the Carpentry Way: This One Rings a Bell (6)                                                          

This One Rings a Bell (6)

    
Well, another week or so has flown by, and I've been hard at work on the bell tower drawing. Today I will bring y'all up to speed with the most recent developments.

I have beefed up the exposed hip rafters for starters. This was accomplished by raising the hip section around the lower end so as to make the komai (battens) sit in housings along the hip, rather than atop the hip:


This added 1cm or so of height to the lower section, and makes for a better joint with the komai to the hip. Also, by having the komai sit in housings, the ceiling boards will attach cleanly to the hip without a gap between each successive set of komai. The upper section of the hip never needed to be backed, so I returned it to a rectilinear section and added about 5cm in height. Also visible in the above picture is the hiro-komai ('wide' komai) which sits at the top of the run of battens, and covers over the small boards - men-do-ita. These boards block the wind from passing in between the rafters, and deter birds from nesting in space like that too! Both the hiro-komai and the mendo-ita are curvilinear like the rest of the battens.

In other news, the fan rafters are finally completed. OMG! These took a long time to draw and stretched me to my limits in layout. These are tough and required lots of calculation and 12 separate descriptive drawings!

I've got lots of pictures to share - here's the first:


I've left the bell out of the drawing for the time being as it speeds up the rendering. One other detail added, visible in the above picture is at the eave edge, where the build up of fascia now features an added layer - the kami-uragō - or, 'upper carapace'. There may be yet another layer going on there, the fukiji, or something else, but I haven't decided yet on that matter.

An aerial view of the fan rafters:


Now from on down, crouching low and looking up:


In the above picture one can also see another small change I have made to the support structure. Notice that on the right side, on top of the lower beam, there are now two bottle-neck struts instead of the one as there used to be, and as remains on the left side. This change improves the strength and resistance to deformation in that section (and the one directly across from it), though it does mean that there are now two different arrangements in view. Now the step is done, I think it looks fine with that small amount of asymmetry, though I was uncertain about it when considering the matter initially.

I have also added the final layer to the decorative eave structure- the ceiling boards:


In this case I have made them to look like Eastern Red Cedar (actually a juniper), however that is just one possibility. The other leading candidate is Western Red Cedar (not a true cedar either). I am looking for something that is light, rot resistant and relatively easy to bend. Funny enough, I can obtain higher quality WRC here in Massachusetts than I could back in B.C. (in Canuckistan) from a lumber yard. That's what they mean by 'export markets' I guess. While some countries experience a brain drain, Canada seems to have a board drain.

Looking straight up, this is the view:


The section in the middle of the roof will have a ceiling fitted, but I am leaving off designing this part of the building until the rest is done. It is a standard in Japanese architectural drawing to provide a plan of the ceilings in a house or other structure, as they are an important design element and subject to considerable elaboration and differentiation. At this stage of the drawing I have left the ceiling boards as an overly-simplified 'mono-board', however in the actual structure they will be individually shaped pieces, just like the rafters that sit below them. Each ceiling board will be a section of the fan, and differentially curved.

The reverse view, looking straight down:


Interesting to note the optical effect of the fan rafters, making two of the beams below in the support structure look like they are curving outward like a pair of parentheses '()'. Take my word for it, those beams are dead straight!

A close up of the eave build up, with the square-section kaya-oi on the bottom, then the uragō, and then the kami-uragō:


Here's a look at the fan rafters with the komai and ceiling boards removed:


Next, a view of the rafter tips looking along the eave edge:


Notice how the rafter tips gradually project out further as they move along to the hip and their downward cuts, along with their top/bottom cuts, vary with each rafter. This treatment provides a very smooth visual flow along the eave edge, point to point along the rafter tips. I think the final one in the row, right next to the hip has a very slight error though in the down cut, which I will attend to shortly.

One for the road:


The exposed eave structure is now complete, and I can move on to the actual structural roof drawing. While I am deciding about how to cap off the eave edge, I can lay in the lower tier of support beams inside the roof and lay out the fanning cantilevers, or ōgi-ha-ne-gi. Are you drowning in the Japanese lingo yet? Sorry about that - just trying to be clear without recourse to such gems of concision as 'whatchamacallit', and 'thingamabob'....

Thanks for swinging by today. Comments most welcome. Take care on your travels, and hope to see you soon. --> on to post 7

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