How to cut an ellipse

How to cut an ellipse


Hi everybody! I’m Mike McCrory and this is Wood U Make It. I have this piece of wood that I intend to use as a serving tray and I’m in the process of making it, so I’ve got a strip of maple down the center and I glued a strip of walnut on each side. Now what I want to do is have a nice gentle curve around the outside edge. Normally when I’m cutting a curve I would use a flexible curve like this that I can bend into any shape. But it’s hard to get it precisely shaped and to get it symmetrical and nice and smooth. So, in this case what I thought I would do is create an ellipse. It’s a very simple process and I thought you might want to see how I go about doing that. So, let’s get started! [theme music playing] I remember learning a lot of complex things about ellipses in college but there are really two important things to remember, and that is that an ellipse has two axes — a major axis and minor axis — so I’m marking the center points across the length and also across the width to define the major axis and the minor axis. After marking the axes all it takes are three pins and some string. So, I’m putting a pin at each end of the major axis. I’m not going all the way to the end because there’s going to be some slack in the string, so I want to be able to account for that and then when I use the slack it will go to the end. Then I put the third pin close to the edge but not all the way to the edge because after I tie the string there’s still going to be a little bit of slack in it, so it’s going to extend a little bit beyond where the pin currently is. The most difficult part of this project, for me at least, was to tie the knot and still keep the string taut. It would have helped if I knew how to tie knots a little bit better. The important thing is to keep the string as tight as possible. You don’t want to have too much slack because any slack is going to cause the string to go beyond the edge of the minor axis. Then I’ll cut the string and remove the third pin so that I just have the pin at each end of the major axis. Then I’ll take a pencil and then, applying an equal amount of pressure on the string, I just trace around the string and that will create an ellipse for me. It’s really pretty simple to draw an ellipse using this method. Here I’m just going to move the knot out of the way. The only difficulty you might have from time to time is that, depending on the type of string you’re using, the end of the pencil may get tangled up in the string. It’s just important to apply an even amount of pressure all the way along. Now over at the bandsaw, I’m cutting around the outside edge of the pencil line. I’m trying to leave a little bit of the pencil line behind so that I can clean it up at the belt sander. I’m using a 1/4″ band saw blade with 10 teeth per inch. I probably could have used a larger blade, maybe even a half inch, but the 1/4″ blade gives me a lot of flexibility. Now over at the belt sander, I can clean up the edge and remove any saw tooth marks that remain and I can trim the edge down right down to the pencil line. The edges are nice and clean now, so there are two main things remaining. One is I want to drill a 2 1/8″ hole in each end of the tray. That way, I have a place to insert a couple of dishes — maybe for a dipping sauce or something like that — and then the other thing I want to do is round over the edge using a 1/4″ roundover bit. This roundover bit that I have is more than 10 years old and it looks like it needs a little bit of sharpening. You can see there’s little bit of a burn mark. Before applying the finish there are a couple of defects in the wood. This one in the center is from a knot, I think, and on the back there are a couple of little gouges as well. I’m going to fill those with epoxy and let this sit overnight. Now it’s been about 24 hours and I can sand the epoxy now that it’s mostly cured. It’s not 100% cured after 24 hours, but it’s good enough for this purpose. Then I’m sanding the entire board with 220 grit sandpaper and then some hand sanding around the edge and inside the holes that I’ve drilled. Now, as I do with all the cutting boards that I make, I like to soak them in water, just quickly. That helps to raise the grain I’ll let that dry and you can really feel the difference when the grain is raised. I’ll let that dry as sand it and repeat the proces one time so the grain can raise just a little bit more. Then it’s ready for the finish. This really brings out the contrast between the maple and walnut, and the appearance of the grain. So, I gotta ask… Would YOU Make It? [Theme music playing]

44 thoughts on “How to cut an ellipse

  1. Brilliant Mike just Brilliant, love the wood you used for the tray, and wow doesn't that grain pop. Plus an added bonus of a Geometry lesson as well. Well Done my Friend.
    Barry (ENG)

  2. I would make it Mike, so sir would you kindly have a look at my cutting Board build on Sumo's Projects with Australian hardwoods & see if it makes the high standards of builds you make, great viewing your content every time 👍

  3. wow this way has blow mi mind.
    what's make me feel like proud and grateful if you was my teacher to learn this beautiful craft .
    this craft is always about brilliancy .innovating and show some proficiency

  4. Beauty job.
    So i will make it when i found pallets Lol. In Greece wood li walnut it's very expensive, the other solution is to made it with olive tree wood the best wood grain ever.

  5. I like the two cutouts using the 2 and 1/8th forstener bit. Might try that next week on a couple of my cheese boards I''m putting together to sell at a local show.

  6. Hey Mike,

    Thank you for another great project. I was excited to see the string trick, as I just made an arc bow for my inlay cutting board I'm making from your other project video. The walnut maple combo is my favorite together. What kind of epoxy do you use? It looked so much easier to use than what I have. Thank you!

  7. The points at each end are not the ends of the major axis, but the foci of the ellipse. With such an eccentric ellipse, I can see how you might get confused, but consider a less eccentric ellipse, or even the least eccentric ellipse of all — a circle.

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