Baby's First Portrait

[catsittingstill]

[Later edit] Catalana has pointed out, in the nicest possible way, that I neglected to explain what I was talking about.  This post is about my new canoe design, Binturong, and about actually getting it down on paper.  [End edit]

I made arrangements to use the drafting table at Carson Newman (with a certain amount of wheel-spinning owing to the fact that someone else had a picture taped to it, and of course the students have first call but it turns out he's just *storing* the picture there because it is too big for the shelves and it is okay if I take it off to work on my stuff as long as I am careful with it and put it back when I am done). 

I began work about 10 this morning and faded out at noon owing to having forgotten to eat breakfast and not having brought a lunch.  So I walked home again and came back at three (an art class runs from 1 pm to 3 pm in that room) to work on it some more.  I have done about half the stations at this point.

I am not sure what I think.  There was an odd bulge in the center station which I actually re-drew (after doing some hasty figuring on the calculator and working out that the volume involved would be roughly 35 grams of water or slightly [Later edit] less more than [End edit] one ounce, which presumably shouldn't matter) but then it turned out that bulge would be nearly exactly the same in the station behind the middle station so now I am not sure I did the right thing.  I am discovering that I trust my eye more than I trust the numbers in the table of offsets, which is a little odd.  I don't normally have such gut faith in my estimates-by-eye.  On the other hand I have now drawn out, um,  3 1/2 sets of plans and have used a fourth set that was pre-printed.  Maybe when my eye says "that must be wrong--no, really, that doesn't look right" it knows what it's doing.

Comments

[catalana.livejournal.com]

Okay, this may be a stupid question, but am I right that what you're drawing is your new canoe design? I've reread this a few times and I'm still not 100% sure that's what you're talking about.

[catsittingstill.livejournal.com]

Hmm. Maybe I should edit this for clarity.

Yes, Binturong is my new canoe design. My very first design. (I've built other boats but they were both well-established designs, designed by other people and built many times by other builders.

[bigbumble.livejournal.com]

35 grams (or milliliters) of water is slightly MORE than one ounce.

[catsittingstill.livejournal.com]

Oops you're right. That's even what I meant to type. My bad.

[bigbumble.livejournal.com]

I figure you did that on purpose just to make sure we were paying attention!

[catsittingstill.livejournal.com]

:-) No, but it had that effect, didn't it?

[randwolf.livejournal.com]

Drafting makes you intimate with the details of geometry; the bulge might be a result of a computational problem. When I was doing a computational modeling class a few years ago, I found it was distressingly easy to produce forms that bulged like parts of 1950s automobiles. Perhaps your software is doing something like that.

[catsittingstill.livejournal.com]

What bothered me was that there was no echo of the bulge in the station before it. However it turned out there was an echo of the bulge in the station after it, so then I was more comfortable with it and put half of it back.

And then, of course, I discovered I had to tweak the design again.

[boywizard.livejournal.com]

Trust your eye, Cat. Boats have been designed with mechanical (or electronic) aid for only a few decades; there are centuries (nay, millenia) of designs by master craftspersons going by experience of what works, and what looks right to them. Many great sailing vessels were built without any plan except what existed in the builder's head. Software is a useful tool, but let your gut speak to you. Just as "if it's true to a sixteenth, it's true", if it looks like it's right, it's right. You know what characteristics you want, and you have a good idea of the shapes that will give those characteristics, so go for it.

[catsittingstill.livejournal.com]

To some extent I am but I also have a tendency to run back-of-the-envelope calculations to see whether the changes I propose to make will have a big effect or not.

I just finished the re-draw and I may go either of two ways on the stern stem--one way has a stern stem that sticks out in back noticeably farther than the other. The computer program version is the one that sticks out more. My eye likes a gentler curve that doesn't stick out as far but before I go with that for sure I'm going to tweak the computer program a bit to try to get that curve and see what it does to the CLA (center of lateral area)--because that part "has the longest lever-arm" and thus relatively small changes back there (it comes to about 2 square inches) might move the CLA noticeably.

But Kip is using that computer right now so it will have to wait until tomorrow.