ots=NmNQ0mFyA-&sig=y3XXe_wXftT5w9WzSgH4UeykfeY&hl=en&ei=HbkaSvqoONmJtgf724D7DA&sa=X&oi=book_result&ct=result&resnum=1#PPA32,M1), is one of the best discussions of clearance and rake angles that I have found. His ideal clearance angle is somewhere between 5 and 1 degree depending on how much wood you want to remove, and how smooth a cut you want.

One thing that is very different between turning and planing is the speed at which the wood and blade meet. I think that the increased speed means that the compressed fibers may not have a chance to spring back fully before they're spun out of the way. I'm no expert on turning, but I've read that increased speed can give a smoother surface, and this may have something to do with it.

When hand planing, the surface speed is generally much slower.

[Bob Strawn]

One thing that is very different between turning and planing is the speed at which the wood and blade meet. I think that the increased speed means that the compressed fibers may not have a chance to spring back fully before they're spun out of the way. I'm no expert on turning, but I've read that increased speed can give a smoother surface, and this may have something to do with it.

When hand planing, the surface speed is generally much slower.

Increased speed does give a smoother finish, but not for the reasons that most folk think. Increased speed means more revolutions are made as you pass. If you control your skew well, you can get just as good a finish by passing across the wood at half the speed, as you get by passing normally at full speed.

A good, well tuned, Japanese middle finish plane will glide though cedar just about how I imagine the perfect plane would. No need for a smoother either. Sadly a knot that would be ignored by a York pitch coffin smoother will stop the same Japanese plane dead.
Bob