Sunday, January 30, 2011

X Marks the Spot (XIII)

Thirteenth and final post in this series, with previous installments found in the archive to the right of the page. In the previous post I completed the development of all the projection lines onto the unfolded view of piece 'b'. All that remains is to decide which lines are to be cut, and in many ways this is the hardest step in the entire process.

Here then is where we ended up in the last post, with the four planes of stick 'a' projected over onto the unfolded view of stick 'b' to give those 4 zig-zagging lines across the faces:

In the above drawing, several elements have been concealed to give a less cluttered view, including the elevation view of stick 'b'.

Now, to decide where to mark the cut lines we need to take a look over at the elevation view of stick 'b', where we had previously established the cutting planes. To refresh, here are the cutting planes for the 'front' and back faces of stick 'a' respectively:

And here are the 'left' and 'right' faces of stick 'a' forming their cutting planes on stick 'b''s elevation (note the outlines of the other two planes in relation to these ones):

In the next picture, I will place all four cutting planes in the scene at the same time, and remove the coloration from all planes so we only see their outlines:

Next I mark what is what in terms of the outlines of these planes and which parts of stick 'a' they represent:

Note carefully the places where one cutting plane intersects another -as i have indicated in the above drawing. A couple of those points are rather close together, so I provide a close up of that area:

Now I'll take one point of intersection between one plane and another and project it over to the unfolded view of stick 'b'. Of course, a point of intersection between planes is the same thing as a corner of the stick 'a':

See how the projection travels over and note its place of intersection - just where two of the lines on the unfolded view of 'b' intersect one another.

Continuing this process then, I find the following points of interest, by projection:

This really is the crux of it - you have to carefully consider where the corners between planes are formed, and, at the same time relate their positions to the various unfolded faces. One area that is likely to confuse is the connection between the arris at far left of the unfolded view with the arris at the far right. Remember that these lines are one and the same thing.

Okay, here then are the areas which need to be removed from the collision of the four plane and their lines projected over to the unfolded view of stick 'b' (drumroll please...):

I've also taken the liberty of shading the portion of the elevation view where material would need to be cut away.

Now, the proof lies in the pudding, so to speak. Since we have been working this past while on an unfolded view, a view that I showed I had developed by taking a virtual stick of wood and treating it as if it were a cardboard walled section and unfolded, then why not reverse the process?

Here's the fully unfolded view popped up off the 2D plan:

Now we start to fold it back together:

Folding is completed in the next picture:

We may as well swing the stick around into the position occupied by stick 'b' and place it at slope:

Next, I'll do a little virtual surgery and remove those shaded areas, then make some connections internally in the stick to create the section that is removed from stick 'b':

Another view:

And now we return to the start, with both sticks combined, to show the fully resolved problem:

The unfolded view could be employed in a couple of ways to actually mark out stick 'b'. If the drawing were at 1:1 scale, we simply place the respective faces of the stick upon their corresponding unfolded faces on the paper/ground, and mark the spots on the arrises of the stick where the cutting plane lines cross through. This process is repeated for each face and then the tick marks at the arrises are connected across the faces, then one has to decide where to cut, and proceed from there. If the drawing is a scaled down, affair because one doesn't have the room for full scale work, then it would be a matter of measuring from point to point on the drawing, converting these measures by the scale, and then transferring to the stick. The angled lines across the unfolded view, including the top and bottom cut lines, could easily be transferred directly with the use of a bevel gauge (or three).

If one needed to detail different joinery, or mark the points of intersection of stick 'b' onto stick 'a', then the same process used to develop 'a' onto 'b' would be applied the other way. No need to detail that process here, as the technical methods are exactly the same as have already been described. Readers who wish to cement their understanding further may wish to do another round or two of this exercise, varying the plan angles of the sticks and seeing what kind of trouble they can get into. And it wouldn't hurt to cut a couple of sticks out to examine how the connection works as well.

I hope those readers that took the opportunity to follow along got something useful out of this drawing process. If I can obtain other useful drawing problems out of that same French text, and I get the sense that there is further interest in these sorts of explorations among readers, then we'll do another round like this later on in the year. Thanks for taking to time to involve yourself in carpentry study!

That my friends is that. Down to one build thread now, so it looks like i may have to introduce other topics soon. Stay tuned.

Saturday, January 29, 2011

Ming Inspiration (21)

The twenty-first post in this thread with previous entries found in the archive to the right of the page. working with a large slab of bubinga, I am designing and building a frame and panel table taking its inspiration from a unique Ming Chinese example.

Work continues apace on the apron joinery. In the preceding post I had roughed out the mortises on all four pieces, and now it was time to process the cuts for the tenons. First off I made some small trimming cuts to the end grain walls of the mortises:

I made up a jig to fix the aprons so that I could perform the cuts:

The jig incorporates captive nuts so that I can clamp the material firmly in place using a ratchet and socket:


For the two short aprons, I made up an arrangement of sawhorses, cleats, and clamps so that the jig could lean at an angle:

Cutting of the end to define the tenons and the mitered abutment could now be completed:

I actually constructed most of the above jig about a month ago, however completing the jig and then processing the 8 cuts on the 4 pieces took me a full two days of work. Here's the two short aprons ready for the next steps:

The two longer aprons required a different set up - here's what I rigged up:

All four pieces now through this stage:

Another view:

The slab of green wood you can see above is lignum vitae.

One issue I've been dealing with for weeks now has been the two slices of wood for the table top panels. Both were sliced out of the same slab and taken down to dimension at the same time. One of those pieces has been behaving quite well, and has only moved a slight amount. The other piece however has been moving quite a bit. I've been engaged in a dance with it on a daily basis in fact and have been a bit stressed out about it at times. I've moistened sides, I've dried sides, I've flipped it around. Lately, my strategy has been to dampen one side and press it down onto the floor, which seems to be helping:

The piece on the right is the table top board, while the piece on the left, also bowed and cupped slightly, is the remnant slab from which the two table top boards were sliced. My back up plan, in case the table top board on the right just won't settle down, is to plane the remnant down to form another board - if the remnant will settle down that is! In the background you can see the other table top panel standing up- it's the quiet and well behaved child that has scarcely been a concern at all.

Another view:

The table top board on the right is being pressed down flat by another slab of lignum vitae that I have kicking around.

Every day when I go into the shop the first thing I check is the situation with these pieces, and make frequent checks during the day to monitor the situation. Things seem to be calming down with these two pieces. Stress levels on my brain are also settling down of late.

All for today. Thanks for coming by! -->on to post 22!

Friday, January 28, 2011


Driving home today from the shop, chugging away at a nice 2200 rpm, which gives me the best fuel economy with my archaic 6-cylinder diesel, I was thinking what to write about on the blog tonight. And then it struck me: today is the 28th! That means this blog is actually two years old now!! Frankly, I can hardly believe I've made it this far, though I'm far from running out of things to say, let me assure you. Actually, I'm bursting at the seams with ideas of late.

At the one year mark, I had posted 181 times, and there were over 53,000 page views with a followers list that had grown to 53. Today, just one year later, followers sits at 80, page views is closing in on 177,000, and the post count, with this entry, reaches 350. Possibly by year-end I will be approaching 500 posts. Again, hard to believe.

This last month has seen quite a spike in visitors for some unfathomable reason. I used to get 250~300 page views a day for most of 2010. This month however I am averaging over 620 page views a day(!). I have no idea why there is a sudden increase, but I would like to thank all of the followers and supporters of this blog for your interest and enthusiasm. I hope that this next year I am able to keep you coming back for more.

And what of year three? I have been doing a fair number of build threads in recent months, and will definitely continue with more of that in the coming year. I haven't done any book reviews in a while, and series from year 1, such as the one on Japanese temples of note, will be coming back in the next while. I have gotten a hold, after considerable effort, of a rare doctoral dissertation from 1975 which involves an anthropological study of a Japanese cabinetmaker. The writer lived with the cabinetmaker for a year and wrote down virtually everything that went on, including cataloging the types of pieces the shop made. So a review of that interesting dissertation should be coming down the pike in the next little while.

I've gained some recent work to design a French timber roof for a house in Pittsburgh, and hopefully I will be able to write about that process. There could be some extra work on that project besides the roof as well involving the final frontier: double circular work.

In the Art of Japanese Carpentry Drawing series, I have been chipping away at completing the second half of the 3rd volume. Though I was aiming to have it ready for distribution by the end of the month, it looks like I will be another couple of weeks. I do appreciate reader's patience in that regard, and must apologize for the delay. I'm intending also to put out a volume 4 in that series this year, which will detail splayed post work, the natural progression from the study of the hopper detailed in volume 2.

Anyhow, lots ahead and in the immediate future I'll be posting more on the Ming table and wrapping up the French carpentry drawing series 'X Marks the Spot'.

Again, thank you one and all for your continued support and engagement in the Carpentry Way.

Wednesday, January 26, 2011

Ming Inspiration (20)

Another post in this series on the design and build of a frame and panel dining table made of bubinga and based on a 16th century Chinese masterpiece. Previous installments are found in the 'blog archive' to the right of the page.

Last post, I finished up with a picture showing the layout for the last bit of work on the tusk tenon mortises, namely the stub tenon mortise and the housing for the sword tip. After laying out, I put the hollow chisel mortiser to use:

Then I chopped out the housing for the sword tip miter, and here is the roughed out opening:

In this view, also note that the dado for the table top panel's tongue has been processed on the top of the apron:

Both tusk tenon mortises are now complete, save for fitting of course:

Next up: the joints which connect the aprons together. These are rather intricate joints and I haven't spent any time in this thread so far describing what I will be doing with these connections. That would spoil the surprise I suppose. So, in that vein, I'll just describe the cut out of the joints as things unfold. Cue suspenseful organ music....

First, some slot mortises needed doing, and again I went to the hollow chisel mortiser:

First plunge was to check that the depth mark I had set has not been exceeded:

The first slot is roughed out:

And then the second:

A while later, the slots are done, now finagled out to their final dimension, on both short and long aprons:

Time for everyone's favorite game show, Sawing for Teens®. Contestants, start sawing!!:

Being a little paranoid today in general, I stayed further off my layout lines than normal, however the final surface isn't being made by the saw, so it's no big deal:

Having a ripping good time as well here on the top of the stick:

More wood bits hit the floor:

The two short aprons are getting closer:

And the two long aprons look much the same after rough cut out, though there are a few differences between them and the shorties:

A final picture where the flash left a neat effect:

All for today. Another snow storm coming tonight, with up to 15 cm. Hmm, quite a winter we're having out here.

Thanks for your visit today.

Tuesday, January 25, 2011

Ming Inspiration (19)

Back to the fun, thrills and spills with the bubinga dining table, a piece based on a unique frame and panel system found in a Ming-period side table. Previous posts are found in the archive to the right side of the page.

Last time, I had dragged the groover, a timber framing power tool of mine, out into the light and used it to clean up some of the waste from the back of the frame aprons. This post continues on with the documentation of that process - the next step was to rout the entire surface down clean and level:

To do all the aprons took most of the morning, a veritable routing frenzy - wood rat heaven. Then I used the bandsaw to trim the remaining edges away from the back of the aprons:

The four aprons now thinned down, I could start working on some joinery. First up was the tusk tenon mortises for the central rail connection to the short side aprons, a cut I commenced with the drill press:

I used the router to plow through to the face side:

Then some chisel work to clean up:

The completed mortise is about 5 thou undersize to the 3/8" tenon (one reason for my choice to drill and rout rather then use the existing .3750" hollow chisel mortise bit):

Along with the paring work came periodic checks with the combo square to ensure that the end grain walls were square to the faces:

Mortising complete on both aprons:

The back side of the same two pieces also shows the effect of removing material, the 'thinning out' mentioned a few paragraphs above:

The mortises were just the start of the process of course - next came the sloped housings, a chance for the trim router to see some action:

Once the routing was complete, a little chisel work was needed to fully define the cut out:

Next up was rebating the short aprons to accommodate the tongue and groove for the table top panels. After fiddling the set up on the shaper for a while, away I went:

The first step in the process is complete:

If you're fussy with the set up, the shaper can do fairly accurate work - here I'm 2 thou from the target depth of 0.500" for the rebate:

And the last picture today shows the marking out for the next steps in the cut out of the tusk tenon mortises:

More to come!

Thanks for coming by the Carpentry Way today my friends. --> on to post 20