RE

Richard Evans

22/07/2008 9:13 PM

Center-finding tape measure

An interesting low-tech gadget. It has two scales, one on each edge.
They are both labelled in inches, but the second scale is actually 50%
the size of the first one. To find the center of what you are
measuring, read the true scale, then find the corresponding number on
the other edge. That is the center.


This topic has 10 replies

RE

Richard Evans

in reply to Richard Evans on 22/07/2008 9:13 PM

22/07/2008 10:28 PM

"Lew Hodgett" <[email protected]> wrote:

>
>"DGDevin" wrote:
>
>> I have a center-finding two-foot steel rule I got from Lee Valley
>> that has proven one of the most useful gadgets I've bought in years,
>> I use it all the time. Whoever invented this thing deserved a big
>> raise.
>
>Been around forever.

As a carpenter's tape measure?

>
>Find an old time drafting machine that still has the scales on it.

I've been around long enough that I took drafting as a shop class in
high school. Same principle, different application.

>
>Engineering scales have full size along one edge, 1/2 size on the
>other edge.

Do they come in 16' lengths?

>
>A little tip to find the centerline of a large piece.
>
>Eyeball the piece, then estimate total length.
>
>Divide that estimate in half, the add 6".
>
>Layout that value from the left and mark, then from right and mark.
>
>Measure between the marks, divide in half, layout and mark from each
>side and mark.
>
>You now have the center.

Or just use the nifty 16' tape I just described.

Pn

Phisherman

in reply to Richard Evans on 22/07/2008 9:13 PM

22/07/2008 10:40 PM

On Tue, 22 Jul 2008 18:38:46 -0700, "DGDevin"
<[email protected]> wrote:

>Richard Evans wrote:
>
>> An interesting low-tech gadget. It has two scales, one on each edge.
>> They are both labelled in inches, but the second scale is actually 50%
>> the size of the first one. To find the center of what you are
>> measuring, read the true scale, then find the corresponding number on
>> the other edge. That is the center.
>
>I have a center-finding two-foot steel rule I got from Lee Valley that has
>proven one of the most useful gadgets I've bought in years, I use it all the
>time. Whoever invented this thing deserved a big raise.
>

A cheap roll of drywall paper tape comes in handy to divide a line
segment into any number of equal sections, plus it's easy to pencil in
marks.

ML

Maxwell Lol

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 6:33 AM

Richard Evans <[email protected]> writes:

> An interesting low-tech gadget. It has two scales, one on each edge.
> They are both labelled in inches, but the second scale is actually 50%
> the size of the first one. To find the center of what you are
> measuring, read the true scale, then find the corresponding number on
> the other edge. That is the center.

I saw that Lee Valley has a Golden Mean version as well.

Lr

"Leon"

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 6:25 AM


"Doug Miller" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, Richard Evans
> <[email protected]> wrote:
>>An interesting low-tech gadget. It has two scales, one on each edge.
>>They are both labelled in inches, but the second scale is actually 50%
>>the size of the first one. To find the center of what you are
>>measuring, read the true scale, then find the corresponding number on
>>the other edge. That is the center.
>
> It's pretty easy to find centers if you're using a metric tape measure:
> just
> measure the width and divide by two -- which is much easier using a whole
> number of millimeters than when using fractional inches. (Quick -- what's
> half
> of 55 13/16 inches?)



What's half of 536 3/8 mm? ;~)

LH

"Lew Hodgett"

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 2:19 AM


"DGDevin" wrote:

> I have a center-finding two-foot steel rule I got from Lee Valley
> that has proven one of the most useful gadgets I've bought in years,
> I use it all the time. Whoever invented this thing deserved a big
> raise.

Been around forever.

Find an old time drafting machine that still has the scales on it.

Engineering scales have full size along one edge, 1/2 size on the
other edge.

Very helpful when doing layouts around centerlines.

A little tip to find the centerline of a large piece.

Eyeball the piece, then estimate total length.

Divide that estimate in half, the add 6".

Layout that value from the left and mark, then from right and mark.

Measure between the marks, divide in half, layout and mark from each
side and mark.

You now have the center.

Laying out twice is usually enough.


Lew

Uu

"Upscale"

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 8:27 AM


"Leon" <[email protected]> wrote in message
> What's half of 536 3/8 mm? ;~)

You have a tape measure that shows 8th's of a millimetre?

DB

"Doug Brown"

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 6:33 PM


"Upscale" <[email protected]> wrote in message
news:[email protected]...
>
> "Leon" <[email protected]> wrote in message
>> What's half of 536 3/8 mm? ;~)
>
> You have a tape measure that shows 8th's of a millimetre?
>
>

You have eyes that can see an 8th of a mm?

sD

[email protected] (Doug Miller)

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 11:16 AM

In article <[email protected]>, Richard Evans <[email protected]> wrote:
>An interesting low-tech gadget. It has two scales, one on each edge.
>They are both labelled in inches, but the second scale is actually 50%
>the size of the first one. To find the center of what you are
>measuring, read the true scale, then find the corresponding number on
>the other edge. That is the center.

It's pretty easy to find centers if you're using a metric tape measure: just
measure the width and divide by two -- which is much easier using a whole
number of millimeters than when using fractional inches. (Quick -- what's half
of 55 13/16 inches?)

Dd

"DGDevin"

in reply to Richard Evans on 22/07/2008 9:13 PM

22/07/2008 6:38 PM

Richard Evans wrote:

> An interesting low-tech gadget. It has two scales, one on each edge.
> They are both labelled in inches, but the second scale is actually 50%
> the size of the first one. To find the center of what you are
> measuring, read the true scale, then find the corresponding number on
> the other edge. That is the center.

I have a center-finding two-foot steel rule I got from Lee Valley that has
proven one of the most useful gadgets I've bought in years, I use it all the
time. Whoever invented this thing deserved a big raise.

sD

[email protected] (Doug Miller)

in reply to Richard Evans on 22/07/2008 9:13 PM

23/07/2008 12:25 PM

In article <[email protected]>, "Leon" <[email protected]> wrote:
>
>"Doug Miller" <[email protected]> wrote in message
>news:[email protected]...
>> In article <[email protected]>, Richard Evans
>> <[email protected]> wrote:
>>>An interesting low-tech gadget. It has two scales, one on each edge.
>>>They are both labelled in inches, but the second scale is actually 50%
>>>the size of the first one. To find the center of what you are
>>>measuring, read the true scale, then find the corresponding number on
>>>the other edge. That is the center.
>>
>> It's pretty easy to find centers if you're using a metric tape measure:
>> just
>> measure the width and divide by two -- which is much easier using a whole
>> number of millimeters than when using fractional inches. (Quick -- what's
>> half
>> of 55 13/16 inches?)
>
>
>What's half of 536 3/8 mm? ;~)
>
<g> My metric tapes don't indicate fractional millimeters. Dunno about yours.


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