Lay out a sine curve?

<[email protected]> wrote in message
news:[email protected]...
>
> [email protected] 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.

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}

On Sun, 19 Feb 2006 21:50:26 -0600, Oleg Lego <[email protected]>
wrote:


>>That's a cycloid, not a sine. Still far and away the easiest is to
>>use a graphing program like Graphmatica

>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?

The address is correct: http://archives.math.utk.edu

Top right, Software section, click "Windows...."
Choose "Graphing programs", and there find Graphmatica.
It's labelled as shareware, but the author generously offers it free
if not affordable.

Click that, then choose grmat16n.zip for the latest Windows version.
It will do for the shop, for the kids in high school, or in college
and university. Type in a function as done normally: e.g. y =
2sin(x), no need for 2*sin(x) etc.. You can graph an ellipse as well,
but that can be done as readily, and to scale in a simple but powerful
CAD such as DeltaCad.

Default is a coloured background, and coloured curves, but you can
change that to white. You can do more than one in one shot. Tons
more software there, but not for this forum. I just mentioned it for
anyone wanting some usual or unusual math curve.

On Thu, 23 Feb 2006 15:32:11 -0600, "Morris Dovey" <[email protected]>
wrote:

>Guess who (in [email protected]) said:
>
>| 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.
>
>Wow! I downloaded Graphmatica and _really_ like it. Wish I'd had
>something like this when I was in school...

Perhaps your kids can use it ..or theirs?

It's mostly math, but anyone doing wood modelling can find a use. A
parabolic arch is the best support [to do with the focus], so would
make a good support for benches, tables, and so on. CAD will draw the
circle and ellipse, but I don't know of one that will draw a parabolic
curve. There are always layout methods, which were likely used in the
past [e.g. by the Romans] since the computer wasn't available way back
then. Layout is still generally the best if not too tedious, and I'm
not sure yet on the best way to get a printout to scale for a large
project. I'll work on that, or offer something about the layout
procedure. ...in time; too busy right now.

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.

Morris Dovey wrote:
> [email protected] (in
> [email protected]) 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

[email protected] 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

Josh wrote:
> [email protected] 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

Draw,
Point,
Multiple Point,
enter co-ordinates of one point (x,y) and press enter, repeat for all
points

Draw,
Spline,
select all then points you made


To make sure your cursor knows how to find these co-ord points you created.
(They will appear as dots), go to

Tools,
Object Snap settings,
select nearest, under running object snap settings.

I always go to
Tools,
Object Snap settings,
and check endpoint and intersection. In combination with the pick box
size it tells the software what to do. Actually just to make changes. Many
things like this can be saved.



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



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[email protected] 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

well thats helpful



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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

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

File,
Print,
select extents,
deselect scaled to fit



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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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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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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

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

-Phil Crow

[email protected] wrote:
> I'm making a wine rack:
>
> http://www.uniqueprojects.com/projects/winerack/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_files/ferl/resources/colleges/itchen/filedownload/amulley/SineCurve.xls

Sine curves don't faintly resemble the conic projections, ellipse and
parabola except that they are all curves, which includes an infinite
family of exponentials, logarithmic, etc. etc.
Since wine bottles are basically cylinders, the family of conic
projections will fit them precisely. If you want some air space between
the bottle and rack, then almost anything should do. Those interested
should open a book on analytical geometry.
Bugs

[email protected] wrote:

> 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?

Generate a sine function in a spreadsheet, plot it on a chart, print it out.

y=h*sine(x)

y: output value
h: height of the spline (above and below zero)
x: input in degrees

Chris

The Guess who entity posted thusly:

>On Sun, 19 Feb 2006 22:50:30 -0600, Oleg Lego <[email protected]>
>wrote:
>
>>That's a slick little program. Gonna try making some paraboloids.
>
>That will be difficult, since it's all 2D. I could point to some 3D
>software, but you still won't get it to leap off the paper. Stick to
>the 2D and rotate the finished template.

That was my plan... I only need a few templates to form a framework to
be filled. I was going to use the "hanging chain catenary" for it, but
this will be easier.

"bent" <[email protected]> wrote in message
news:[email protected]...
> 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

[email protected] wrote:
> I'm making a wine rack:
>
> http://www.uniqueprojects.com/projects/winerack/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.

"CW" <[email protected]> wrote in message
news:[email protected]...
> 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" <[email protected]> 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.

"bent" <[email protected]> wrote in message
news:[email protected]...
> well thats helpful

Your welcome.

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.

The Guess who entity posted thusly:

>On Mon, 20 Feb 2006 12:50:59 -0600, Oleg Lego <[email protected]>
>wrote:
>
>>That was my plan... I only need a few templates to form a framework to
>>be filled. I was going to use the "hanging chain catenary" for it, but
>>this will be easier.
>
>They are different. You can still as easily plot the catenary though
>if that's what you want. Nobody will notice the difference [or be too
>interested.] You'll need the parabola if you need a focal point.

Interesting. I was told that a catenary was a parabola. Of course it
was a web page somewhere that told me this, and we all know how
absolutely accurate web pages are. I will need a focal point, so
thanks for the info.

"Lowell Holmes" <[email protected]> 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. ;~)

<[email protected]> wrote in message
news:[email protected]...
> I'm making a wine rack:
>
> http://www.uniqueprojects.com/projects/winerack/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

The Guess who entity posted thusly:

>On Sun, 19 Feb 2006 21:50:26 -0600, Oleg Lego <[email protected]>
>wrote:
>
>
>>>That's a cycloid, not a sine. Still far and away the easiest is to
>>>use a graphing program like Graphmatica
>
>>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?
>
>The address is correct: http://archives.math.utk.edu

Ahh.. thanks. My problem was in using ftp, and couldn't find it in the
directory tree. Turns out Enoch pointed me at it, in a directory
(msdos) that I would never have thought to look in. Anyway, that
pointed me to the author's web site, and I grabbed the latest version
(2.0n).

That's a slick little program. Gonna try making some paraboloids.

Christian (in [email protected]) said:

| you could use something like this:
|
|
http://www.leevalley.com/wood/page.aspx?c=1&p=51161&cat=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

[email protected] 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

Guess who (in [email protected]) said:

| 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.

Wow! I downloaded Graphmatica and _really_ like it. Wish I'd had
something like this when I was in school...

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

In article <[email protected]>, [email protected] wrote:
>I'm making a wine rack:
>
>http://www.uniqueprojects.com/projects/winerack/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.

In article <[email protected]>,
[email protected] says...
> I'm making a wine rack:
>
> http://www.uniqueprojects.com/projects/winerack/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

"Lowell Holmes" <[email protected]> wrote in message
news:%gJJf.2715$6f2.438@trnddc02...
>
> <[email protected]> wrote in message
> news:[email protected]...
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/manufacturing/article/articleDetail.jsp?id=150513

You're kidding, right?

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

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" <[email protected]> wrote in message
news:[email protected]...
> On 18 Feb 2006 06:59:47 -0800, [email protected] wrote:
>
> >I'm making a wine rack:
> >
> >http://www.uniqueprojects.com/projects/winerack/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.
>

[email protected] (in
[email protected]) said:

| 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?

This is the easiest part of all. Draw a sinusoid (a sine or cosine
curve) with any amplitude or wavelength, then stretch (or squash) to
the amplitude and wavelength you want. Copy and paste as many cycles
as you want.

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

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" <[email protected]> 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.

"CW" <[email protected]> wrote in message
news:[email protected]...
> You're kidding, right?
>
> "Lowell Holmes" <[email protected]> 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.

[email protected] wrote in
news:[email protected]:

> I'm making a wine rack:
>
> http://www.uniqueprojects.com/projects/winerack/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.

Guess who <[email protected]> wrote:

> On 18 Feb 2006 06:59:47 -0800, [email protected] wrote:
>
>>I'm making a wine rack:
>>
>>http://www.uniqueprojects.com/projects/winerack/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.

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

On Sun, 19 Feb 2006 04:41:32 GMT, "Phil-in-MI" <NO Spam &
[email protected]> wrote:

>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.

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.

It can be done by hand, it can be approximated by hand. ifthat's good
enough then that's the best way, but most people don't have a clue on
how to do that.

Now, let's empty this can of worms and get on with it.

"Bugs" <[email protected]> wrote in message
news:[email protected]...
> Sine curves don't faintly resemble the conic projections, ellipse and
> parabola except that they are all curves, which includes an infinite
> family of exponentials, logarithmic, etc. etc.

Except that ellipses have curves with more than 1 radius similar to
sections of a sine wave.


> Since wine bottles are basically cylinders, the family of conic
> projections will fit them precisely.

Which is why I indicated an arc will fit more closely fit or follow the
shape of a bottle than an ellipse. An arc is a section of a circle. An
ellipse is a circle illustrated in isometric or 3d format.

On Sun, 19 Feb 2006 22:50:30 -0600, Oleg Lego <[email protected]>
wrote:

>That's a slick little program. Gonna try making some paraboloids.

That will be difficult, since it's all 2D. I could point to some 3D
software, but you still won't get it to leap off the paper. Stick to
the 2D and rotate the finished template.

On 18 Feb 2006 06:59:47 -0800, [email protected] wrote:

>I'm making a wine rack:
>
>http://www.uniqueprojects.com/projects/winerack/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.

[email protected] (in
[email protected]) said:

| 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.

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

"Bugs" <[email protected]> wrote in message
news:[email protected]...
> 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.

On 18 Feb 2006 06:59:47 -0800, [email protected] wrote:

>I'm making a wine rack:
>
>http://www.uniqueprojects.com/projects/winerack/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.

On Mon, 20 Feb 2006 12:50:59 -0600, Oleg Lego <[email protected]>
wrote:

>That was my plan... I only need a few templates to form a framework to
>be filled. I was going to use the "hanging chain catenary" for it, but
>this will be easier.

They are different. You can still as easily plot the catenary though
if that's what you want. Nobody will notice the difference [or be too
interested.] You'll need the parabola if you need a focal point.

Oleg Lego (in [email protected]) said:

| The Guess who entity posted thusly:
|
|| On Mon, 20 Feb 2006 12:50:59 -0600, Oleg Lego
|| <[email protected]> wrote:
||
||| That was my plan... I only need a few templates to form a
||| framework to be filled. I was going to use the "hanging chain
||| catenary" for it, but this will be easier.
||
|| They are different. You can still as easily plot the catenary
|| though if that's what you want. Nobody will notice the difference
|| [or be too interested.] You'll need the parabola if you need a
|| focal point.
|
| Interesting. I was told that a catenary was a parabola. Of course it
| was a web page somewhere that told me this, and we all know how
| absolutely accurate web pages are. I will need a focal point, so
| thanks for the info.

They're actually very different critters, as you can see from the
"shape" of their defining equations (source: Burington's "Handbook of
Mathematical Tables and Formulas") -

Catenary: y = a * (exp(x / a) + exp(-x / a)) / 2

Parabola: 4 * a * (y - k) = (x - h) * (x - h)

For a wine rack, I think I'd want concave circular arcs to support the
bottles - with either a horizontal flat or an ornamental convex curve
connecting those arcs. A repeating ogee might give an interesting
appearance...

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

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" <[email protected]> wrote in message
news:V3NJf.1398$0z.561@trnddc01...
>
> "CW" <[email protected]> wrote in message
> news:[email protected]...
> > You're kidding, right?
> >
> > "Lowell Holmes" <[email protected]> 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.
>
>

Oleg Lego wrote:
> 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?

http://archives.math.utk.edu/software/msdos/graphing/grmat/.html

er
--
email not valid

you could use something like this:

http://www.leevalley.com/wood/page.aspx?c=1&p=51161&cat=1,42936,42958&ap=1

Christian


<[email protected]> wrote in message
news:[email protected]...
> I'm making a wine rack:
>
> http://www.uniqueprojects.com/projects/winerack/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
>