Friday, December 28, 2012

She'll be coming down the valley when she comes...

When math-geeks get into roofing carpentry, some strange things result:

Thursday, December 27, 2012

Fun with Funeboko

I often come across surprising things when doing research into Japanese carpentry. Looking for information on a particular type of joint, I then find some fascinating stuff on wooden bridges, or boat building. Well, I came across another kind of boat - a boat that won't float but also a boat that is a float. Lost? This post ties in bit with yesterday's effort, which looked at a Japanese tradition that takes place around New Years, in that it involves a Japanese traditional event marking a special time of year.

In Kyoto there is an annual festival which spans the entire month of July called the Gion Matsuri. 'Matsuri' means festival, and most towns in Japan have one at some point in the year.

Taking its name from Gion, a district in the city, the crowning moment of the festival is a massive parade of floats which takes place on July 17th called the Yamaboko Junkō (山鉾巡行). Yamaboko (山鉾) literally means mountain (halberd (). I imagine the word 'halberd' might be a new one to some readers - a halberd, or naginata as the Japanese otherwise call it, is an edged weapon on a long shaft, a bit like a spear, 1.5 to 1.8 meters (5 to 6 feet) long, used two-handed and often incorporating an axe or hook:

The Gion Matsuri began humbly enough as a purification ritual to appease the gods thought responsible for floods, fire, pestilence, etc. In 869 there was an outbreak of plague, and the emperor ordered people to pray to the god of Yasaka Shrine, located in Gion. At that time Japan consisted of 66 provinces, and so at the Yasaka Shrine people set up 66 halberds, stylized and decorated, in the Shinsen-en, a garden of the shrine. Next to the halberds were various mikoshi, or portable shrines. This practice was repeated whenever there was an outbreak of plague, and over time the event became more and more elaborate. Eventually the halberds would be mounted individually, or in groups, upon carts, called yama-dashi (山車):

Yama-dashi literally means mountain (山) on wheels (車). As they grew larger and more ornate, they grew heavier, and could only be moved about on large wheels. Today, many festivals in Japan feature yama-dashi, and these contraptions have become fabulously elaborate in some cases:

In the Gion Matsuri, the yama-dashi are collectively termed 'yamahoko' because of the historical tie to the halberd. The floats in the parade are divided into two types, one called simply 'yama' and the other 'hoko'. The hoko are fewer in number but are very large and grandly adorned, and are each topped with a decorated halberd - again, as a representation of the original provinces of Japan. Currently there are 9 hoko and 23 of the smaller yama floats. Hoko are on wheels, while the yama are typically carried.

Looking through the many floats used in the Gion festival parade, one in particular caught my eye: the funeboko, or boat-halberd float, which I first came across in a book on old paintings:

These are wonderful structures, combing many classic solid wood arts: wheel-building, boat-building, lacquering, gilt metal, and, yes,  roof work. These boats on wheels are also called funehoko.

The Gion Matsuri used to have a funeboko, however it has been sidelined since 2009 for some reason. It is a remarkable piece of woodworking:

On the prow of the 'boat' is a mythical bird called the geki (鷁). Apparently the funeboko was made to commemorate the birth of the 15th Emperor of Japan (named Ōjin), and is also believed to bring good health to expectant mothers. After Ōjin died his widow, Jingū, then spent three years in conquest of a promised land, which is conjectured to be Korea, but the story is largely dismissed by scholars for lack of evidence. Then, after her return to Japanese islands, the boy was born, three years after the death of the father.

I came across some basic framing schematics for this float:

In Kyoto there is also a museum with a display featuring the lower half of a funeboko:

 You can see to the left of the next picture a wall display showing various types of hoko and yama:

It turns out that Gion in Kyoto is not the only place in Japan where funeboko are paraded about. In Toyama Prefecture's Nanto city there is a spring festival called the Fukuno Yotaka Matsuri. The festival's big parade happens in the evening and largely features enormous andon, or paper lanterns, and a battles between different parade floats - literally like a demolition derby:

One of the parade vehicles is a stunning funeboko:

A close up of the geki on the prow:

The wheels are of a slightly unusual design and beautifully made:

The empress Jingū and a warrior ride on the deck:

I love that handrail!

The stern is only half there for some reason:

One more:

The roof combines a cross-wise irimoya (hipped gable) with a lengthwise karahafu (cusped gable). Just a stunning piece of woodwork overall.

Thanks for coming by the Carpentry Way! Hope you liked the boat ride today.

Wednesday, December 26, 2012


I've been fortunate to have had the experience of living in a variety of countries for extended periods. I was born in England, have lived in Canada, Japan, and now the Northeast US. I've also spent extended multi-month long spells in countries like Thailand, Australia, New Zealand, and Fiji. Each of those places leaves a mark on a person, changes you a little bit, and as an adult I can't claim to have an identity that is wrapped up with any particular nationality. I'm from nowhere and everywhere at the same time. I spent much of my late 20's and early 30's in a search for 'rooted-ness' somewhere, but that hunger seems to have subsided now. I am where I am I guess, and glad to be here.

In many countries in which I've visited and lived, some of the locals will tell me that their country and way of life is the best. It's a curious form of parochialism, though I do admire sometimes the surety of conviction which accompanies the sentiments expressed. The first time I visited the Berkshire region of Western Massachusetts, I met a timber framer named Jack Sobon, who assured me that, just as the sun rises and sets, the Berkshires were the best place to live on earth. He'd been a few other places, but there was nowhere like the Berkshires as far as he was concerned. That must be nice to have such certainty.

Every culture has it's pluses and minuses, and an internal propaganda system that keeps reinforcing certain messages about the validity and uniqueness of that cuture. Those who think propaganda is something connected only with warfare are sadly mistaken, for each of us swims like fish in a sea of propaganda every day. It's particularly pronounced in the US, where I am continually shocked to find from the media I receive bombardment from that there really aren't any other countries on earth worth paying any attention to, unless perhaps bombs need to be dropped on them. One American friend smirked and told me once that Canada was 'America Lite', while another asked me in all seriousness why he should give a damn about what went on in other countries. Land of the free, home of the brave, or so it is said. I've heard many Canadians also sneer and mutter about 'f*ckin' American's!", as if they were all the same somehow, thought the same things, supported the same ideas.

It's a human tendency I guess to stereotype and a means of ordering reality into more digestible chunks.

It was interesting living in Japan, a country, like Korea, of intense ethnic homogeneity. It's very hard for people living in cultures like that to have a real idea about what people of other cultures are really like as they have no opportunity to interact with them, and the messaging otherwise comes from the their TV, which usually features programming of a slant like "look how weird all these other people are." One time a Japanese colleague who'd had a drink or two asked me, "where are you from again?", as if was not quite able to keep it straight in his head. I told him I was from Canada. He then snarled, "ugh, Canada, France, it's all the same"(!).

It's a very interesting experience to be a white person and be on the other side of someone's stereotyped idea of what you are about.  I always value the chance I had to experience the other side, as I've lived most of my life as a white person in a land of white privilege, a privilege that is not always obvious, especially if you happen to be white....

That particular fellow, Mr. Kato, a slender fellow in his 50's, was civil enough until he'd had precisely two drinks, at which point he'd turn into Mr. Hyde like a switch had been flicked. When I first met him he expressed a liking for a pocket bilingual dictionary I was carrying. I told him that if I came across another one I'd get it for him. I kept an eye out for the little dictionary every time I went into Sendai city and visited the bookstore. It was never there to be found. Meanwhile, Mr. Kato continued his erratic behavior, to the point where I was starting to dread seeing him. He didn't seem to have a good impression of westerners in general. Several months went by and then lo and behold I happened upon that little dictionary in a bookstore. I picked up a copy, remembering my promise.

The following Monday morning I went into the office as usual, and there was Mr. Kato sitting at his desk, with the usual none-too-pleased look on his face - not uncommon among the salarymen class. I walked right up to him and placed the dictionary on his desk right in front of him, smiled and said, "There you go. Sorry for the wait." The expression on his face was something I will never forget - and Japanese people tend to conceal their emotional states rather well - his eyes opened wide, he stood up immediately from his desk, gave me a short bow, and then shook my hand. As he shook my hand, he said, almost as if he couldn't believe it, "Why, Hall-san, you're a man of your word". I was a bit taken aback, and said, "well, uh, glad you like the book, and again, sorry it took me so long to obtain a copy". After that, Mr. Kato was very nice to me indeed. Mr Hyde went away altogether. It seems that my small gesture had broken a fixed image in his head that all westerners were liars. I have studied a fair amount of the history between the western powers and Japan, and can well understand how he might have formed that impression of the hairy red-nosed barbarians. I was glad to have been in just a small, and accidental way, part of an interaction that changed at least a part of that for him. I certainly could not have attained that end by means of lecturing him on western virtues!

 So that was a point in my life where a strong impression was formed. Japan is a country of seasonal rhythms and cycles, and the events that marks those cycles are fairly formal and ordered. There's a comfort in that I found. One Japanese cultural practice that I have absorbed to a certain extent is the ritual of house cleaning prior to New Year's eave. This is called 'o-soji', or 'honorable cleaning'. I've always like the sense of starting the year with a clean slate and a clean house, though I must confess I have not always followed through on the house cleaning, though part of that has associated to living in rented accommodation. This year my wife and I live in our own house now, so I feel more reason to make the place our own and am following the o-soji practice.

Another way I am following this practice is what I call 'o-togi' - or, "honorable sharpening". I want to start the new year with all my tools sharp and ready to go. I have 80 or 90 edged hand tools, so it takes a while to plow through them all, and I am a bit more than 2/3rds of the way as of today. I also tune the wooden dai that associate to my planes, flatten the faces of the marking gauges, kebiki, file the auger drills, put a new blade in the bandsaw, make sure my planing beam is flat and clean, and, of course, clean the shop. A bit of this process of o-togi is akin to running up a sand dune, with a certain amount of downhill slippage, as I am using the freshly-sharpened tools for projects I am working on at the same time as I strive to get things in order. And that's kind of what it's about, a physical manifestation of wanting to collect my thoughts, come to a place of equilibrium, and clarity before the new year begins.

Maybe you might find a bit of o-togi a good thing for your shop and/or work situation too?

Monday, December 24, 2012

Getting your bearings with Festool

I've had the mid-size Festool router, the OF1400, since it was first released. I think I bought it in 2004. Festool's 1400 was the first mid-size router they came out with, and the first in a wave of improvements to their router line, which later saw revamps to the 1000 and 2000 models. In the last couple of weeks the bearings started making that special noise which told me their end was nigh. This goes beyond the end of the Mayan calendar my friends - we're talking about a calamity of epic proportions! Well, let's say I didn't want to wait and see just how far the bearings would go before imploding.

I went on Festool's parts catalog and located the two bearings which are used in that router. More specifically, they are as follows:

Lower bearing (large), part # 400635,  $20.75
Upper bearing (small), part # 401524,  $6.16

I decided to order the bearings direct from Festool rather than take them out of the machine and try and order them from a bearing supply house based on the numbers on the bearing seals. My reasoning here was that the bearings were probably proprietary items, and by ordering directly from Festool I could be sure that I would have the exact replacements needed without hassle.

As it turns, out, I was right and wrong in that supposition. The original bearings in the router are NKS bearings, made in Japan. The replacements I got from Festool are NKS from Poland. Slight difference, probably not amounting to much as the bearings are made on large automated machinery. I did get numbers off the bearing seals and called a bearing supply house in Boston, and sure enough, the bearings are proprietary and unavailable except from the OEM (Original Equipment Manufacturer) side. No surprise. At least Festool carries the parts still!

With bearings in hand, it was time to tackle the replacement, and I thought I'd photo-doc the process in case anyone else out there is contemplating the same task with their Festool router. I imagine the process would be similar for a lot of other routers too.

I hadn't had this router apart before and I do not have official Festool™technical certification to be doing this - not even the right sort of logo-emblazoned baseball cap or t-shirt even - but then again I don't generally care much about certification as a general matter. You have been warned. Fools rush in where angels fear to tread, etc.

To replace both bearings, you will ideally have the following tools:

Torx T-15 screwdriver or insert-driver bit
Torx T-15 socket, 1/4" drive, and 1/4" ratchet
Snap ring pliers
Drift (wooden or brass)
Small bearing puller
Small screwdriver or probe

I say ideally, because I did not have all the right tools, in one case because they were at home instead of my shop (snap ring pliers), and in another because I just didn't have them (small bearing puller). I didn't have the Torx T-15 bits either, but I acquired these at a local hardware store for about $10. Generally speaking, i would always advocate for having the right tools on hand, however I am fairly experienced at working on bearings, both on bicycles and trucks, so I often find a way to get the job done when the right tool is absent. But you have to be careful as using a less-than ideal tool for a task can set you up for making a mess of things sometimes. That's not going to happen here.

First off I flipped the router upside down, which, thanks to Festool's flat upper cover, is an orientation in which the router is quite stable. Remove the collet from the chuck. Then remove the Torx T-15 screws holding the black plastic cover in place:

Four screws undone, and the cover comes off:

Next you'll see a snap ring on the end of the router arbor, just above the ratchet gear. Here's where you get out the snap ring pliers. I had omitted to bring mine, so I carefully pried the ring off using a screwdriver and pair of needle nose pliers:

You want to be careful to remove the snap ring cleanly so as not to scar the outside face of the arbor.

The gear, which is used when you ratchet the collet tight with the collet wrench, simply slides off the arbor:

Then I flipped the router back to the upright position and removed the 4 screws holding the top cover in place:

It's like cranial surgery now, as we glimpse the 'brain':

This next part is a minor sidetrack, and not related to the bearing replacement task. I removed three more screws so I could separate the tool handle:

With the tool handle off, I could blow out dust and crud from the switch area:

Back to the separation anxiety portion of the job - flip the router upside-down again and remove the four long screws, also T-15 size, that ring the lower casting:

As you remove the last of these four screws, the springs in the plunge mechanism (one in each post) will push the motor housing and lower casting apart - lift and separate:

Here's a look at the upper bearing, a little tiddly thing, which is open on the upper side and has a rubber seal on the lower side:

This upper bearing was in decent shape, however my policy in such cases is always to replace it given the fact I have gone to the trouble of taking the dang thing apart. It's a $6 bearing and there's no point in making false economies.

To access the lower bearing, the ratchet mechanism is removed. It simply slides off:

Fortunately it's not one of those sprung mechanisms where things go flying when you pull it off - everything is tied together:

Now to the heavy lifting. I didn't know what sort of fit existed between the router arbor and the bearings, but I hoped it would be, at worst, a light interference fit and not require a press. I set the aluminum casting on a pair of blocks and then used a piece of hardwood as a drift pin to tap the arbor downward:

After a tap or two I could see that the parts would separate without going into an impersonation of Thor with the hammer, and a few moments later the arbor was off the bearing:

Then I set up the base casting again, right side up this time, and used a smaller wooden drift to tap the bearing down and out:

It also came out fairly easily:

You can see in the above photo that I have removed the bakelite base and insert ring from the shoe casting - neither of these steps is required for bearing replacement, I just wanted to clean in all the nooks and crannies.

I wiped the housing clean, got out the new bearing, and carefully tapped it into place in the housing:

The key point with bearing installation is not to bugger it up by getting the bearing going at an angle so that it binds up in the housing. You really want to avoid this! Just some patient tapping around the perimeter of the bearing (never tap against the seals directly), carefully observing what is going on and you should be golden. It doesn't take a lot of force to tap back in.

Now for the upper bearing. I hoped I might simply pull it off with my fingers, but no such luck. I tried putting the bearing in a vise and pulling on the arbor, but it didn't want to budge. I was trying these routes as I lack a small enough bearing puller. Time to improvise - I grabbed a metal plate which is a setting jig on my Makita portable chisel mortiser and clamped it to my planing beam:

I jammed the under side of the bearing into the 90˚ inside corner of the metal jig, and then, holding the arbor tight to the corner, used a drift to tap the arbor down. It took 3 or 4 taps and it was out:

That white plastic thing on top is called a solenoid ring and it has a copper band around it which is an electrical contact. When you reinstall the arbor, you will have to move a pair of spring-loaded contacts in the field assembly outward so as to allow this ring to slide past.

I reinstalled the upper bearing using a Bessey clamp, since it clamps nice and parallel:

Again, not much force needed here - make sure the bearing is fully seated however.

The next step is to slide the arbor back into the lower bearing. First I gave the surface of the arbor a visual inspection for any burrs, then a swipe with some emery cloth just for peace of mind.

Now, nothing keeps the lower bearing in place at this point except for a bit of friction, so you can't just tap the arbor down. If you did, the bearing will pop back out. So, what I did was take a hardwood block about the diameter of the lower bearing, drill a hole in one end that would allow the end of the arbor to slip inside, and then used the Bessey clamp to squeeze the assembly together:

If you look carefully, you will see the yellow hardwood block against the left clamp jaw.

So, the next thing was my camera battery ran out of juice, with its usual inimitable timing. Text alone will have to suffice from here on out. Sorry!

With the arbor re-assembled to the lower bearing, the next order of business is to put the plastic motor housing back on. If you haven't taken a motor out of a housing before, you may run into certain difficulties upon putting the parts together, for they come apart easily but require a bit of trickery to put back as one. Many people can run into all sort of trouble when trying to reassemble things, and often give up here. There's no need - it's all rational, you just have to observe closely and think it through.

As noted a few pictures previously, the white solenoid ring is meant to fit between a pair of sprung contacts, called 'brushes'. These brushes actually rub against the portion of the armature below the solenoid ring, an area referred to as the commutator. When the arbor was removed, these brushes sprung inward all by themselves, quite furtively if you ask me, and now block the path of the solenoid ring and commutator when they are pushed back into the same location. What you'll find happening during the reinstall is that the small bearing on the end of the arbor will readily slide in between the two brushes, and then the solenoid ring will bump into the lower surfaces of the brushes. At that point the arbor can enter no further - but it needs to! Bringing out the BFH or having a fit of rage here and throwing the works across the shop floor will do no good. What you have to do at this point is keep a light pressure on the arbor, holding the solenoid ring against the brushes, and then reach in with a small screwdriver or probe from the top of the housing and carefully push each brush back (outwards). By keeping light pressure with the arbor and solenoid ring, you hold the brushes from springing inward again. When you have them backed away far enough, the arbor will then slide all the way up - tah-dah!! I'll add that it's a little tricky, a bit of a juggling act, because the two main plunge springs are working against you the whole time. Don't be shy to recruit an extra pair of hands if you feel the need. Locking the router plunge mechanism is also helpful here.

*One additional caution: on this router there is a small wavy shim atop the upper bearing. When I removed the arbor it stayed in place against the plastic of the motor housing. I noticed it later on, pulled it out, and put a blob of grease on it so that it could adhere to the top of the upper bearing during the re-installation of the arbor.  I mention this because if it wasn't noticed there is a chance it could crash the party, so to speak, when trying to wiggle that solenoid ring past the brushes.

With the arbor all the way up, the four long screws are reinserted and tightened. Check now that the arbor spins freely. Slide the ratchet mechanism back in place, using a screwdriver to push the sprung bits back so it will drop all the way down. Replace the ratchet gear and the snap ring. Replace the plastic lower cover and the router collet. Test the pluge action to confirm it is smooth. If it isn't you'll be taking things apart again. It should be fine though, so next plug the router in and give it a test run, working the speed control up and down. All should be good. you'll be a new man or woman and feel like standing under a waterfall in Ireland and washing yourself all over with scented soap

My router sounds like new again with the new bearings so I am very pleased with the outcome. It's a fairly straightforward job requiring basic tools. Next time this job come up I'll make sure to have those snap ring pliers on hand.

Thanks for coming by the Carpentry Way. Merry Christmas to those of you who celebrate pagan rituals. Remember, according to ancient Roman law, during this period gambling and dice-playing are permitted for all, even slaves.

Saturday, December 22, 2012

Chasing Transcendence

Several years ago I became aware of the work of Kintaro Yazawa, who, according to a 1986 article in FWW (issue 61), had taught furniture maker Alan Peters about the twisted dovetail joint, or nejiri ari gata. The name of the joint in Japanese, I might add, terms what we call a 'dovetail' in the west an 'ant-shape'. The 'twisted ant-form' joint then.

A while later, Yazawa had re-established himself in Japan as a specialist in joinery and makes small presentation boxes and pieces of furniture incorporating technically difficult or 'impossible' looking joints. A few years ago there was a second article in FWW by Yazawa illustrating a couple of his methods and this seems to be the point where a bunch more people, in North America at least, became aware of the craftsman and his marvelous work.

I've had pictures of a couple of his pieces on my computer, in a special folder, for several years now. Like Yazawa, I love joinery and also share a liking for puzzle joints of all kinds.

There are various basic forms of 'puzzle joints'. Some are made to be puzzles which just so happen to be wooden, though they could be in other materials. The other is a form of wooden joint which is assembled by apparently impossible means.

Of the former type of puzzle, there are what are known as karakuri. These have long been known in the west, as examples were brought over from Japan since the late part of the 19th century. Here's a very simple form of karakuri puzzle box:

There are boxes like this with hundreds of moves required to get them open - one that I've come across requires 1536 moves!

Another popular type of puzzle involves interlocking sticks - these are termed kumiki in Japanese, and ’burr puzzles’ in English-speaking countries. Here's a typical example sitting on my desk:

In the above types of puzzles, while the mechanism by which the puzzle goes together may be mysterious at first - or for a long while, as the case may be - with puzzle joints in woodworking, the joints cannot often be readily separated, either because they are incorporated in a larger structure, or because they are glued together, or because the assembly of the joint is such that it will not permit dis-assembly. There are also a small number of joints in which dis-assembly is possible, but difficult, in which case they are not significantly different than the wooden puzzles above.

The key difference, it appears to me, is that puzzles are usually readily recognized as puzzles - like the burr above, or are quickly found to be puzzles, as one might readily discover when trying to open one of those puzzle boxes. You know it's a box, and there might be something inside, but how does it open?

With wooden joints which are puzzles, I would say that unless one is a woodworker who does joinery in solid wood (a minority of woodworkers) and knew how such joinery goes together, one likely wouldn't notice anything odd about a puzzle joint. It's the ultimate in stealth I suppose, however the message, as such, is more or less lost on most who see the construction.

A great case in point would be the Ōtemon, a gate at Ōsaka Castle:

Here's a view from the inside looking out:

Both gateposts have unusual 'rot joints' - these are spliced in replacements for the bottom few feet of a posts that have rotted out.

A closer look at the joint on the post seen to the left in the above picture:

Here's one side:

And the other:

Ignoring the other stuff going on at the connection, such as the missing plug part way into the front dovetail (to cover a metal bolt anchoring the joint to a lateral tie to the rear), and the end of a diagonal brace sticking out above the joint, we see a splice in which two opposing faces are dovetails, and two opposing faces are like a sword tip, or mountain peak if you prefer. If your response is 'so what?' perhaps take a moment to consider how such a connection might assemble in wood....

I would guess several million people walk past that gatepost every year, but only a tiny fraction notice anything unusual about that joint. For carpentry geeks of all stripes however, this is a delight! The Ōtemon-splice is famous in Japanese carpentry, and also goes by the name of basara-tsugi. Lots of Japanese carpenters know about it and have incorporated it into their work. Here's an example of a freshly-installed one:

I just finished cutting one for a client, as on of several joinery models I am making. I might add that there are many other forms of rot-splice joints, and several of them incorporate a 'how'd they do that?' aspect. I'll save that for another blog entry some day. I do detail the mechanism of the basara joint in the Volume III essay of the TAJCD series, BTW.

Getting back to Yazawa, some of his joints are mysterious from the aspect of being incredibly hard to execute, like this one:

The assembled joint:


Other joints he makes however feature a means of assembly which is, to put it mildly, hard to determine. Case in point is this box, which employs what Yazawa calls a 'key hall' joint on the Japanese portion of his site (I'm sure he means 'key-hole' joint):

Another view of the corner of the above box:

A view from the inside reveals nothing special, which is itself special in this case:

That joint is but a warm up of sorts, however, for this one, a joint that Yazawa terms the 'transcendence joint':

A look at an 'impossible' corner:

Please be clear that all these joints are done in solid wood without recourse to veneering or gluing pieces together. I've read some online discussions where people put forth theories involving such ideas, and they are false.

I spent some time working on the joint for the 'key-hole' joint above, thinking it was an easier puzzle to crack than the transcendence joint, and thinking they may have some commonalities in their mechanism.

I emailed Yazawa several years back asking him for a hint, and he replied that the secrets were going with him to the grave. Okay, well, then, I see how it's going to be....

So, I left the puzzle on the digital 'shelf' of my computer, occasionally bringing it down to look at it again. Recently I got a bit more fired up about it and managed to solve the key-hole joint, working at it with a 3D drawing. I figured out an initial solution involving pivoting moves. I shared my drawings with Yazawa, and he gave me all sorts of encouragement (indicating that I had it wrong, but keep trying). No hints of course, or even a nod that I might be on the right track, which I don't mind. I don't want the solution simply handed to me on a platter. When I found a second solution to the problem, and the only solution (probably) which can work for a 4 sided box, I sent him those drawings. He hasn't replied and it has been a week, so not quite sure what to make of that. Maybe he's annoyed. I won't presume to reveal the secret of that joint here - if it intrigues you, put some time in and try and solve it yourself.

The transcendence joint is next in my sights, and it is proving to be quite tough to solve so far. I'll keep plugging away at it however and hopefully will also transcend the problem at some point myself.

I think that the study of karakuri puzzle mechanisms of all kinds will be very helpful for solving such mysterious joints, and for creating new ones.

Thanks for coming by the Carpentry Way.