Tuesday, December 8, 2009

Tréteau dit Cadet

Again, not a whole lot of new stuff for the 'Tréteau' series for today, though I continue to draw that little monster. As part of that process, I explored another sawhorse in the Mazerolle book, this one a more basic model- the 'Cadet'. It has 90˚-section legs all around, and unlike the other drawing nightmare, each leg is rotated the same way in this piece. Instead of cross-braces between the legs, and between the long side braces, it has stretchers on the short sides, and one central scissor brace. What led me to draw this model was that if features some variations of the drawing method for producing certain sections, and I decided it wouldn't hurt to walk down the path a little bit to see if I might learn something. And I definitely did, in regards to the method for drawing the footprints of the feet on the ground, one of the challenges to this form of carpentry layout.

The sawhorse is a sound design, and perhaps I'll make a pair at some future date- these are taller than the sawhorse I am going to be cutting out any day now, at 80 cm/31.5" tall, and I can see having some use for taller horses - perhaps for a planing beam(?).

So, here's a few pictures of the Cadet model of tréteau, in all its glory, with a few rearrangements of the joinery from me.

Here's the overview of the plan development:


The tréteau dit Cadet:


A close of up the stretcher, its twin through-tenons (haunched, of course) and barbes:


The scissor braces through-tenon into the stretchers and are blind-tenoned into the beam:


A view of the top showing the leg tenons coming through (I would wedge them):


Just to give an update on my progress on the more complex tréteau - the process has been slowed due to some work in recent days repairing a Japanese exterior door for a museum in Boston, along with all the time I have been putting in on getting the first essay on Japanese compound joinery layout into print. This essay, the Volume II section at least, features an in-depth explanation of the kō-ko-gen method, an elegant way of tackling regular compound joinery using a framing square. The writing, drawing, and editing is a process that can soak up amazing amounts of time! So far I have completed the table of contents, and about 54 pages of text dealing with a review of mathematical operations and a thorough explanation of trigonometry. I'm nearly finished the section on cosine, which will conclude the trig stuff.

With the more complex tréteau, I have completed the rough layout of the legs, including the cut lines at the floor and the top beam, along with the top tenons. To finish their layout, I need to draw the mortises on the legs to house the various braces that attach to them. I've also laid out 2 of the 4 short side x-braces. All the interior x-braces are laid out. Not much left to do.

Swapping over to the new computer meant I lost my license to the 2D drawing software I had used for previous writings on trigonometry, which has given the delightful result that I have needed to re-do almost all of my drawings, now using SketchUp. I can't get the 2D software's license again because the marketing company from which I bought the software, and with whom I registered the product, is now defunct. I'm glad I only spent $250 on MacDraft, and it did serve me well for several years.

Later today I expect to begin editing the section on kō-ko-gen as it relates to the layout of a hopper. Then I have to put together an index, and a few appendices. Then I need to put together a set of exams for the material completed, though the essay (Volume I and II) can go out for distribution before that. So, my apologies to those who are waiting, you'll have to wait a little longer yet. I'm doing the best I can.

The mountain of work this has become has led to me revising the prices upward from where I last thought they would be, sorry to say. This essay comprises two volumes, and I will make them available separately or together. Separately, these volumes will sell for $17.50 each, together they are priced at $30. Later volumes will vary in price depending upon how much work needs to go into them. The exams will be $5 per Volume, and the Volume content can be 'challenged' (in other words, you can tackle the exam without needing to buy the essay). The pass level for the exams will be 75%, and if you flunk it you can take it again (the re-take exam will however have different questions) at no charge. To progress in the series, you need to pass the exam in order to qualify for the next section, kind of like taking pre-requisites at school. Some volumes will also have a requirement to make the project in question - the hopper and sawhorse essays will be like that for sure. So, along with the completed exam, I will need to see a picture of the completed piece before you can move along. Ya gotta engage the hands as well as the mind and heart in this process.

Here's how I see the preliminary bunch of Volumes might devolve:

Volume I: Carpentry Mathematics (including trigonometry)
Volume II: Introduction to kō-ko-gen (the hopper or asa-gao kata)
Volume III: Carpentry Drawing I
Volume IV: kō-ko-gen II (the splayed stool or shihō tate korobi)
Volume V: Japanese Joinery I (mortise and tenon, dovetail)
Volume VI: Regular Hip Rafter (bō-zumi) I (overview, proportioning, rafter end cut types)
Volume VII: Regular Hip Rafter (bō-zumi) II (joinery options/discussion)
Volume VIII: Regular Hip Rafter (bō-zumi) III (drawing the hip development, nage-zumi cut)
Volume IX:
Regular Hip Rafter (bō-zumi) IV (valley rafters)
Volume X: Carpentry Drawing II (polygons)
Volume XI: Japanese Joinery II (scarf joints and other splices)
Volume XII: Polygon II The Ki-no-mi kaeshi method (polygonal hoppers)
Volume XIII: Polygon III (polygonal stool)
Volume XIV: Polygon IV (polygonal hipped roofwork)
Volume XV: Joinery III (splines, hiyo-dori sen, hi-uchi sen, etc.)

And on it will go, if there's interest out there among readers to sustain its development and I have the time available to keep plugging away at the writing and drawing end. After polygons, the next sections would cover drawing methods, then irregular layout work, proceeding from irregular hopper, to irregular splay sawhorse, to irregular hip rafter work. Probably a section of joinery particulars too. After that, I will get into curvilinear work, again in the order of drawing methods, then hopper, sawhorse, hip rafter, then that would be followed by irregular curvilinear work. Probably at some point I will cover Japanese joined staircase work and approaches to kara-hafu (a form of eyebrow dormer) and minoko (gable roof edge roll-over treatment too. It could easily run 30 volumes when all is said and done, each volume 30~80 pages I imagine - there's so much ground to cover. We'll see what happens. At least there's a plan in place at this point.

Thanks for visiting today. To read more on french sawhorses, please check the label index to the right of the page, for "French Sawhorse", and "Louis Mazerolle Tréteau".





9 comments:

  1. G'Day Chris,
    I've expressed my interest in your essays before, however the prospect of having a course that is so comprehensive (with appropriate practical exams) is very exciting indeed. $30 dollars - sounds like peanuts for the work that I suspect you'll put into it. Count me in for the whole series, will it come with attractive binders to keep all the volumes together on my bookcase?

    Regards

    Derek Cox

    ReplyDelete
  2. Hi Derek,

    I haven't decided upon that issue of binders yet. The individual volumes will be .pdf documents, as will the exams. The user can decide whether to print out the material and put it in a binder, or keep the section on the computer. Overall that will save paper waste and keeps the cost down. There is another possibility as well, which involves the putting large and complex files in SketchUp directly into the format (not sure how to do that yet) so that it would be possible to examine drawings in detail which are much larger than the typical printed page of @ 8.5" x 11" allows. Then there is the matter of printers in other countries which format in metric sizes, A3, A4 etc - so I think the universally available (free to download).pdf file makes the most sense for the short term at least. I would like to do fold-out sheets for some drawings as well, and that is a tricky matter with printers. Hah, I don't even own a printer at the moment, and the large format units look pretty expensive.

    Once the book's material is all written and drawn, I will have the volumes bound into a hardcover book (possibly a multi-volume set) eventually. Part of the advantage of the method of putting out the book in a series of volume is that it allows for reader feedback, criticisms, suggestions, so that I can improve the text in various places over time. Plus, over the months, my own study of layout will inevitably lead to places where I might choose to fine-tune the text/format, share new insights, methods, etc..

    ~Chris

    ReplyDelete
  3. G'Day Chris,
    Humour doesn't come accross easily in a comment post. I was expecting electronic distribution - with the covers I was making a reference to those tacky plastic binders that the magazine distributors offer to keep your periodicals together. Please disregard my comments regarding binders.

    Derek

    ReplyDelete
  4. Hi Derek,

    no worries - I understood that you were joking around in your post, however the issue of how to compile and package the information in a serial format is still a subject under consideration for me.

    ~Chris

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  5. Are the 'barbes' purely aesthetic in these designs? Especially in the Cadet example, it seems to be an incredibly thin wedge that wouldn't seem to have any functional purpose. If the leg was mortised to allow a thicker wedge, it would make more sense... but I would simply joint the leg so both faces were parallel.

    ReplyDelete
  6. Hi Daniel,

    no, the 'barbes' aren't purely aesthetic, though I do agree with you in regards to their seeming illogicality. While you would have to ask the French carpenters who came up with the idea, as I pointed out a post or two back, the barbes are the unfortunate result of a seeming unwillingness in the French tradition to back the leg to bring it into plane with the prism which is formed by the splayed-leg shape.

    As for the purpose of the 'barbe': if you consider the Cadet sawhorse, the stretchers are analogous to the purlin meeting the hip in a roof, leg leg of course being the hip rafter. Since the roof surface will be planked over, the 'barbes' on the purlin would allow the surface to cleanly transfer over from the purlin to the arris of the hip.

    Of course, as you say, it is better to back the hip to bring it into plane - the best method, I feel is the Japanese one, in which all four faces are backed. This allows for easy mortising, and centered alignment of pieces, like purlins/stretchers, where they meet the side of the leg and where the tenon emerges on the other side. The French method means that one is left cutting these slender 'barbes', and perhaps cutting housings for them (which the French do not appear to do), and another effect is that some of the mortise and tenon configurations are most awkward to cut. Still, my study continues of French drawing technique because their particular method teaches me a lot, rounds out my perspective, present me with some different options, and moreover gives me a window into the thinking behind their classic wooden architecture in terms of how it is configured and put together.

    ~Chris

    ReplyDelete
  7. One more point I omitted to make about the 'barbes' in the Cadet sawhorse - if one rotated the legs so as to be flush to the short side of the floor plan instead of the long side as they are done in the model, there would be no 'barbes', however the tenon on the top of the leg and it's mortise would be slightly more difficult to cut. With the legs rotated to the long axis, the mortise and tenon work between the legs and the beams is the simplest to cut out. It's a 'six of one, half a dozen of the other' situation.

    ~Chris

    ReplyDelete
  8. Hello Chris,
     
    I could not follow all the entries of this topic but I wanted to ask if you sell or no way and get the drawings in this post. He forgives my English, google's fault because it is not my mother tongue: D
    If you can contact me through my email I would greatly appreciate it.
    Thank you.
    Sincerely, Olau Puig from Barcelona
    olaupuig@gmail.com

    ReplyDelete
    Replies
    1. Olau,

      thanks for the email. At this time i do not offer drawings for sale, however it is food for thought.

      ~C

      Delete

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