Can't make the servo-motors (using computer's keyboard) to align the arm in a perfect cross-like position.
The servo will move its arms only in limited angle (less than 70 degrees to the right and more than 100 degrees to the left).

Expected position:

.....*
.....*
---------
.....*
.....*

What I get:

.....*.../
.....*./
..../*
../..*
.....*

If I align the arms from keyboard as close as possible to a cross then I turn off the power, I can move servo's arm manually in a perfect cross position. So, the is enough 'space' or 'degrees' for the engine to spin.

Hello,

- be sure the Yeti calibration program is loaded into Yeti
- be sure Yeti can communicate with hyperterminal
- remove the servo arm's from the servo's
- start Yeti, after 3 seconds, Yeti will beep
- after beeping within 3 seconds press any Hyperterminal key
- press the [-] minus key on the numeric part at the right side of your keyboard
Yeti will now set his servo's in the mechanical uncalibrated centre position
- mount the arms as 'crossed' as possible (servo arms pointing to the sides of Yeti)
- now use the keyboard keys to calibrate the servo's into exactly straight positions.
Do not forget to press the [1] or [2] key to save the calibration values into Eeprom.
Yeti functions will automatically use these in Eeprom stored values.

Regards,

Henk

Thanks Henk.

I think that my problem will be solved by point 8: Yeti will now set his servo's in the mechanical uncalibrated centre position. mount the arms as 'crossed' as possible.

Probably I mounted the arms while the servo motor was not in its middle position.

Done. It worked. But the robot is very unstable. Sometimes it falls.
I will try to calibrate it again.