What are the features of 'freeCAD'?

'freeCAD' is capable of full 3D pan, zoom, tilt and rotate. Available solids are extrusions of rectangles, circles, ellipses and polygons. The solids can be positioned and oriented exactly in space, as are markers on the solids. Exact specification of linear and angular velocities of solids in space are also possible. Mass and inertia properties can be user specified or automatically computed based on uniform density. Individual parts can be save into files and reinserted into any assembly repeatedly.

Available joints are spherical (ball), revolute (pin), translational (slider), cylindrical, planar, fixed, universal, point in line, point in plane, parallel, perpendicular, no rotation, constant velocity, rack pinion, screw. Both open and closed 3D loops are permitted. The curve-curve contact allows liftoffs and collisions based on coefficient of restitution. Available actuators are rotational and translational. Their motions are user prescribed functions of time.

Forces and torques are user prescribed functions of time, displacements and velocities in all three components or along connecting markers. Example formulas for spring, damper, bushing, beam, aerodynamic, inverse square law and other forces and torques are given. Available functions are sqrt, exp, ln, lg, sin, cos, tan, arctan, arctan2, spline, spectral density. Users can specify constant gravity of arbitrary magnitude and direction.

'freeCAD' can compute kinematic, quasi-static or dynamic solutions for any interval of time going forward or backward based on the assembly and user requests. It does redundant constraint removal automatically and nondimensionalizes the equations for improved accuracy and stability of models that are microscopic or gigantic. Simulation progress is animated and the simulation can be stopped any time. After simulation, the computed solution can be used for animation or frame by frame analysis. Full 3D pan, zoom, tilt and rotate is available during simulation and animation.

Users can obtain engineering data in the form of plots and tabular output. XY plots can be zoomed and set to equal scales. Data series available include linear and angular displacements, velocities, accelerations, forces, torques, momenta and kinetic energies. Acceleration data include transverse, centripetal and Coriollis accelerations. Users can view forces and torques from joints, constraints, actuators, springs, dampers, applied forces and inertia. Fourier tranforms of all times series are available.

Assemblies can be saved in binary or human readable, tab delimited, text format with notes and simulation data for later reload. The text format allows pre and post processing of assemblies by other programs, especially spreadsheet programs. Other specific text formats are for MOSES, PDMS Review and . 'freeCAD' runs on Windows, Linux PC, Macintosh PPC and other Unix's. Assembly data are unchanged across platforms.