How To Draw an Ellipse With String

Drawing a perfect ellipse freehand can be challenging. To help you out, we’ll explain an easy and cost-effective way to draw ellipses using just a few everyday household items. This Old House general contractor Tom Silva demonstrates this clever technique in the video above and shares tips to perfect your elliptical drawing.

Practical Applications of Ellipses

Ellipses have numerous applications in home improvement and woodworking projects. Some common uses include:

• Picture frames: Elliptical picture frames add a touch of elegance to any space and can be customized to perfectly match your decor.
• Tabletops: An elliptical tabletop can serve as a unique centerpiece in your dining or living room. 
• Decorative accents: Ellipses can be used to craft decorative elements, such as wall art or mirrors, adding visual interest to your home.
• Architectural features: Incorporate ellipses into architectural features like arched windows and doors to give your home a classic and sophisticated look.
• Furniture templates: When designing custom furniture, using an ellipse for templates can result in elegant, curved lines that enhance the overall design.

Materials and Tools Needed

Before you begin, gather the following materials and tools. These items can be found at local home centers or may already be in your toolbox:

• Hammer
• Pencil
• Ruler or straight-edge
• String
• Thin scrap wood or luan
• Two nails
• Utility knife or pocket knife

The String Method: Step-by-Step Guide

Silva’s string method is a practical technique for drawing ellipses without requiring specialized equipment. We’ve outlined the steps below:

1. Lay out the workpiece and draw a straight line through the center of the board to prepare your work surface.
2. Use a utility knife or pocket knife to cut a small kerf, or notch,  near the base of the pencil, towards the tip. This notch will help hold the string in place as you draw.
3. Lightly drive two nails into the workpiece along the center line. The spacing between these nails will determine the shape and size of your ellipse, so you may need to experiment to get the desired result.
4. Tie a knot on one end of the string and place it over one of the nails. Loop the other end of the string around the second nail.
5. Adjust the string’s length so that when stretched, it reaches the desired height of your ellipse. Wrap the excess string around the nail and tie it securely in place.
6. Loop the string around the pencil’s kerf and position it at one end of the ellipse.
7. Keeping the pencil upright and maintaining tension on the string, slowly trace the ellipse. Start outside of one nail and end outside of the other nail.
8. Flip the string over to the other side of the nails and repeat the process to complete the ellipse.

Tip: If the ellipse isn’t the perfect size or shape, simply adjust the nail spacing or string length to suit your needs.

Common Problems When Drawing Ellipses

While the method is simple, it’s not always easy. Here are a few common problems you may run into.

• Uneven curves: If your curves are uneven, practice maintaining even pressure as you move the pencil along the string. Additionally, check that the string remains taut and consistently positioned throughout the drawing process.
• Lopsided shapes: Lopsided ellipses often result from incorrectly spaced nails. Verify that the nails are evenly spaced along the center line and adjust if necessary. Use a measuring tool to ensure precise placement of the nails.
• Pencil slipping: Make sure the kerf in your pencil is deep enough to grip the string firmly. If the pencil continues to slip, try a different type of string or a new pencil. Applying slight pressure to the pencil while drawing can also help maintain control.

Tips and Techniques for Mastering Ellipses

Achieving smooth and accurate ellipses with string requires a combination of careful technique and quality tools. Follow these tips and techniques to perfect your ellipse-drawing skills:

• Use quality materials: To ensure durability and better results, start with high-quality string, pencils, and nails suited to your project’s scale.
• Work on a stable surface: Set up a stable and flat work surface to prevent any movement or wobbling that could distort the ellipse.
• Measure carefully: Accurately place your nails and measure distances to avoid small errors that significantly impact the final shape.
• Maintain consistent tension: Keep the string taut throughout the drawing process to achieve smooth, even curves.
• Keep your pencil perpendicular: Position your pencil perpendicular to the work surface to create clean, accurate lines.
• Use a sharp pencil: Keep your pencil sharp for cleaner, more defined lines.
• Practice on scrap material: Refine your technique by practicing on scrap wood before committing to your final project.
• Experiment with sizes: Try different nail spacings and string lengths to understand how they affect the ellipse’s shape and size.
• Create reusable templates: Once proficient, make templates from durable materials like plywood or MDF to streamline future projects and ensure consistent accuracy.

Alternative Methods for Drawing Ellipses

While the string method is simple and effective, there are alternative techniques for drawing ellipses. We’ve outlined these techniques below:

• Using a jig: This method involves creating a 90-degree piece with a kerf for nails to ride in. While more complex to set up initially, a jig can be useful for repeated ellipse drawings of the same size. Make sure the jig is well-constructed to avoid inconsistencies in the final shape.
• Trammel method: The trammel method uses two sliding points on perpendicular axes to trace an ellipse. It’s more precise than the string method but requires additional tools and setup. Calibrate the trammel carefully to maintain accurate measurements throughout the drawing process.
• Digital tools: Computer-aided design (CAD) software can create perfect ellipses for those comfortable with technology. However, this method lacks the hands-on approach and may not be suitable for all projects. Familiarize yourself with the software’s ellipse tools to maximize its effectiveness.