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Default Lay out a sine curve?

I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles. If I can't finger this one out,
that's probably what I'll wind up doing, but I was wondering if y'all
had done something like this.

Thanks,

-Phil Crow

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Frank Ketchum
 
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Default Lay out a sine curve?


wrote in message
oups.com...
I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles. If I can't finger this one out,
that's probably what I'll wind up doing, but I was wondering if y'all
had done something like this.


The plans give a link to the pattern that they used

http://www.uniqueprojects.com/projects/winerack/3b.pdf

Print and attach to the wood!

Frank


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Frank Ketchum wrote:


The plans give a link to the pattern that they used

http://www.uniqueprojects.com/projects/winerack/3b.pdf

Print and attach to the wood!

Frank


D'oh! Must have missed that on the read-through. Boy, is my face red.

However, the question remains--what if I wanted a curve with a
different amplitude or wavelength? This template idea crossed my mind,
but how to generate such a curve? Can Autocad do it? I've just
received a copy of Autocad 2005, but really don't have much clue as to
how to actually use it. I've bought the "for dummies" book, but
haven't sat down and dug in yet.

At any rate, thanks, Frank.

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Doug Miller
 
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Default Lay out a sine curve?

In article .com, wrote:
I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it.


Well, you could do what they suggest in the plans:

"You can use the pattern that we used by printing it out and transferring it
to the wood in succession until you have the desired number of holes."

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.
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Guess who
 
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Default Lay out a sine curve?

On 18 Feb 2006 06:59:47 -0800, wrote:

I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it.


For future reference, if you want a real sine curve, and not an
approximation [within the bounds of the tools and shaky hands] use a
math program like Graphmatica, then copy/paste into a word processor
or image editor for printing to the scale you want/need.

Graphmatica is shareware, but free for those who can't afford it [so
just use it if you can't.] PhotoFiltre , or "The Gimp" are freeware
image editors. OpenOffice is a great free office suite with a
wordprocessor and spreadsheet and much more.

If you do it intelligently, you can do it to suit your project scale.
One hint: in Graphmatica type in y = sin(x) for the unit sine curve,
and you might want to change the default colours to black and white.
You can change the equation if you want varied results; something like
y = 3sin(x) or y = sin(3x) or whatever. You likely don't need that
though.

Or, any basic trig text shows how to draw it from the unit circle.



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Morris Dovey wrote:
(in
) said:


Phil...

I use DesignCAD and found that the "curve" (connect-the-dots with a
smooth line) function will provide a close approximation when
sufficiently many points are provided. I ended up writing a macro to
produce a half-cycle cosine curve given the two end points (This gave
me the ability to make smooth transitions between two horizontal
lines, which was what I really wanted.)

If you'd like, I can produce a full-cycle sine/cosine curve and
attempt to export as a dwg or dxf file...

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto


Thanks, Morris, but I think I'll just use the pattern in the plans for
this one. I do appreciate the effort, though. I guess my post was
more in the spirit of knowing how for the next time, rather than having
a "canned" curve to use.

Writing macros, huh? Is that a hard thing to do? I can barely draw a
straight line with Autocad, so I guess macros are not in my immediate
future, but it's good to know that when I get there, there's a utility
that will help me out for the next time.

'Preciate the feedback.

-Phil Crow

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Josh
 
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Default Lay out a sine curve?

wrote:

D'oh! Must have missed that on the read-through. Boy, is my face red.

However, the question remains--what if I wanted a curve with a
different amplitude or wavelength? This template idea crossed my mind,
but how to generate such a curve? Can Autocad do it? I've just
received a copy of Autocad 2005, but really don't have much clue as to
how to actually use it. I've bought the "for dummies" book, but
haven't sat down and dug in yet.

At any rate, thanks, Frank.


You could make a somewhat complicated jig to do it, but it's probably a
lot easier to just plot points. First, pick your wavelength
(horizontal distance from peak to peak or trough to trough). Let's say
it's 6", which is pretty close to what they used in their pattern.
We'll call that "L". Then pick your amplitude. That's the height of
the waves from the midpoint. In their example, I think the pattern is
about 2 1/2" from peak to trough, which means that it's 1 1/4" to the
midpoint. So the amplitude is 1.25; we'll call that "A". Then you
simply take a piece of graph paper, plug in the formula for a sine wave
into a calculator or into a spreadsheet, like Excel, and start plotting
points. It's definitely easier on Excel, because you can do it once,
and just copy and paste a bunch of times to get the rest of the points.
The formula is y = A*sin(2*pi*x/L). If you're calculator is in degree
mode, rather than radian mode, the 2*pi simply becomes 360. Just plug
in values for x, and plot the corresponding value of y on a sheet of
graph paper.

As I said, it's easier in Excel. Here's how you'd do it:

(1) Open up a blank worksheet.
(2) In the first cell (A1), put your desired wavelength (e.g. 6).
(3) In cell B1, put in your desired amplitude (e.g. 1.25).
(4) In cell A3, put in this formula: =(ROW()-3)*$A$1/24
(5) In cell B3, put in this formula: =$B$1*COS(2*PI()*A3/$A$1)
(6) Select cells A3 and B3 and copy them to the clipboard
(7) Select a block of cells from A4 to B27 and paste from the clipboard
(8) Select all cells (ctrl-a), then format cells (ctrl-1). Select the
"Number" tab, and force the category to be "Number" with 3 decimal
places.

The results should be as follows:

6.000 1.250

0.000 1.250
0.250 1.207
0.500 1.083
0.750 0.884
1.000 0.625
1.250 0.324
1.500 0.000
1.750 -0.324
2.000 -0.625
2.250 -0.884
2.500 -1.083
2.750 -1.207
3.000 -1.250
3.250 -1.207
3.500 -1.083
3.750 -0.884
4.000 -0.625
4.250 -0.324
4.500 0.000
4.750 0.324
5.000 0.625
5.250 0.884
5.500 1.083
5.750 1.207
6.000 1.250


At this point, the first column is a list of x-values ranging from 0 to
6 (in 1/4" increments in this particular example). The second column
is a list of corresponding y-values ranging between -1.25 and +1.25.
Just plot this pairs of point on graph paper, connect the dots, and cut
out your pattern. You could also create a scatter plot in Excel and
experiment with the page scale until you can print it out at exactly
1:1 scale.

You may notice that I chose to use cosine, rather than sine, in my
formula. Either one will give you the same shape in the end, but a
cosine curve will start and end at a peak, whereas a sine would start
and end at the midpoint.

Josh

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Josh wrote:
wrote:

D'oh! Must have missed that on the read-through. Boy, is my face red.

However, the question remains--what if I wanted a curve with a
different amplitude or wavelength? This template idea crossed my mind,
but how to generate such a curve? Can Autocad do it? I've just
received a copy of Autocad 2005, but really don't have much clue as to
how to actually use it. I've bought the "for dummies" book, but
haven't sat down and dug in yet.

At any rate, thanks, Frank.


You could make a somewhat complicated jig to do it, but it's probably a
lot easier to just plot points. First, pick your wavelength
(horizontal distance from peak to peak or trough to trough). Let's say
it's 6", which is pretty close to what they used in their pattern.
We'll call that "L". Then pick your amplitude. That's the height of
the waves from the midpoint. In their example, I think the pattern is
about 2 1/2" from peak to trough, which means that it's 1 1/4" to the
midpoint. So the amplitude is 1.25; we'll call that "A". Then you
simply take a piece of graph paper, plug in the formula for a sine wave
into a calculator or into a spreadsheet, like Excel, and start plotting
points. It's definitely easier on Excel, because you can do it once,
and just copy and paste a bunch of times to get the rest of the points.
The formula is y = A*sin(2*pi*x/L). If you're calculator is in degree
mode, rather than radian mode, the 2*pi simply becomes 360. Just plug
in values for x, and plot the corresponding value of y on a sheet of
graph paper.

As I said, it's easier in Excel. Here's how you'd do it:

(1) Open up a blank worksheet.
(2) In the first cell (A1), put your desired wavelength (e.g. 6).
(3) In cell B1, put in your desired amplitude (e.g. 1.25).
(4) In cell A3, put in this formula: =(ROW()-3)*$A$1/24
(5) In cell B3, put in this formula: =$B$1*COS(2*PI()*A3/$A$1)
(6) Select cells A3 and B3 and copy them to the clipboard
(7) Select a block of cells from A4 to B27 and paste from the clipboard
(8) Select all cells (ctrl-a), then format cells (ctrl-1). Select the
"Number" tab, and force the category to be "Number" with 3 decimal
places.

The results should be as follows:

6.000 1.250

0.000 1.250
0.250 1.207
0.500 1.083
0.750 0.884
1.000 0.625
1.250 0.324
1.500 0.000
1.750 -0.324
2.000 -0.625
2.250 -0.884
2.500 -1.083
2.750 -1.207
3.000 -1.250
3.250 -1.207
3.500 -1.083
3.750 -0.884
4.000 -0.625
4.250 -0.324
4.500 0.000
4.750 0.324
5.000 0.625
5.250 0.884
5.500 1.083
5.750 1.207
6.000 1.250


At this point, the first column is a list of x-values ranging from 0 to
6 (in 1/4" increments in this particular example). The second column
is a list of corresponding y-values ranging between -1.25 and +1.25.
Just plot this pairs of point on graph paper, connect the dots, and cut
out your pattern. You could also create a scatter plot in Excel and
experiment with the page scale until you can print it out at exactly
1:1 scale.

You may notice that I chose to use cosine, rather than sine, in my
formula. Either one will give you the same shape in the end, but a
cosine curve will start and end at a peak, whereas a sine would start
and end at the midpoint.

Josh


Thanks, Josh. Scuse me, I've got a spreadsheet to build.

-Phil Crow

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dnoyeB
 
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Default Lay out a sine curve?

wrote:
Frank Ketchum wrote:

The plans give a link to the pattern that they used

http://www.uniqueprojects.com/projects/winerack/3b.pdf

Print and attach to the wood!

Frank



D'oh! Must have missed that on the read-through. Boy, is my face red.

However, the question remains--what if I wanted a curve with a
different amplitude or wavelength? This template idea crossed my mind,
but how to generate such a curve? Can Autocad do it? I've just
received a copy of Autocad 2005, but really don't have much clue as to
how to actually use it. I've bought the "for dummies" book, but
haven't sat down and dug in yet.


Sure, most CAD packages can do curve fitting or there not very much
"CAD." I do it in turbocad. However, historically the problem with
Autocad is that its more of a workbench. Its a corporate product and
lots of the nifty features come in add-ons that you also have to pay
for. But this particular feature should be built in. It may not be
tweakable by the parameters you wish to tweak, but it can be done.


At any rate, thanks, Frank.



--
Thank you,



"Then said I, Wisdom [is] better than strength: nevertheless the poor
man's wisdom [is] despised, and his words are not heard." Ecclesiastes 9:16
  #10   Report Post  
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bent
 
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Default Lay out a sine curve?

press F2 to see the commands/ review the co-ords you entered. F2 again to
close the window



----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
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Lowell Holmes
 
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wrote in message
oups.com...

wrote:
Frank Ketchum wrote:


The plans give a link to the pattern that they used

http://www.uniqueprojects.com/projects/winerack/3b.pdf

Print and attach to the wood!

Frank


D'oh! Must have missed that on the read-through. Boy, is my face red.

However, the question remains--what if I wanted a curve with a
different amplitude or wavelength? This template idea crossed my mind,
but how to generate such a curve? Can Autocad do it? I've just
received a copy of Autocad 2005, but really don't have much clue as to
how to actually use it. I've bought the "for dummies" book, but
haven't sat down and dug in yet.



You could plot points on paper for 0 to 90 degrees,
connect the dots with a french curve, cut it out and use it
as a template, flipping it from right-to-left and upside down
as needed.

--

FF

Get Mastering Autocad by George O'mura. Autocad 2005 is a state of the art
cad program. You need a good source of info.
You probably can find a lisp routine using Google that will draw it.
I suspect Mathcad could draw it.


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Lowell Holmes
 
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"Lowell Holmes" wrote in message
news:%gJJf.2715$6f2.438@trnddc02...

wrote in message
oups.com...

SNIP

FF

Get Mastering Autocad by George O'mura. Autocad 2005 is a state of the art
cad program. You need a good source of info.
You probably can find a lisp routine using Google that will draw it.
I suspect Mathcad could draw it.

As I thought, the link will lead you to a free lisp routine.

http://manufacturing.cadalyst.com/ma....jsp?id=150513


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CW
 
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Default Lay out a sine curve?

What's the chances of someone throwing his wine rack up on comparator and
measuring the frequency and amplitude of it. The man said he had AutoCAD.
Those curves can be drawn in about a minute. Close enough for a wine rack.

"Guess who" wrote in message
news
On 18 Feb 2006 06:59:47 -0800, wrote:

I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it.


For future reference, if you want a real sine curve, and not an
approximation [within the bounds of the tools and shaky hands] use a
math program like Graphmatica, then copy/paste into a word processor
or image editor for printing to the scale you want/need.

Graphmatica is shareware, but free for those who can't afford it [so
just use it if you can't.] PhotoFiltre , or "The Gimp" are freeware
image editors. OpenOffice is a great free office suite with a
wordprocessor and spreadsheet and much more.

If you do it intelligently, you can do it to suit your project scale.
One hint: in Graphmatica type in y = sin(x) for the unit sine curve,
and you might want to change the default colours to black and white.
You can change the equation if you want varied results; something like
y = 3sin(x) or y = sin(3x) or whatever. You likely don't need that
though.

Or, any basic trig text shows how to draw it from the unit circle.



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CW
 
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Default Lay out a sine curve?

You're kidding, right?

"Lowell Holmes" wrote in message
news:%gJJf.2715$6f2.438@trnddc02...
Autocad 2005 is a state of the art
cad program.



  #15   Report Post  
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CW
 
Posts: n/a
Default Lay out a sine curve?

You can lay out a curve like this in Autocad just fine though, in Turbocad,
you can edit the shape in ways Autocad can't.

"dnoyeB" wrote in message news:Ep-

Sure, most CAD packages can do curve fitting or there not very much
"CAD." I do it in turbocad. However, historically the problem with
Autocad is that its more of a workbench. Its a corporate product and
lots of the nifty features come in add-ons that you also have to pay
for. But this particular feature should be built in. It may not be
tweakable by the parameters you wish to tweak, but it can be done.





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Leon
 
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Default Lay out a sine curve?


"bent" wrote in message
...
Draw,
Point,
Multiple Point,
enter co-ordinates of one point (x,y) and press enter, repeat for all
points



Why go to that much trouble entering coordinates? DDE/Direct Distance Entry
would be much simpler and faster


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Lowell Holmes
 
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"CW" wrote in message
.net...
You're kidding, right?

"Lowell Holmes" wrote in message
news:%gJJf.2715$6f2.438@trnddc02...
Autocad 2005 is a state of the art
cad program.


Nope, not kidding. Been using it for 25 years, make my living with it. I
have a legal seat on my home computer. I know what it can do.


  #18   Report Post  
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Karl B
 
Posts: n/a
Default Lay out a sine curve?

wrote in
oups.com:

I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of
wood to cut it. At first I thought of using a disk of some sort, but
that would yield a series of half-circles. If I can't finger this one
out, that's probably what I'll wind up doing, but I was wondering if
y'all had done something like this.

Thanks,

-Phil Crow


In the days before computers and fancy stuff, we used nails, sheet metal
or thin wood. Layout the points of the peaks and valleys (or wave points
if you prefer) and spot a 4d nail at the point. Take the sheet metal (
1" wide x 20 - 24 ga. ) and weave it through the nails. Trace the
pattern and now you know the rest of the story.
  #19   Report Post  
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Phisherman
 
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Default Lay out a sine curve?

On 18 Feb 2006 06:59:47 -0800, wrote:

I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles. If I can't finger this one out,
that's probably what I'll wind up doing, but I was wondering if y'all
had done something like this.

Thanks,

-Phil Crow



Make a template. Lay out a grid. Use a spreadsheet to plot points.
Use a French curve to connect the dots. Read up on how to use a
French curve.
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CW
 
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State of the art as long as you don't compare it to Inventor, Alibre,
Solidworks, Solidedge, Catia, Mastercam, Surfcam, ect, ect. AutoCAD survives
for two reasons, name and the fact that a great many people don't need the
power and flexibility that other programs provide. In the industry I'm in,
aerospace, AutoCAD has long been a has-been. Seen from time to time but
generally only in low level support roles.

"Lowell Holmes" wrote in message
news:V3NJf.1398$0z.561@trnddc01...

"CW" wrote in message
.net...
You're kidding, right?

"Lowell Holmes" wrote in message
news:%gJJf.2715$6f2.438@trnddc02...
Autocad 2005 is a state of the art
cad program.


Nope, not kidding. Been using it for 25 years, make my living with it. I
have a legal seat on my home computer. I know what it can do.






  #21   Report Post  
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Lowell Holmes
 
Posts: n/a
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"CW" wrote in message
nk.net...
State of the art as long as you don't compare it to Inventor, Alibre,
Solidworks, Solidedge, Catia, Mastercam, Surfcam, ect, ect. AutoCAD
survives
for two reasons, name and the fact that a great many people don't need
the
power and flexibility that other programs provide. In the industry I'm in,
aerospace, AutoCAD has long been a has-been. Seen from time to time but
generally only in low level support roles.

"Lowell Holmes" wrote in message


Well, one thing is for sure, neither of us is going to change the others
mind, and this is a ridiculous exchange. I don't know why anyone needs cad
to draw a sine curve anyway. :-)
OBTW, my quartersawn white oak rocking chair is coming along just fine.


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Brooks Moses
 
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Default Lay out a sine curve?

wrote:
I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles. If I can't finger this one out,
that's probably what I'll wind up doing, but I was wondering if y'all
had done something like this.


You've had all sorts of answers for how to do this with various computer
programs (or a pocket calculator), but here's another way that doesn't
involve anything but a compass, straightedge and protractor, and you can
lay it out directly on the board:

1.) Draw a horizontal line down the middle of where you want to put the
sine curve, with the ends aligned with where you want the ends of the
curve to go. Call this the "center line"

2.) Make marks (call them "section marks") to divide this line into
equally-spaced sections, one section for each up-and-down-and-back-up of
the sine curve that you want. Mark off divisions of each of the
sections into 16ths.

3.) Set the compass to draw circles with a diameter equal to the height
of the sine curve that you want to draw. Draw a half-circle centered at
each end of the center line, so it looks sort of like a C at the right
end and a reverse-C at the left end, and the center line goes from the
center of one half-circle to the center of the other.

4.) With the protractor, mark off angles on each half circle, at every
45-degree point, and every 22.5-degree point between these.

5.) Draw lines parallel to the center line by connecting the tops and
bottoms of the half-circles, and each corresponding pair of angle-marks.

6.) Go back to the marks you made in step 2. Starting at the left-hand
end of the center line, draw a line perpendicular to the center line
that goes all the way up to the top line. Put a dot where it crosses
the top line. (You don't actually need to draw the perpendicular line;
just draw the dot. But it's easier to explain if I say to draw the line.)

7.) Go to the right along the center line. For the next mark, draw
another perpendicular line and dot, but put the dot where it crosses the
second line from the top. For the next one, draw the dot on the third
line, then the fourth, and so on. When you get to the bottom, start
going back up. If you've counted right, you should get back to the top
line when you get to the first section-mark. Keep going until you get
to the other end.

8.) Connect the dots. If you're not good at sketching smooth lines, use
a french curve or something.

Obviously, the division into 16ths and the angles I picked are somewhat
arbitrary -- just so long as you divide the sections on the center-line
into twice as many divisions as you divide the half-circles into, it
will work out. If you're using drafting triangles instead of a
protractor, 12ths and marks at 30-degrees and 60-degrees will work well.
Or, if you're good at sketching with only a few dots (I'm not), just
make marks at 45 degrees and divide it into 8ths.

Is that clear enough, or should I do up some sketches and post them?

- Brooks


--
The "bmoses-nospam" address is valid; no unmunging needed.
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Christian
 
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Default Lay out a sine curve?

you could use something like this:

http://www.leevalley.com/wood/page.a...936,42958&ap=1

Christian


wrote in message
oups.com...
I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles. If I can't finger this one out,
that's probably what I'll wind up doing, but I was wondering if y'all
had done something like this.

Thanks,

-Phil Crow



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Morris Dovey
 
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Christian (in ) said:

| you could use something like this:
|
|
http://www.leevalley.com/wood/page.a...1,42936,42958&
ap=1

You'd probably want to find one with a smaller minimum radius. ;-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto


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Josh
 
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Brooks Moses wrote:
... Is that clear enough, or should I do up some sketches and post them?

- Brooks


--
The "bmoses-nospam" address is valid; no unmunging needed.


That's a pretty good idea. Plotting points, but no need to calculate
their values.

Josh



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bent
 
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if you enter the co-ors in the size you need

File,
Print,
select extents,
deselect scaled to fit



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bent
 
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do a FULL preview to not only see the outline of the objects, but the
actual innards. Select each time. Multi-preview before printing.



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bent
 
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if it takes up the whole page, but in the wrong direction, change the
rotation 90. Thats for scaled to fit. origin is if it is offset, integral
with the other print settings required = to center it, for instance



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Leon
 
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"bent" wrote in message
...
well thats helpful


Your welcome.


  #30   Report Post  
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Leon
 
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"Lowell Holmes" wrote in message
news:4nPJf.9869$dO2.5831@trnddc07...

Well, one thing is for sure, neither of us is going to change the others
mind, and this is a ridiculous exchange. I don't know why anyone needs cad
to draw a sine curve anyway. :-)


LOL. Well if it is there why not use it. ;~)




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Phil-in-MI
 
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I cheated once. Took a coffee can lid and made a hole very near the outside
edge for a pencil.

Put a straight edge at the bottom where the sine wave was to go and rolled
the lid across the straight edge, marking the plywood.

The cutting and sanding were much, much more of a problem than the layout.
I gave up after a few attempts, because even the smallest error is
noticeable be everyone. Just a guess but the wine rack mentioned by OP
might hide small errors in the sine wave due to other objects which would
draw the eye.

Phil


You've had all sorts of answers for how to do this with various computer
programs (or a pocket calculator), but here's another way that doesn't
involve anything but a compass, straightedge and protractor, and you can
lay it out directly on the board:

1.) Draw a horizontal line down the middle of where you want to put the
sine curve, with the ends aligned with where you want the ends of the
curve to go. Call this the "center line"

2.) Make marks (call them "section marks") to divide this line into
equally-spaced sections, one section for each up-and-down-and-back-up of
the sine curve that you want. Mark off divisions of each of the sections
into 16ths.

{snip}

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Joe Barta
 
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Phil-in-MI wrote:

The cutting and sanding were much, much more of a problem than the
layout. I gave up after a few attempts, because even the smallest
error is noticeable be everyone.


When I need to make a curved cut in a piece of wood, I make a pattern
from 1/4" hardboard and pattern-route it. Hardboard is easy to cut and
sand smooth and if you make a mistake or cut a little too deep, you
can fill/repair it with a little 5 minute epoxy and file it smooth.

Once the pattern is perfect and smooth with the curve I want, I attach
it to the wood and route it. The end result is wonderful and perfect
the *first* time with very little sanding.

Plus, in some of my woodworking I often make many of the same items,
several at a time over a period of time. The pattern allows to me to
make perfect pieces time after time and very quickly.

Joe Barta
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darkon
 
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Guess who wrote:

On 18 Feb 2006 06:59:47 -0800, wrote:

I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece
of wood to cut it.


For future reference, if you want a real sine curve, and not an
approximation [within the bounds of the tools and shaky hands]
use a math program like Graphmatica, then copy/paste into a word
processor or image editor for printing to the scale you
want/need.

[snip]

Or, any basic trig text shows how to draw it from the unit
circle.


That's what I was going to suggest. It's easy, and you can easily
scale the sine curve as large or small as you like by choosing an
appropriately-sized circle. Since all that's required is a compass
and straightedge you don't even have to leave the shop.

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Bugs
 
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If this thread is about making support cutouts for wine bottles, I
believe you should be talking ellipses or parabolas, not sine curves.
Much simpler formulas too.
Bugs

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Well, thanks everybody for the replies. Apparently there are about 15
ways to skin this particular push stick.

-Phil Crow



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Leon
 
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"Bugs" wrote in message
ups.com...
If this thread is about making support cutouts for wine bottles, I
believe you should be talking ellipses or parabolas, not sine curves.
Much simpler formulas too.
Bugs



Perhaps Arcs rather than an ellipse. An Ellipse is very much like a sine
curve/wave.


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Doug Miller
 
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In article .com,
says...
I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles.


Well, sort of... This isn't a sine curve, but it's attractive, and easy
to lay out with a disk:

http://mathworld.wolfram.com/CurtateCycloid.html
  #39   Report Post  
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Larry Bud
 
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wrote:
I'm making a wine rack:

http://www.uniqueprojects.com/projec...k/winerack.htm

and I was wondering how to lay out that sine curve on the piece of wood
to cut it. At first I thought of using a disk of some sort, but that
would yield a series of half-circles. If I can't finger this one out,
that's probably what I'll wind up doing, but I was wondering if y'all
had done something like this.



Found this for ya

http://ferl.becta.org.uk/content_fil.../SineCurve.xls

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Oleg Lego
 
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The Guess who entity posted thusly:

That's a cycloid, not a sine. Still far and away the easiest is to
use a graphing program like Graphmatica [download from
archives.math.utk.edu ...it's awesome and free.] Type in y=sin(x)
ENTER, and you then print from there or copy/paste into a word
processor. Less than a minute if you have both programs up and
running.


Sounds interesting, but I have not been able to find it. Is that name
correct? If so, would you happen to know what directory it's in?

Thanks.

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