Thought I’d share my method for laying out ellipses, since that seems to get discussed often enough. I haven’t seen anyone else use this method (carpenters, anyway!), so…….here goes:
- draw an “ell”, with the long leg representing 1/2 of the total width of the ellipse, and the short leg representing the height.
- divide each leg in half, in half again, and so on. Do this as many times as you like. The more points you have, the smoother the resulting curve will be.
- begin connecting the points as shown in the drawing.
- When you’re finished, you will have a perfect ellipse defined by the intersecting lines you’ve drawn.
I use this method alot, drawing full scale on a sheet of 1/2″ plywood, when framing elliptical openings. Once you lay out and cut the first piece of plywood, you use it to trace out the other three. With this done, I insert blocks of wood between the plywood pieces, to make up the thickness of the wall. I then nail these units up and they’re ready for drywall.
The thing I like about this method is that all you need is a tape, pencil and straightedge. Also, I can never remember how to set the d*** string and nail method up!!
Anyway, hope ya’ll find it as quick and easy as I have.
Mike
Replies
Mike,
Just so you know that method has been discussed here before. It’s a method that I’ve used often, but it’s not an elliptical curve, it’s a parabolic curve.
Joe,
OK, I'll bite (since I'm not a math guy!). What's the difference between an ellipse and a parabolic curve? It's been a loooooong time since I learned that in school!
Mike
Mike,
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That would make a nice graphic on a business card
say, what does ur nic mean?
thank you mike, i will use that.
The easiest way I know to construct an ellipse is to take a straight edge and mark two points on it. Point "A" will be half the length of the major axis from the end, Point "B" will be half the distance of the minor axis from the end. (point "C" will be the end)
Draw two lines perpendicular to each other, set point "B" at the intersection and point "A" along the vertical axis then just slide point "A" up and point "B" over, keeping them on the horizontal and vertical axis'. Mark point "C" as you go along. (see attached)
Viola - A perfect ellipse every time!
Kevin Halliburton
"In him the whole building is joined together ..." Ephes. 2:21
add a framing sq. at the center / center...and two finish nails at the 1/2 major, 1/2 minor points measured from a penskill at the end...draws 1/4th at a shot..flip sq. and do again...been doing it for yrs...
edit. clip the nails short to "ride" along the sq. let the penskill drag the arc...
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Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations.
Edited 3/4/2004 7:47:49 PM ET by SPHERE
Well sure, that would work, if you want to get all fancy about it. (actually that was pretty dang smart)
One of these days I'm going to have to get me one of them framin' sqare thingies. They sound pretty useful. :-)>Kevin Halliburton
"In him the whole building is joined together ..." Ephes. 2:21