Copyright (C) 2000, Aik-Siong Koh, All Rights Reserved.

		freeCAD
      3D CAD with Motion Simulation
                  by
             Aik-Siong Koh
        askoh@alumni.princeton.edu


    What is 'freeCAD'?
    What are the features of 'freeCAD'?
    What is new in this release?
    Are there tutorials or examples?
    Where can I get help with 'freeCAD'?
    Disclaimer


  What is 'freeCAD'?

'freeCAD' is meant to be an introductory 3D Computer Aided Design (CAD) package with Motion Simulation capabilities. It 
is suitable for anyone interested in learning 3D CAD and Motion Simulation for free before upgrading to commercial 
packages. It is sponsor supported. Releases will be made quarterly.

'freeCAD' allows users to create and manipulate assemblies, which are collections of 3D parts. The parts are 3D solid 
models, which can be connected or assembled by joints, constraints, actuators, springs, dampers or forces. The parts and 
connections define the structure or mechanism that the assembly is meant to represent. By changing the part shape and size 
and the connection types, the user can understand the system under study without any real prototype.

If the assembly can move, 'freeCAD' has the capability of doing full Multibody Dynamics analysis on the assembly. In 
addition to pure geometric and connection information, mass, moment of inertia, gravity, force and torque information are 
also modeled and used to predict the motion according to Newton's Laws. Animation using the simulated data produces 
realistic dynamic behaviour of the system under study.

Users can also obtain engineering data in the form of plots and tabular output. 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.


  What are the features of 'freeCAD'?

'freeCAD' is capable of full 3D pan, zoom, tilt and rotate. Available solids are extrusions of rectangle, circle and ellipse. 
Exact positioning and orientation of the solids in space and markers on solids are possible. 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. Available joints are spherical (ball), revolute (pin), translational (slider), cylindrical, 
planar, fixed, universal. Available actuators are rotary and translational. Their motions are linear functions of time. 
Available forces are spring-dampers and applied action-reactions. Spring-dampers accept offset, linear stiffness and linear 
damping. Applied action-reactions are linear functions of time. Available torques are similar. Users can specify constant 
gravity of arbitrary magnitude and direction. 'freeCAD' can compute kinematic, quasi-static or dynamic solutions based on 
the assembly and user requests. 'freeCAD' also does redundant constraint removal automatically. 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 also 
obtain engineering data in the form of plots and tabular output. 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. Assemblies can be save with simulation data for later reload.


  What is new in this release?

Zoom, precise inputs (sizes, positions, velocities), tutorials, plotting and export of kinematic and dynamic quantities.


  How to install 'freeCAD'?

To try 'freeCAD' in Windows 95/98/NT or better with 64MB or more RAM:
Download  freecad1.zip  (4MB)
Unzip the file into a directory, say, C:\freecad1
Double click on freecad1.exe to launch the application
If double clicking doesn't work, run the full command:
C:\freecad1\freecad1.exe  C:\freecad1\freecad1.im
Inside 'freeCAD', click the first menu item, Explain, to find instructions and tutorials.

Quick test 'freeCAD':
Click File/Open/Assembly/ to get list of example assemblies.
Choose one, say, fourbar.asm
Click View/Tilt Rotate/ to center the model.  Drag the handles to tilt and rotate the 3D assembly.
Click Motion/Animation/ to get the animation dialog. Click Play to start animation.
You can click View/Tilt Rotate/ even during animation.
Please report any problems.

Known problem:
On some machnines, freeCAD.exe crashes on startup. The problem is probably font related and is encountered on W95, W98 
and NT4. One easy thing that you can do to test this is to force your applications to use only true-type fonts. You can do this 
by: Control Panel->Fonts->View->Options and check 'show only true-type fonts'. You might have to restart Windows after 
this for it to take effect. For more details and other possible causes visit:
http://wiki.cs.uiuc.edu/VisualWorks/VisualWorks+crashes+on+startup.


  Are there tutorials or examples?

Inside 'freeCAD', click Explain/Tutorials/ for a list of examples on projectiles, circular motion, relative motion, pendulums, 
spring-masses, four bar linkages, piston crank, gyro.


  Where can I get help with 'freeCAD'?

For the latest information, visit:
http://www.geocities.com/askoh_us

To pose a question, submit it to the newsgroup alt.cad. Prefix the question with [freeCAD] to distinguish it from other 
questions on different topics.

Finally, you can email:
Aik-Siong Koh
askoh@alumni.princeton.edu


  Disclaimer

'freeCAD' is provided 'AS-IS' with no warranty as to its use or performance. By using it, you agree to indemnify the author 
from any liabilities that you may incur from the use of the software.
