Thursday, October 8, 2015

Yosemune no Sumi II

Ok, before you complain for the poor fits and the fast cut joinery (and the use of band saw) let me tell you one thing. This thing is addictive. I could just not wait too see if it was actually going to fit.

But it kinda did.

The ga is because the distance between the two points under the hip rafter was computed along the plane and not the pitch... I see it now. But that's close enough for a first trial.

Some pictures of the drawing:

I made just the nose, since I wanted to understand the rafter I didn't need the back part. Once it's in place I draw the lines. Now you need to pass the centre line of the rafter to the beams... at 45 degrees and sloping. The slope you see on the sides.

It took me 3 trials to find out which pitch was the one going there. Half roof pitch, triangle marked line according to yesterday's drawing.

Sorry for the poor lighting.  Looks cool isn't it?

I kept on marking the lines to keep track of where I was. 

 And another poor light photo. I make the other dovetail and post it later.

 From the back side.

Remember that I draw the lines with the dovetail in? Well, I also chiseled it and broke it a bit, that's why the nose is bent a bit now.

Naked joint:

 and disassembled.

This part was real fast. I did use the band saw to speed up the cross cuts, and even tried the other dovetail in it. It sucks.

I'm a bit on an adrenaline kick, feel like having reached the top of the mountain and now you can say "it wasn't that hard, was it?"

Oh, and something I wanted to comment on after reading a piece of Chris Schwarz about learning. I also had it in the university, all the homeworks that made you feel really stupid, overstressed and depressed. You learn like that, it's true. But it's a bit stupid to pay people to enslave you so you can learn just because you are not free enough to teach yourself something. (Maybe this doesn't apply to medicine though.) What university (and courses) does is to organise time for you. From 9 to 12 lectures, then you need to eat, and homework. It kinda works. ( One of the professors I was assistant of used to say that 90% of the people didn't learn anything in the university... and then proceeded to blame the people and not university. I dated his daughter too.) But there are ways of learning otherwise... programming for example. I do not know any good programmer who had learnt in classes what he knew. They read, program and make mistakes. And document the whole thing. That way they made linux.  That's because they know they can do anything they want in the computer, they just need to learn how to write it in code. I'm starting to think that the world is the same. We can do whatever we want with it, and just need a few tools to do it. We just need to learn the how. And document it, so it's not lost.

Enough bla bla. I need to get larger timber to make the real model.

EDIT: I moved the model where there's more light. I should look like this

This is how Chilean standards for construction work: if it can hold a beer, it won't fall in an earthquake.

The line of the pitch.

And the oversized cut... I planed a bit too much that part.

The problem with the gap at the was that I put the base where the point should go. So I took it out and fitted "perfectly" (I made another mistake at measuring the depth of the cut, that's why you need a 160mm height piece...


  1. Ahhhhhhh! How is it we both do not have sashigane with sqare root scale? You are spot on, we learn practicing what we suck at, it would have been so tempting to practice another joint that I know wouldn't be too much trouble to lay out. I'm still trying to learn to name the parts, can hold it all in my head without knowing the names...Chogen, nage sumi line, toge, kuchiwaki line, gotta know the names.

    The internet has put the university system in peril, especially so here in America where colleges are bloated and fat with student loan money bubbles.

    1. actually I think it's not so necessary. Marking the 14.14 for bevels is good enough for this joint at least.

      That;s funny, I don't need names at all, just to see how things go together in my mind. Once I have the "image" (which is not an image actually but you get the idea) I can repeat the process and translate from the 2D drawing to the model.

      I'm tired, mentally tired, but feeling good. As soon as I get some energy I go planing those bevels on the rafter.

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  3. You're square root of two is the same truck a spar gauge works on.

    Might be able to work something similar out and use that to lay out the hip in this joint.

    1. Nice! Yeah, I'm constantly using Thales theorem in my mind. Which is kind of moving a spar gauge along imaginary surfaces. I think what I would like to make is patterns with the angles of the pitch, like a mitre marking gauge. It was slow to have to measure each time the pitch from the sashigane and then each time you move it you need to set it again. That or steel stops for a ruler.

  4. Wow, it's the same in Vermont! If it can hold a beer, it won't fail in a blizzard!

    As for layout of lines, I suspect it is like the proper order of stroke count in kanji writing, or drawing. Also, I suspect there are story poles for various parts of the building. I know the floor plan is drawn on wood, to scale, locating post centres. From there, story poles full scale are made, and then the foundation is layed out on the ground, no need for steel spring self winding tapes. Then the guy with the story poles, floor plan and sashigane keeps track of it all, and there was probably more than one way to go from there, because the carpenter families were not sharing secrets, from some date?

    The common thing was to have a method from which there was no deviation because it was the bones of beauty. Sumi is fundamental in this sense; just ground charcoal, or lampblack, and some starch or hide glue.

    It is a beauty, like Haiku, where essential nature is not dressed-up so as to distract everyone from the transitory. The Poet, the artist, the carpenter, just get out of the way and the process is the form.

  5. We usually use wine to judge construction here. Occasionally beer.
    Haven't had ice storms in a while, too much warming but we are having more tornadoes and regular storms...Branches are dangerous.

    Joint turned out well, I'll be learning through you guys until summer comes again.