Friday, June 24, 2011

Comings and goings

It's been a few days between postings and seemed like a good time for an update. I was down in Washington D.C. for the past 5 days, where I had the opportunity to spend some full days in the Library of Congress. It's a great library with 1.5 million volumes, but more than a little frustrating as far as libraries go. You see, almost all the books are down in storage, and you have to search for them using an online system. Once you've found the book you want, then you have to fill out a slip of paper detailing the book, your name, address, and library card number, etc., using a stubby blunt pencil, and hand that form in to the desk clerk. One form for each book. Why the computer cannot be used directly for this is a mystery. Further, each reading room in the library has its own unique request form, also for no sensible reason I can ascertain. In some cases I had filled out forms in one room, discovered the books needed to be requested from a different reading room, went over there only to find I needed to refill out the info on different forms. You get the idea. And the library, composed of three main buildings, is like a labyrinth inside, and even after three visits there I still get lost in the catacombs.

Once the request form(s) are submitted, you have to wait 60~90 minutes for the book to appear. Sometimes you wait that long and all you get back is a notice saying 'book not on shelf', which could a bunch of things, none of which are known to the desk clerk. Sometimes the clerk omits to tell you this and you have waited for more than two hours wondering where the damn book is, only to find out, 'not on shelf'. You'll order a 2-volume set, one volume of which is plates and one of which is text, and you'll get one back. The other one, 'not on the shelf' though you would think the two volumes would be side by side (?), and of course, in these set ups, common to books pre-1950, if you have only one volume you are screwed as far as making sense of things. The LOC is a place filled with government employees in secure jobs moving at a relaxed pace and generally not too concerned with the situation, if you know what I mean, overflowing with tourists moving about in massive mobs on tours of the building. The reading room themselves are largely devoid of researchers. Only members of congress can actually take book out of the library, though i serious am beginning to wonder how often this ever happens (or just how literate such members may be :^)). There's a special reading room for members of congress only, luxuriously paneled like some sort of high end legal office, and I've never seen anyone actually using it in the times I've been there.

Anyway, it became quite an exasperating process after plowing through more than 100 books, so I abandoned ship after the second day. I think I'm done with that place. I did find some good Japanese material, which I photocopied, and was most impressed by the works of Peter Nicholson, a 19th century writer on the building arts. I researched further on the origins of the word 'gambrel' and was unable to find much reference to it before 1900. The old term for both 'gambrel' and Mansard roof forms, as they are termed in English-speaking countries today, was 'curb roof'. Mansard and Curb roof were synonyms. Today, the term 'curb roof' appears to have all but disappeared for some reason. Anyway, my research on this matter is on-going.

Back home now, I am dealing with a whole bunch of emails (I'm sure most of you can relate to this situation). I guess some people who receive lots of email each day are having to declare e-mail bankruptcy if they go off somewhere without access for a few days. I can understand! I'm only now coming up for air.

Today I sent out the 3rd revision of the volume I and II essay set, so if you are one of the people who purchased that set, please check your inbox.

There has been a lot of interest and excitement about the online carpentry study group. So far 15 people have signed up, which is awesome!! This study group will be using the material brought out in Volume II of the Art of Japanese Carpentry Drawing series, the hopper, as the springboard, and moving forward into all sorts of entertaining directions. Once we deal with hopper joinery and enlarge the scope of the kō-ko-gen method, we will turn to splayed post structures, dealing with both French and Japanese approaches. From there it will be on to regular hip roof work. I'm looking forward to it and lot of folks seem pretty psyched to get involved as well.

To that end, I have purchased a domain name so as to be able to upload a online forum software, the good ole' phpbb forum template. This forum will be a place where Study Group members can discuss the problems at hand and share their knowledge with one another as they see fit, with the option to be anonymous or not, as with all forums. I figured this would be a more straightforward approach than using a group email conversation format. And unlike previous forums I've been involved in (and found frustrating after a while), I will be fully able to devote some energy to making this forum of optimal relevance to its users. And, unlike other carpentry forums, this one is not attached to a commercial website so there is no possibility to slant things in that respect and members can feel free to say pretty much what they want to.  Like this blog, the forum will not be bombarded with advertising. If there is enough interest, I may open the forum up more generally as a place to discuss traditional woodworking and layout techniques. I realize there are plenty of forums already out there and so I'll just play this part by ear for the time being.

Online study group members will be receiving a mailing soon enough providing further details, along with a link to the forum.

As for the coffee table project. I received a sample of the leg from the CNC people, and with some minor tweaks made, the parts should be produced today and I'll have them in my hands soon enough.  I also ordered, once the top frame pieces had been cut, the table top glass, I figured that the CAD drawing which programmed the cutting would be the most accurate possible to share with the glass cutters, who also have CNC-operated glass cutting equipment. Unfortunately, the glass people had some recent large orders just come in ahead of mine, so the glass delivery is pushed back to July 18th at the latest. So, this coffee table project is going slower then expected, but is progressing smoothly otherwise. I think by the end of next week I should have most of the cut out completed and be commencing the finishing.

All for today - thanks for dropping by the Carpentry Way.

Friday, June 17, 2011

Coffee Anyone? (9)

Station 9 on the route, here on the tour, a 'build thread' of a coffee table design/build. Earlier posts are found in the blog archive in the sidebar to the right of the page.

Last time, I had made a trip out to the CNC place and returned with the table top frame pieces. The legs have not been started yet, but they are next in the production stream, and should be completed sometime next week. Meanwhile, I have been working on the joinery to connect the frame corners together. I've chosen to use a combination of a floating stub tenon, which keeps the pieces from moving vertically in respect to one another, along with a quadruple-wedged drawbar, which will both align the joint horizontally and mechanically squeeze it together around the leg twin rebated tenons.

The first task was making the floating stub tenons, which were a hair over-dimension. Once trimmed to length, I got ready to do some final adjusting:


You can see in the above photo that the mortise in the frame miter has already been cut. These I did using a router and chisel.

The floating tenons were then trimmed for width using an improvised shooting board and a skewed block plane:


Here's the first one fitted into its mortise:


I next checked to see if the insertion depth was correct, a little under 0.375":


Then, let's see if it will assemble:


It was a little tight, but could be pressed together:


The same steps were followed with the remaining pieces, and soon enough I had the frame members stub-tenoned together:


Well, I guess it's time to get busy on the drawbar mortises. First I placed a piece of MDF down, intending to use it as a fixture base plate:


The next bit was a little tricky - laying out the locations of the mortises. I had no straight lines, edges or corners to work from, so I had to think awhile before proceeding. Once I had some reference lines established, I used a trammel to set and then double-check the centerpoints of each mortise on the miter line:


Here's how the mortise lines shaped up:


I next prepared a piece of MDF to use as a router guide. This needed to be carefully set in position prior to routing, which took place in three separate steps, two routers, and two tool changes:


As I got closer to completion, I checked and adjusted until I had cut the mortise to the target depth of 1.000":


I was happy to be only 0.001" off:


Just lucky I guess, but I'll take it!

Taking the MDF template off, the drawbar mortise is revealed in 'rough' form:


Though the mortise is dimensionally accurate, I still need to trim the end walls of the mortise square, but that will have to wait a bit - first I needed to get the other three done:


That's where I'll leave off today.  The mortise slots still need some work on them,which will be described in posts to come. All in all, I think they're going to work quite fine. Thanks for coming by the Carpentry Way today.

I'm heading to D.C. for a few days to visit the Library of Congress and do some research. I've got a long list of old books to dig through and it should be fun, and -as usual- a little maddening given the antiquated systems they use in that venerable facility.

The Online Carpentry Study group already has several members. Those wishing to get involved can email me and request a Paypal invoice for July. Lot's of fun ahead - I can hardly wait! --> on to post 10

Wednesday, June 15, 2011

Online Carpentry Study Group

I've been chewing over the responses I have had to my previous announcement about possible Japanese carpentry study courses later this year, and have drawn some new conclusions I'd like to share.

A couple of people suggested an online study format of some sort, and I have been thinking this over more seriously and do believe it holds much promise. One thing I recognize and acknowledge is that there are blog readers and followers here who do not live remotely close by my location, and for whom the costs of flying out to take a workshop, with the attendant time off of work and away from family, along with added food and sundry costs, makes a workshop a tough proposition time-wise and financially. Also, the pace of study in a workshop does not suit all participants. If we move along at a pace I like to work, or in effort of covering a lot of material, many people get overwhelmed, understandably, and really can't keep up. Once the glass is full, so to speak, there's little to be gained from pouring more water in there, and those that have attended some workshops I have given in the past would concur that such an overflowing does characterize much of the experience. And if I slow the pace down to the 'average' course participant's rate of work, as I did in the last course I taught, a lot less material tends to get covered and some participants may end up feeling frustrated or shortchanged by that. Finally, some people freeze up a bit in group settings and may feel intimidated or pressured for one reason or another, and this holds them back from getting the most out of the process.

So, online learning seems like a good option for many. There is the matter of individual motivation, and that will vary among folks out there, but the opportunity is there to study at your own pace and as one's personal schedule allows. So, the pressure is largely off. Some may prefer to be entirely passive about the whole thing, and such has been the case for the majority of people who have purchased the first two volumes of my Carpentry essay, where the assignments involved completing a table of values using repetition of calculation, and the construction of a non-joinery hopper. And that's fine-  I would prefer people take the information from the essays and actually start cutting wood, but I certainly can't force anyone to do so.

Another point on my mind concerns the content of this blog. It varies from personal reflections and process analysis, to detailed looks at history and culture, to build threads, to technical/instructional exposes, such as the 'X' Marks the Spot series from earlier this year. From doing that drawing series, I realized there was a contingent out there who were interested in a step-by-step learning approach to carpentry drawing, and at the same time, there were undoubtedly other readers out there who found it all a bit outside their area of interest. Indeed, during those series I was a bit concerned that despite the huge number of hours that went into the work on my end, that I might have been turning some people off of the blog as a result.

Here's what I have decided to do: the blog will continue as usual with build threads, photo essays, book reviews, etc., however there will be no more technical/instructional series. For that side of things, I will be starting an online Carpentry Study Group, which will be by paid subscription. The format will allow for inter-activity among members of the study group, so that people can both ask me questions and discuss/share stuff with other members. At the conclusion of a project, members can post up pictures of their competed pieces - or not - and will have the option of letting those picture(s) being posted on this blog. You don't have to make anything if you don't want to, or don't have the time, but I hope you will! I am planning to release study material in a graduated fashion so as to allow enough time for students to make the pieces, and keep a good flow to the process. We'll explore both Japanese, French, and even German carpentry.  The focus will be on carpentry drawing, that is, layout. I'll be making the pieces too and will provide photo essays of how I go about the cutting, in more detail than I typically share on the blog. While I already have a good idea of a logical progression of learning tasks, I will be open to participant needs/wants, and flexible enough to take side trips from time to time.

The subscription fee will be $20/month. People can opt in or out anytime they like. So long as 'dues' are paid by the first of the month, subscribers will continue to receive installments. If you didn't pay dues, then I take you off the list. If you pay your dues and don't like the material after receiving the first installment, I'll refund your money. These installments will be mailed out to subscribers in much the same way as I currently provide the carpentry essays, and will have much larger photo files than the blog so that the drawings will have much better detail than what you see on the blog. I will also look at doing video presentations of certain aspects of the material.

So, we'll see what happens - I'm very much wanting to form a community of people interested in delving into technical carpentry practice, who want to study and make stuff. If you're interested in getting involved, and want to push your technical carpentry savvy into new areas, please contact me at the usual email address. Subscription is by way of Paypal (to my email) or personal check drawn on a US bank and mailed to me. The first course is slated to start on July 1st, 2011, and will be delving into splayed box joinery and from there moving into splayed leg sawhorse/table construction. After that, we'll probably make a Japanese hip roof model. And again, to be clear, this blog will be continuing in it's usual way, with much the same content as before, sans technical drawing threads.

I'm looking forward to seeing what the repsonse is. Nothing ventured, nothing gained, as they say.  Thanks for coming by the Carpentry Way, and comments always welcome.

Tuesday, June 14, 2011

Coffee Anyone? (8)

Post eight in a build thread showing the design and construction of a glass-topped coffee table having a frame of bubinga. Previous installments to be found in the 'blog archive' to the right of the page.

I needed to make a trip out to New York state yesterday to the CNC sub-contractor, as there was a glitch in the cutting which resulted in an odd appearance on the lower front face of the sticks where they met at a miter.  This problem had showed up after two test pieces had been cut and placed together:


Note how the lower surface turns inward rather too abruptly. This is due to a peculiarity in the geometry of the piece, something that in the design phase I had struggled to render properly in SketchUp, which is poor when it comes to manipulating curvilinear forms. At the CNC place, they had Autocad, so I was able to sit down with a programmer and make the necessary tweaks with relative ease.

Then I spent most of the afternoon there as the pieces were milled up in a series of steps. The milling is done on top of an MDF fixturing jig, which is milled out by the CNC so that vacuum can be used to hold the piece down. To aid in that, a groove is milled so as to take a rubber gasket:


In addition, small squares of adhesive-backed stair tread grip tape are affixed around the points where the vacuum is pulled so as to allow the vacuum to reach a wider area of the underside of the piece:


Further, a couple of dowel-locating holes are drilled, both in the jig and in the pieces to be worked, so that after several passes are done to produce the front face profile, the piece can be flipped upside-down and located to the exact same position for the cutting work in the inside curve portion.

Here's the profiling cutter in action:


It's an insert-knife shaper cutter running on a 3/4" spindle. I noted that they buy their shaper tooling at the same place I do. The CNC  makes the above cut a lot safer proposition, and gives a smoother result, I do believe, than if I were to have made a fixture to template-shape the piece in my shaper.

Here's a look as the front face profile is nearly complete:


The gantry then moves out of the way, the table automatically moves forward, and then the operator uses an air line to blow the shavings off. Here's the piece after the front face profiling is done and the piece has been flipped and re-set in the jig in preparation for milling the rear face, where the vacuum also holds the piece firmly in place:


The cutting on the rear face employs a multi-step process. First a series of passes are made of increasing depth:


Then, once the cut is about 3 mm from going through the bottom of the piece, another cutter is brought in, this one taking a final cleaning pass about 0.003~0.004" further in.

At this point, the piece is done as far as the CNC cutting goes - the vacuum is then cut, and the piece removed from the fixture:


At the top of the above photo you can see that this CNC machine has two tables and each moves independently of the other. The upper table has a fixing jig similar to the lower one, except it is for milling the short side table top frame pieces on this job.

Here's a look at the two short side pieces after cutting is complete:


I was pleased with the result. The cutting was quite clean for the most part, with only a modest amount of chatter marks left in a couple of spots where the cutter was working most strongly cross-grain. These two pieces above only had a slight amount of material left on their inside corners to guard against tear-out, and it was actually adequate. For the long side pieces though I had them change the program slightly to add even more material to those spots. Call me paranoid. I'll hand-dress these areas down to  sharp irizumi ('re-entrant') points later on.

Back at the shop I used the bandsaw to sever the support sections away, leaving me with the four frame pieces:


 The long and the short sides, one of each I mean, are abutted in the next few shots so as to show how things look:


With the pieces upside-down on the table, here's a closer look at the two frame members coming together:


There were very slight discrepancies here and there where the two face profiles meet, but it will be a very straightforward procedure to file and smooth that interface to give a clean look.

A look now with the pieces right-side up, looking at the inside-corner:


Here, the difference in the amount of material left at the re-entrant corners on each piece is very apparent. I leave myself more filing work to do on the one with the extra chunk left in place, but better that than risking tear-out in that location from the routing. In the above picture I have not cleaned the remaining material from the bandsaw cut, but again, a simple matter to take care of. A good fit between pieces I think, and the rebate for the glass piece is exactly the same depth on each. Nice!

Finally, a look at the front profile where the two pieces come together:


Compare this picture with the first one in the post showing the test pieces and I'm sure you will agree the appearance is much improved in regards to how the lower portion of the profile comes together. It was good to take the trip to see the process firsthand and work with the programmer to solve the issues.

Next up with these pieces are the cross-splined, draw-barred and wedged locking joints, and before I can start that phase I have a couple of fixturing jigs to make. The legs are due to enter the world of 5-axis CNC cutting by the end of the week, so they should be in my hands within the next 7 days or so. More to come in this thread, so please stay tuned.

Thanks for dropping by the Carpentry Way. --> on to post 9

Thursday, June 9, 2011

Coffee Anyone? (7)

Post 7 in a series describing the design and construction of a coffee table, the frame and legs of which will be make of bubinga, along with the shelf frame. The shelf panel is to be wenge, and the main table top will be glass. Previous posts in this thread can be found in the 'blog archive' to the right of the page (not visible to you if you are using a mobile device or Google reader).

I've been making steady progress over the past while, though this project has been somewhat on slow mode in the past two weeks as I have been waiting for the CNC work to be done. That was scheduled to happen on the 16th~24th of last month, but there have been delays for a variety of reasons - I'll not get into that here. Today I received a message from the sub-contractor that the cut out has commenced on the table top frame members, which are of semi-elliptical plan. Here's a sneak peak of a test piece - the piece's front face now profiled (it's upside-down in the picture):


The cut quality looks excellent from the picture at least. Hopefully, these frame pieces will be done tomorrow, and the legs are scheduled to be done about a week later.

In the last post, I had moved the locking miter joint joinery along for the table shelf. The next order of work on those parts was to mortise some of the pieces for pins which will secure drawbars connecting the frame to the legs:



Pin mortises cut on a couple of frame pieces now:



With all four complete, I moved on to mortising for the drawbars:



As a general rule, I always mortise for pins first.

The draw bar mortises roughed out:


 
I then used a router to dimension the mortises for width. This was followed by cleaning the mortise end walls to the line with a chisel and guide block:



A cleaned out mortise, albeit with some kuzu in the bottom:



Next step was to use gauge blocks, 0.5"x 0.75" (the exact size required) to test the fit, followed by cleaning out and trimming as necessary:



Once the fit of the gauge block was decent, I tried the fit of the drawbars, which are just slightly fat for the hole, by about 0.002" or so:



That made for a decent fit for those parts.

A short while later, all 4 were done:



These drawbars will be fitted into corresponding pinned mortises on the legs, and that is how the shelf and leg lock to one another.  Housings have yet to be cut on the above-illustrated pieces. The connections will be done without recourse to glue, as has become my habit of late.

Another task on the list was to mortise the long side frame rails of the stretched octagonal shelf unit for the shelf batten's male half-dovetail tenons. Again, the hollow chisel mortiser got the ball rolling, this time with the aid of the machine's table being tilted:



The roughed out dovetail mortises:



Again, I used my router to clean the mortise side walls to required point.

Then, out come the chisels, along with an angled paring guide:

 

That's those two out of the way, though I can see they still a little loving yet in a couple of places with a paring chisel:



 Next it was time to move the Wenge panel along a bit, working the top surface over with my plane:



Then I made up a jig and routed the backside of the panel for the sliding dovetail female - starting with a first set of passes to rough out the trench:


 Then the trench was trimmed down to the right depth, and brought into the dovetail shape:



The tongue is still a little thick in the above picture, so...

...then I completed the trimming of the tongue around the perimeter of the panel, first working on the router table and then some final clean-up to dimension using a shoulder plane :


I've been doing some tests on wood samples with Vermont Coatings whey-based finishes, and so far the results look pretty good. It dries quickly, in about 2 hours, is virtually non-toxic and odor-free, and doesn't darken the wood as much as Tung Oil does. I'm not sure though whether I want to have the bubinga kept light or not. I might prefer a darker overtone to the bubinga, and use the whey-based finish on the shelf panel. I can also use a mix of the two (I've done tests and they seem compatible), strating with the Tung Oil and finishing with the whey. I'm not quite done with the testing yet.

All for today.  Comments always welcome. Thanks for coming by!  On to post 8

Sunday, June 5, 2011

Computer Numeric Re-Considerations (VIII)

It's time, I think to cut to the chase in this series. Over the past 7 posts on the topic of CNC automation, a technology which began innocuously enough with developments in such things as automated looms, windmills, and census survey tabulators, I have delved into some of the historical currents in technological development that have led to this point in time. Obviously, this is a highly complex topic and at best I have only touched upon certain points here and there. Readers wishing to examine this topic in further detail may wish to consider reading the works of far more learned scholars than I - such books as David Noble's Forces of Production and America By Design, Lewis Mumford's Technics and Civilization, and Jacques Ellul's The Technological Society would be worthwhile starting points. In those books, if you're looking to receive happy confirmation about the rightness of technology as the cure for all our civilization's ills, you will likely be rather disappointed. As Pink Floyd put it, Welcome my son... to the machine! Of course, this message doesn't market quite so well as the bright shiny futures otherwise laid out for us, so perhaps these works are to an extent condemned to a certain amount of obscurity.

It is quite obvious, reading David Noble, that advances in automation were taken up by industry for the principal reason of eradicating the 'problem of labor' and 'soldiering', and not because they were essential to 95% of the sort of work normally performed by machine shops. The vast majority of machine shop work occurs in 3-axis format, that is, in the x-, y- and z-axes. Conventional lathes and milling machines, run by humans, accomplish this sort of work easily and with good precision. Human skill is definitely involved. The large NC and later CNC machines developed primarily by the US Air Force and MIT were to solve problems in forming shapes of helicopter blades and jet aircraft frames, which are complex shapes not even do-able accurately with conventional 3-axis work. For those, what was needed was servomechanism-controlled motors to move the cutters with utter smoothness in the 3 basic axes, along with the capacity to work in two additional axes. Some may be unclear on how there could be any other axes besides x-y-, and z. Consider the 4th axis: the piece to be machined can also be spun, like a lathe spins a piece. This spin can happen with the piece turned in either a vertical or horizontal axial orientation - depends upon the type of machine. That's the 4th axis - part rotation. The 5th axis is that the cutterhead itself can rotate in an orbital fashion.

Here's a video of a CR Onsrud 5-axis machine cutting a sphere inside a cube using that orbital head movement and a moving table:



5-axis machining is what you would need for pattern-making complex helicopter blades, or certain types of staircase handrails, or some chair parts. Most machining however, doesn't require 5 axes, and many machine tool businesses were not initially interested in the Air Force's new toy, especially given the very high capital cost expenditure they represented. In order to spread 5-axis technology, the Air Force tilted the playing field a bit, both providing the machines to certain shops and then specifying that the machines be used for certain projects, and later by having product specification programs created so that the only machines which could use the programming were 5-axis. The Air Force at one point decided to stockpile machine tools, and a certain percentage were specified to be NC/CNC type, and this eventually encouraged the machine tool shops to jump into the arena. Like a lot of what passes for capitalism, state and big business are joined at the hip, cost inefficiencies/waste are socialized, as they say, while profits are privatized. Sounds like a crazy way to do things, but it works for some I guess.

CNC was not promoted because it was a cost effective approach to machining. The machines weren't that. Plain and simple, management wanted control as a long-cherished goal, and management got that control eventually by technological means. That's the story told by David Noble, and I am persuaded by the evidence, personally. But does that history change the fact that this technology exists and that I, and you, are faced with the fact that many of the things in the physical, manufactured environment are produced by robots and automation? Not a whit. It's there, and some of the outcomes of that technology are admittedly good things, but not all.

Anyone who watches a film such as Manufactured Landscapes and sees people in China on assembly lines doing nothing all day but test aerosol nozzles, would be hard-pressed, I think, to come away from that thinking that it was a good thing that there were humans doing such jobs, and would prefer seeing such tasks automated. Take a look and judge for yourself:



Now, at present it must be so cheap to have a human do it all day that it makes the most economic sense for the owners of such factories, and perhaps soldiering isn't such a problem in China, I don't know. These workers are toiling away with dedication, doing work I don't think I could do, or would ever want to sign up for, that's for sure. One place where CNC manufacturing makes a lot of sense are such repetitive tasks as seen above, and yes, it is, when you get down to it, a luxury to use CNC (except when labor costs are higher, then the equation changes). But if you're going to have a society built around mass production and consumption, then either you have humans doing utterly mindless work like that, or you have machines doing it and, as a result of those machines, people out of work. In North America, the choice has long been to automate and/or offshore the production, with a result that the manufacturing base here is very nearly non-existent these days. What's left are service jobs. Curious too that the word service stems from the same root meaning - slave -which gives us the word servitude... but I digress.

Today I want to look outside the historical context and consider why a craftsperson may want to use CNC. It's there, it's a tool, and (while it might be purely illusory) I have some choice, it would appear, in whether I want to make use of that technology or not, regardless of how and why it came about, just like I do with cars, washing machines, toaster ovens, etc,. Craftsmen in the 1800's would have had the same choice in respect to the advent of powered woodworking machinery, and craftsmen even further back in time would have a similar choice to make about the new-fangled hand saw, which could ignore the run of the wood's grain, or, even earlier, the chisel now fixed into place in the configuration of a plane. Sacrilege!

What is new and radical in one era becomes a standard piece of kit in another, and later perhaps a quaint anachronism in an even later period - - as planes, saws, and chisels are for the bulk of woodworking companies these days. Possibly every period has those who are reactionary towards the new and deliberately choose not to employ it because of a belief in the virtue of 'tradition', or philosophical objections of some other sort, subjective and temporary as those ultimately prove to be in most cases. While it is not inevitable that technology marches on, I live within a system where technological change has become normalized and encouraged, and that change has a force of movement hard to resist, a river with a hard current to swim against. It could be other ways, but it is not - not at the moment at least.

Most woodworking machines are popular these days as they reduce what I might call grunt labor. Almost all woodworkers, I would imagine, would prefer to re-saw a piece of timber with a powered saw (bandsaw or circular saw) than to rip it with a handsaw, especially if there is a stack of such material to be dealt with. Now if I was a scabbard maker for a Japanese sword, I might choose to follow tradition and hand rip the 1 meter long (or so) board for that scabbard down into two, even if it took 50 or 100 times longer to do it than by machine. But if that scabbard was instead a stick 12 feet long, and I had to rip 10 of them in a row, I can imagine the pressure would be there to adopt some sort of machinery after a while. So, the scale of work tends to also be a factor in whether machinery is adopted or not. The more you have to do, and the larger the material, the more likely it is you will choose to use powered equipment. Some take machine use as the only way to work the material however, and that does have certain shortcomings. Does CNC woodworking equipment reduce labor in many circumstances? Sure it does. I'll return to the labor issue from another angle shortly.

Another reason to use machinery is for precision, or at least, predictable results. Here, woodworking machinery is really no better than hand tools in achieving precision. That said, many woodworkers, due to lack of experience with hand tools, or at least with quality hand tools, struggle to achieve precision with them. I wonder sometimes how many Stanley planes have been thrown across the shop in frustration after another piece of fine wood was torn out by the blade? Looking in antique shops, I see no shortage of hand planes that are beat to shit. Somewhere along the line, someone used that tool with no idea as to what they were doing. it has long been a mistake, I think, to confuse apparent mechanical simplicity with actual simplicity. The humblest hand tool is a summation of a huge amount of knowledge in some cases.

If you buy a powered plane though, most times you can achieve decent results by plugging it in and running stock through (or under) it. Much easier, even if a power-planed surface is no match for a cleanly hand-planed one.

Let's say I had a new guy in the shop and wanted him to cut the end of some sticks at 90˚. On the one hand I could walk him/her over to a powered chop saw, set up a stop and in 30 seconds or so familiarize him/her with how to use the machine, make sure they have the appropriate safety gear on, and away they go. They'd be producing work at a high accuracy level repetitively. On the other hand, I could show them how to check a try square, then sharpen a marking knife, then layout the cut lines, then get a cross cut handsaw and make that cut. Would I let them have my best handmade saw with the teeth nicely filed and set, and the blade evenly tensioned? Would you? No - you'd probably give them a 'jobber' sort of tool and you would well expect that they would damage the saw soon enough, either by muscling the cut and kinking the blade, or breaking a tooth, etc. And, odds are high that they would take a long time to make the cut and the result would not be all that high quality. We've all got to start somewhere. So then one would need to show them how to sharpen a plane or chisel, set up a plane perhaps, and then demonstrate how to clean off the end grain until a 90˚ surface is obtained. If that person did nothing all week but make 90˚ cuts, and I was willing to soak up the cost of that as their employer, then probably by the end of a week they would be getting decent at it. A month later, they would be executing fairly accurate work, at least as far as that task goes. One could lay out a similar choice between hand-planing a surface clean and machine planing it down with a super-surfacer.

Obviously, the vast majority of people would want to take that new worker over to the chop saw for the 30 second primer in operating the tool and put them to work, and not lead them down the other path. In the end, the worker who learns to make the accurate cut by hand really develops a skill which is something not inherent in the work using the powered chop saw. The quality of the work is fairly close between the two, though the chop saw will always be faster in that case.

One point in the hand saw's favor in such a scenario is safety. A mistake with the chopsaw can be a quick way to lose a finger, while it would be tough for a person to do more than nick themselves with the handsaw.

To obtain highly accurate results with either hand or machine tools requires a lot of knowledge and patience/desire to learn the details. Once the machine is well set up though, the production speed is greater than by hand, but I would say that ultimately one can in fact achieve higher precision by hand, with the use of jigs (like, say, a shooting board), than by machine. By most machines at least. You see, most woodworking machines are not made with a particularly high degree of precision (something they share with cheaper lines of hand tools), and worse, most people using the machines do not know or care about setting up the machines to obtain precise results as they are not particularly concerned, it would appear, with getting such results as a part of what they do. I make these comments on the basis of my observations of shop practices in several shops I have worked in or visited over the years. People by and large who do woodwork are dependent upon their machinery, but curiously seem to have no grasp of the workings or adjustments of those machines. It's a form of helplessness, let's face it.

Now, do CNC machines add to that technological dependence? I think the answer to that is both yes and no. In most cases, I would suspect that the people using the CNC-based woodworking machines, due to the characteristic divisions of labor which are employed for reasons of efficiency, are in the zone of helplessness. The programmer will have a specialized form of knowledge that allows him to do his/her job, but they are not actually woodworking at all. Those handling the wood are often doing little more than preparing the wood blanks for cutting and then loading, observing the machine work, then cleaning and unloading. That's not really woodwork either and, further, many of those workers would probably have no idea what to do if a glitch arose in the program. And if the machine broke down, I suspect that another technical specialist would have to be called in to fix the equipment.

On the other hand, there is an intriguing DIY aspect to CNC automation that accounts for a small slice of the pie. There is a certain segment of people designing and making their own CNC machines, welding up support tables, building a gantry, fitting in linear slide mechanisms, hooking up their own PC and then designing and programming. That's a totally different kettle of fish and is in fact a far more empowered and engaged process of making than that which characterizes a lot of woodworking. How many woodworkers out there build their own machines? Yes, it is some to be sure, but only a very small minority of people. The vast majority of us are consumers of machinery and tools, not makers.

If you're a designer/maker, then the DIY CNC has a definite appeal, and quite empowering it seems to me. I think if working with CNC is otherwise a division of labor where one person designs, another programs, another loads and unloads the machine and another packages the parts, then any one of those individual tasks are not the sort of woodworking I would personally like to do. It would suit some folks though, to be sure.

I think the issue, for me, really boils down to this point - am I using the machine to produce what my mind envisions, or am I working for the machine, only a cog in a larger mechanism of production? There's a sizable gulf between the two places.

I should mention one thing about programming - in order for the outcome of the cutting to be good, the person doing the programming has to have a good knowledge of wood as a material and of tooling, and be able to envision a logical series of steps to effect the final product, and direct the machine to employ tool paths that are safe and give a clean result. So, in that sense, there is a definite connection between CNC programming and regular woodworking, in terms of how the job is carried out and how the cut out must respect the nature of the material.

Now, the 5-axis CNC woodworking machines are able to accomplish things which are very difficult (if not impossible) or very time consuming for a human to do, and in all cases, the 5-axis machine can accomplish a highly precise result. I can totally see the advantage in using such a machine for cutting out the complex forms of handrails which are employed in geometrical staircases. And if one has to make a series of identical parts of complex form and high precision, the CNC clearly offers advantages.

I've been communicating with several glass companies in recent weeks in regards to the glass panel for the current coffee table project. This glass top has a form consisting of 4 half ellipses that meet with re-entrant corners. I've found companies that want me to send them a paper or cardstock templete of the top and then they will hand-cut and hand grind the glass to that template. I've found other companies which have CNC glass cutting equipment on hand and I can send them my drawings directly. And guess which option I have more faith in, in terms of achieving a product which conforms exactly to my design? Yes, the CNC. I don't have much faith, sad to say, that the hand-cutting will be done by people who will really care to work exactly to my template or who have the skill to work to the level of accuracy I want. That's a rare sort of person, in my experience. I do trust the CNC to produce exactly what I want, within a thousandth or at worst a hundredth of an inch. Maybe I'm imagining this, as some sort of techno-fantasy? If the hand-cutting added a certain hand-cut nuance to the result which would be charming or desirable, that would perhaps change the situation for me, but no, I want the glass to be made exactly as I have designed it, and with an even edge finish and an even edge chamfer.

So, okay, I've looked at the issues of accuracy, repeatability, and skillful work in terms of CNC or not. Another issue, of a more personal sort, relates to the nature of the work I am engaged in from a dollars and cents perspective. Obviously, if dollars and cents were my main concern in life, then woodworking would not have been a wise career choice. That said, if the dollars and cents do not roll in with at least some frequency or reliability, then the shop doors get closed, creditors might be owed, machines might need to be sold off, depression might ensue, and personal relationships can suffer, etc. If you have a trust fund, woodworking might make perfect sense, but furniture making on a small scale is tough sledding sometimes. Well, almost all the time actually.

In the kind of work I do, as some may have noticed, I tend to employ rather time-consuming methods to achieve the end results. I use these methods because I believe they are the highest quality way to do things. This means that in order to make a living, and I mean that in the middle class sense of the term, the work isn't what you might call 'inexpensive'. That means that the consumer base for my work is out at the truly thin end of the wedge, if you know what I mean. Japanese architectural work, the real stuff, starts somewhere north of $500/square foot. I've worked on projects where the price was around $1000/square foot, and there are definitely levels above that in terms of quality and intricacy. The number of people in the US who can afford such prices are fairly tiny - perhaps in the 1% zone. And out of all those few million individuals, the number who have an interest in Japanese architecture is probably again on the order of 1~2%. Still, that is a potential market perhaps of 2500~3000 individuals, as a bit of a 'guesstimate'. Doesn't sound too bad, but boy it is hard to crack into that group and get the steady work that I would like to have. Since I moved to the US three years ago, while I have had some near misses in terms of projects, I still have not gained a single client for such work. And I've tried hard to make those contacts. So, I make furniture in the meantime, but the furniture equation still adds up to seeking clients at the thin end of the wedge, and it is still hard to find those clients as well. It is definitely true that marketing is an area requiring a lot of effort and perseverance and it can take time for things to pay off.

Obviously, it would make sense to find a way to bring the cost of the product down a bit so that I could appeal to a thicker bit of that wedge and have a dramatically larger pool of potential clients to draw from. I would also like to make the work more affordable for more people. The only ways I know of to make the price lower, while still remaining economically viable is to lower the quality/technical sophistication so that the work is faster to do, and/or to do that work faster somehow, and/or to employ cheaper materials masquerading as higher quality ones. Many shops will choose to find cheaper ways - using dowels or biscuits instead of joinery, veneered particle board or plywood instead of solid wood, etc., etc.. Make the material inherently predictable, then jig up and set up so that identical pieces can be predictably cranked out in volume, preferably, once the shop gets a bit more work on hand, by relatively un-skilled people receiving lower wages. We all know the routine.

And if the choice is not to hire unskilled people and instead to do the work yourself, to not get big, then for most the work becomes, from all appearances, rather dull. I have yet to meet someone doing the MDF-plywood substrate, glued veneer, biscuit-joined carcase, orbital sand 'til you drop and spray it with pre-cat lacquer routine on a regular basis, making boxes as it get called, who finds the work remotely interesting, who goes home at night psyched to come back the next day, who finds a delight and engagement in the challenge of the work, and who tells me with a glint in their eye about the next project they have lined up to do. It could happen I suppose.

"But, it pays the bills".

"Hey, I've got a job"

Fair enough. Maybe for many the concept that work should have any fun to it at all is counter-intuitive. Maybe for many the social conditioning has taken hold that making stuff, blue collar work, the trades, is primarily a matter of physical exertion, not intellect, not the heart, not one's passion. Too bad, because I think they're quite wrong about that, at least in terms of what can be done.

For philosophical reasons, I choose not to go down those avenues with the parade of the boxes. So, I am left with finding ways to do the work faster without lowering the quality if I am to get the price down. My own physical speed of work can increase only so much, a few percent here and there, and in fact there's obviously a point where the likelihood of injury would increase, or the odds of messing up a piece, as well if I'm flying along too fast. The only possibility really is to make the same exact things over and over again so the jigs are done, the bugs worked out, the material bought in quantity, and then one can crank away to heart's content.

People suggest to me all the time that I should develop a product line, something I make in runs of a dozen, or fifty, or a hundred. Sounds good, but first there is the delicate and not to be overlooked matter of generating the sales for those massive product runs. Perhaps one day when I land a job to furnish a hotel or some pie-in-the-sky thing like that, the opportunity will be there to jig up to make 100 identical tables, but until that time, the closest situation will be making a set of chairs for a dining table, where the same piece, more or less, gets made 4, 6, 8, or 10 times over.

Another matter too is following the train of thought out a little further, of the factory approach, and see where it leads. Once I'm cranking it out, then I'm limited by machinery and employees, and once I go down that path of getting more of each I am entering into competition with Thos. Moser; get any bigger and I'll have to open my own Furniture Barn outlet and be wondering how to take Ikea down. By that point there will be a board of directors who will probably fire me as CEO since I would be in the way of getting the profit margin to the place where investors are likely to be more attracted to the proposition. That's not a path I want to walk, and that's not an arms race I want to engage in.

If you're making one-of-a-kind pieces, some would suggest that one day such pieces will be collectible. And how does the volume production of a piece affect that? Usually in a downwards manner. So I think the craftsman needs to consider all angles in terms of whether to up the volume.

Possibly, too, a client will come along who will see a piece I have made and want the exact same thing made for themselves. It hasn't happened yet. One of the things I offer that the factory approach generally cannot is truly bespoke, one-of-a-kind pieces made for each client. I'd like to keep offering that type of product, but somewhere between the one-of-a-kind and limited production there has to be a sweet spot that would work, right?

Let's look at the employee side of things. Right now, one of the limits on the amount I can get done is the fact that there's only me doing it. But when I consider an employee, it's not so appetizing a proposition actually. I know for a fact that pretty much anyone I would hire is going to make all the same mistakes I would make, plus a bunch I wouldn't (because I've already made them and have learned my lesson - hopefully). Those mistakes will cost me money. I don't meet too many folks who are as much of a perfectionist about woodwork as I am, and thus I expect most anyone I would hire would produce things at a lower quality standard than I might like. I would anticipate friction over such matters in fact. If the person is a beginner, they are unlikely to have much in the way of tools - am I to supply them? Then there's the long learning curve with sharpening and plane set up... And if they are already skilled and tooled up, why would they want to work for me? They could have their own woodworking business.

So, in delineating some of the issues, I have come to see the CNC router for woodworking as a means of accomplishing accurate, limited batch production in the woodworking shop. One interesting point about CNC operated machines as compared to regular woodworking machines is that once the set ups are complete, the machine can be largely left alone to do the work, freeing up the craftsman to focus on other aspects of the project at the time the CNC is doing the cutting work. You can leave the machine working overnight in some cases. That's a definite plus.

I'm already doing an extensive amount of CAD drawing, and am very familiar with the correct sort of tools paths and cut sequences one would want for various woodworking cut out tasks, so the steps in getting to the point of becoming savvy with the programming end of things are not too many in number in my estimation. I've already started playing around a bit with Rhino 3D, one of the more popular design software systems.

And when I think about the nature of woodwork, at least as I do it, what it boils down to really is intellectual property. That's what design is, intellectual property. Is the fact that I can run a stick of wood through a bandsaw or planer, or chop a clean mortise some sort of unique thing to me as a worker? No. Is knowing how to go about a job from start to finish unique to me? No. Is knowing how and when to sharpen a tool, knowing what a cleanly planed surface is supposed to look like, knowing what a good fit of a dovetail consists of - are any of those unique to me? No, not at all. But the sum package of design savvy, knowledge of joinery, knowledge of historical underpinnings, knowledge of and sensitivity to materials, knowledge of hand tool and machine tool use, ability to market the work and interact with the client to produce something they really want - - it's that package that comprises my intellectual property, and is unique to what I do and make.

Another point: when it comes down to it, few if any clients are going to care in the slightest whether I used a bandsaw to rough out the curve or an adze, or whether the dovetails are hand cut or come out of a router jig, whether the joint is held together with a Domino or a locking Japanese hako dome miter joint. Those things might matter to me a great deal, but for most clients, they care about the beauty and apparent quality of the finished product, and I think for many clients just knowing that the maker is a fanatic is all they need to know. Just as if I were to buy a Ferrari, say - I might have no idea or have little care about the metallurgical techniques behind the titanium connecting rods in the engine, but because it IS Ferrari, I know they will do their utmost. And that's the main thing. U-huh, branding.

In some cases, the rough cutting of a thing has only distant relation to the finished product, Why on earth would it matter if the part was cut one way or another? Consider the table frame piece for the coffee table I am making right now. It's a semi-elliptical section with a moulded edge profile and a rebate on the top surface. To make this part I might typically:

  1. Cut the blank to rough size
  2. joint and plane the blank close to dimension
  3. make a template of the elliptical plan
  4. trace the template outline onto the stock and rough it out with the bandsaw or jigsaw
  5. joint and plane again, taking the stock to dimension
  6. make a fixturing jig to hold the stock and process the cut in several stages using on-hand and/or custom shaper/router tooling to achieve the desired edge profile and top rebate
Or, I could do this:

  1. Cut the blank to rough size
  2. joint and plane the blank close to dimension
  3. trace the template outline onto the stock and rough it out with the bandsaw or jigsaw
  4. joint and plane again, taking the stock to dimension
  5. fix stock in CNC router. Router executes the profiling cuts, using stock and /or custom tooling
In the end, I will have much the same product in my hand, a piece of wood that still requires joinery to be cut on the ends, and the surfaces planed and scraped, and finished. Did it really matter at all that the cutting of the shape and profile was achieved with a hand-guided fixturing/pattern jig on the shaper and/or router table or that the work was fixed in place on a table and a computer controlled cutter achieved those same cuts? I don't think so. In both cases, I designed the piece and decided how I would effect the cut out, and in both cases my hands are going to be involved in getting to the finish line. In both cases a spinning cutter, a router/shaper, did the work.

In fact, cutting an elliptical form on the router or shaper involves a certain amount of risk at the ends of the cut where the curve of the ellipse swings sharply around and across the run of the grain - an easy place to have some blow-out or worse. In this case the CNC router would actually be a safer way to do the same task.

Of course, I'm not in a financial position to buy a large CNC machine right now. The 5-axis Onsrud machine featured in the first video above costs more than $100,000, maybe more than $200,000. So, if I am going to explore CNC a little further, I will need to buy an old 3-axis machine (still more than $20,000) or make my own machine. The DIY thing appeals to me a lot.

First though, I have decided that a good way to get my feet wet and see how satisfactory a product could be achieved, is by having some of the coffee table parts I designed cut by CNC router by a company in NY state which offers CNC manufacturing services. At this point they are several weeks behind schedule, but I hope to have some frame pieces in my hands by the beginning of next week or so. I'll post up about the results on that thread and have more reflections about it at that point. Fingers are crossed. For now, I'd like to draw this thread to a close - thanks for hanging in there and I trust that the fairly long entry today hasn't been overly tiresome.

Thanks for coming by the Carpentry Way. Comments always welcome.

Thursday, June 2, 2011

TAJCD: Volume III Now Complete!!

If you've been wondering why the apparent slowdown in the blog posting rate the past week, well, one reason is that I've been putting quite a few hours into completing Volume III of my essay series on Japanese carpentry drawing and techniques. I had released a 'part 1A' of this essay, which delves into splicing joints, in January, promising the rest, a part 1B, in another 'month or so'. Well, I'm afraid it took a lot longer than I thought, and part of the reason for that is that I got a bit more ambitious in what I was trying to achieve. Volume 3 now runs to three parts, A, B, and C, and totals out at 284 pages! I believe it is the most detailed look at Japanese splicing joints you will find anywhere, in any language.

Those that have already paid for this volume will be receiving the new updated volumes in the next day or so, and I will be putting the essay up on Ebay as well, in the hope that more people will see it and possibly, who knows, drop by this blog to take a look-see. The Ebay price will be $5.00 higher, to cover the costs of listing and selling.


Those who are interested in the series but wanting more information can contact me and I'll send you screen shots from the tables of contents and that sort of thing. Hundreds and hundreds of hours work went into it, so the $40 selling price (if you buy direct from me) is quite reasonable I feel. Obviously, if I were selling thousands of copies, the pricing would come down, but that sort of situation remains a,uh, mist-shrouded dream at this point.

It was surprising in my course of research for this volume how much misinformation and confusion I found on this topic, even on Japanese sites and in Japanese books. One of the leading Western websites on the subject of Japanese wooden architecture, JAANUS, has, it seems, numerous mistakes in content and various inaccuracies. I've sent them several emails bringing various points to their attention, however they don't seem to be too responsive. Too bad- I greatly respect the work of Mary Parent, who's dissertation The Roof in Japanese Buddhist Architecture served as a foundation for that site.

I'm going to take a month or two breather from the essay series, but do plan to get the next one going, which will look at sawhorse layout, soon enough. I appreciate all the support and feedback I've received so far in this endeavor, both from readers and family.