Tag: Japanese handplanes

Japanese Handplanes Part 7: Bedding the Blade – Correcting Some Common Misunderstandings

Rokuza the carpenter adjusting his plane close by old Edo’s Nihonbashi while thinking wistfully of his lover, no doubt a great beauty and dab hand with a sharpening stone. Mount Fuji can be seen in the background.

Whether made into a wooden pillow or table, wood with excellent fine grain is a guarantee of splendid poems, and the composition of perfect documents.

~Liú Shèng (d. 113 BC), “Ode to Fine-Grained Wood,”

s Gentle Reader is no doubt aware, quality Japanese handplanes, like those we are deeply honored to share with our Beloved Customers, are simple tools with excellent blades but relatively few parts compared to its Western counterpart, the Bailey-style metal-bodied handplane, and therefore present fewer opportunities for dull blades and misadventures.

Sadly, there is much confusion on the subject of how to setup and maintain such tools. Indeed, the path to enlightenment in this regard is blocked by mist-bound mountain passes of ignorance and hedged about with bottomless pits of boiling BS that prevent many noble woodworkers around the globe from gaining a true understanding of their tools.

In this article, your humble servant will attempt to untangle some of that confusion, dispel some of those dark mists, and using pump and shovel, fill in a few of those roiling pits. So please don your headlamp, put on your rubber mud boots, shoulder your shovel and join me as we travel a little further along the path.

The Two (problematic) Methods

In Part 4 of this series we briefly discussed how to fit the plane’s wooden body to its blade. Such a happy wedding it was! I dance like a gleeful baby goat in new pajamas whenever I view the photo album.

While the explanation in Part 4 was not meant to be comprehensive or exhaustive, just today a Gentle Reader posed some perspicacious questions the answers to which may benefit others, and so with fear and trembling I make this addition to the series. Your noble indulgence is requested.

The Gentle Reader’s question was as follows:

“I have encountered two schools of thought about fitting blades. The first is that the blade should be bedded more or less uniformly to the dai (i.e.: with heavy contact, ideally across all points ). The second, which I have seen more experienced practitioners espouse and teach in classes, is to maintain contact across a U-shaped area of the bed, under the side grooves and along the mouth, and removing significant material from the rest.”

Your humble servant is aware of and has even tested these two hit-and-miss methods, and while general befuddlement is the rule in all human endeavors, I was simply shocked, shocked to learn there are lost souls who boldly brag in their befuddlement and actively promote either. Call the gestapo and round them all up!

Casablanca jokes aside, please humor your dimwitted unworthy servant as I attempt to perform a brief, summary, comparative analysis beginning with the conclusion thereof because I was trained to begin any analysis that way, and I find it most helpful.

As mentioned in Part 3 and Part 4, when setup and maintained properly, the forces that secure the blade in the wooden body (dai) are solely friction acting on the top and bottom faces of the right and left portion of the blade contained inside the two retention grooves cut into the sidewalls of the blade opening, NOT friction between the back of the blade in general and the bed of the dai. Ergo, neither of the two methods listed above are useful IMHO.

This is the essence of the matter, but since many still struggle to understand, a deeper analysis is called for.

How did this worm of confusion gnaw its way into the brains of woodworkers to take up squatter’s rights? Some dark malfeasance by Murphy? Perhaps, but dollars to donuts I’d wager it springs from a difference in traditions.

But this begs the question: what traditions or knowledge or experience regarding Western planes could engender such misapprehension about Japanese planes? Hmmmm.

Perhaps it’s the knowledge of and experience dealing with the potato-chip thin blades of Western planes that rely on screws, complicated linkage mechanisms and high pressure between the blade and its cast-iron or ductile iron bed in order to retain and adjust, and to prevent them from vibrating/chattering in-use?

Oh oh oh! Could it be that those accustomed to Bailey-style planes feel compelled to deploy similar chatter-prevention measures in their Japanese planes?

Or could it be brain worms, maybe?? Don’t sneeze on me, pleeze.

I’m clueless about the source of these repugnant brain worms and the reasons behind this widespread befuddlement, but what is not fuddled is that the Japanese plane has an entirely different blade and body that relies on entirely different retention and adjustment systems, and experiences entirely different forces acting in entirely different vectors, and so requires entirely different solutions.

Realization of these facts is necessary and wonderous, but even the blessed defuddled few will experience grief if they attempt to indiscriminately apply setup and maintenance solutions effective for Western planes on Japanese planes. In fact, I’ll go one step further: the misapplication and/or co-mingling of Japanese and Western setup and maintenance techniques causes many entirely avoidable problems.

These points are worthy of further consideration, but to ensure we are singing from the same sheet music, let’s take a quick side-trip in our comparative analysis to examine the Bailey-style plane.

The Bailey-style Handplane

The Bailey design includes an arched cap iron (aka “chipbreaker”) and a flat cutting iron (aka “blade”) attached to each other by a screw “springing” the blade slightly, and forming a single unit. This is good and necessary considering how thin and prone to vibrate the flimsy blade is. 

The lever cap, using a clever cam mechanism, applies forces to the cap iron acting through the lever cap screw flowing into the frog, thereby clamping the assembly comprised of blade, cap iron (aka chipbreaker) and lever cap to the frog. Lots of caps…

The frog, in turn, is attached to the body via two machine screws, in the case of standard Stanley planes as shown in the illustration above, or a more complicated arrangement of hold-down pins and locking screws in the case of the old Stanley Bedrock planes and the modern Lie-Nielson reproductions.

A lateral adjustment lever attached to the frog is used to shift the blade to left or right to correct the angle of the blade through the mouth.

A lot of parts providing many opportunities for Murphy to twerk his spotty bottom with glee and swill celebratory tequila shots with cocaine chasers.

Please note that it is the frog, not the plane’s metallic body, which supports the blade, and that tolerances between the blade and its froggy bed must be fairly tight and apply fairly uniform pressure to keep the potato chip cutting without twisting and vibrating.

Too make matters worse, despite shiny surfaces and pretty paint jobs, the manufacturing tolerances of complicated Bailey-style planes are often sloppy to the point that achieving precise work without a lot of tuning is difficult.

But despite these failings and their poor-quality blades nowadays, Bailey planes will often still take shavings, and so, to the amateur, they appear to be working well. Who was it who said “ignorance is bliss?”

By comparison the Japanese plane is the essence of simplicity, and much less likely to misbehave, but on the other hand, it is comparatively less tolerant of improper set-up and shoddy maintenance. If the blacksmith has done well, these are primarily woodworking tasks and therefore the job of the craftsman that owns the plane.

The Japanese Handplane

The blade of the Japanese plane is no sea salt and vinegar snack but a comparatively thick blade which includes a lamination of dead-soft iron that is highly effective at preventing chatter. Please, don’t take my word, just try and make it vibrate.

I suggest you study the metallurgy, shape, tapers and curves of the high-quality Japanese plane blade as described in Part 3 of this series to better understand the details of this deceptively simple but highly sophisticated part to confirm the truth of my babbling. After a careful review of the information provided in Part 3, if you imagine any of these details to be less than carefully planned and entirely functional, then I prescribe immediate, thorough and frequent applications of massive quantities of Idiot-be-Gone salve sufficient to gag Beldar and Prymaat. Sorry we’re entirely out-of-stock right now, but a squirt or two of Windex may be somewhat efficacious and improve symptoms of halitosis at the same time.

The blade, therefore, doesn’t need to be clamped, damped or supported by a cast-steel frog, nor does it need pressure on its back, much less near the cutting edge, to function perfectly, despite what some befuddled folk imagine.

In the case of the Japanese plane it’s useful to have more-or-less uniform contact between the blade’s back and bed to help keep the blade aligned in the dai and to aid adjustment, but unlike the Bailey plane, more than just a tiny bit of pressure serves no useful purpose at all, while high pressure is definitely detrimental.

Allow me to restate. The blade does not need pressure between its back and the dai to prevent chatter or to make it work. Period. Anyone who says otherwise has their engineering mind and scientific eyes stuck in Bailey land, a common ailment. Another bucketful of ointment may be called for.

Accordingly, there is no need for either pattern of pressure between bed and blade outlined in the two questions above.

In fact, if you pay attention to the shape of the bed of a quality Japanese plane, you will observe that the cross-sectional area of the wedge-shaped volume of wood that forms the bed decreases, indeed thins, moving from the top surface of the body towards the mouth, making it progressively weaker and less-resistant to deflection when pressure is applied by the wedge-shaped iron and steel blade to the bed.

The weakest point of the wooden ramp that forms the bed and supports the blade, therefore, is located near the mouth where it is thinnest, so pressure here can be especially problematic. This blows the “U” method of fitting the dai to the blade entirely out of the water.

The indisputable result of this geometry, combined with the engineering properties of wood, ensures that any high-pressure forces occurring anywhere between the blade’s back and the bed will distort the dai downwards away from the blade creating a protruding sole. But how much is too much?

  • No pressure = no problem.
  • A little pressure = little deflection = little or no problem.
  • A lot of pressure = large deflection = large problem.

Please grasp this concept with all your might with both horned heels, both clawed hands, both thorny arms and all your needle-like teeth because excessive pressure and the resulting excessive deflection of the sole will cause a plane to cut erratically and even stop cutting entirely, depending on the depth of the blade’s projection through the mouth and the body’s fettle.

If you ignore this warning and your planes fail to function consistently, which they will, please check this area carefully to save your tool and maybe even your sanity.

Concluding the analysis, what we need are nice pinching forces acting uniformly on ONLY the back and face surfaces of the blade (not the side edges) contained INSIDE the retention grooves, usually a strip about 4~5mm wide. And we need only the lightest contact and practically no pressure between the blade’s back and the bed. Anything more is pointless and often counterproductive.

Teachers, Tubers and Trolls

I don’t care how much you paid for the book, video or class, or how famous your teacher or PoopTuber may be, anyone who argues with these obvious facts is simply bragging of their ignorance of engineering principles and/or lack of practical experience with Japanese handplanes.

Personal opinion and preference is fine, and like fundaments, we all have at least one, but not all warrant a sniff.

I’m confident these last few paragraphs will offend some self-taught teachers and all self-designated geniuses. Any Gentle Readers among that gaggle of silly geese need not send an invitation to your birthday party. All others are welcome to attend mine.

As always, RSVP + PWP (please wear pants).

YMHOS

If you have questions or would like to learn more about the tools we sell, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or the CCP’s IT manager for Hillary’s bathroom server farm and so won’t sell, share, or profitably “misplace” your information. If I lie, may I fall face-first into a bottomless pit of boiling BS.

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Japanese Handplanes: The Adjustable Chamfer Plane

An old-fashioned adjustable chamfer plane. It lacks the convenient screw adjusters of the modern version, but it does a fine job nonetheless.

The edge separates the average from the exceptional.

Anon

In this installment in our series of articles about Japanese handplanes, your most humble and obedient servant would like to present one of the most useful woodworking tools of Japan, the adjustable chamfer plane.

Terminology

In Japanese this handplane is called a kadomenganna, written 角面鉋 in Chinese characters. “角Kado” means “corner,” “面 men” means “surface,” and “鉋 ganna” is a tweaked pronunciation of “kanna” which means “handplane.” Since it’s mainly used to cut 45˚chamfers on the 90˚ corners and edges of wooden objects, and being fully adjustable, I choose to call it an “adjustable chamfer plane” in English. I beg Gentle Reader’s kind undulgence.

Side view of a standard kakumenganna chamfer plane.
Top view of a new kakumenganna chamfer plane. Of course, the 2 Chinese characters stamped on its leg read, top to bottom, “kadomen.” This version has a slightly skewed blade to reduce tearout. The blade and chipbreaker are mounted in a movable block connected to the right and left legs by a tongue and groove joint forming what I call a “carriage.” These two legs serve as fences which can can be opened or closed, using the bolts and nuts seen, to adjust the gap which determines the width of the chamfer to be cut. You can see two graduated brass bars inlet into the legs to help with alignment and in judging the gap.

Components

Your humble servant’s old and well-used chamfer plane. The block which houses the blade is located to the left of the image with two fences I call legs in the middle. Together these form a “carriage.” The horizontal line in the center of both legs was cut by the blade as I shifted the carriage right and left.
A side view of the block (left), the underside of the legs (center), and back of the blade (lower right). The cedar block (upper right) is used to adjust the block and remove the blade in combination with a smallish wooden mallet.
You can see the brass mouth reinforcement inlet into the sole of the block. This is very important for a chamfer plane that will see heavy use shaping various materials. Although it has become dim over the years, the line drawn across the legs indicate the position of the blade, an important point to watch for when starting and stopping some cuts.
I’m sharing these photos of my old plane as a practical example. When new, the edge of the blade’s head had a sharp burr which I filed down for comfort. This is a type of plane that does not take ham-handed abuse from fools well. Please note that, unlike most such planes used by less knowledgeable folk, the head of the blade is not mushroomed and the blade’s face is not dinged. Why? I have never struck this plane, purchased in 2009, with a steel hammer, not even once. For the same reason the wooden parts, while discolored and less-than-perfect through much use, exhibit none of the deformation, cracking, splitting, chipping and denting planes adjusted using steel hammers always do. This is the fruit of wisdom shared with me by an ancient plane maker on Shikoku island far back in the mists of time (ツ). Rejoice! You and your planes are now free of the chains of ignorance.

The modern Japanese chamfer plane, which is the only type we currently carry, is comprised of a small block of white oak housing a relatively narrow laminated steel blade as well as a chipbreaker.

This block (aka “dai” 台 in Japanese) fits into a “carriage” comprised of two sticks of white oak joined by steel and brass nuts and bolts held in place by captured wing nuts. The block fits tightly into grooves cut into the carriage so the user can shift the block and its blade right or left as necessary to either accommodate the required width of cut, or to expose a sharp portion of the blade when one portion becomes dull.

The width of cut can be quickly adjusted from zero to 24mm wide by rotating the two wing nuts smoothly opening or closing the gap between the two legs of the carriage. Eazy peazy Japaneezy.

The most common variety of chamfer plane has a blade inlet into the block with its mouth oriented 90˚ to the direction of travel. The next most common variety has a blade that is slightly skewed to produce a smoother cut with less tearout. We carry both types.

Standard chamfer plane (left) and skewed chamfer plane (right).

Uses for the Chamfer Plane

Japanese chamfer planes are essentially molding planes with two mutually adjustable fences used to produce chamfered edge treatments on wooden objects. Molding handplanes typically have blades ground to specific profiles intended to plane the edges and corners of wooden objects. Some produce purely decorative, curved shapes such as the Roman ogee, while others produce functional and/or structural edges such as tongue and groove joints.

But 45˚chamfer planes have a simple straight blade intended to produce a flat surface at 45˚ to the adjacent faces of the board. However, some varieties are used to cut chamfered surfaces at various angles.

The ancient, attractive and functional lambs tongue chamfer stop use in wood, stone and ivory.

Once cut this 45˚ chamfer is often left as-is in many projects and especially structural wood members as a finished surface. It tends to make make the board, beam or column look more refined. It also prevents the corners from being easily chipped or torn off, a safety feature in some cases. A hard 90˚ corner in exposed wood is seldom durable and given time and abuse often becomes ouchy.

Nowadays the electric router has sadly replaced practically all molding planes, and although I haven’t used an electric router in 15 years or so, I won’t deny they are very useful tools even if they are ultimately more expensive, destroy the user’s inner peace along with their hearing, fills their lungs with dust, chews their fingers, leaves unsightly ripple marks on the wood, and goes through expensive bits like Homer Simpson does donuts… mmmm donuts.

But routers are not all evil, for they do have the advantage of being able to treat the inside surfaces of curved edge whereas the plane under consideration can only do straight edges and outside curved surfaces. Of course, it’s possible to make chamfer planes that cut inside curved surfaces like those used by coopers (barrel makers).

The Joinery Chamfer Plane

An old but unused chamfer plane for kumiko and cabinet sash with wooden adjustment screws.
Chamfers cut on standard kumiko. Being much less than 45˚, this angle gives the kumiko a refined appearance.
Even thinner kumiko with yet a different chamfer angle. Assembly of such continuous kumiko can be challenging.

As mentioned above there are a very few varieties of specialty chamfer planes long used in joinery to produce different angles. Why angles other than 45˚ you say? Ah, perspicacious as always. Well, a simple 45˚ chamfer sheds dust and water well, but in the case of windows, doors and shoji, for example, it removes too much wood weakening mullions and kumiko to the point of structural frailty, and often appears less refined to boot. Sadly, these are no longer being made and are hard to find.

Advantages

As I suggested above, the chamfer plane produces lots of of fragrant shavings but little unhealthy dust. It won’t make your fingers bleed, and won’t grab your clothes.

Indeed, I can still remember the night I was working late on a custom door using a 15amp 1/2″ collet electrical plunge router with a long 3/4″ Ø carbide bit to cut deep mortises. This was before the days of automatic mechanisms to stop the spinning mass of copper and steel that is the armature when the power switch is released. Suddenly, out of pure evil malice, the howling beast grabbed my loose soccer jersey nearly chewing a hole in my chest! Ah, good times!

The chamfer plane works slower than a router, but it won’t gouge your work if you loose concentration for a second, it won’t make burn marks on your boards, or cause She Who Must Be Obeyed to lob complaints about racket and dust at you like barbed arrows smeared with toxic tree frog goop. To the contrary, it’s an efficient, well-behaved, forgiving, even gentle tool, one that produces a flat, sometimes even shiny surface with perfectly crisp edges on wood instead of the burnt and pounded washboard surfaces violent routers often inflict.

Another advantage to the Japanese chamfer plane is its relative light weight and small bulk, compared to the bulky, clunky, mind-numbing electrical equivalent. Much easier to store in the toolbox or work apron. And of course, being a simpler and more honest tool, it’s much less likely to be commandeered by Murphy’s painful pointy purple pecker to wreak death and destruction.

And of course, while its blade does need to be sharpened occasionally, the chamfer plane will provide many decades of continuous service without having to purchase a single nasty spinning bit from the CCP.

While it incorporates a couple of bolts, it has no cord and needs neither piggish chargers, nor poisonous batteries. It is a tool in total denial of the principles of planned obsolescence, predetermined service life, corporate profitability and hidden environmental destruction advocated by the high priests of profit at the Harvard School of Business and Monkey Butts. One might even say it’s a pragmatically contrarian tool. But whatever you choose to call it, I call mine a faithful servant, indeed, a friend.

How to Adjust

Adjusting the width of the chamfer is accomplished by first loosening the two wing nuts on the bolts. If increasing the width of cut, continue to spin the wingnuts out. Then once the gap between the legs is the right width, set the locknuts to the right position, check that the legs are parallel either by using a caliper to measure the distance between the legs at the front and rear of the carriage, and lock the legs in place using the wingnuts.

These planes have graduated brass indicators inlaid across the front legs and another across the rear sides of the carriage that are useful for rough use, but should not be relied on for precise settings.

Alternately, you can rest the plane on the corner of the board and examine the gap between the legs and board. If a significant gap exists, simple adjust the wing nuts until it closes.

When considering the purchase of a chamfer plane, be sure it has a brass plate inlaid in front of the mouth to prevent wear at this high-pressure area.

When you receive your chamfer plane, the block should fit tightly into it’s carriage. This will loosen with use, or applying a bit of oil or wax on the tongues of the block will help. Worse case, use a metal file and a bit of 220grit sandpaper to lightly adjust the width of the tongue.

When removing the block from the carriage, please do not use a steel hammer to strike the block. A wooden mallet works well, but holding a small block of softwood, like the one shown in the photo above, as a cushion between hammer/mallet and plane is best.

A Professional Technique

Quite frequently we need to cut a stopped chamfer, whether it’s for a lambs tongue chamfer detail or where stile meets rail in joinery. In any case, when we need to judge exactly where the blade of our planes starts and stops a cut, it helps to make marks on the chamfer plane’s legs indicating the location of the cutting edge, and corresponding pencil marks on the workpiece, to help with starting and stopping chamfer cuts in the right place.

Summary

The Japanese kakumenganna 45˚chamfer plane is a lightweight, compact, safe, healthy, cost efficient, environmentally sustainable and pleasant tool for quickly cutting chamfers in wood without leaving ugly ripples or burn marks on the wood, or ruining our hearing, or filling our lungs with sawdust. I couldn’t work without mine.

YMHOS

Link to Pricelist and pics of the Japanese Adjustable Chamfer Plane

Other Posts in the Japanese Handplane Series:

If you have questions or would like to learn more about our tools, please click the “Pricelist” link here or at the top of the page and use the “Contact Us” form located immediately below.

Please share your insights and comments with everyone in the form located further below labeled “Leave a Reply.” We aren’t evil Google, fascist facebook, or or the IT manager for HRC’s bathroom server farm, and so won’t sell, share, or profitably “misplace” your information. If I lie may all my chamfers chip and become slivers in my fundament

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