Comments on: Divide And Rule http://toolmonger.com/2008/07/14/divide-and-rule/ All tools. All the time. Your source for news, information, and reviews of hand tools, power tools, and tools of all kinds. Sun, 22 Nov 2009 13:02:45 +0000 http://wordpress.org/?v=2.6.1 By: fred http://toolmonger.com/2008/07/14/divide-and-rule/#comment-391114 fred Tue, 15 Jul 2008 15:34:12 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-391114 Re Nick Says: Dressed or finished dimension lumber is called out by nominal size. Even with that there may be some variability on dimensions of a 2x12 depending upon the mill or lumber company - who may shave a bit here and there. To further confuse things - we sometimes work on old balloon framed houses that have "full dimension" lumber. Doing remodel work on these you either need to rip oversized lumber to the full dimension - or cheat by addinding some plywood. All that aside - if you physically divide a piece of lumber into sections (halves, thirds etc. by the method I described above - or by using he Veritas tool - you will get the correct result. Re Nick Says:

Dressed or finished dimension lumber is called out by nominal size. Even with that there may be some variability on dimensions of a 2×12 depending upon the mill or lumber company - who may shave a bit here and there. To further confuse things - we sometimes work on old balloon framed houses that have “full dimension” lumber. Doing remodel work on these you either need to rip oversized lumber to the full dimension - or cheat by addinding some plywood.

All that aside - if you physically divide a piece of lumber into sections (halves, thirds etc. by the method I described above - or by using he Veritas tool - you will get the correct result.

]]> By: Shopmonger (aka Donny B) http://toolmonger.com/2008/07/14/divide-and-rule/#comment-391104 Shopmonger (aka Donny B) Tue, 15 Jul 2008 15:22:13 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-391104 12 is a common division from way backin the egyptian days becaus of how useful 30-60-90 triangles were and if you take 360 deg and devide by the commmon angle "30" you get 12 equal parts. then later it became a common use for the calander....... after that in england when they used the "foot" of the king for a relative dimension they finall settled on a specific size and then they devided by 12 and got what we not use as an inch...... Pahtagorean theory Rules!!!!!!! By the way nice peice of equipment, but fred is right, just learn come quick simple geometry.... as in geometry where all spacial relations can be drawn with a straight edge (not a ruler) a compass and a great pencil...... or Watch Ask this old house and see Tom Silva use these techniques all the time. 12 is a common division from way backin the egyptian days becaus of how useful 30-60-90 triangles were and if you take 360 deg and devide by the commmon angle “30″ you get 12 equal parts. then later it became a common use for the calander……. after that in england when they used the “foot” of the king for a relative dimension they finall settled on a specific size and then they devided by 12 and got what we not use as an inch……

Pahtagorean theory Rules!!!!!!!

By the way nice peice of equipment, but fred is right, just learn come quick simple geometry…. as in geometry where all spacial relations can be drawn with a straight edge (not a ruler) a compass and a great pencil……

or Watch Ask this old house and see Tom Silva use these techniques all the time.

]]> By: Geoff K. http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390910 Geoff K. Tue, 15 Jul 2008 11:38:36 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390910 Bisecting a 2x12 into 2 equal parts should -- by definition -- give you 2 equal parts. If you mean cutting a 2x12 @ 6" then you're right, because a 2x12 is not actually 12" wide. This is a matter of semantics, not math. Just because it's called a 2x12 doesn't mean those are its precise dimensions. It's a little annoying that it's dimensions are not those in its name, but I think most folks who work with lumber are aware of this concept. This technique has been around for a long time, but Veritas does a nice job of simplifying these "tricks" with simple, relatively inexpensive tools. Sure, one could make a jig or tool that performs the same function, but who doesn't like getting new stuff? And the Veritas line lets people get those new gizmos without breaking the bank. I'm not employed by Lee Valley, but I do like their stuff and I recommend them often. Bisecting a 2×12 into 2 equal parts should — by definition — give you 2 equal parts. If you mean cutting a 2×12 @ 6″ then you’re right, because a 2×12 is not actually 12″ wide. This is a matter of semantics, not math. Just because it’s called a 2×12 doesn’t mean those are its precise dimensions. It’s a little annoying that it’s dimensions are not those in its name, but I think most folks who work with lumber are aware of this concept.

This technique has been around for a long time, but Veritas does a nice job of simplifying these “tricks” with simple, relatively inexpensive tools. Sure, one could make a jig or tool that performs the same function, but who doesn’t like getting new stuff? And the Veritas line lets people get those new gizmos without breaking the bank. I’m not employed by Lee Valley, but I do like their stuff and I recommend them often.

]]> By: Nick http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390562 Nick Tue, 15 Jul 2008 03:05:04 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390562 o man some of you people drive me nuts, if you have a 2x12 and you divide that by two, you don't get two equal parts. Its like a 2x4 if you make a rip at 2inches you end up with one piece that is 2 inches and one piece that is inch and a half. Im curious if this would do a 2x4 as 2 1 1/3 pieces or just a 2 inches o man some of you people drive me nuts, if you have a 2×12 and you divide that by two, you don’t get two equal parts. Its like a 2×4 if you make a rip at 2inches you end up with one piece that is 2 inches and one piece that is inch and a half.

Im curious if this would do a 2×4 as 2 1 1/3 pieces or just a 2 inches

]]> By: Zathrus http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390539 Zathrus Tue, 15 Jul 2008 02:40:15 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390539 It's unclear why it was decided that 12 inches is equal to a foot, but it dates back to the Egyptians (who the Greeks, then the Romans, and then the English inherited it from) around 3000 BC. Yeah, the concept is that old. The actual unit of length has varied widely over history though. Anyway, yes, 12 inches in a foot makes dividing into <i>some</i> fractions easier, at the expense of making everything else harder. Give me the metric system any day (even though I'm not used to it; I'll learn). It’s unclear why it was decided that 12 inches is equal to a foot, but it dates back to the Egyptians (who the Greeks, then the Romans, and then the English inherited it from) around 3000 BC. Yeah, the concept is that old. The actual unit of length has varied widely over history though.

Anyway, yes, 12 inches in a foot makes dividing into some fractions easier, at the expense of making everything else harder. Give me the metric system any day (even though I’m not used to it; I’ll learn).

]]> By: Frank Townend http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390465 Frank Townend Tue, 15 Jul 2008 01:16:00 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390465 Points well taken, but I am happy Veritas is still spending money in R&D. Points well taken, but I am happy Veritas is still spending money in R&D.

]]> By: BG http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390354 BG Mon, 14 Jul 2008 22:04:10 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390354 I recently came under the impression that this is why a foot has 12 inches instead of 10. It was a lot easier to divide 12 into 1/2, 1/3rd, 1/4th. No idea if it is true or not but it sounds reasonable. I recently came under the impression that this is why a foot has 12 inches instead of 10. It was a lot easier to divide 12 into 1/2, 1/3rd, 1/4th. No idea if it is true or not but it sounds reasonable.

]]> By: fred http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390198 fred Mon, 14 Jul 2008 18:52:22 +0000 http://toolmonger.com/2008/07/14/divide-and-rule/#comment-390198 For a lot less money - you can do the same with any ruler or tape that is longer than the width of the board. Just lay the ruler/tape at an angle across the width of the board - such that the-edge-to-edge measurement is easily divided by 2 (e.g. 14 inches for a 2x12) then mark the board at the 7 inch position. This is the center of the board. If you repeat the process at another spot along the board - you have 2 marks that can be used to pencil-in a centerline. For a lot less money - you can do the same with any ruler or tape that is longer than the width of the board. Just lay the ruler/tape at an angle across the width of the board - such that the-edge-to-edge measurement is easily divided by 2 (e.g. 14 inches for a 2×12) then mark the board at the 7 inch position. This is the center of the board. If you repeat the process at another spot along the board - you have 2 marks that can be used to pencil-in a centerline.

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