Hi Pedro, Seems that FS has most of the required parameters. The trick for accurate motion is to bring them in a quick fashion to the outside, most probably to another PC, that does the math manipulation of the parameters. Then this PC sends the required drive signals to the servo system. (my servo system accepted voltages from 0 ~ 5V)With the 50Hz I mean the update rate of the parameters. I believe X-plane shows a max update rate of 50 times per second, although I heard that this rate fluctuates considerably depending on the simulation situation. Note that the update rate needs to be consistent thoughout the data transmission, up to the servo response. In practice this is going to be more limited. As John suggested, good tactile feedback may already do a lot. The transducers in my setup did a lot for realism, even though it was only the engine rumble and touchdown. Again, first solve the software and interfacing before you start on the mechanics and power servo stuff. Roland

Hi Roland,Thanks for your input. Can you tell me how do you interface the servo to a PC, can we connect it directly to a serial port??Best regards,Pedro

FSBus has a servo system implemented in the design, which is accessed via the serial port, but whether it can be used for your purpose I'm not sure, maybe someone else can fill you in on that one.

By the way, this is kind of interesting:http://www-sdb.larc.nasa.gov/Simulations/S.../DMS/gseat.htmlCould also simulate turbulence I guess :-)"Please fasten your seatbelts to avoid hitting the roof"...Tuomas

Basically, you need a PC driven D/A converter for driving a servo system. The FSbus servo drive is suitable for driving servo's that are used in radio control kits. It is based on a pulsetrain with a 1 ~ 2msec pulse for controlling the servo position. It normally works with a repetition rate of 50 Hz or so. (I don't have FS bus, so don't know for sure) However in a power servo system, a varying DC voltage is more suitable. The PIC program that Dirk uses for driving the servo's could be modified to make PWM output, (= cheap DAC) then a simple RC could make it into a DC voltage. To keep the timeconstant small, a 20kHz repetition PWM would work. Not sure if this can be done, and then the question how fast FSbus can update the parameters to the PWM's is crucial. Not sure who can answer that question. Roland