Remotely Controlled Excavator 8294 . A fully motorized LEGO Technic Excavator, with 5 Power Functions motors and proportional infrared remote control from a PC with dedicated hardware and software. . See the YouTube video as embedded below for the functions.
Available are instructions at photobucket, but beware this is a pretty hard (re)build! Plus you need various extra parts.
It is clear that LEGO set 8294 is a very nice model, with good use of the linear actuators. What i liked less in the model is that manually operating it makes you turn and turn and turn...
So i decided to have a go at it with power functions motors. The LEGO provided instructions to combine with the PF motor set are ok, and this saves your wrists, but it still requires manual driving and swinging...
So i took it all the way and fully motorized it.
By taking out the clutch mechanism i obtained space for three motors in the superstructure, mounting two IR receivers behind the cabin.
I totally revised the lower part with turntable, to get a slightly wider construction to fit another two motors and one IR receiver.
Because the swinging action is way too fast, and to control the five motors more easily, i used dedicated hardware and software on a Windows PC. This allows to fully control the excavator from a single joystick.
The details of the Power Functions infrared protocol are published by LEGO. From that i created a configuration file for WinLIRC, an application to send IR commands from a Windows PC. Sacrificing a RS-232 serial cable and an outdated remote control, i soldered an IR led, a diode and a resistor to the cable end. After starting WinLIRC and loading the configuration file, i managed to actually control Power Functions from my PC!
Then i wrote a Java application that translates joystick input into commands and sends these to the WinLIRC server.
Credits should go to a LOT of people who made this possible, by providing various tools, scripts and applications!
It is fair to say that the above took me elapsed several months, and i spent many hours on "research". Unfortunately, it is currently not possible for me to easily share the software, and i am sorry for that. I have not yet given up on that however, so maybe i'll manage some day...