Kite Aerial Photography E-Resources

BASICS / CAMERA CRADLE / 360° SERVO CONVERSIONS

Method 4 - Modified Final Servo Gear - Recommended

Futaba S3003 servo stop tabs Figure 10 Inside the Futaba S3003 servo case Figure 11 Cross Section of Final Drive Gear Figure 12 This method is probably the easiest to implement. This method originated from Scott Kroger and was first published in an article by Brooks Leffler in the Aerial Eye (5:2). Remove the servo case top and the final drive gear making sure not to turn the final drive gear. The final drive gear is connected to the servo "pot" and we want it to remain in its neutral position. Cut or file away the stops found inside the case top and file or grind off the stop located on the final drive gear (Fig. 10).

Next turn the final drive gear over (Fig. 11) and drill out the center portion that engages the end of the "pot" and causes it to turn (white area Fig. 12). This will allow the final drive gear to turn without moving the "pot". If the "pot" does not move then the servo will continue turning until the transmitter joystick is returned to the central neutral position. An alternative to drilling out the final drive gear is to cut off the shaft of the "pot". This can be done easily if you have a Dremel tool with an emory saw.

If you wish to connect the pan servo directly to your picavet cross or pendulum without gearing the servo down, then drill a hole the diameter of a #4 bolt through the center of the final drive gear output shaft (yellow area Fig. 12).

Different makes of servos have different methods of connecting the final drive gear to the servo "pot" but can still be modified. All one has to do is figure out a way to keep the final drive gear from turning the "pot", and make sure that all stops have been removed.

Advantages-
Simple, using simple tools.
The rig can be hung directly from the servo output.
External gears are not required.
(some KAPers go ahead and gear the final output down 4:1 to make the panning action slower.)
With no external gears the panning action will be at the servo's normal operating speed.
With no external gears the servo requires minimal space on the KAP rig.


Disadvantages-
Servo must be open and modified.
Can not use most mini-servos because of partial gears.