Wednesday, October 7, 2015

Yosemune no Sumi: Rpoject Mahyem intermezzo

You know that that is, isn't it?

While we wait for Jason to finish his joint I decided to start with something more complex. Or rather, something I don't understand well how to make. Once you learn it they are all the same easy joint. 

This is what I want to make this week:

The horizontal members are easy to make, dovetailed on into the other. Once they form a T (or an x, depends where you look from) you need to put the hip rafter on top. That was the part I had trouble with. 

I remember o have studied this joint in some airport, I managed to understand the geometry and the square roots of the pitch, but one thing is to understand on the paper, a ver 2D being, and other completely different to pass that into 3D timber. At least for me. 

It took me around 4 hours to understand what pitch was the one I needed to put on the rafter. 

I even had a nap in between to activate my brain zones that have to do with mathematics and sleep. 

(Now you see that the mathematics problem from the last joint was useful?)

Of course, once I understood which pitch was the one needed there, I found a small legend:

I was complaining why it was nowhere written the pitch of the line... but it was the whole time in front of me, I just wasn't seeing. 

There are a lot of square roots of 2 going on in this joint, that's because the pitch is regular, so the same on both sides of the roof. 

This was another difficult one. But I don't want to give too many details so you can find out by yourself.

I also got my sashigane today. Looks small and doesn't come with sqrt(2) marking on the other side, so I'm thinking of filing a notch at 10.14cm. Shit, I meant 14.14, I'm a bit dyslexic.  I guess I have a mistake on my layout.

Using the sashigane was like meeting an old friend. It's light, flexible, square. It's easy to use. Like in EASY!!!!! I really don't know how I lived without one before and I may get a 50cm one. It's one of those tools that once they go into your hand you don't want to let them go

And another square. I was a bit short of squares for the course. I know, I should make some for the students, lousy excuse. I just love starrett squares. They fit so well in the hand. I will go down and make a wooden square now as punishment for buying another tool. (There was some roosewood left from the sashisen of last joint.)

 Anyway, after 5 or 6 hours nap and walk in the city included, I started to cut the joint.

 Exactly, first cut and went over the line. Idiot.

Chopping was easy and fast

 and later had to sharpen Opa's 1" chisel again, western steel lasts nothing. I should have brought one of my paring chisels.

I'm working here with a 3"x3", but the drawing is for 120x160mm so I need to visit the home centre before making the real model.


  1. Wow! Sashigane and hip roof model, you're really pushing forward. I've looked at the layout for this a bit, but my brain melted. I'm going to have to give this a try, just go for it. Do you think this could be our next project mayhem joint? Feel up to it Jason? Its a major milestone.

    1. mine did too but I'm still alive. The mathematics is not so difficult as it's the rotation back and forth between how to lay out and where the lines will be once put in place, if that makes sense.

      I'm really curious how long it will take to someone without a physics background to understand it. Probably less than to me, hahahaha.

  2. Congratulations! I've yet to try this one.