Monday, March 16, 2015

Le connard de ma mère m'a trompé son foutre

You never know when your French it's gonna be useful.

As you should know by know, we are moving soon and my tools are packed. Boring. Real boring.

I contemplated my options and it was either drugs in the park or some more learning. I still need to work for 3 weeks, and the spring doesn't want to come, so the park is cold. I took learning.

The french Art du Trait is beautiful. Seems to be useful too. And very very mysterious.

I found a french book and at the third plate I was done:

The 3D image I kinda see but when you project into a plane it's just too much. Far, far too much.

Let's look at something simpler. An acute miter of two angled boards.

(from here

That's what they call compound angles. (Physicist rant: why do they call it compound? It's always the same geometry going on only that sometimes things lay in a plane and other not. Welcome to 3D worlds. It's like naming the elements when you only need the number of protons... but I digress.)

The previous drawing comes with the following explanation: "Let ABC be the plan of an acute angle, BD the line of intersection, and E the piece placed oblique to the base. To find the line for teh face of the piece, place one point of the compass at I, and describe the arc AC; draw the tangential line GH parallel to AB; join BD and HD, then in the angle GHD will be found the bevel or the face of the piece E. To find the line to cut the edge, place one point of the compass I, and describe the arc JK; draw the tangential line KL parallel to AB, join LD; then in the angle KLD will be found the bevel for the edge of the piece E. 

My personal task is to understand how to produce the previous drawing. I like the idea of doing your stuff with pen and compass and let the electrons at home. I have no problem with google maps but man I like the old engravings more. 

To see if it works, I took the bevels of the drawing and put them in my favourite line maker program, keynote. 

 I was feeling good so I went with the other side too:

 No idea whatsoever where my bevel gauge is, so print the pattern and transfer it to the wood.

First time was a bit on the edge, so had to draw the line again.

That's the meeting point of the marking, not so bad.

 Sawing was awkward. The grain runs really in diagonal so neither the rip side nor the cross cut are nice to use. I was missing the madonoko, and this saw has not been cutting the same since it went that night with a piece of wenge.

 Close up. Just follow the line.

 The last face I was cutting was slightly goofied, you can see it.

There, on the bottom left. If I were to do this more seriously I would leave the line and then pare to it, maybe with some kind of jig since holding the piece straight is far from easy.

 First try directly from the saw:

Now, as a good snob, I will excuse myself for the next picture since all my kanna are in the other house already.  I know it's impolite to put naked western tools on the pictures, but at least this is not, say, a blue disposable saw. No pun intended, Jason.

 Good thing is, japanese modus operandi applies so the plane was put in the drawer (yes, that's the plane I leave in the kitchen drawer) with a sharpened iron:

 A bit of touching here and there.

 And they look better already. Here the boards are laying flat because I cannot take them in the hand and take a good picture, this is easier.

 But they were not square to begin with.

When you bring those faces together you get your acute miter.

That was it boys. All my wood is going to the trash this week so in the following month most of the pictures will be of lines and perhaps a table for Julia's new house. (She stays here in Graz till september, while I freeze my ass in the chilean winter, so she got a smaller apartment.)  Perhaps I manage to arrange a visit to Venice and Bologna to see the woodworking and the porkworking over there. Then in may some german violins and a dutch surprise....

Tomorrow or so some comments on hip rafter lay out, this time from a japanese book.

Wait. there was something about Newton and Leibniz, and how calculus took over geometry at the same time that capitalism took over whatever it was before. Long time ago you used to "produce" mathematical proofs, whereas after Decartes you could map geometry into algebra and everything got slightly more boring, abstract and senseless. I guess Bruegel was more of a geometrician than a mathematician, say like the bored Durer in his transvesti self portrait in the Melancholia, the one with the tools in the ground and the matrix on the heavens (you didn't see that coming, did you?).


  1. Hi Sebastian,
    congratulation, you cut your first hopper! well the problem is what do you want to learn or what for. The basic of carpentry drawing are pretty straight forward, a twelve century carpenter working on a cathedral roof knew very little math and a few simple geometrical operation, floor plan, cross section, rotation of a few plans to find the true lenght and a good knowledge of the compass. But he had a tremendous experience of wood and how to best use it! The way you dealt with japanese sharpenning gave you a good insight on practical knowledge, studying from old books can be misleading, too much information, too many unnecessary lines and not the basic knowledge to sort it out! So ask yourself first what do I want to do? and spend the rest of your life learning!

    1. Thanks François!

      I was looking at the church in front of my house the other day, it's quite old. The roof are just octogonal towers, very high, from what I guess is a late gothic. And once you know a bit of theory, pretty simple/basic/beautiful.

      What I want to learn... that's actually a very good question. Almost two years ago I told a very good friend of mine that I needed more time in Europe to learn, but I was not very clear on what I wanted to. I think the most interesting thing for me is that very very basic knowledge that allows you to make cool things from scratch, and the rationale for doing things one way or the other, more than the actual doing of something. For example, I'm not really interested in making violins at the moment, but in understanding the whole process and exchange between toolmakers, violin makers and lumber seller such that you can make violins in your little town... I don't know if that makes sense, but I'm coming back to the topic in a future post. Now you got me thinking.