RoboFac: a Hexapod Machine Tool Controller


As used in this document, hexapods are devices which use 6 linear actuators to precisely control the position of a tool. A hexapod is also known as a Stewart-Gough platform. RoboFac is designed to control a hexapod which manipulates some sort of tool, such as a router or pen.

About This Version

Version 0.9.2 fixes several bugs with "Pause" functionality and adds an extra speed up by allowing you to disable actuator length simulation while in simulation mode.


RoboFac should run on any system where Java 5.0 is installed. This includes the various flavors of Windows, Mac OS, Linux and Unix. It may or may not work with other versions of Java.

You also need the Java3D API installed to use the tool path visualization.

Java3D for Linux is available at

Java3D for other platforms:

RoboFac sends its commands to the step motors of the hexapod via the parallel port under Linux. This has been tested only on Fedora Core 3 Linux, kernel 2.6.10, glibc-2.3.4. You may need to recompile the library on other systems.

I have noticed that under Linux 2.4.x and Fedora Core 2 stepper motors run far more slowly and unevenly. Linux 2.6.9 is strongly recommended.

To compile RoboFac from source, you'll need both the VisAd library and the JModalWindow library:

These are included with the source distribution.

Running RoboFac


From the command line, in directory where you've installed RoboFac run the following command:


Make sure that is in the current directory. You may need to become root in order to access the parallel port properly.

Other operating systems

Note that parallel port access, and therefore stepper motor control, is not implemented on any system other than Linux. You can still run RoboFac in simulation mode.

From the command line, in the directory where you installed RoboFac, run the following command:

java -jar RoboFac.jar

RoboFac Home Page

Download links and documentation:


Simon Arthur


RoboFac is Copyright (C) 2004-2005 by Simon Arthur. RoboFac is released free of charge under the terms of the GNU GPL. Commercial licenses are available upon request.

RoboFac includes the VisAd library. (C) 1996 - 2002 Bill Hibbard, Curtis Rueden, Tom
Rink, Dave Glowacki, Steve Emmerson, Tom Whittaker, Don Murray, and
Tommy Jasmin. GNU Library General Public License.

RoboFac includes the JModalWindow library. Copyright (c) 2001-2005 Jene Jasper. GNU Lesser General Public License.