Thread: Chris Hall's Carpentry Study Group - First Project

For those of you who don't follow Chris Hall's Blog, I implore you to rectify this oversight immediately - his blog can be found here, And for any serious wood enthusiast, it is some of the best reading on the web

But fair warning, you will need to allocate some serious time to work through it all, at last count I think he had nearly 500 posts in the three odd years since he started. Nor are there a raft of posts just placed there to add fluff and padding that you can be justified in skimming over to get to the 'guts' of it. No all you will find there are profound musings on the art of using wood, past and present, alternating with series of posts detailing the construction of some unique and beautiful projects.

A word of background on my own interest on the subject. I have always loved the Japanese aesthetic when it comes to built structures and have admired the heights to which they cultivated the art of carpentry in the building of their temples and other wooden structures. I admired all this from a distance, despairing that useful knowledge on the subject would probably never be available to me in any useful or practical sense (not living in Japan and not speaking or reading Japanese). So you can appreciate my elation when Chris announced that he intended to commence a course in the study of traditional Japanese Carpentry. The form of this study group has changed around a bit since inception and is now quite a mature product. As an aside Chris has also written a series of essays on several aspects of Japanese Carpentry - I am happy to relay my thoughts on these if anyone is interested however the topic of this post is the first project in the Carpentry Study Group.

The Hopper:

If you are unfamiliar with the name, a hopper can be thought of as any section through a four sided pyramid, parallel with the base. In short a four sided funnel, square or rectangular in plan, all four sides having the same slope.

The focus of this study is to determine the three angles at the edges of the boards where they intersect at the corners. These are the face cut, the edge cut for a but joint and the edge cut for a miter joint. These angles will vary in relation to the slope that you choose for the sides and, of course, be related to that angle. From memory I chose a slope of 5/10 for the sides. The slope in this case is measured as a deviation from a perfectly vertical board, as opposed to a roof slope where the slope would be measured as a deviation from horizontal. Although the maths for all three angles was covered in this first project, the task was to complete a hopper with four but joints. No joinery was required as the corners were to be simply nailed.

So, what does the hopper look like you ask?



Well,



Just using some scrap pieces of pine laying around,



and it's only nailed remember



OK, here it is,




Ta da!!


Attachment 201576


Ok so it's not all that exciting, however the three angles in question can be seen, here is the face cut angle, which you can see is some slope shallower than the 5/10 slope of the sides:

Attachment 201577

And here is the but joint edge cut, perhaps non intuitively, the board is longer on the inside that the outside, that is the board angles outwards from the outer face to the inside face (if that makes sense)

Attachment 201578

And of course the aim is for it all to be square:

Attachment 201579

So the first project is quite a modest undertaking but the concepts learnt here are a foundation to more difficult joinery options and that is the focus of the second project which will be the topic of my next post.

Hope this might be of some interest to you.

Regards

Derek