Oval kitchen table....?

[Dennis Peacock]

I need to design a kitchen table that is Oval. Dimensions are 38" wide by 60" long. How do I know when the circular part is "enough"? Is it as simple as a circular arc from some point on the surface to give me the rounded ends of the table?

[tod evans]

dennis, if you want a true oval (ellipse) it`s pretty easy to lay out, start by drawing a cross in the center with the lines at 90deg, then you need to find the foci, to do so use a trammell (stick will do) and mark half of your long length (30") then on the cross you`ve drawn from center measure half the short distance(19") and mark the line. next take the trammell and place one mark on your 19" mark and swing it `till it crosses the long side of your cross, do this on both sides of center, these points are the foci....now drive a nail in each foci and one in your 19" mark and tie a string around all three, remove the nail at the 19" mark and replace it with a pencil and keeping the string taunt discribe your ellipse.....02 tod

[Dennis Peacock]

Great info there Tod....but I'm looking for the preverbial straight sides and rounded ends.....I think. I'll call her and find out for sure.

[Ken Fitzgerald]

Dennis..........this is just a personal observation or taste, if I may.

A number of years ago I worked as a draftsman so I have some experience drawing.....ovals....

To me.........if you were to draw two parallel lines and then pick 2 points near the ends of those parallel lines .....and use them as the centers points.....and draw two semi-circles to form the ends of the "ovals"....it looks....again...personal observation and tastes......too "mechanical"...too "crude" to have a flowing...almost soothing feeling.......A true oval is varying in both the x and y planes......gradually.....so gradually that one plane almost seems to change without notice......but it is...... There are tools out there that you can make for drawing true ovals....I forget the name of the tool....that will accurately allow you to draw an oval......they make a "flowing" oval that doesn't look as if it was as I described above. A trammel?.........

I'll do some searching to see if I can come up with the tool and design....

Just my personal thoughts....

[Jamie Buxton]

Dennis said "oval", and Tod jumped to "ellipse". An ellipse is a kind of oval, but there are many other oval shapes. To my eye, an ellipse is too pointy on the ends for a good table top. The people seated at the ends or near the ends don't get enough table surface.

Dennis, many oval tables are laid out the way you describe: half-circles at the ends, and straight lines connecting them.

Another way to lay out an oval is to eyeball it. Get a big piece of paper or plywood and start drawing, looking for a shape you like. To make an exact layout, make a clean template of just one quarter of the oval, and use it four times to make the complete oval, rotating it and flipping it to produce the other three quadrants.

You can draw a clean but curved line with a trick from boatbuilders. Cut a wood strip thin enough to bend to your curve, but not just flop around. Hold it in the curved shape with weights -- bricks, heavy tools, whatever. Hold it in only a few places, and let it curve between the places. It will form a nice smooth curve.

[Dennis Peacock]

Wow....some very good info here. Elipse, circles, ovals......

Different shapes of an Oval? But isn't an Oval and "Oval"?

I drew a table with straight sides and rounded ends. It looks pretty bad when looking at an eliptical table. Unfortunately, I haven't figure out how to draw an Oval in DeltaCAD yet....so I can't play with the shape to get a "feel" for it.

I've wanted Sketchup for a drawing package....but it's a LOT of money for me to buy....so I'll have to stick with DeltaCAD.

This is taking on a form of being a very interesting and educational thread.

[Lee DeRaud]

Dennis, leaving aside the technical definitions of ellipse and oval, IMHO you won't be happy with an elliptical table of those dimensions. The ends will be too narrow to sit at comfortably: you lose too much area at the "corners" vs the "round ends with straight sides" option.

Are you thinking in terms of an expandable table (ie. a round table with rectangular leaves)?

[Dave Richards]

Maybe what you really want is a super ellipse. Take a look at this link or Google it. http://www.oberonplace.com/products/...or/lesson2.htm

[Jamie Buxton]

I attach a drawing. The first line has ovals of various sorts. The first one is common in furniture: two half-circles connected by straight lines. The second is just eyeballed. The third is the classical egg shape. (The Latin root for "oval" is "ovum", which means "egg".) Dave's superellipses are ovals too.

The second line contains ellipses. Ellipses are a special kind of oval. There is a specific mathematical definition for them. They can be drawn with several techniques -- a loop of string around the two foci, a fancy mechanism with two sliding crossed sticks, and such.

[Ken Fitzgerald]

Thanks Jamie.........I've been trying to get my cheap Cad program to output in some format that would be recognizeable to something other that IT so I could post a similar drawing.

Dennis show something like this to your customer and get their personal take on it!

Regardless.........as stated by Jamie IIRC.....once you decide on the shape I'd use a template and router to cut it!

[Jamie Buxton]

Unfortunately, I haven't figure out how to draw an Oval in DeltaCAD yet....so I can't play with the shape to get a "feel" for it.

Dennis, in DeltaCad, go to the tab marked "circle". There is a button with an ellipse icon. On the 6.0 version, it is the seventh button counting from the left. (I dunno, it might be something else on other revs.) Select that tool. Click on your drawing anyplace. Move your mouse and click again. Move your mouse and click once more. These mouse clicks set the size and shape of the ellipse. You'll see how they work as you play with them.

This tool draws a true ellipse. You can also draw other ovals, but it takes a couple more clicks. That's how I drew the above attachment.

[Dennis Peacock]

Maybe what you really want is a super ellipse. Take a look at this link or Google it. http://www.oberonplace.com/products/...or/lesson2.htm

Dave,

That's more of what I'm looking for but maybe the customer has a different shape for the "oval table".

BTW, Here's what I got from that link and had to translate some of it:

Original text:
X(t) = 3*sign(cos(t)*(abs(cos(t)))^(2/2.5)
Y(t) = 2*sign(sin(t)*(abs(sin(t)))^(2/2.5)

Translated text:
Xt = 3 signs that cost an absolute cost of something higher than 2 divided by 2.5.....with that said....then......
Yt = 2 signs that sint to an absolute sint, that cost us all higher than 2 divided by 2.5......

So.....with all that said? Just keep scratchin' it out until you like what you see.

[Jim DeLaney]

I need to design a kitchen table that is Oval. Dimensions are 38" wide by 60" long. How do I know when the circular part is "enough"? Is it as simple as a circular arc from some point on the surface to give me the rounded ends of the table?

Yeah, it's as simple as that.

For your 39 X 60 table, start with a 38 X 60 rectangle. Come in 19" from each end, and 19" from the side. That will be the center point for your circles (arcs, actually).

Draw your arcs, and you're done. You should end up with a straight run of 22" between the half-circle arcs.

[Jamie Buxton]

Thanks Jamie.........I've been trying to get my cheap Cad program to output in some format that would be recognizeable to something other that IT so I could post a similar drawing.

Ken --
Here's what I do to get from my inexpensive CAD program to SMC. I draw whatever I want on the CAD. I select it and Copy it to the clipboard (cntrl-C). Then I open a photograph-processing program (mine's photoshop, but most any should do), open a new file, and hit Paste. This pastes the picture from my CAD into the photo file. Maybe I crop it or change the size, and then I hit Save for Web. In your photo program, it might be called something else, but the result is that the picture gets saved as a jpeg. This is a form that SMC's software understands. You can upload it, and it will display for the rest of us to read.

[Steve Clardy]

Dennis. Ya gotta add in the mustard color formula in there somewhere