Example of sheet metal unfolding: simple lofting by intersecting line method

The development diagram of sheet metal parts is an important step in the production of sheet metal parts. The intersection method is a simple and easy lofting method, which does not need complicated calculation formulas. Drawing software helps you draw easily. This paper will introduce the method of manual lofting for you, so that you can easily master the skills of sheet metal expansion drawing.

1 drawing side projection

First, according to the actual size, draw the side projection of the elbow and add the stitching. This is the basis of making unfolded patterns.

2. Split graph

Next, divide each closed wireframe graph into independent parts. Cut or repaint, as you like.

Draw a rectangle

Take a pattern, set the center line vertically, and then draw it on another piece of paper. Draw two parallel horizontal lines perpendicular to the center line along the height of the pattern, the length of which is exactly the circumference of the pattern diameter. This forms a closed rectangle.

Divide into four parts and mark them.

Divide the pattern vertically and mark it. Next, draw these bisectors vertically into the newly expanded rectangle. The points on the expanded graph must correspond to the points on the projected graph.

5 Divide diagonally.

Divide the diagonal line on the pattern into equal parts along the horizontal direction, and pull it to the unfolded pattern in parallel, corresponding to the corresponding points. Connect the intersection points obtained on the expanded sample smoothly to obtain the expanded curve. The denser the bisection, the more accurate the curve.

6 release bite size

Finally, don't forget the biting amount and the thickness of the processing plate. When making elbows, you must know the bending radius, thickness and number of joints. If necessary, we can also provide you with drawing services.