Saturday, January 25, 2014

Sidling Up to Sideboards (3)

The design process with the sideboard, fast becoming an 'odyssey', continues, a series of posts that started back in the fall of 2012.

In one of the comments received after the previous post in this series, a reader noted that,

...also, spending a lot of time with something can over-complicate the problem and/or solutions.

I suspect there are more than a few people out there who feel the same way, and I think there is a lot of truth to that comment. During this process there have been times where I feel like I have truly wandered out into the weeds. Certainly, spending a lot of time thinking about the design of a piece can lead to the consideration of solutions which are themselves complicated, maybe more so than is necessary to accomplish the task at hand. As to whether something is 'overly complex' or 'overly simple' for that matter, those are value judgments, and nothing more. Indeed, whether something appears 'complex' or 'simple' usually relates to how much time one has spent examining it. Funny enough, the opposite sometimes holds true: there are things which might appear dauntingly complicated which in reality are not.

Breathing appears simple enough, we do it all the time without thought, but at a chemical level, I suspect the process is still not fully understood by science, as we don't fully understand the behavior of molecules and atoms.

I think that there are many things which appear simple but the underlying reality is very different. I think one of the reasons that Japanese wooden architecture is successful is due to the attention paid to many small and subtle issues, the sum of the parts in the end being greater than the whole, and I have tried to learn from that approach as best I can.

I think really the bigger question relates to patience: at what point do you settle for what you have come up with? It can be frustrating when a design doesn't easily resolve itself after banging away at it for a while, and sometimes I think to myself that I must not be a good designer because the ideas don't all come to me in some sort of flash of inspiration. And if an idea does happen to come to me that way, it is equally likely that further consideration will reveal shortcomings. At what point does one stop working on a design and start cutting wood? I've certainly seen enough designs in wood which clearly look as if not much thought went into the design. Indeed, observing other woodworkers I have noticed that very little time is spent on design by most, the desire to 'get on with it', or a hunger to use the hands and not the mind, overriding all else perhaps.

I've noticed that with virtually every piece I have made for myself, after I've lived with it for a while certain aspects are revealed that I think I would change were I to make the piece again. And if one does get the chance to revisit a design time and time again, like Sam Maloof did with his rocking chair, then one can tweak and fine tune, often to great benefit. Not to say that all steps may be forwards in that regard. Sometimes an idea seems great in the mind but after it has become manifest in the piece isn't quite what you'd thought it would be, for better or for worse. Sometimes a casual afterthought during design, something that seemed relatively unimportant, might in the end turn out to be a very successful move, an aspect that makes for a winning design. I think in the end there are things you can be fairly sure will work well, and things you will be less certain about. This can be said: there are risks anytime you are not slavishly following a pattern laid down previously by someone else.

As for things laid down previous, in the world of furniture making, it can be said that it has all been done before, and I'm sure it has, and yet I still prefer to try and examine the issues of structure with a fresh perspective. I always like to consider the 'why' of a thing, and when you are looking at the design of a cabinet there are various approaches which can be taken, each with pluses and minuses. Should the carcase be made from wide boards connected at the corners with dovetails, or should it be frame and panel? And those are only the coarsest divisions, as within each category there are variant forms. Ruhlmann, for example, had a cabinet framing system using short pieces connecting down the length of the cabinet:

(from FWW, Issue #51)

This is interesting, however I would never choose to build a cabinet with such construction. It may have held together well enough since 1914, but it's all about the glue really - remove it from the equation and the piece would fall apart. Ruhlmann pieces are a case - no pun intended - of meticulous and highly technical construction and great elaboration of detail, coming together quite successfully, however at the end of the day they are veneered cabinets using some materials which are endangered, and I have no interest in that, even though I might admire the form and the achievement of beauty to a certain extent. Some forms can only be achieved in veneer, and those are forms I have no desire to emulate. In terms of Ruhlmann's pieces, the form intimately connects to the constructional system, and yet trumps it, the forms in many cases being impossibilities if solid wood were used. I prefer things the other way around, and prefer to construct using solid wood, joined to make a strong durable structure, as I have far more faith in the real material to stand the test of time.

In this sideboard design of mine materials count in a number of respects. I'm planning to use quartersawn bubinga throughout, as it is a beautiful wood, and one of the few hardwoods that can be obtained in wider quartersawn pieces. It's not easy to work however. To my way of thinking, using precious materials in a somewhat lavish way demands that I sit on the design until I am as sure as I can be that I will do honor to the material. I ask myself, could this be improved yet? There have been enough ghastly things made using rare and costly materials over the years and I have no desire to add to that ash heap of history. I can't guarantee I won't, and who knows what fate befalls anything one makes, but I think one can at least try to be mindful in this regard.

So, in the interest of realizing a successful design, I look to the past and I try to base my design work on classic patterning, however the problem you run into with a lot of pieces is that the world has changed and that classic form may no longer be terribly useful. A Newport Secretary cabinet, for example: few people today would use such a piece as intended since they keep such information in their computer (or their accountant's computer). There are no 'classic' computer desks to draw upon for that matter - indeed, a computer desk, like the eight track in a 1970's car, is doomed to be out of date all too soon. Some older pieces can be re-purposed of course, and I think weighting a design with a view to what is more easily re-purposeable makes sense. Consider  what works well generally instead of in a narrow manner. It's hard to think long term as we are really wired the other way!

A hutch is one pattern I could have drawn upon for this piece, and did look at various hutches in some detail, but the idea of having a cabinet in which a main purpose is the display of fine chinaware is not of interest to me or my wife. We're not looking to make such an expansive display - we don't live in that pattern where we have a fine set of chinaware that only comes out a few times per year, or a collection of fine silverware to show off. We don't own that sort of stuff and have no intention to own it. I grew up with that cultural practice, to a certain extent, but have no interest in that pattern in my own life - not that I don't appreciate a well made piece of china.

So, the idea of useful storage of things which we would use in and around the dining table drives the design in terms of the intended function, and the idea of displaying things, as such, has been minimized, as it is not an attribute of great importance.

An architectural parallel that comes to mind is the Japanese tokonoma, or display alcove. These are, or were, a standard piece of kit in a Japanese residence, and appear also in teahouses and certain temple buildings. The idea with these display alcoves, which are meant for the room in which guests would be entertained, or might stay the night, is that a seasonally appropriate display of a wall-hung scroll with poetry, a fine piece of pottery, a delicate flower arrangement, and the like would be set up for the benefit of the guest. Presumably that guest would be culturally literate enough to understand the reference made by the poem on the scroll, see how the presence of the lone peony in the 15th century vase suggests the pathos of the season, or some such thing. Such a tradition is pretty alien to this culture, and indeed is not something of interest to many in modern Japanese culture.

Speaking of special flowers, if you've read the novel Musashi, there is a scene where the protagonist and another warrior named Denshichirō visit Koyagyū Castle, home of the famous swordsman Sekishūsai. Overtly they have come to ask him for a 'lesson' - but their real intent is to challenge him to a duel and measure themselves accordingly. They found that Sekishūsai was not able or willing to receive their call and they are stopped at the castle gate. Sekishūsai sends a note expressing regret that they cannot meet, and presents them also with a single cut peony. Denshichirō is annoyed and feels insult at the apparent rudeness of the famous swordsman they came to confront. He sees the peony as a waste of a gift since they had plenty of peony growing in his home town, and concluded that the Yagyū school has gone to pot. He leaves in disgust.

Musashi however, later seeing that the flower stem is too long for it to be properly placed in a vase, asks to see the flower so he can trim the stem down a bit. Looking at it more closely, he is then struck by how perfectly sliced the end of the delicate flower stem is, realizes that it was not made with scissors, and tries a cut with his own sword on the stem. Then, "com-

That's a wonderful episode in that story, but like so many things, the message transmitted so subtly and carefully by the sliced end of a flower is going to be lost on most people. In this culture we are so bombarded by stuff all the time that the normal adaptation is to be largely oblivious to our surroundings.

My point here - excuse the above digression - is that there is a level of appropriateness to given cultural artifacts, and that matters when you are designing a piece of furniture. The meaning and use of the Newport Secretary, as one example, associates to a time, a society, and a cultural milieu that is long gone. Same for the classic Chinese canopy bed, or Japanese sea chest or funa-dansu. Just duplicating the form of one of those pieces without considering how it will be used today is likely to create a somewhat useless piece of furniture, maybe to be little more than a large ornament for the most part. I'm trying to avoid that fate with what I design, and thus, while I can take cues from classic designs, I have to vary from them in certain respects. And that's part of what it means to look closely at a design, to dissolve the form, to understand the structure, and to reassemble what is useful from there. And I cannot assume that the way I use it today, if the piece lasts for as long as I hope, will remain unchanged over time.

it seems to me that those pieces of furniture which have stood the test of time, and lasted 150, 250, 350 years, or more, have done so partly because they were useful, but maybe more so because they were well made and beautiful. People like to have beautiful objects around them, and being well made helps ensure these pieces remain desirable, and useful and beautiful. A beautiful object doesn't look good eventually if it suffers from being poorly made. Subjective as the sense of beauty may be, a lot can be learned by looking at antique pieces, because they have worked in some respect quite successfully.

Because bubinga is a very bold and strikingly beautiful material, it means that I would be wise to tone down other aspects of the design expression, in order to achieve a certain balance. I want the piece to look composed, a bit serene, and yet have a degree of vibrancy - not to have the volume turned to '11', but not something so quiet it becomes pure background either. In the quest to achieve that, in exploring various design possibilities, I have surely overstepped the line more than once, and had to reign things in. The challenge then, when the lines and details of the piece and so forth are to be quieter, is to find just enough of a way to give the piece some zing. I'm not sure I have at all succeeded in that regard, but that is the direction in which I'm striving. It's hard to achieve the right mix.

The past month or so I have been working on 'finalizing' the details of the lower cabinet. For some reason I have had a much easier time with the lower cabinet than the upper one with this piece, so I have worked on, here and there, those aspects I thought I could resolve, or at least to put to one side for the time being, considering them more or less 'done'. Is it ever really done? Hah - not sure about that at all!

The leg profile is where I started in my final revamp. I wanted to create a more defined visual outline along the outer arris of the legs, and also have a liking for a concave molding, so in trying to address those two ideas, here's what I came up with:

I like the concave bead as a place where I can run my fingertip along, tracing the line. It's present on a walnut cabinet I made a few years back and I quite like it.

And the bottom of the legs, I realized, would benefit from levelers. I tried a few designs in wood to no avail, and later settled upon a design which I will make in bronze:

An Allen head adjusting bolt will be slightly recessed into the hole you can see on the bottom of the foot, and connect to a t-nut inside the leg.

The bronze foot will have a tenon formed on the upper end, and be patinated to be a dark red-brown color:

Have I ever cast bronze hardware before, or done chemical patination? Well, only a little actually, and in fact my casting experience was with iron. But I'd like to give it a try and think I can tackle these feet. I've picked up a book on bronze casting and it looks very doable, but we'll see of course.

On the front of the cabinet, I struggled with the spandrel design. I wanted to add a spandrel below the main rail so as to considerably stiffen the cabinet against vertical deflection, which would ensue that the doors and drawers would fit well over the long term. I eventually settled upon a structurally logical form, the I-beam, running full length. I added a slight lift to the bottom edge, along with a slight jog up and recess to the rail above, as this ties the piece in visually with the tsuitate (room divider) already present in the living space:

One change I made concerns the juncture of lower rails and post. Formerly, I was going with both rails in the same plane, crossing within the post using haunched half tenons. I decided however to rearrange the junction in interests of greater strength, which led to staggering the heights of the two rails:

The staggered arrangement allows for taller tenon sections, which are easily pegged. I am trying to use pegged connections where possible instead of wedged ones, as the pegged configuration is more readily demountable.

Here's the exploded view from the narrow side:

The pegs you can see are 1/4" in section.

The trade off involved, besides the jogged horizontal line around the lower end of the cabinet, is that on one end of the main compartment the rail sticks up a bit from the floor:

It seems a minor tradeoff, something I can live with.

The drawer construction remains the same as was described in an earlier post in this series. I've slimmed down some of the lignum vitae runners:

The runners will be removable, and fastened in place with three screws each - the only metal fasteners in the cabinet other than what associates to the door and drawer hardware.

I changed the arrangement of the rear panels. They are now fitted into sub-frames, to be fastened by wooden clips, which allows them to be easily removed if need be:

I used such removable framed panels in a bookcase I made a while back, and prefer this system. If the drawers ever need repair or adjustment, the process will be greatly aided by the expedient of quickly removing the rear panel assembly. With a regular panel, it is trapped in the frame and thus the entire frame would need to come apart to remove the panel.

This cabinet combines a frame and panel structural system with a slab top. The slab top is intended to be a surface upon which things are placed temporarily, and I didn't want the frame and panel for the top as the expansion gaps on the panels are a place where grunge can accumulate. I also like the solidity, visually, of the thick tabletop.

Here's a view of the cabinet with the top removed, to show the underlying framing:

The top will attach by way of multiple floating sliding dovetail keys (not illustrated).

A last one is a perspective view from the front:

The doors on the front have not been refined yet and are simply carry-overs from the previous iteration. I intend to mold the door frames and panels a bit differently (than they appear now) in the near future. I've also got to detail the junction between door edges and the door stops.

I'm not sure about whether I will place spandrels on the short ends under the rails. Then there's the door and drawer hardware, which remains an open question. I did settle on knife hinges for the doors.

Getting pretty close overall I think.

I've got the lower cabinet near to the point where I could produce a cut list fairly soon. I can proceed with work on the lower cabinet in advance of completing the design on upper one, though I will move the finalization of the upper cabinet design along a certain distance before any wood gets sliced.

I have almost all the bubinga I need but may acquire another couple of boards yet.

All for today. Thanks for visiting the Carpentry Way.

Tuesday, January 21, 2014

Buttoning Things Up? (mystery solved)

In yesterday's post I mentioned that I had at last managed to get the lower spindle height counter on my shaper to reset, to a value of 6.000". While I was glad that the counter could be reset, I was confused as to why the Martin maintenance manual stated that it would reset to 0.00, while the dealer of the machine, in checking a T-26 shaper of similar vintage, found that it reset to a value of 5.000". I was unclear on the concept behind the secondary lower readout, and the differences between my machine, the other machine, and the manual were mystifying.

A reader sent me a note shortly afterwards saying that there were other Martin shaper owners out there who would understand the situation and would possibly be able to help me out. With the mail, he had cc'd a few of those people. This morning I awoke to find a long detailed email from a fellow in California named Scott Slate who runs bespoken woodworks. He explained the situation clearly and now I am no longer in the dark. Awesome!

Here's the low down:

- the reason the T-26 shaper resets to 5.000" while my machine, the T-20, resets to 6.000" is due to the fact that the T-26 is a tilting spindle machine and has less available travel in the height adjustment. It's supposed to reset to 5.000" and mine is supposed to reset to 6.000"

-the manual is simply wrong about an number of things in this regard. The display does not reset to 0.000". I guess I shouldn't be surprised. The manual for my T-54 jointer was so ridden with errors in translation that I rewrote it for Martin.

So, still the question: why the two displays for spindle height? The two counters function a bit differently, and for very good reasons, as it turns out.

The upper display is the 'relative' counter and can be reset at any time to 0.000" by pushing the reset button. It also works in concert with the calibration device to establish the point at which the top edge of the cutter reaches dead level with the table top. If you were using a rebating head, as I have set up in the machine, then once you have the cutter zeroed to the tabletop and registering 0.000 in the counter, it is simple to raise the cutter to the depth of the rebate required, say 0.375" or whatnot, and make your cut. If you then need to make another rebate a bit deeper, then you could either climb directly to that value, or reset the counter to 0.000 and add the extra depth when you raise the cutter. Similarly, if you were using a grooving cutter, you would zero the cutter to the table using the calibration device, then you could raise the cutter to the desired offset. If the grooving cutter were 0.250", and it was offset 0.500" from the edge of the board, you would raise the cutter to a value of 0.7500" on the readout. Same process moving up from there, and you would have the choice to reset to zero for each jump, or perform a bit of addition.

The lower counter, which cannot be set by the calibration device, and only by raising the spindle all the way to the top, is the 'absolute' counter. This is especially helpful when the cutter you are using does not have a flat surface on top, or is of some complicated form upon which you cannot readily obtain a reference. Let's say it's a cutter for forming door or winder rail and stile joints. You position the cutter onto the spindle, atop a specific thickness of spacer, and then lower it to the position you need for the cut, adjusting the fence and table opening as necessary. Then you would make some test cuts until you have found the correct position for the cutter to achieve crisp mating surfaces in the joints between the rails and stiles. At this point, you've done a bunch of work and the machine is finally ready for work. 90% of the time goes into the set up for the cut, and once you're done that you can produce a bunch of work.

A lot of the technological changes in shapers of late have come about in effort to reduce the costly set up times. By having an absolute counter, you have a reference point you can return to next time you have occasion to use the same cutter to make the same doors or windows. You would have a notebook or data sheet, in which you record the specific cutter, its position on the spindle (i.e., the thickness of the spacer below the cutter), and the absolute readout value when you had it dialed in.

Essentially what my machine has is a manual version of the present-day system Martin uses, in which the cutter stays together with the spindle all the time, and the spindle has a chip in it which the machine reads. That enables the machine to automatically reset the fence, the cutter height and possibly tilt, the fence position, and even the table opening size. All of more or less automated in other words. The following video shows depicts this process in the making of a simple window frame - I think it is especially clear just after the 6:00 mark when he refits the fence to the table:

While similar in most respects, that's a newer machine than mine and has a newer type of spindle system which happens to be the same system used on some CNC routing equipment, called HSK. My machine has the 'Dornfix' system. The machine in the video also would sell for at least 3 times the cost of mine, so I'm feeling quite content! The difference in speed in interchanging tooling, comparing the dornfix to HSK systems is there, but it is not a huge difference in time. The chip reading capability and automatic positioning would save a fair amount of set up time, and that makes sense in some businesses, but not so much in mine. I have a manual, low tech version which will take a few extra minutes to set up, and will require taking notes about the sets ups of various tools instead of entering it into the touch screen as another memory setting, and that's fine with me. I actually like the 'low-tech' aspect, although it is all relative. A 2000 Martin T20 is leagues more complex (and safer to operate) than a 1950's Whitney or the like, obviously.

I've noticed that other German shaper manufacturers also make use of a calibration device, like Panhans, which has one called the Zeromaster:

Scott mentioned in a later email that he thought it made sense to have the spindle reset its absolute count at the top of the stroke, and not the bottom, as that would be the only option in some cases if you wanted to reset the counter when a tool was already fitted to the spindle. It might be that the tool is too large to drop down past the table rings. Makes sense to me.

I'm glad to understand this aspect of the shaper function better. I still have a ways to go in terms of learning the ropes with shapers mind you, and I'm looking forward to learning more. Towards that end I've signed up for a 4 day workshop this spring out in Colorado to learn the processes for making energy efficient European tilt and turn windows. After that I should be able to make some informed decisions about tooling.

All for today. Looks like another major snowstorm is rolling in, so battening down the hatches here. Hope it's warmer where you are.

Monday, January 20, 2014

Buttoning Things Up? (update)

Still trying to get to the bottom of the mysterious lower counter on my Martin shaper's display. Where we last left off I had found a section in the maintenance manual where it stated that if the spindle was raised to the top position, the lower display would reset to 0.0. I tried that, and it did not reset.

I talked to Ed at Simantech in Mew York some more and he said he would visit another customer nearby who had a T-26 shaper of the same vintage who also had a calibration device. The T-26 was the tilting version of the T-20 shaper that I have.

Ed got back to me and said that you have to raise the spindle ALL THE WAY to the top, and that when I did the lower counter would reset to 5.00".

Hmm, okay. Well, I gave that a try today. When you raise the spindle by pushing the '↑' button, it begins rising at slow speed. If you keep the button held down, it starts then to rise at higher speed, until it gets near to the top of it's travel, whereupon it begins rising at slow speed once again. I guess last time I hadn't kept on with the slow raise portion until the very last gasp. This time I kept that button pushed down until the cutter came to a dead stop and would raise no further. I looked over at the readout, expecting the same result as before, and was pleasantly surprised to see that the lower readout had actually reset - to 6.000"(!):

So, that's interesting. The manual says it will reset to 0.0, Ed said it will reset to 5.000", and mine resets to 6.000" for some reason. But at least it resets, which means the digital readout isn't pooched and in need of replacement. That's good news.

Still, I remain puzzled at the discrepancy between the 0.0 that the manual says, 5.000" that Ed obtained on the machine he looked at, and the 6.000" reset obtained on mine.

Here's the cutter in the very top position, with a combo square placed nearby so you can readily see the position relative to the tabletop:

A closer look:

You can see that the bottom of the ruler (top of the tabletop) is about 1cm down on the collar of the main spindle housing. Above that you can see a slight space, then the bottom of the 1.25" spindle itself, and above that the first of the spacing rings. This is the position that has been reset on the lower counter as 6.000". It doesn't really make sense to me. Shouldn't the reset be to a value such that when the bottom support surface of the spindle (immediately below the bottommost spacer) is exactly in plane with the top of the table, the readout would be 0.000"? If not that, then what exactly is being referenced by this lower counter and how is it supposed to be employed? If I put a taller cutter on the spindle, and have it sit right on the bottom of the spindle, the readout would be saying 6.000" and yet the bottom of the cutter would be something like 1.25" or so off the top of the table. I'm not quite getting it, but perhaps that is because it is really obvious and sometimes I don't see things right in front of my face. Any readers have any idea?

I've asked the tech guy at Martin, who also thinks the counter should reset to 0.0" at the top, to ask the people at Martin in Germany. Hopefully I'll get to the bottom of this soon enough. I like to know how things work and why, that's all.

Thanks for dropping by on your travels.

Friday, January 17, 2014

Buttoning things Up?

A month or two back I managed to a acquire a 2000 Martin T20 shaper with sliding table. It was a couple of weeks later that I managed to get power to it as the main load centers for my shop space were in the process of being replaced with new by the landlord.  When I finally got power to the machine, a 45 amp capable service line, everything turned on and seemed to work fine. I wasn't expecting anything different as I knew the seller, Ed Papa of Simantech Inc. and his fine reputation, so I expected the machine to be ready for service.

Well, I guess I should qualify the expression, everything worked just a little bit. There was one thing that didn't quite work like I thought it should and that was the digital readout. Actually, there are two digital readouts of the spindle position:

Could use a cleaning I guess. The upper one is termed the 'absolute dimension height' and the lower one is termed the 'relative dimension height' in the Martin maintenance manual for the machine. Both readouts are active when the spindle is raised or lowered by the up/down buttons you can see to the right of the readout. If you push the 'reset' button, the upper readout will reset to zero, regardless of the height of the spindle.

The lower readout however, was bugging me as I couldn't reset it to zero, and the number in the display had nothing to do whatsoever with the spindle base height or any cutter I might place on the spindle. What use is the lower readout if it cannot be reset or calibrated to some known position?

I did a little digging around and learned that there was a calibration unit available, designated T2004, with which one could zero the readout when the cutter on the spindle came perfectly level with the table top. I contacted Ed and asked him about this calibration device and whether he could confirm that it was necessary for resetting the lower counter. Ed's a busy guy with lots going on and hasn't worked on a shaper of my 'vintage' for a while, and, as best as he could recollect, he agreed that I was correct in my thoughts about the calibration device. So I ordered one and it happened to be in stock in North America. A week later it was in my hands.

The T2004 calibration device is a heavy chunk of machined aluminum billet. It has a push button on the top, and a pad on one end of the bottom which acts a a sprung button to register the cutter against as it is raised up to the table height - as you can see here:

To connect the T2004 to the machine I had to drill a hole through the front of the control panel for the cable. Many of you with woodworking machines can, I'm sure, relate to the trepidation that comes with the idea of drilling holes in otherwise unmolested machinery for any purpose. Of course, I could access the inside of the control panel and was sure that the hole wasn't in line with any electrical equipment, but it was still a little nerve wracking. In the first picture I show above, you can see the strain relief connector for the calibration unit's cord installed just below the digital counter.

I wired the unit up to the digital counter as instructed, and turned the shaper back on. No crackling, smoke or blown fuse - always a good sign. The calibration unit did not come with any instructions, so I was left to figure out how it worked. It only had one button, how complicated could it be?

I found that if I pushed the button and depressed the plunger pad on the underside, a green light would come on - you can see the light bulb just in front of my finger in the above photo in fact. Cool! It seemed to work, but after getting the green light did the lower counter reset? Nope. I tried this, I tried that. No change to the lower counter.

So, I got the number for the tech person at Martin in South Carolina, Al Briggs, and dropped him a line. He's only been at Martin for 2 years, so he wasn't personally familiar with my machine, and he had never seen or installed the T2004 calibration device. It's not a common option and i think newer machines must have the calibration function built in to the touch screen. Not sure.

I told Al what the situation was, and he said he would contact Martin in Germany and see what they had to say. The next day, We were in touch again and he asked me to perform some electrical tests on the digital readout using a multimeter, as recommended by headquarters in Germany. This I did and reported the results back to him. It appeared that when the calibration device was activated, power, a bit over 12v. DC, was being sent to the correct terminal on the readout. So that seemed to be a good sign. Al relayed the results back to Germany.

Then the tech guy at Martin Germany, Manfred is his name, suggested that I check the 'parametric functions' on the readout. I was somewhat familiar with these, as the SCM planer I have also has various parametric functions which, unfortunately, can only be accessed on the inside of the machine. That means, for example, that if you want to change the digital readout from inch measurement to metric measurement, you have to remove bolts and the front control panel to access to appropriate switch. Not what you would call an intelligent design. But that's SCM.

The Martin readout's parametric functions are accessed from the front, without having to open the machine up, which is much more sensible. But accessing the parametric functions - how is that done? Manfred sent me an instruction sheet with 7 or 8 steps detailed, all in German. I don't happen to read German, other than the odd word like fledermausgauben (a type of dormer), gesamptkunstwerk, or treppenwitz, the German translation of the French l'esprit de l'escalier. Great for casual party conversations, but little else - ahem!

I emailed Al and asked him what I was supposed to do with this German document. He said he'd translate it for me. Now, Al doesn't speak German either, so his method was to use Google translate. He sent the results to me a few hours later. They were partially intelligible, but you know how it is, miss one key word in a sentence and you can lose the meaning almost entirely. I could see that certain words in the piece that Al sent had not been translated at all, which either meant that they were fairly rare or esoteric words which were not in Google's database, or there was some other issue, like misspelling. I decided to have a go with Google translate and soon enough I discovered the problem: Al had not been able to input those accented Latin letters one finds in German, and without them, using 'O' instead of 'Ö' for example, and the translation software chokes. At least Google translate can do a half decent job with German, as it does have some close ties to English in certain respects, unlike trying to translate Japanese into English, where one quickly discovers it is all but useless. Fortunately my computer allows for easy insertion of accented Latin, so i was able to obtain a much more complete translation.

Anyway, section one of the document read:

 Which Google translated as:

For parameterization for the hidden keys, hold the up/down buttons together for 3 seconds.Then appear in the upper display the parameter number (starting from P01). The lower display shows the current value of the parameter.

--> Sounds good, but WTF are the 'hidden keys'? I assumed that the translation on Google must be slightly amiss. The only up and down keys I could see were the up/down buttons to effect raising and lowering of the spindle. With that idea in mind i went to the shop and tried following the instructions, to no avail. I wasn't able to access the parametric functions on the readout. At this point I was beginning to wonder if the readout was defective in some way, even though it did provide a readout otherwise.

Getting back in touch with Al, I told him how I'd re-translated the German document, had followed the direction and yet had no luck whatsoever with getting the parameter function to activate. He said he'd talk to the people at Martin Germany again and see what they had to say.

The next day I received a message from Manfred, by way of Al, with a rather interesting annotated photo of the digital readout:

It turns out it actually does have hidden buttons!? 'X' marks the spots where they are located. You've got to be kidding me. I was incredulous. How is someone supposed to know where hidden buttons like that are located? You can't feel them on the face of the display -they are indeed hidden.

I went back to the shop and tried pushing the front of the display in those two indicated locations and voila! the parametric functions came on to the display! It's alive!!

I checked the 10 different parametric functions, noted the numbers shown on the display, and relayed this information back to Al, who then relayed it on to Germany.  The news came back the next day that all the function values were as they should be.

That wasn't the news I was hoping for I guess - I was thinking that one of the values might be out of whack and with a simple reset of some particular parametric value all would be well. Such was not the case. At this point it seemed that the calibration unit was working fine and the digital readout was working fine. And yet, no reset of that lower readout was accomplished by any of the steps, measurements, confirmations and many days of back and forth communications across the Atlantic. Was there nothing to be done? Just live with it?

I asked Al what the next step might be, if there was one. He again contacted Germany. The next day they got back to us and wondered if I was using the calibration unit correctly - and described the steps one follows to make use of it. They were the same steps I had followed previously, however I said I'd go back to the shop and double check. I did so, and took the added measure of photographing each step so there could be no misunderstanding. I sent those photos on back and waited.

A couple of days later Manfred wrote and said that, wait a minute, the counter which gets reset by the calibration unit is NOT the lower counter, it is the upper counter (!). Wha -?

The entire time I've been working on this problem I have been staring at that lower digital readout, looking to see if it could be reset. As the upper readout could be reset to 0 at anytime by pressing the reset button I hadn't been paying any attention to it. I know - I know - it's only an inch above the lower display, but I'm a guy, and while I can spot an antelope rustling in the trees from 200 yards I have a hard time finding something, say, in the fridge, particularly if it is on the front of the top shelf and right in front of me.

I went back to the shop to see if the calibration unit would reset the upper readout, and, why, yes, it does! Hallelujah! And man, did I feel like a bonehead, not noticing the entire time that the calibration unit was actually working to reset the upper counter.

On the plus side, this functionality at least meant that the purchase of the calibration unit, and the drilling of a hole in front of the control panel were not for naught. That was a relief, and yet... do you reset the frickin' lower readout? Is an act of god required? Do I have to pay somebody off? Should I put black tape over the damn thing?

Later on, I was looking through the maintenance manual (which is not where one would normally expect to find information relating to the operation of the machine), and wouldn't you know it, I found a paragraph or two on the digital readout and its operation. There it mentioned, in a section called 'Re-calibration of height', that the spindle needs to be raised to its uppermost position, at which point the raise motor automatically shuts off and,
If calibration device T2004 will be used, the display B will be calibrated to "0,0"
Oh really? You think after all this hardship, hair pulling and sacrifice I'm going to be fobbed off by some simple explanation like that? Are you kidding me? 

Feeling sheepish, I returned to the shop to confirm whether this magical combo of fully raised spindle and T2004 activation would reset the lower display.

Here's the spindle all the way to the top:

Activated the calibration unit and...

No change to the lower display. The upper one reset to zero of course.

As they say, it's the journey, not the destination. We'll see where this leads from here.

Thanks for coming by the Carpentry Way.

Monday, January 6, 2014

Can't See the forest for the Trees (V)

The previous post concluded by looking at how a log is typically sawn up: first into a squared-up cant, then sawn through and through to produce boards. Only a few of the boards produced by this method have truly straight grain, most will have some degree of grain run out. This method does produce a decently high yield of timber for relatively few cuts and log maneuvers however, and is thus cost efficient. That's why it is the most common method seen in cant cutting.

I came across a video for a new(er) and rather massive Woodmizer mill which illustrates the aforementioned cutting method perfectly. This mill, the WM1000, is designed specifically for sawing up large diameter logs:

This is  pretty grand piece of equipment and features some nice hydraulically-operated options which make handling a large log quite easy - beats hanging off a peavey any day. It also costs in the neighborhood of $55,000, so it probably won't be showing up in everyone's backyard anytime soon. A hardwood supplier in South eastern Massachusetts, Berkshire Products, recently acquired one of these mills, and that's where I first saw it.

There are other approaches to sawing a log up when the goal is to produce boards with very straight grain. With this, and some other methods, a greater amount of 'waste' may be produced, however it should be noted that 'waste' is often a value judgment, generally based on profitability as yield, or, at the very least, for the perspective of what humans can get out of it. Sawdust and wood offcuts may of course be converted into fuel, and even if left on the ground are food for many creatures. Wood is part of the natural carbon cycle and a tree left entirely alone by humans eventually dies and decomposes on the forest floor where it is of great benefit to many other organisms. Most cases, I don't tend to get overly-exercised by the idea of 'waste' when it comes to sawing logs or cants or boards up into smaller - I'd rather try and obtain the highest quality material I can as an operating principle, than to saw for volumetric conversion efficiency. That said, as far as 'waste' is concerned, a thin kerf blade is highly desirable when trying to squeeze every last bit of good material out of a cant of quality material. As a final caveat, it is certainly a shame when high quality material is sawn up into firewood, which has been known to happen from time to time, though IF it is a question of freezing to death or staying warm, that point admittedly becomes rather moot. Such was that fate of some fine pieces of classic Ming furniture during the cultural revolution in China.

Alright, before I wander too far off topic then, let's look at another way to saw a log. Of course, there are so many potential situations to consider and so many variables in terms of the logs themselves, which may not be especially cylindrical, or may have defects which need to be sawn around, that the cutting plans I suggest here should be taken a generalizations only. There's no substitute for experience, and anytime you open up a log there are uncertainties, things to be discovered which may or may not be good news. I can't possibly consider every variable, so please keep that in mind.

Here we have our log on the mill deck, and this time we have shimmed the log so that the outside of the trunk, the upper surface, is parallel to the cut:

Our first cut will be to slab off a chunk of sapwood from the upper surface, just as was done when preparing a cant with the log adjusted so that the cut followed the pith (shown in the previous post):

Again, though it is mostly sapwood, with a large log there's likely to be at least a usable board which could be cut out of that slab, but we'll set it aside all the same.

Now, for comparisons sake with the process shown in the previous post, let's say we still have the goal of obtaining a nice quartersawn plank out of the widest part of the log. Above that plank, we are going to cut a pair of larger slabs which will be re-sawn later into timbers:

Notice the straight grain visible on all the cut faces.

Removing those two slabs and setting them to one side, we arrive at the widest part of the log, and we look to obtain that nice piece of quartersawn material. We pull out the shim at the front of the log and swap in one which is about half the thickness, making the line of cut now parallel to the pith, as you'll see on the following sketch:

I've left the old thick shim to the side so you can more clearly see the comparison to the new shim.

We then slice off a piece to adjust the surface so that it is also parallel to the pith:

Notice that the waste piece is a large triangular slice. That is the form of waste piece that will be produced characteristically with this method. In this case, there might be enough meat in that slice to obtain some quartersawn board stock, if we were to re-saw the piece once again. At the very least, a shorter board could likely be obtained.

Next, we slice and obtain our quartersawn board of perfection from the log:

The same cut process can be repeated if desired with the other half of the log if so desired.

Returning to the two large slabs we off cut previously, we can now slice them. In this case, the choice is to obtain mostly square section timbers, mostly 7x7's, from those two slabs, though of course they could be re-cut for a variety of other shapes. Here's the result, including the lower quartersawn board:

Note that I have swung the camera around in the above sketch and we are now viewing the butt end of the log. Notice also the wedge-shaped waste pieces at the center of each slabbed piece of the log.

Next, the waste pieces are separated out and placed above the rest, so we can see what remains more clearly:

Most of the scrap pieces contain a high percentage of sapwood, and the center piece contains the pith, so they are not desirable, except to insects and fungi. There are two tapered boards which came from the middle section of the two large cants, and these may yield another slender quartersawn board or two. I think you'll agree that the quality of the boards obtained, lined up at the bottom portion of the sketch above, is very high.

In the previous post we looked at two methods of sawing:

  1. Sawing through and through
  2. Cant Sawing

I've been using the terms 'sawn to the outside' (parallel to the bark) and 'sawn to the inside' (parallel to the pith) in this series. Those are colloquial terms, in the same way that 'live edge' is a stand-in for 'waney'.  The technical industry term for sawing to the inside is "split-taper sawing", and the term for sawing to the outside is "full-taper sawing". The reasons for those two terms should be clear from the processes and set ups illustrated so far in the last few posts in this series.

In this post and the previous, I have gone about breaking down the log in a somewhat academic manner, and the patterns shown are by no means representative of the dizzying array of options which are out there. There are in fact some 8 different standard cutting patterns.  Through-and through is by far and away the most prevalent. Here are the eight patterns, for reference's sake:
  1. Live-sawing, split-taper
  2. Live-sawing, full-taper
  3. Cant; split-taper-split-taper
  4. Cant; full-taper-split-taper
  5. Cant; split-taper-full-taper-fixed fence
  6. Cant; full-taper-full-taper-fixed fence
  7. Cant; split-taper-full-taper-variable fence
  8. Cant; full-taper-full-taper-variable fence
'Live' sawing, as you may have gathered, is when you do not first slab down the log to make a cant. After the distinction between 'live' and 'cant' sawing, the next term, full-taper or split taper, describes the initial cut to produce a working face, and how the log is adjusted.

Those eight methods are illustrated and compared in the 1976 US Forest Products Laboratory Publication, Is there a 'Best' Sawing Method? which you can find online and download if you like. The methods illustrated are representative of a vertical sawing mill:

 The smaller circle we see is the skinny end of the log, closest to the mill head. The study generally concerned 'smaller' mill logs, those from 5" to 20" diameter. The study considered 'best' as being the method which produced the greatest yield. The conclusion was that method eight, sawing a cant and then breaking it down as 'full-taper-full-taper-variable fence' gave the highest recovery rate. The worst average recovery rates were accomplished using live sawing, split taper. Since this study was intended for the sawmill industry, where a consistent cutting method used over many logs is employed rather than making special individual considerations for each log to be cut. so, the recommendations from this article come less into play than it might with someone re-sawing their own material for personal use. Still, cant-based cutting, accommodating for full taper seems to make sense for both quality and quantity reasons.

Lastly, I'd like to share a picture from a Japanese book I have on log selection and sawing, showing the cant-based, full taper method employed there in many instances:

You can see three different possible destination for a log. At the top, the log is flatsawn for boards, as might be used for roof eaves, etc.. In the middle, we see that the log is to be divided into posts  (), and is considered akin to a 4-sided pyramid in form. To the the right of that we see the waste portions, here designated as useful for making chopsticks, etc.. Finally, at the bottom we see one potential treatment for using a bowed log as a beam, slabbed on two sides. There are other treatments besides, outside the scope of this posting.

And the method I illustrated in this post for breaking down a log into square section timbers, is quite similar to one termed hachi-men-biki (八面引き), or "eight-face drawing" in Japanese:

 Of course, how a log gets sawn up depends hugely on what sort of material you are looking to obtain. The above method shows a log sawn up for posts. One might equally saw up a log exclusively for thin boards, and in that case there are several choices for how it might be cut. Here are a few options in Japanese sawing:

And it is often the case that a log may be sawn up to yield both larger posts as well as thinner boards, and shapes in between.

There are many possibilities in terms of how a log might be cut, and I can't cover them all there. Just wanted to touch on the topic, and show the advantages to sawing to the outside is all. I hope I succeeded in getting that point across.

I'm thinking to do another post or so in this series, dealing with lumber selection relative to how it may move in service, which is a related kettle of fish. I hope you're keeping warm during the cold snap - the polar vortex - engulfing most of North America right now.

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