About
About 3D Mechanic
3D Mechanic is an app for iPhone and iPad that teaches how cars work by letting you take real car systems apart in 3D.
Why it exists
Most explanations of how a car works are flat: a cross-section in a textbook, or a video filmed from one angle. A clutch makes sense when you press the pedal and watch the diaphragm spring let go of the disc. A MacPherson strut makes sense when you push the wheel up and see the spring compress and the camber change. 3D Mechanic is built around that idea. Every system is a working assembly you can turn around, pull apart, test and put back together.
How the models are built
Each system is modelled part by part as it would be on a generic compact front-wheel-drive car. Parts have their real shapes, sit in their real positions and move the way they do on a car: the pistons follow the crankshaft, the pads close on the disc, the rack slides when the pinion turns.
The numbers are teaching values, chosen to be realistic and kept consistent across the app. The clutch clamps the disc with 5,176 N at rest and starts to bite at 18% of pedal travel. The engine has an 86 mm bore and stroke. At 60 bar of brake pressure, the caliper clamps the disc with 15.3 kN. These are not the specification of any one car, and the app is not a repair manual: on a real car, follow the maker's procedures and torque values.
About this website
The guides on this site explain each system in plain words. Their interactive diagrams run on the same numbers as the app wherever the app has them; where it does not, they use typical textbook values and say so. Screenshots are taken from the app.
3D Mechanic: How Cars Work, on the App Store for iPhone and iPad.
