For the latest information, freeware downloads, patches, examples and open 
source of 'freeCAD', visit:
http://www.askoh.com



                        freeCAD
 3D CAD with Motion Simulation
                             by
                     Aik-Siong Koh
                        curriculum vitae
                   askoh@alumni.princeton.edu
                     http://www.askoh.com

Page updated: 2001/09/30
'freeCAD4' was created on 2001/09/30.
patch40.zip supersedes all other patch4*.zip.
patch40.tar.gz supersedes all other patch4*.tar.gz.

     What is 'freeCAD'?
     What are the features of 'freeCAD'?
     What is new in this release?
     Are there any reviews?
     Is 'freeCAD' open source?
     How to download, install, patch and 
     quick test 'freeCAD'?
     What are the known problems?
     Are there documentation, tutorials or 
     examples?
     Where can I get help with 'freeCAD'?
     What is a sponsor?
     How can I help?
     How to use 'freeCAD'?
     Disclaimer

   What is 'freeCAD'?

'freeCAD' is a basic 3D CAD with advanced Motion Simulation capabilities. 
It is suitable for anyone interested in learning 3D CAD and Motion Simulation 
for free before using more sophisticated packages. Educators, students and 
new engineers will find it ideal for the teaching and learning of geometry, 
kinematics, dynamics, vibrations, mechanisms, linkages, cams, machine design 
and physics. The program runs on Windows, Macintosh PPC, Linux PC and 
other Unix's. Assembly data are unchanged across platforms. It is a 
FREEWARE which is sponsor supported. Releases will be made quarterly.

'freeCAD' allows users to create and manipulate assemblies, which are 
collections of parts. The parts are simple 3D solids, which can be connected 
by joints, constraints, contacts, motors, actuators, springs, dampers, forces, 
torques or gravity. The parts and connections define the structure, mechanism 
or machine of interest. Both open and closed 3D loops are permitted. 
'freeCAD' performs full Multibody Dynamics analysis on the assembly to 
predict the motion according to Newton's Laws. Animation using the 
simulated data produces realistic dynamic behavior of the system.

Users can also study the mechanical dynamics 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.

 Screen Shot


   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. 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. 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' 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. Individual parts can be save into files and reinserted into any assembly 
repeatedly. Assemblies can be save with simulation data for later reload. 
'freeCAD' runs on Windows, Macintosh PPC, Linux PC and other Unix's. 
Assembly data are unchanged across platforms.


   What is new in this release?

The symbolic function parser allows the user to define functions of time, 
displacements and velocities for forces and torques in all three components or 
along connecting markers. Example formulas include: linear, hardening, 
softening springs; linear damper, aerodynamic forces, beam, bushing, inverse 
square law and van der pol equation.


   Are there any reviews?

Search for 'freeCAD' at the following web sites:
TUCOWS http://www.tucows.com
Simtel http://www.simtel.net
ZDNet http://www.zdnet.com
CNet http://www.cnet.com
Top Quality Freeware http://www.topqualityfreeware.com
Cad Depot http://www.caddepot.com
             The Internet Resource for Engineering Professionals
Mechanical Engineering magazine, September 2001, "Software Exchange, 
3D-CAD", http://www.asme.org
CADENCE magazine, October 2001, "Analysis Tools For The Desktop", 
http://www.cadenceweb.com


   Is 'freeCAD' open source?

'freeCAD' is created with the open source StCAD: 3D CAD Framework for 
Smalltalk and a private motion simulation program. All the source code is in 
Smalltalk which is a pure object oriented programming language. The 
development environment used is VisualWorks which is also open source.


   How to download, install, patch and quick 
test 'freeCAD'?

If your internet connect is unreliable, use Download Accelerator Plus to 
resume incomplete downloads.
For previous version of 'freeCAD', go to freeCAD3

To try 'freeCAD' in Windows 95/NT or higher with 64MB or more 
RAM:
Create a directory, say, C:\freecad4 for the downloads.
Download freecad4.zip  (5.4MB).
Download patch40.zip  (257KB).
For alternative download web sites, go to the reviews section above.
Unzip freecad4.zip into the same directory.
Unzip patch40.zip into the same directory. Let it overwrite other files.
Double click on freecad4.exe to launch the application.
If double clicking doesn't work, create a shortcut containing the full command 
below:
C:\freecad4\freecad4.exe  C:\freecad4\freecad4.im
The working directory should be C:\freecad4
Then double click the shortcut.
Known Problems:
Please report any problems.

To try 'freeCAD' in Macintosh PowerPC:
Create a folder, say, freecad4 for the downloads.
Download  freecad4.tar.gz  (5.3MB).
Download  patch40.tar.gz  (12KB).
Locate and download PowerMac virtual machine at 
http://www.cincom.com:80/scripts/smalltalk.exe/downloads/index.asp?content=visualworks
Open Stuffit Expander's preferences dialog to Cross Platform options, and 
select
"Never" for "Convert Text Files to Macintosh text format".
Then for the Destination options, select
"Same as original" for "Destination"
"Never" for "Create Surrounding Folder".
Decompress freecad4.tar.gz into the same folder.
Decompress patch40.tar.gz into the same folder. Let it overwrite other files.
Decompress virtual machine file into the same folder.
Make a copy of freecad4:bin:powermac:visual (or visualnc or vw5i.4) in 
freecad4.
Drag freecad4:freecad4.im and drop onto freecad4:visual (or visualnc or 
vw5i.4).
Alternatively, create a shortcut containing the full command below:
freecad4:visual (or visualnc or vw5i.4)  freecad4:freecad4.im
The working directory should be freecad4
Then double click the shortcut.
Known Problems:
Please report any problems. Let me know if you can make this installation 
process easier.


To try 'freeCAD' in Linux PC:
Create a directory, say, /home/username/freecad4 for the downloads.
Download  freecad4.tar.gz  (5.3MB).
Download  patch40.tar.gz  (12KB).
Locate and download Linux virtual machine at 
http://www.cincom.com:80/scripts/smalltalk.exe/downloads/index.asp?content=visualworks
Decompress freecad4.tar.gz into the same directory.
Decompress patch40.tar.gz into the same directory. Let it overwrite other 
files.
Decompress virtual machine file into the same directory.
Make a copy of /home/username/freecad4/bin/linux86/visual in 
/home/username/freecad4.
Make a copy of /home/username/freecad4/bin/linux86/herald.so in 
/home/username/freecad4.
Change directory to /home/username/freecad4
In a terminal window, execute: ./visual freecad4.im
Alternatively, create a shortcut containing the full command below:
/home/username/freecad4/visual  /home/username/freecad4/freecad4.im
The working directory should be /home/username/freecad4
Then double click the shortcut.
Known Problems:
Please report any problems. Let me know if you can make this installation 
process easier.

To try 'freeCAD' in other Unix's:
Follow instructions for Linux PC.
Locate and download your virtual machine at 
http://www.cincom.com:80/scripts/smalltalk.exe/downloads/index.asp?content=visualworks

Version check:
Since 'freeCAD' can be downloaded from many locations, it is good to check 
that you have the latest version.
Inside 'freeCAD', click Explain/About/ to locate the creation date:
'freeCADx' was created on yyyy/mm/dd.
Verify that you have the latest copy by comparing with the creation date 
published at:
http://www.askoh.com

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.
If necessary, Click Edit/Marker Size/ to set marker sizes suitable for the 
drawing.
Click Simulation/Animation/ to get the animation dialog. Click Play to start 
animation.
You can click any View menu item and drag the tilt and rotate handles, even 
during animation.
Close animation window when done.
Please report problems to
Aik-Siong Koh
askoh@alumni.princeton.edu


   What are the known problems?

All Platforms:
If an error message comes up, click on "Continue" to let Smalltalk recover. 
You can usually continue if you avoid the offending steps. Every error is 
logged in a file called error.log. Email that file to the author for debugging. 
Patches and workarounds will be posted as soon as possible. Thank you in 
advance.
On Windows:
Right clicking on some mice does not bring up the correct menu. Try right 
clicking while holding the ctrl key down.

Please report problems to
Aik-Siong Koh
askoh@alumni.princeton.edu


   Are there documentation, tutorials or 
examples?

Documentation are inside the program. The are collected in a series of menu 
items labeled 'Explain'. Click on them anytime.
Inside 'freeCAD', click Explain/Tutorials/ for a list of tutorials on projectiles, 
circular motion, relative motion, pendulums, spring-masses, four bar linkages, 
piston crank, gyro, cam follower.

More Example Assemblies


   Where can I get help with 'freeCAD'?

For the latest information, freeware downloads, patches, examples and open 
source of 'freeCAD', visit:
http://www.askoh.com

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

You can email your questions to:
Aik-Siong Koh
askoh@alumni.princeton.edu


   What is a sponsor?

'freeCAD' is a freeware suitable for anyone interested in learning 3D CAD 
and Motion Simulation for free before using more sophisticated packages. 
Educators, students and new engineers will find it ideal for the teaching and 
learning of geometry, kinematics, dynamics, vibrations, mechanisms, linkages, 
cams, machine design and physics. Since its release in July 2000, 'freeCAD' 
has been downloaded at least 40,000 times. For proof, search for 'freeCAD' 
at the web sites mentioned in the reviews section. The master website 
(http://www.askoh.com) receives 120 unique clients who download 250MBs 
daily. Since 'freeCAD' is freeware, it can be downloaded from many sites that 
are not accounted for in the above numbers. A search for 'freeCAD' on any 
major search engine will point to about 100 relevant links worldwide.

Sponsors can advertise on the 'freeCAD' web site and inside the 
'freeCAD' program to promote their products, services, publications 
and job opportunities. There will be no more than ten advertisers inside the 
program at any one time. Each advertiser gets equal time to show his/her 
messages at various points (title bar, menu item, dialog boxes, status bar) in 
the program as the users use the program. Advertisers can change their 
messages every quarter when new releases of 'freeCAD' are made. For the 
price of US$500 per month, sponsors can advertise to over 3000 new users 
of 'freeCAD' per month. In addition, continuing users of 'freeCAD' will still 
see their advertisements.

Sponsors can also request for customizations of 'freeCAD' and other 
consultancy services from the author. Aik-Siong Koh's curriculum vitae

For more information, please contact Aik-Siong Koh at (505) 661-9779 or 
askoh@alumni.princeton.edu


   How can I help?

Your bug reports and suggestions are most valuable for improvements in 
'freeCAD'. If you have example assemblies to share so that others can benefit 
from your work, please let me and others know about them. I can include 
them on this site if you want. If you like programming, I welcome you to look 
at the open source and discover the wonders of pure object oriented 
programming and the productivity gains that can be had. Finally, but not least, 
please tell your friends and colleagues about 'freeCAD'. Thank you very much 
for your contributions.


   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.


Copyright (C) 2000-2001, Aik-Siong Koh, All Rights Reserved.

