How can I locate the center-line on one of the flat sides of an oblong piece of wood?

On Jun 30, 5:41*am, gary wrote:
How can I locate the center-line on one of the flat sides of an oblong piece of wood?

A ruler?

Assuming the side is a rectangle, draw diagonals (lines from alternate
corners); the point of intersection will be the center of the side.

There are several ways to extend it to the length of the side--using a
compass to "bisect an angle" comes to mind.

I imagine that construction is explained in more than one place on the web.

Bill

On Fri, 29 Jun 2012 21:41:55 -0700 (PDT), gary
wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Depends on how important the exact center is-- If 'close enough' is
close enough then take your ruler and find the longest axis through
the oval. draw a line. Go roughly 90 degrees from that one and
find the 'long spot' - draw another line. X marks the center.

If you need to be exact then-
(x - a)2/p2 + (y - b)2/q2 = 1
[I have no idea what that means- it is a copy/paste from
http://mathcentral.uregina.ca/QQ/dat...6/s/sima1.html
but it looks like it might work.]


Jim

On Jun 30, 3:56*am, Jim Elbrecht wrote:
On Fri, 29 Jun 2012 21:41:55 -0700 (PDT), gary
wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Depends on how important the exact center is-- *If 'close enough' is
close enough then take your ruler and find the longest axis through
the oval. draw a line. * * Go roughly 90 degrees from that one and
find the 'long spot' - draw another line. * * X marks the center.

If you need to be exact then-
(x - a)2/p2 + (y - b)2/q2 = 1
[I have no idea what that means- it is a copy/paste fromhttp://mathcentral.uregina.ca/QQ/database/QQ.09.06/s/sima1.html
but it looks like it might work.]

Jim

great URL!

I usually just take a piece of paper, cut out to the size of the
board, then simply fold the paper in half, put back down and then use
compass point to make little dots through the fold mark along the
board.

The paper will quickly show you if the board is wonky, not
symmetrical, too. .

On Jun 30, 11:07*am, Robert Macy wrote:
On Jun 30, 3:56*am, Jim Elbrecht wrote:





On Fri, 29 Jun 2012 21:41:55 -0700 (PDT), gary
wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Depends on how important the exact center is-- *If 'close enough' is
close enough then take your ruler and find the longest axis through
the oval. draw a line. * * Go roughly 90 degrees from that one and
find the 'long spot' - draw another line. * * X marks the center.

If you need to be exact then-
(x - a)2/p2 + (y - b)2/q2 = 1
[I have no idea what that means- it is a copy/paste fromhttp://mathcentral.uregina.ca/QQ/database/QQ.09.06/s/sima1.html
but it looks like it might work.]

Jim

great URL!

I usually just take a piece of paper, cut out to the size of the
board, then simply fold the paper in half, put back down and then use
compass point to make little dots through the fold mark along the
board.

The paper will quickly show you if the board is wonky, not
symmetrical, too. .- Hide quoted text -

- Show quoted text -

That's too easy, I like the formula better.

gary wrote:
How can I locate the center-line on one of the flat sides of an
oblong piece of wood?

Balance the board on a thin straight-edge.

On Sun, 1 Jul 2012 10:41:49 -0500, "HeyBub" wrote:

gary wrote:
How can I locate the center-line on one of the flat sides of an
oblong piece of wood?

Balance the board on a thin straight-edge.

I guess that depends on your definition of center-line. Your method would
find (the line through) the center of gravity, which may or may not be the
same as the mid-point of a side.

On Jun 29, 11:41*pm, gary wrote:
How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

On Jun 29, 11:41*pm, gary wrote:
How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

On Jul 1, 11:37*pm, Joe wrote:
On Jun 29, 11:41*pm, gary wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

Where are the corners on an oblong piece of wood?

On 7/1/2012 11:41 PM, DerbyDad03 wrote:
On Jul 1, 11:37 pm, wrote:
On Jun 29, 11:41 pm, wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

Where are the corners on an oblong piece of wood?

At the intersections of the edges?

On Sun, 1 Jul 2012 20:37:24 -0700 (PDT), Joe wrote
in
Re Locating centerline:

On Jun 29, 11:41*pm, gary wrote:
How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

An oblong shape does not have "corners". An oblong shape is a
rectangle with the corners replaced by curves.

On Jul 2, 5:28*am, Moe Gasser
wrote:
On 7/1/2012 11:41 PM, DerbyDad03 wrote:

On Jul 1, 11:37 pm, *wrote:
On Jun 29, 11:41 pm, *wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

Where are the corners on an oblong piece of wood?

At the intersections of the edges?

Huh?

On Sun, 1 Jul 2012 20:41:21 -0700 (PDT), DerbyDad03
wrote:

On Jul 1, 11:37*pm, Joe wrote:
On Jun 29, 11:41*pm, gary wrote:

How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

Where are the corners on an oblong piece of wood?

Define "oblong".

On Mon, 02 Jul 2012 04:56:20 -0500, CRNG wrote:

On Sun, 1 Jul 2012 20:37:24 -0700 (PDT), Joe wrote
in
Re Locating centerline:

On Jun 29, 11:41*pm, gary wrote:
How can I locate the center-line on one of the flat sides of an oblong piece of wood?

Draw lines from each corner to the opposite diagonal corner. The
intersection is the center both ways.

Joe

An oblong shape does not have "corners". An oblong shape is a
rectangle with the corners replaced by curves.

That's not a definition of "oblong" I've encountered.

http://www.thefreedictionary.com/oblong
ob·long (blông, -lng)
adj.
1. Deviating from a square, circular, or spherical form by being elongated in
one direction.
2. Having the shape of or resembling a rectangle or an ellipse.
3. Botany Having a somewhat elongated form with approximately parallel sides:
an oblong leaf.
n.

On Mon, 02 Jul 2012 06:40:28 -0700, DerbyDad03 wrote:
Where are the corners on an oblong piece of wood?

At the intersections of the edges?

Huh?

I'm not Moe, but "oblong" always meant a rectangle (with four corners)
when I was very young; it was only later that I saw it referred to as an
elongated form of a base shape. I think some of the posters are assuming
the OP meant an oval (although they make mention of a flat side, so maybe
not?) and others are assuming a rectangle...

On Mon, 2 Jul 2012 14:14:19 +0000 (UTC), Jules Richardson
wrote:

On Mon, 02 Jul 2012 06:40:28 -0700, DerbyDad03 wrote:
Where are the corners on an oblong piece of wood?

At the intersections of the edges?

Huh?

I'm not Moe, but "oblong" always meant a rectangle (with four corners)
when I was very young; it was only later that I saw it referred to as an
elongated form of a base shape. I think some of the posters are assuming
the OP meant an oval (although they make mention of a flat side, so maybe
not?) and others are assuming a rectangle...

I not only assumed 'oval'- I also mis-read 'centerline' as 'center'.

'Centerline' seems to favor the idea of an oval-- but has the op been
back to straighten any of us out?

Jim