Curved support structure and wood grain

[Tetsuaiga]

I've been trying to work this out myself and couldnt really find much on the subject. If anyone could answer or direct me to where I can learn about it that would be great.

What im wondering is if i had say a bookshelf with curved sides and no back. Would you try to maximise the grain to cover the longest section thats possible down the two side supports?

Thanks

 

[9fingers]

I don't understand how a bookshelf can have sides? A shelf is a flat surface to me.

A picture might help?

Bob

 

[Tetsuaiga]

Sorry i'm a bit poor when it comes to using the correct terminologies.

Perhaps a chair would be a better anaology. If you wanted a chair leg with a mild curve, how would you orient the grain to maximise strength. I'm guessing you would just cut it so the grain travels the longest distance possible along the curve, because a straight vertical grain wouldnt reach from one end to the other due to the curve.

 

[AndyT]

I'm not sure I'm thinking of the same things as you but I'll have a go...

As you know, wood can split along the grain, so if you cut a curved piece, with the grain passing through the curve, it may fail under load. So, if you want a curved chair leg you try to do some of these:

a) select a piece of wood where the grain is already curved and follows along the curve
b) use only a slight curve
c) use a naturally stronger wood
d) use a thicker section
e) build up the curve by laminating thin pieces
f) steam wood to soften it and bend it while it is soft.

A commercial maker might well ignore all of these except c and d and just have machine operators cut components ignoring grain direction.

You could apply the same principles to a bookcase, which is what I think you were first asking about, but I'm struggling to visualise it. Books are cuboid, so they fit nicely into right-angled spaces! It would help if you could sketch what you mean - and show in which direction the curve would run.

 

[Tetsuaiga]

Thanks, some helpful stuff there.

Heres the shape im after,

There would be two of these, the other mirrored, both joined to a base and the shelf part enclosed in mortices joint about 3/4 way up. When I was working it out myself it seemed about a 7degree tilt anti clockwise of the grain would provide the longest continual grain lengths, though not in all parts.

The wood I intend to use is maple.