dipper

thingiverse

The first 3D shape showcases a cross section of a dipper that utilizes air pressure to retain water. Gripping the knob on top with your index and middle finger, submerge the container into water. Next, plug the hole in the knob with your thumb and lift the dipper out of the water. Water will stay inside the container until you remove your thumb. The project requires explaining the underlying physics principles and creating a design based on them to demonstrate how they function. This project was designed using FreeCAD, exclusively utilizing basic primitives. Dipper Project Objectives: This is an introduction to CAD learning boolean operations on primitives to create more complex shapes. It also explores basic physics concepts involving atmosphere, gas, and pressure. Audiences: This project could be incorporated into teaching the physics of atmosphere, gas, and pressure. Preparation: A fundamental understanding of primitives, position, and boolean operations is required, as well as a basic comprehension of pressure physics. The design should be simple and feasible to create in any chosen program. Steps: First, design the outer shape as a solid, combining cones and cylinders. Then create a similar, smaller core within the outer shape. I have replicated the core outside the solid shape for illustration purposes. Next, subtract the core from the solid shape, leaving about 2mm walls. Finally, use the "Fillet" tool to round off the edges. Remember to apply the "Fillet" tool on the core as well or the walls may be too thin. Use the "cross section" tool to verify wall thickness before printing and ensure you do not have excessive overhangs requiring support structures; 45 degrees is a safe margin. Results: Innovative designs grounded in physical principles deserve recognition. Important design considerations include avoiding internal support structures, matching the core to the surface for consistent walls, ergonomics, and a deeper understanding of pressure physics.