Wednesday, February 20, 2013

French Connection 12

I had moved my drawing of the three-legged bench, a layout project intended for the study of placing Saltaire crosses with their pieces in various rotations in between posts and beams which are not orthogonal to one another, to the point where I was about to start in on the third pair of braces. Then I had a re-think about it, and decided I really wasn't going to be happy enough with the aesthetics to devote the time to building the piece. So, back to the drawing board - either that or abandon ship.

Stepping back and considering the issues relevant to the layout of this piece, i was able to achieve a few breakthroughs in understanding in terms of the basic associations and slopes between members. As i result of that, I was able to try an idea I had a long while ago about making the tripod beam assembly from pieces which had a bend at their ends. This bend brings the end of the beam into alignment with the post below, which gets rid of the annoying off-set interface between the two sticks, an annoyance I could never really come to terms with.

Here's a look at where things stand in the virtual world at least - I've nearly finished with brace set one, the 'faisant lattis entre elle' set:

Actually, starting the layout from scratch, with different slopes for the posts and the inclined brace pair, led to some further breakthroughs in understanding, after hours of puzzlement, as I came to see that I had not properly understood a portion of the layout in my previous go-rounds. This method of Mazerolle's involves the production of 'footprints', which are like projections of the stick's cross-sections onto the floor - you can see one in the above drawing at the left, a grey parallelogram just near the foot of the post. Once you obtain the correct parallelogram footprint, you are able to draw an accurate plan view of the braces and determine their intersection points with the plan views of the posts and beams, and from there construct the cuts for the ends of the braces.

Mazerolle's drawing is fairly cryptic, as most of the geometrical development lines are omitted, and the text's explanation is not of much help once deciphered. So, a fair amount of head scratching is involved. I found that the method I had used previously for developing the footprints on this side of the bench was not working in the new drawing. Eventually I realized that I had understood the method incorrectly, and had produced the wrong shape of parallelograms in my previous sketches. Measuring the 3D constructed sticks, I found they had cross sections of 93˚/87˚ instead of 90˚. Even though the sticks weren't square in section, they will construct from 2D to 3D just fine and lap one another cleanly, so it all looked good. But it wasn't. One of those aha! moments ensued, and I was able to figure the method out correctly a while later.

I have figured the footprint method out, and feel like I have a solid understanding of it. The same can not be said for other aspects of the layout, though I'm getting there. In terms of understanding, my grasp of the problems, I may be hanging from my fingertips on the ledge, so to speak, but I feel like my grip is slightly strengthening at least.

Clearing away some of the lines, here is a pic giving a better look at the revamped design:

Next, a plan view - I'm thinking about a glass top again for this project, so a view somewhat like this will be apparent, given the overall height of 20":

Once all the brace sets are in it starts to look a bit like a snowflake.

One more:

Other slight changes I have made involve the tenons on the top of the posts and on the ends of the tripod beams, which have been squared back on one side to facilitate assembly. I have had some further ideas about joinery for connecting the braces to the beams, and will be exploring those ideas further as I move the drawing along.

So, what do you think - does it look any better with the bent tripod beams? Even if the aesthetics don't seem to show any great improvement overall, the bent tripod cleans up the junction between post and beam and that was the main purpose.

All for now, thanks for dropping by. Comments always welcome.


  1. It is exiting to see that you are finding solutions for the difficulties you encountered earlier. To answer your question about the looks.
    I think the shape looks more 'sophisticated' then before and I this is not so appealing to me personally. But if this is the compromise you should make in order to make things work or even consider continuing the project there is little you can doubt about.
    I think if you actually get to build it with joinery as you intend it will be an improvement on what has been done earlier with this model anyway.
    Looking forward to see your progress.

    1. Mathieu,

      thanks for the feedback. I'll definitely accept a little sophistication in the evolution of this project. The complexity and genius of the piece lies in the drawing techniques Mazerolle shows in his book. My aim is to understand them better, decoding bit by bit.


  2. To 'Adam',

    I posted your comments and have since decided that they contribute little of useful value to this blog, so they have been deleted. I welcome public comments and input, including constructive criticism, however those who make abrasive comments intended to hurt another, while hiding behind anonymity, amount to trolling and have no place here. If you wish to communicate, and are willing to put your real name to your words, as I do, then I welcome further engagement.


  3. Chris,
    I was interested to read that you had had to change the footprint method. Had you been using the method described in your blog-series "X Marks the Spot" ? If so, could you give any details of how the new method is different ?
    Perhaps the development of an isolated leg would be illustrative.

    1. Rob,

      thanks for the comment and question. I'll see about taking that up in the next entry in this series.



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