I had spent a lot of time thinking about what to build. In addition to the criteria required, and recognizing that time was a critical aspect (the project has to be completed next Friday), I had to consider a blend of what I wanted to do, what I knew how to do, and what we would be permitted to do. My first couple of ideas were rejected, either by me or by the instructor, as requiring more work than could reasonable be completed in a week, given not only the degree of difficulty of the project, but also factoring in the scheduled lectures and other work interrupting things (eating, sleeping, etc.) that would cut into the available work time. Other reasons for rejection included aesthetics - it just didn't look right; didn't show off an intended decorative feature (the dovetails) or was just plain wrong.
I finally settled on a relatively simple book rack. It could be thought of as the bench I showed in yesterday's posting turned on its side and then tilted it back about 8 degrees. The actual amount of tilt is derived from the 1:7 ratio (see below for an explanation of sorts) we're using for the angles in our dovetails, so I call it my 1:7 Book rack.
Once I had a design, I commenced drawing. Again, having prior drawing experience helped a lot. Because of the screwy angles I've included, it took a lot of head-scratching to figure out how to put the idea on paper. I did it in about two hours. Then the instructor checked it; he pointed out some things I hadn't thought of. The way I had the wood grain going, it was going to be hard to cut out the two side pieces. Also, he pointed out that I had made the stretcher piece, which was intended for the mortise and tenon piece, so wide that I would have difficulty cutting the mortise by hand, and that it probably wasn't supported well enough. He suggested two smaller stretchers, with a different shoulder arrangement. The total mortise length would be the same, but taken in two smaller chunks rather than one long one.
As they say, "back to the drawing board." I tried modifying the drawing I'd already made, but soon discovered that with just a slight change in the concept, almost all of the dimension and the layout had changed. Rather than erasing a bunch of lines, I decided to abandon the original drawing and start over.
The revision took another hour. I grabbed Aaron (instructor) just as he was about the leave for the day and asked him to check it again. Yet again, he laid a whole new idea of how to construct the drawing on me. Fortunately, I had saved the old drawing, which was done in the manner he was describing, and I convinced him that further drawings would not add any new information. Finally, he agreed. He checked my "cut list" which is really the goal of this part of the exercise and pronounced me ready to move on.
Then I went out to the lumber racks and picked out what I think is a very nice piece of cherry. It doesn't have too much cup or twist or sapwood, and it should be more than wide enough to leave me plenty of wood to build the rack, with a good piece left over for some other project.
Now I'm back at my apartment. I've met my landlady's parents. Today is her father's birthday, and they were going out to dinner. So, I'm here using her washing machine to do a week of accumulated laundry.
Tomorrow I and two of my fellow students are going to Liberty, ME, to the Liberty Tool Company. Liberty Tool Company sells used tools, and is the parent of the Captain Tinkum's Emporia that Steve and I visited in Searsport, ME last summer. I'm looking for a Record #43 or #44 plough plane or whatever else strikes me.
The 1: 7 ratio refers to the angle produced by one inch horizontal in seven inches vertical or the acute angle produced by right triangle with a 7 inch near side and a one inch side opposite the acute angle. The beauty of this method is that you don't have to find a protractor or a special dovetail marking gauge to determine the angle. You can draw the triangle on a handy piece of paper or your workbench, and then set a bevel gauge to the angle.
Enough? For more information, see the article at Popular Woodworking Magazine |
| 1:6 and 1:8 ratios. 1:7 is about 8 degrees. |
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