               Thrustmaster RCS Recalibration Procedure
                    By Bob Church  CIS: 73207,3242

The following procedure describes how to readjust the Thrustmaster RCS to give
better calibration. The new calibration point achieved is being adopted by 
Thrustmaster and will be implemented in their production units. This new 
calibration will correct certain rudder problems which were occurring with 
Red Baron, Red Baron/TSN, Aces of the Pacific, Falcon 3.0, and MiG. It should 
not interfere with proper operation of any programs which are already working 
correctly, other than requiring that the rudder be re-calibrated in programs 
which recognize the RCS.

Most existing RCS units will benefit from the recalibration. Those built after 
the new procedure was implemented at Thrustmaster should not be re-calibrated. 
You can determine if you need to do the adjustment or not with the aid of a 
joystick test program which is capable of showing the values which the RCS 
generates. Suitable programs include TMSA, GRAVTEST, CALAP, CALRB, and most
other programs that will read the Joystick 2 X-Axis.

To determine if you need to do the adjustment, proceed as follows:

 1. Run your stick test program and verify that it is reading the RCS
    and that the values change as you move the pedals.

 2. Center the rudder pedals and note the value displayed for the RCS.

 3. Move the rudders to full left and note the RCS value at that point.

The value noted at center should be at least 3 times as large as that noted 
at full left. Typically, the RCS units manufactured before the calibration 
change would have a center value which was a little less than twice the value 
for full left.

If you determine that recalibration is necessary, the procedure is relatively
simple. You DO NOT need to remove the small gear from the pot shaft to do
the re-calibration. The only tool required is a 10 mm open-end wrench.

To re-calibrate the RCS, proceed as follows:

 1. Disconnect the RCS from the computer game port. 

 2. Turn the RCS upside down and remove the plastic cover which snaps into the 
    center channel. This will expose the RCS control pot. Some earlier RCS
    units did not have this pot cover installed.

 3. Turn the RCS right side up and locate the pot and gear assembly. Below 
    the gear is the nut which mounts the pot to the center channel. Using the 
    10 mm wrench, loosen the nut and unscrew it until it is completely free of
    the threaded pot shaft housing. It will still be around the shaft but 
    up under the small gear.

 4. Push the pot and gear assembly straight down until the gear on the pot 
    is disengaged from the gear on the pedal crossbar assembly. Do not
    allow the pot or shaft to rotate during this operation. 

 5. Holding the pot body from the back of the RCS to keep it in its original
    position, rotate the pot shaft and gear exactly two teeth counterclockwise 
    (as viewed from the top). 

 6. Push the pot and gear assembly back up to re-engage the gear located on 
    the pedal crossbar assembly. Thread the nut back onto the pot shaft until 
    it just comes in contact with the center channel. Do not tighten the nut 
    completely yet.

 7. Holding the pot body in position, gently move the pedals to the full left 
    rudder position. The shaft should rotate without hitting the end stop
    on the pot. If it does hit the stop, you should be able to feel the 
    pot body start to rotate before the left pedal stop is reached.

 8. If it does hit the end stop, undo the nut again. Turn the pot shaft and
    gear back (clockwise when viewed from the top) one tooth and go back to 
    step 5.

 9. Tighten the nut on the pot securely. Be sure that the pot body does not
    rotate during this operation. 

10. Replace the plastic pot cover on the back of the RCS.. 

11. Re-connect the RCS to the computer game port.

This completes the recalibration procedure. Run the joystick test program
again. You should see a definite increase in the ratio of center to full
left values. Remember to recalibrate any programs which recognize the
RCS to compensate for the changes.
