Wood Expansion/Contraction Calculator

• posted on December 25, 2012, 6:07 pm
I created a webpage that lets you enter your lumber species, starting and final moisture content and width and it will calculate your lumber expansion or contraction.
Let me know what you think.
Enjoy! AND Merry Christmas!
http://www.garagewoodworks.com/moisture.php

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• posted on December 25, 2012, 6:23 pm
snipped-for-privacy@garagewoodworks.com wrote in

content and width and it will calculate your lumber expansion or contraction.

Cool. Thanks.
A few suggestions, though, Brian:
1. Don't clear the form when you display the answer. I'd like to see what I entered for species, moisture content, and width. This would also make it possible to see the dimensional change for different widths of the same species at the same moisture contents, without having to re-enter anything except the width.
2. Round the answer to either three or two decimal places. "... contract by 0.13872 inches" is a bit overly precise, dontcha think? :-)
3. Some folks might find it useful to have the dimensional change shown in fractional inches as well as decimal inches.
4. Our neighbors to the north might find it useful to be able to specify dimensions, and get their answers, in metric units. Perhaps some of them will comment on that, and on whether mm or cm would be more convenient.

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• posted on December 25, 2012, 6:28 pm
On Tuesday, December 25, 2012 1:23:50 PM UTC-5, Doug Miller wrote:

Thanks for the suggestions. The precision has already been adjusted to thou inches.
This is a work in progress (I just created it today). Please check back as I continue to improve it and make it prettier. :)

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• posted on December 25, 2012, 7:21 pm
On Tuesday, December 25, 2012 1:23:50 PM UTC-5, Doug Miller wrote:

Ok. I've implemented most of your suggestions. Still need to work on metric conversion which should be straight forward.

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• posted on December 25, 2012, 11:02 pm
snipped-for-privacy@garagewoodworks.com wrote in

which should be straight forward.

Nice. One more suggestion: decrease the vertical height of the form, so that the answer is visible without scrolling.

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• posted on December 29, 2012, 4:28 am
On Tuesday, December 25, 2012 1:23:50 PM UTC-5, Doug Miller wrote:

Implemented this. Now gives fraction to the nearest 1/16". This was a tricky one for me. :)

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• posted on December 25, 2012, 11:01 pm
On Tue, 25 Dec 2012 10:07:58 -0800 (PST), snipped-for-privacy@garagewoodworks.com wrote:

moisture content and width and it will calculate your lumber expansion or contraction.

Quite useful! For the novice woodworkers some suggested starting and ending moisture percentages would be nice. Green, air dried, kiln dried, after six months in an air conditioned home, etc.
May not be important, but your form will accept percentages above 100. Sanity checks are typically done on input forms to prevent people from entering stuff like this, http://xkcd.com/327 /
--
William

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• posted on December 26, 2012, 2:16 am
On Tuesday, December 25, 2012 6:01:53 PM UTC-5, William Bagwell wrote:

final moisture content and width and it will calculate your lumber expansion or contraction.

Thank you.

Check! :)