Saturday, May 28, 2016

A Ming-Inspired Cabinet (58)

The upper compartment of these cabinets are guarded by a pair of sliding doors. These doors will have bubinga frames, shedua back panels, and a special type of latticework in the Matsu-kawa-bishi pattern.

Matsu-kawa is pine bark, and hishi/~bishi means diamond. It's a pattern thought to resemble a chunk of pine bark, and is composed of three overlapping diamonds, or lozenges if you prefer, one large and two small:

If the form can be tiled over a larger area, thereby a pattern such as this can be obtained:

There are countless variations on the theme.

Matsu-kawa-bishi  is a popular design motif, seen in many Japanese arts and crafts, including textiles, pottery, and even as an architectural roof tile ornament. Here it is incorporated into a tsuba:

This pattern is infrequently used for shōji lattice (kumiko) as well, and it was seeing a few examples of screen doors with this pattern that led to my interest in making it a part of this cabinet project.

Just drawing out the pattern of sloping zig-zag kumiko was challenging enough, and making the pieces and cutting the joinery has also been keeping me quite preoccupied of late.

Here's how the upper sliding doors are intended to look once complete:

Making slender sticks with a zig-zagged form, if you want the parts to be predictably uniform - which certainly facilitates the joinery work - will require jigging and fixturing whether working with hand or power tools. In my case, I have that Zimmermann pattern making mill, and that was the go-to choice. If I didn't have the mill, I would have found another way, but, well, I'm glad I have the mill!

Once I had the design work complete to the required level of detail, I jointed, re-sawed, planed and dimensioned some blanks about 3" thick and 8" wide. These were then processed on the mill into boards which had a staircase-like form on two sides.

Here, I'm cleaning up milling marks on the completed blank:

Notice that the blank sits atop a MDF support jig which was also cut so as to mirror the stepped pattern. This jig provided support and positioning when milling the backside of the blanks.

I later re-sawed those stepped blanks into oversized zig-zagged-form strips, and then planed these strips, the kumiko, to size.

Just getting to the point of having the kumiko in hand and ready to join required many days of standing in front of the mill, moving the tables back and forth, in and out. During that process the mill went down for a day when one of the gib bars self-tightened slightly and make the y-travel extremely tight after hundreds of movements. At first I though that the lead screw's bronze threaded nuts had gotten choked with dust, however I later determined that the gib had moved. A day was lost as a result, the mill partially disassembled and reassembled, and some hours of sleep were lost too! I do know the mill better as a result.

With the FZ-5V back up and running, I set to work preparing a fixture for cutting lap joints. This is where a pattern mill with a large rotary table really comes in handy.

Here's the first cut completed:

And then the other is done similarly:

There was a fair amount of head-scratching, calculator work, and pre-planning which went into those two zig-zagged cuts. They must cross each other in the dead center of the rotary table. It took me three tries to get it right.

Here's (most of) the kumiko after finish planing:

Another view - I feel the mill gave me excellent results in terms of repeatability, as these alignments show:

Packing the kumiko together like that would make for an interesting pattern to use in other areas perhaps. Another time.

I had about 6~8 sticks which came out bowed after resawing, however a few of them were usable when cut into shorter segments.

Making minor thickness adjustments to the 'steps' was accomplished by plane, card scraper, and a small hardwood block with affixed #220 sandpaper:

On the mill table, I prepared some cross-wise slots for the purposed of indexing. In the next photo I'm milling half laps in one of the kumiko:

These cuts were made in a series of half a dozen steps to preclude blow out. All positioning was made using the DRO.

Proof of concept was attained a short while later:

Toward the later part of the afternoon, a pile of parts was steadily mounting:

There are 72 sticks altogether, and 240 half laps to cut. It's very repetitive work, but one has to pay attention at each and every step so as to get good results and not to mess up any parts, so it is mentally tiring. 'Auto pilot' doesn't help much.

Another stick, another round of laps:

The rotary table's vernier scale allows precision to 0.25˚, which helped me feel confident when setting table position to the required 21.79˚ angulation. I'm milling the laps which slope one direction first, and then will rotate to the table to complete all the laps which slope the other way.

I'm thinking that another full day in the shop should see me through the rest of the half laps. Hah - nothing like a little optimism! After that, there are joints at the perimeter of the lattice panel to cut, and some small tenons to be formed so the lattice can be connected to the surrounding frame. These matsukawabishi pattern lattice doors are one of the points of focus in the overall design, a pleasant surprise to discover (I hope) when opening the cabinet, and I am striving, as always, for clean execution and high precision in my work. So far so good, and more than a week so far has been soaked up attending to my new second wife, Ms. Zimmerman.

All for this time-  thanks for visiting the Carpentry Way. On to post 59.

Friday, May 27, 2016

A Ming-Inspired Cabinet (57)

This is turning into a fairly long build thread it seems. This post has sat on blogger for a couple of weeks - I forgot to post it! Whoops!

Recent work on the shedua drawer fronts. After trimming them to about .06" over finished height, the parts were cross cut close to the target. Then, to deal with reducing thickness, the mill was the only option given the propensity of curly shedua to tear out by most other approaches:

An even amount was decked off of both faces, and in the process the board was made dead flat:

I've heard that super surfacers don't work on hard woods:

Make love not war - - make chips not dust:

The eighteen drawer fronts are now processed close to final dimensions in thickness, width, and length:

A feast of VG material:

These will be set aside and I'll start work on some latticed doors next. Next post will be appearing in a blindingly fast fashion.

Thanks for visiting the Carpentry Way - comments always welcome.

Monday, May 16, 2016

Not of Interest to the Unplugged Shop

A video I recently came across which may be of interest - indeed, I would think thought-provoking - to readers here. One would not normally associate CNC work to irregular timbers and forked branches, and yet:

It is intriguing to glimpse what is coming in terms of wood processing machinery and techniques, but sometimes I am taken unawares by what is here already.

Thursday, May 12, 2016

A Ming-Inspired Cabinet (56)

Hello again my friends.

Before I got sidetracked with working on one of those teak wheelbarrows for another client, I got a few coats of finish on the sides of the carcases:

Each day I decked the finish off and applied another coat:

The pictures above are of the first coat only, which was almost completely decked off. With a water-based finish, a slight amount of grain raising can occur, so I tend to think of the first coat as a general prep coat only. Subsequent coats had a little amber aniline dye added to darken things slightly. Currently, the cabinets have been sitting for nearly a week with four coats applied. I'll probably add one or two more coats at some later point.

Once the teak wheelbarrow was done for the other client (three down and one to go in that regard), I returned to work on the framing for these cabinets. The next assemblies to be tackled are the frameworks which affix atop their respective carcases, where they will receive the door hinge pins and support the bonnet to be placed on top.

These frameworks are somewhat similar to the cornice frames at the top of the support stands in the basic arrangement of two rails and four cross pieces, however these assemblies are without a mitered corner treatment. The door hinge pins are located right in the middle of where the miters would run, which I feared was not a structurally sound arrangement, so a stronger set up was desired, employing haunched tenons on butted joint corners:

The tenons do double duty in this case as the front rail is overhanging considerably and the tenons provide a fair amount of structural support for the rail. Hence I bumped the tenon size up to 0.4 of section thickness, instead of the more usual 0.33, and employed double pegging.

Here's half of one frame assembly after the four cross-members have been test fitted:

A little video now showing the frames being put together, to give you a sense of how things fit:

With the camera rolling, about half-way along in the video I managed to insert not one but two cross members in the wrong way around - you can see the mix up with the match marks - but it went together okay. I should have noticed something was off when the second cross member's tenon slid in just a little too easily. I get a little nervous when the camera is rolling for some unknown reason which causes me to be less attentive than otherwise. I'll put the parts together correctly, of course, when it comes time to peg the joints.

You may also notice that the front rails are taller sections than the rest of the parts. There is a reason for this which will become apparent soon enough.

The frames were then parked atop their respective cabinet boxes for a look-see:

Another view:

Onward and upward. I'll be working on the attachment mechanism between the assemblies just completed and their respective top boards on each carcase. Some further cut out is also required on these frames to accept the next tier of material in the cabinets. It was good to move them along and have good the joinery fits come out as planned.

All for this round of crazed ramblings and flights of fancy - thanks for visiting. On to post 57 next.

Wednesday, May 4, 2016

A Ming-Inspired Cabinet (55)

Having finally remembered to bring the camera data cord back from the shop, I can get on with post 55 in a continuing series.

I glued up carcase #2, filmed the entire process, which went just fine, and then discovered once again the entire piece wasn't quite in view despite having elevated the camera atop the shaper and thinking that everything was in frame. Oh well. I'll get the hang of filming sooner or later. How many more filming mistakes can possibly be made I wonder?

Once the clamps were removed a day later, I got on with trimming the excess material off of the dovetails:

Ichi-mai-ba-kanna work great for trimming end grain:

Here they are, cabinets #1 and #2, both upside-down at this juncture:

Now, an attentive reader named Marc pointed out that in a previous post, where I was mortising the drawer rails for front stops, I had said I would be placing stop mortises as well on the lower carcase panel. He wondered, looking at the assembled cabinet, why I hadn't done that. A very good question indeed. Yes, quite incisive.

Answer: I had completely overlooked it. The drawer rails are recessed 1/4" in from the outer carcase, so different settings were needed for mortising the carcases for the same stops, and what got set aside to be done later got forgotten entirely. It happens. In such a situation, is seppuku the honorable course, I wondered? Will my family have to follow me into the afterlife as well to preserve our honor?

Well, at first read of that comment/question a few days back, I had a cold rush and a sinking feeling, later followed by annoyance, which was then superseded by a bit of head scratching. How am I going to mortise for those bottom-most stops? With the drawer rails in place, there was not enough room to mortise, either by hand or power tool. Desperate plans cause for desperate measures they say. So, I came up with a plan 'b', which was rather more of a neat solution, I thought, than anything else.

Here are the stops for the lower carcase board on one cabinet - six stops plus two spares:

The carcase of each cabinet was upside down so as to facilitate mortising for the stops from the backside. Afterwards, I tucked the stops in their mortises prior to finishing off for the session:

Next day, once the mortises were cleaned out and flared, the stops were inserted thusly:

The fit was snug, requiring some hammer taps to seat the stop all the way down to its shoulders:

On the emergent face (the bottom face of the carcase board), wedges were fitted, however the wedges were not driven into kerfs in the stops as they would split the stops upon insertion. There were no kerfs done at all. Instead, the wedges received a smear of glue and were inserted on the outer ends:

The glue bonds the wedges to the stop, and nothing else, forming the stop's tenoned portion into a dovetail shape. This means the stop will stay put, and if it ever had to be removed, the lack of glue will make it relatively easy to replace.

After the wedging comes the flush-trimming:

I was satisfied with the way plan 'b' came out - - actually I prefer it for the lower carcase board to the method used in the drawer rails.

Here's a pair of stops after fitting and wedging:

Two cabinets - the one in the foreground has its six stops fitted and a first coat of finish applied on the sides, and the cabinet in the background has yet to have the same stages completed but you can spot the wedges in their temporary parking spots:

Today I brought the second cabinet up to the same stage as the first. This week, I'm back to working on Chinese teak wheelbarrow #3 for Jeff Koons, so work on the cabinets has been curtailed greatly of late and for the next day or three.

All for this installment - thanks for visiting the Carpentry Way. Post 56 is up next.