Saturday, September 12, 2009

First Light XLIV

Post number 44 in this thread. Is this now a candidate for world's longest blog/build-up thread on a Japanese Shrine Lantern? Am I not set for fame and glory? Is it time to wear the appropriate fashionable sunglasses, and consider getting myself a security detail to fend off the inevitable paparazzi?

Anyhow, in the last post I was trying to make sense of sen, the Japanese term for fixing pin, without getting overly sentimental about it. I'll continue now with that sensational story....

The top end of the Lignum Vitae draw bar, to show the rift grain orientation:


Here's the bar in relation to the draw bar mortises, shared between post quarters:


One of the mortises is longer than the other due to the fact that the post quarters attach to one another with sliding dovetail keys.

The draw bar seated in place:


Post quarters assembled into a half-section, with the draw bar protruding:


I've omitting fitting the internal dovetail keys for this assembly (hence the temporary use of the clamp), as it simplifies the process a bit and I have to knock it all apart again soon enough when it comes time to trim the bars to length and mortise them for their wedges. It's better to reduce the wear and tear from assembly when possible, though this piece is very much designed to be easily assembled and disassembled.

The support post quarters now united as one, with both draw bars in place:


Now it's time to slide the panoply of components that constitute the bracket complex into place. First, the lower support arms (hijiki):


This first row of hijiki serve to also lock the support post top together as they engage with cogged joints at the post end.

A closer look prior to the fitting of the Goncalo Alves top cap - the keyhole-shaped slot is to allow the electrical cable to slide over from the center to the side, where it enters a corresponding hole in the cap:


Cap in place, further locking the lower hijiki together, along with the tier of pillow blocks:


Now it was time to fit another set of sen - these are to be of two types for this situation. The ones for the corner blocks are made of mahogany, and simply serve as a tie through the lower hijiki to upper hijiki:


The upper hijiki will be mortised for these corner pins, however the sill above is fully occupied with the lantern housing post tenons, and sits atop the hijiki in a housed half lap joint, so the corner pins will end at the upper hijiki line in the seat of the half laps.

Just for reference, these corner pins, in final assembly, would be saw-kerfed and wedged to lock internally to the lower hijiki mortises, a process called 'fox-tailing' in Western woodworking, and the 'hell tenon', jigoku kusabi hozo, in Japanese. Since these connections are irreversible, I'll leave off the wedging at this point.

The four corner sen installed:


Next it was time for the sen that occupy the short side, 90˚ oriented positions- these are different than the ones placed at the corners in these will pierce right through to the lantern housing sill, do-dai, and be fixed in place there with a special joint (to be detailed soon enough). I made these pins out of Lignum Vitae:


It looks like a forest of pins.

Now it was time for the upper hijiki to be fitted, but first I had to complete the mortising for the perimeter sen. These I drilled, chopped, and pared to size:


First component of the upper tier of hijiki slid into place:


Down slides piece number two:


Hijiki number two now seated:


That's my 15 pictures for today (10 for Charlie in Idaho it would seem), so end of the line folks. More to come - stay tuned for post 45. Hope you're enjoying watching and reading about this as much I am doing it!

3 comments:

  1. Chris it amazes me how precise you get everything... Is it literally a process of taking a slice w a sharp chisel, checking with calipers, then taking another if needed?

    I suppose it also helps to have precise drawings...

    Thanks,
    Matt

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    Replies
    1. Hi Matt,

      thanks for your comment.

      Precise drawings are a starting point. Being able to measure precisely is the second thing. Being able to make cuts in predictable increments in the third.

      When you are able to measure precisely, you can get to know how much is being taken off by a pass of the plane, etc. , and then working towards a target dimension becomes more predictable. I don't generally measure after each pass, more likely I will know that a pass with the plane will remove 0.001", say, and if i need to take off 0.005", then 4~5 passes should do it. If I'm using a router, I know exactly how much will be removed when I move the depth stop one click, so that makes it more predictable to adjust a cut after knowing the initial dimension.

      A lot of people will say that precision measurement is not part of woodworking somehow, that cut and fit is the way to do things, but I do not find the two incompatible at all and being able to measure well and process cuts with some degree of precision leads me to obtain a good fit with less trial and error.

      ~C

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