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

Now that we have our stock dimensioned to size and rough cut to length we can start some joinery work.

Mark some lines in strategic locations:
Attachment 203325Attachment 203326Attachment 203327

Cut a few tenons here:
Attachment 203331Attachment 203332Attachment 203333

Drill and chop some matching mortises there:
Attachment 203334Attachment 203335Attachment 203336

Drill some holes and square them all up:
Attachment 203337Attachment 203338

Run some trenches through where they need to go:
Attachment 203339


We're getting closer...

Now that we have all our Lego blocks we can assemble in accordance with the instruction booklet that came with the box:
Attachment 204399Attachment 204400

At this stage the preparatory work is complete and we are ready to start the focus of this this particular carpentry exercise - Does it look like there is some unused real estate to the right of the two straight rafters in the photo? Yes? That is because the work so far is simply a receptacle for another rafter that attaches to the right most rafter in the model and skews outwards. The complete model is shown in this graphic from some of Chris' material where the skewed rafter or 'fure-daruki' can be seen:
Attachment 204401

The skewed rafter slopes in a compound manner, firstly at the common slope of the roof (the same as the straight rafters) and secondly at a slope away from the common rafters. What geometric machinations will result from this angular foolery I wonder...

Stay tuned

I get lost trying to keep joints square, so there's no way I could handle all those angles. I'm impressed (confused) with the complexity but I like the neatness and accuracy of you're work - well done.

Sheets,
Thank you for the very kind words, though I have to confess that each of these projects seemed daunting to me as I started them (well except for the first one). I am not an accomplished woodworker - there is a wide gulf between the likes of Des. K. who can earn a living from his work and myself who works as a hobbyist after work. When faced with something daunting I try to remember that even the most complex projects are just a series of simpler steps - sometimes that step is one pass of a plane, the more complex the project, the more I break it down into smaller steps. Fortunately the group has it's own forum where I have asked many questions and other members have been very generous with their time answering.

In addition, I have found that compound joinery is not so much a harder way of working, more just a different way. There are tricks and techniques, methodologies and so forth that are more suited to this style of work than others. In many ways it is more exacting but in others it is just different. Importantly I find that this kind of work has a flow on improvement into my more 'traditional' kind of woodworking.

I say this in the hope that it will encourage others to explore this discipline. If you find this sort of thing interesting but believe that it is beyond you then please understand that if I can do it, you can too. As I have said earlier I find the Japanese woodworking legacy fascinating, so seeing such little interest in the forums (all Japanese woodworking forums seem very quiet) is a little frustrating. This is my bit to try and garner more interest instead of just complaining about it.

Regards

Derek

P.S. When faced with new and difficult tasks, I have always found Picasso's quote a source of comfort and inspiration:

'I am always doing that which I can not do, in order that I may learn how to do it"

Great progress Derek. Well done.

I've been following your threads, but haven't commented because it's way out of my area.

The carpentry students (two-year course) at the college in Toyama where I studied shoji focused on this kind of work. This photo shows their final examination project.

Attachment 204875

They obviously covered a lot of the various complex joints that make up traditional Japanese carpentry, but ultimately, they were judged on how well they could make the roofing joints. In fact, one of the carpentry students who graduated the year I completed my 12-month course won a prize at one of the carpentry skills competitions a year or two ago, and sure enough, the requirement was that they had to draw up and construct a section of roofing, obviously involving (traditional) compound joinery. That's how important these skills are.

Over my time at the college, I spoke to the carpentry students, and the main difficulty they seemed to have was getting their heads around the relationship between the individual pieces, angles and joints. Once they had that "light-bulb" moment and managed to overcome these initial difficulties with, I suppose, the overall spatial concept, it became much easier. Not just with roofing, but with all their joinery projects.

So I think the traditional Japanese carpentry skills you are gaining from Chris, and in English I believe there are none better than he is at this kind of instruction, will help you tremendously in all aspects of woodworking, even if you never make a roof.

Hang in there and keep up the good work.

Des

I know its just a matter of connecting all the small steps, but when one sees the beginning and the end without having tried the small steps, it looks like a very difficult thing to do. As Des mentioned, its getting it all straight in the mind, which at my stage, has not happened and I've not applied myself studiously enough to overcome such a barrier. Perhaps one day, but for now, I'm happy to stick to easier (at least mentally) concepts.

Anyway, its great that you've taken on the challenge and succeeded - and thanks for posting. I know there are lots of us who enjoy the activity.

Steve

Des and Sheets,
Thank you for your comments and I apologise for the Extremely tardy reply. Work descended into mayhem over the last couple of months and my employer decided that I needed to be away from home for lengthy periods.

Des, I appreciate your comments and photos from the carpentry students you came in contact with. Any other anecdotes or photos that you can share from that time would be of great interest to me.

Oh - and I definitely would like to make a roof/s one day!!

Sheets - please don't take my comments as suggestion for what you personally should or shouldn't do, I would never be that presumptuous. Consider it a general 'call to arms' for those who are interested but fear it may be beyond their capability.

Regards
Derek

Now, where were we before the need to earn money to buy food waylaid this endeavour?

We had reached this stage where the receiving structure was built ready to accept our skewed rafter:
Attachment 222850

And our skewed rafter needed to be inserted as shown in this diagram:
Attachment 222851

What we want to be able to do is draw the skew rafter in accurate life size dimensions. To discuss this let's start with a drawing in plan view:
Attachment 222853

A little thinking will tell us that we cannot take measurements directly from this drawing because the rafters don't sit in this plane but slope down and away from the drawing. To get full size dimensions and something we can measure from we need to do a projection that depends on the slope of the roof. Without going into the laborious details, here is a picture of the completed drawing. Note the numerous lines projected from strategic points on the plan view across to the right where we have an expanded, rolled out view of our skew rafter. Note here we have determined the parallelogram cross section required for the skewed rafter:
Attachment 222854

The rolled out rafter is full size and we can take real measurements from this (including angles) that can be transferred to our rafter stock. First let's achieve the correct cross-section:
Attachment 222855

Does it sit in it's trench correctly? Fortunately yes:
Attachment 222856

Next the receiving mortice in the common rafter which will accept a half lap tenon from the skew rafter:
Attachment 222857

Now the tennoned end of the skew rafter:
Attachment 222858

And let's put it all together:
Attachment 222859
Attachment 222860

And, importantly, it achieves several aims; that the top surfaces of the rafters all sit in the same plane:

Attachment 222861

That the ends of the rafters (square cut) all sit in the same plane:

Attachment 222862

And that the sides of the skew rafter, like the common rafters, are plumb:

Attachment 222863

Thank you to all and any that have shown an interest in the projects so far. This is not the end but just barely the beginning and I will share the next project in sequence with you all as soon as I can.

Regards

Derek

Great read,thanks for sharing.



Regards,



Frank.

Frank,
It's a pleasure. Your comments are appreciated.

Derek

thank you Derek

Having seen Japanese joinery in the flesh, it's great to see it under construction in minature