FreeCAD: let’s get curvy! TUTORIAL
FreeCAD: let’s get curvy! Add bendy transitions to your parts for a more elegant look
Figure 1
Two sketches in the XY plane with one sketch raised above the other on the Z-axis
F Jo Hinchliffe @concreted0g Jo Hinchliffe is a constant tinkerer and is passionate about all things DIY. He loves designing and scratch-building both model and high-power rockets, and releases the designs and components as open-source. He also has a shed full of lathes and milling machines and CNC kit!
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irst up is the Additive Loft function, which is a method that creates straight or curved transitions between sketches – it’s a great way of creating complex flowing shapes. To start with, we will make a nonsense object just to see how it works, and then we will create a small ornamental bowl that can be 3D-printed. On the part design workbench, create a new body and then create a new sketch on the XY plane – this should move you onto the sketcher workbench. Select the rectangle tool and draw a rectangle in this sketch. As this is a test, we don’t need to add constraints, so close this sketch now. In the part design workbench again, within the same body, create a second sketch. Click the 'New sketch' button, and select the XY plane for our second sketch. In this second sketch, use the regular polygon tool to draw a hexagon that is smaller than the rectangle you drew – draw it inside the rectangle, and don’t worry if it overlaps a little.
Figure 2
Using the lofting tool can create pleasing curved results
Again, we don’t need to constrain the hexagon, so close the sketch. The next step is to move the hexagon sketch away from the rectangle sketch in the Z-axis. As both of the sketches are part of the same body, we can’t move the basic position of the hexagon sketch, but we can move the relative attachment point of the sketch. With the sketch containing the hexagon selected, you should see the dialogue box for the sketch in the combo view panel. In this dialogue box, there are three sections of values separated under the headings 'Attachment', 'Base', and 'Sketch'. Making sure you are in the Attachment section, click the Attachment menu, and then click to expand the Position menu. In this drop-down menu, adjust the Z-axis to raise the hexagon sketch over the rectangle – this can be any amount, but we went for 20 mm. If you are in an isometric view in the part design workbench, you should see the hexagon sketch rise above the rectangle sketch (Figure 1). Next, select the original rectangle sketch in the file tree view, and then click the yellow and red 'loft a