Help with a herringbone pattern

[Dan Mages]

Good morning all.

I am about to do a herring bone top for a project. This will be my first attempt at doing one. The area for the herringbone is 12"x36" and will be glued to a .25" piece of luan plywood. The herringbone will be done in figured cherry. The plywood sits in a frame of black walnut. Here is a mock-up of the top.

http://img.photobucket.com/albums/v647/DanMages/P1010117.jpg

There are two sizes. 2"x6" and 2"x4" Which scale do you like more? Any tips on doing a herringbone pattern? Any special math that can help me optimize the size so I dont have small pieces at the top?

Thanks!

[Jim Becker]

I like the smaller pieces due to the narrow field.

[Doug Shepard]

Dan
My trig is pretty rusty, but I'll take a stab. There's 3 ways you can tweak the math to get a even number of pieces to span the space.
1) Keep the width of your pieces fixed and adjust the angle. This will either increase or decrease the length of the angled cut line depending on whether you angle the 2 pcs inwards or outward from each other.
2) Adjust both the width of your pieces and the angle where they meet. Calculation-wise, this is the hardest one of the 3.
3) Keep the angle fixed and adjust the width of the pieces. This one is probably the easiest and from your pic it looks like you're planning on fixing the angle at 45 degrees, so that's the one I'll go with.
At 45 degrees, the length of the angled cut-line will be the square root of 2 times the width of your pattern pieces. So if L is the length you want to span with the pattern, N is the number of segments you want in the pattern, and W is the width of your pattern pieces, you get a formula like this: L = N x W X SqRoot(2)
Rearrange it into L/(N x SqRoot(2)) = W and plug in your length and number of segments, and you'll get the width that your pattern pieces need to be.

As far as which looks better, the 4" or 6" length of your pieces. I'd wait until you figure out what W needs to be and then take another look at it.

[Dan Mages]

Doug, to make things more interesting, the length of the pieces must be divisable by its width. It also needs to remain at a 45 degree angle to keep the pattern correct.

[Ted Shrader]

Dan -

I like the smaller pieces. When doing the layout, start from the center of the field backing. Lay out two lines N/S and E/W (for lack of a better description). Then Start with the end of the first piece at the center point. Check the size of the pieces at the edges. Too small? Try laying out with the starter block right in the center of the field. Starting from the center ensures all the border pieces will be the same and avoids math to the greatest extent.

Ted

[Doug Shepard]

Doug, to make things more interesting, the length of the pieces must be divisable by its width. It also needs to remain at a 45 degree angle to keep the pattern correct.
Hmmm. Well making the length of the pieces an even multiple of the width shouldn't be a problem, but I think I missed something too. I assumed (incorrectly) from your pic that you had the pieces overlapped instead of butted and were going to miter both sides of the pattern. But that would give you a chevron, and not a herringbone pattern. The L in my math above would be the length from the front point in the pic to the back inside 45 on your herringbone. I'll have to think on this a bit more.

[Doug Shepard]

Ok Uncle Jed
Ize been workin on my syferin and gazintas and I think Ize got it pret near figgered. Less'n i dint scrood the pooch too bad (dont tell Ellie Mae), this aughta work.:cool:
Well I kept messing with this. Mostly as an opportunity to blow some cobwebs off my math memory so I don't forget it. Dan - I'm kind of curious to have you check the length of your mockup layout to see if I butchered this.

My previous attempt just measured along the line from the front point to the back inside 45. This time L goes from the front point to the farthest point that's on the same side as the starting piece.
The math starts getting a bit twisted, but the extra part H was not in my original equation. The vertical height of that section is going to be
Radius (or Hypotenuse) x sin 45 or Radius x 1/SqRoot(2) and the Radius in this case is either going to be 2 x W or 3 x W. But then we've got to subtract back out the portion of H that's still getting measured in the original equation. That portion is (W x SqRoot(2))/2

I end up with a formula that looks like this
L = N X W X SqRt(2) + R/SqRt(2) - (W x SqRoot(2))/2
N is the number of pieces on the side that has the starter piece. In your pic, the LH pattern has N=4 and the RH has N=3
R is the length of the pieces (either 2 X W or 3 X W in your case)
W is the width of the pieces

After simplifying and factoring out stuff and solving for W, I end up with this
For R = 2 x W
W = (L x SqRt(2))/(2 x (N+1) - 1 )

For R = 3 x W
W = (L x SqRt(2)) / (2 x (N+1))

From your pic and using W=2 I come up with the following lengths. For the RH pattern, L = 11.314". That one looks about right. The one I'm thinking may have a math bug in it still, is the LH pattern. I come up with L=12.728" which looks a tiny bit too short from the amount I can see hanging over the background.

[Dan Mages]

Well I kept messing with this. Mostly as an opportunity to blow some cobwebs off my math memory so I don't forget it. Dan - I'm kind of curious to have you check the length of your mockup layout to see if I butchered this.

My previous attempt just measured along the line from the front point to the back inside 45. This time L goes from the front point to the farthest point that's on the same side as the starting piece.
The math starts getting a bit twisted, but the extra part H was not in my original equation. The vertical height of that section is going to be
Radius (or Hypotenuse) x sin 45 or Radius x 1/SqRoot(2) and the Radius in this case is either going to be 2 x W or 3 x W. But then we've got to subtract back out the portion of H that's still getting measured in the original equation. That portion is (W x SqRoot(2))/2

I end up with a formula that looks like this
L = N X W X SqRt(2) + R/SqRt(2) - (W x SqRoot(2))/2
N is the number of pieces on the side that has the starter piece. In your pic, the LH pattern has N=4 and the RH has N=3
R is the length of the pieces (either 2 X W or 3 X W in your case)
W is the width of the pieces

After simplifying and factoring out stuff and solving for W, I end up with this
For R = 2 x W
W = (L x SqRt(2))/(2 x (N+1) - 1 )

For R = 3 x W
W = (L x SqRt(2)) / (2 x (N+1))

From your pic and using W=2 I come up with the following lengths. For the RH pattern, L = 11.314". That one looks about right. The one I'm thinking may have a math bug in it still, is the LH pattern. I come up with L=12.728" which looks a tiny bit too short from the amount I can see hanging over the background.

Oh boy.... math.... I think I am going crosseyed. :rolleyes:

The one piece that is hanging over is also sitting on a 5/16 ledge which may cause the appearance that it may be wrong. It could also be that this is a mock up and I did not take too much consideration into how acurate I was with the layout.

Thanks for the help..

Dan

[Doug Shepard]

The bad news is that if my math is right, there's no nice round number for W that will exactly span your 12" space. I plugged the formulas into Excel and had it calc the width for counts of N from 2 to 10. Here's what comes out.


<TABLE style="WIDTH: 248pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=330 border=0 x:str><COLGROUP><COL style="WIDTH: 32pt; mso-width-source: userset; mso-width-alt: 1536" width=42><COL style="WIDTH: 102pt; mso-width-source: userset; mso-width-alt: 4973" width=136><COL style="WIDTH: 114pt; mso-width-source: userset; mso-width-alt: 5558" width=152><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; WIDTH: 32pt; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" width=42 height=17>N</TD><TD style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; WIDTH: 102pt; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" width=136>For R = 2 x W, W = ?</TD><TD style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; WIDTH: 114pt; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" width=152>For R = 3 x W, W = ?</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>2</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="3.3941125999999997" x:fmla="=16.970563/(2*(A2+1)-1)">3.3941</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="2.8284271666666663" x:fmla="=16.970563/(2*(A2+1))">2.8284</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>3</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="2.4243661428571426" x:fmla="=16.970563/(2*(A3+1)-1)">2.4244</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="2.1213203749999998" x:fmla="=16.970563/(2*(A3+1))">2.1213</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>4</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.885618111111111" x:fmla="=16.970563/(2*(A4+1)-1)">1.8856</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.6970562999999999" x:fmla="=16.970563/(2*(A4+1))">1.6971</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>5</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.5427784545454544" x:fmla="=16.970563/(2*(A5+1)-1)">1.5428</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.4142135833333331" x:fmla="=16.970563/(2*(A5+1))">1.4142</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>6</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.305427923076923" x:fmla="=16.970563/(2*(A6+1)-1)">1.3054</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.2121830714285713" x:fmla="=16.970563/(2*(A6+1))">1.2122</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>7</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.1313708666666666" x:fmla="=16.970563/(2*(A7+1)-1)">1.1314</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.0606601874999999" x:fmla="=16.970563/(2*(A7+1))">1.0607</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>8</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.99826841176470582" x:fmla="=16.970563/(2*(A8+1)-1)">0.9983</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.9428090555555555" x:fmla="=16.970563/(2*(A8+1))">0.9428</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>9</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.89318752631578935" x:fmla="=16.970563/(2*(A9+1)-1)">0.8932</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.84852814999999993" x:fmla="=16.970563/(2*(A9+1))">0.8485</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>10</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.8081220476190476" x:fmla="=16.970563/(2*(A10+1)-1)">0.8081</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.77138922727272718" x:fmla="=16.970563/(2*(A10+1))">0.7714</TD></TR></TBODY></TABLE>

[Doug Shepard]

Ok - One last time.
Not sure why I selected the farthest point on the last board on the starter side to get the length. It occured to me that's not near as useful as knowing the length to the nearer point at the end of the same piece. So here's the final math (which got even simpler as a result).

L = (N-1) x W x SqRt(2) + R/SqRt(2)

After simplifying and solving for W:
For R = 2 x W
W = (L x SqRt(2))/(2 x N )

For R = 3 x W
W = (L x SqRt(2)) / (2 x (N-1) + 3)

For your case of L=12" the redone table now looks like this:
<TABLE style="WIDTH: 248pt; BORDER-COLLAPSE: collapse" cellSpacing=0 cellPadding=0 width=330 border=0 x:str><COLGROUP><COL style="WIDTH: 32pt; mso-width-source: userset; mso-width-alt: 1536" width=42><COL style="WIDTH: 102pt; mso-width-source: userset; mso-width-alt: 4973" width=136><COL style="WIDTH: 114pt; mso-width-source: userset; mso-width-alt: 5558" width=152><TBODY><TR style="HEIGHT: 12.75pt" height=17><TD style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; WIDTH: 32pt; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" width=42 height=17>N</TD><TD style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; WIDTH: 102pt; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" width=136>For R = 2 x W, W = ?</TD><TD style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; WIDTH: 114pt; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" width=152>For R = 3 x W, W = ?</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>2</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="4.2426407499999996" x:fmla="=16.970563/(2*A2)">4.2426</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="3.3941125999999997" x:fmla="=16.970563/(2*(A2 - 1) +3)">3.3941</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>3</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="2.8284271666666663" x:fmla="=16.970563/(2*A3)">2.8284</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="2.4243661428571426" x:fmla="=16.970563/(2*(A3 - 1) +3)">2.4244</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>4</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="2.1213203749999998" x:fmla="=16.970563/(2*A4)">2.1213</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.885618111111111" x:fmla="=16.970563/(2*(A4 - 1) +3)">1.8856</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>5</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.6970562999999999" x:fmla="=16.970563/(2*A5)">1.6971</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.5427784545454544" x:fmla="=16.970563/(2*(A5 - 1) +3)">1.5428</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>6</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.4142135833333331" x:fmla="=16.970563/(2*A6)">1.4142</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.305427923076923" x:fmla="=16.970563/(2*(A6 - 1) +3)">1.3054</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>7</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.2121830714285713" x:fmla="=16.970563/(2*A7)">1.2122</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.1313708666666666" x:fmla="=16.970563/(2*(A7 - 1) +3)">1.1314</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>8</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="1.0606601874999999" x:fmla="=16.970563/(2*A8)">1.0607</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.99826841176470582" x:fmla="=16.970563/(2*(A8 - 1) +3)">0.9983</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>9</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.9428090555555555" x:fmla="=16.970563/(2*A9)">0.9428</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.89318752631578935" x:fmla="=16.970563/(2*(A9 - 1) +3)">0.8932</TD></TR><TR style="HEIGHT: 12.75pt" height=17><TD class=xl24 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; HEIGHT: 12.75pt; BACKGROUND-COLOR: transparent" height=17 x:num>10</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.84852814999999993" x:fmla="=16.970563/(2*A10)">0.8485</TD><TD class=xl25 style="BORDER-RIGHT: #c0c0c0; BORDER-TOP: #c0c0c0; BORDER-LEFT: #c0c0c0; BORDER-BOTTOM: #c0c0c0; BACKGROUND-COLOR: transparent" x:num="0.8081220476190476" x:fmla="=16.970563/(2*(A10 - 1) +3)">0.8081</TD></TR></TBODY></TABLE>

[Dan Mages]

Thanks!! And ummm... in english... I take it that your numbers say that I should cut them to 4.25"x2.125"?

Dan

[Doug Shepard]

If you're using 4 pieces on the starter course side and are going with the length being twice the width, then yes. Just do me a favor and cut some that size out of paper first and lay them out to make sure I didn't foul something up. I'd hate to have you waste any wood if I hit a wrong calculator button. Or you could get a pretty good verification that the math is right if you measure the L's on your existing 2x4 and 2x6 proto layouts.
The LH layout should end up with L=11.3137"
The RH layout should end up with L=9.8994"