Some questions regarding a servo motor's data sheet.

[selbstdual]

I would never put a gear that would multiply the rotational speed on a servo motor. The "play" might be so much that an effect as the one you describe here could happen, and obviously it does. Also as I stated to your P.M. do not use maths in the FOR command. Put directly the number you want, not the 1000/20.

More, the 50 pulses of the FOR-NEXT loop might be little. Try to raise the number to 500.

Ioannis

Interesting. What I found is that starting from 0° and rotating to 360° by using trial-and-error values without stopping in the middle makes the motor stop at very much the same position, ie causing a very close to 360° turn being much more exact than the "return-to-the-middle"-routine. In Short 0° <-> 360° works. 0° -> 180° doesn't. 360° -> 180° doesn't(notice the pointer's(->) direction).

What I found additionally: It is normally not the position that is to be driven to. It is the return. So (RotMin+RotMax)/2 changes its effective position. In other words, even though (RotMin+RotMax)/2 must be constant, the motor does not stop at the same place when being directed to.