Checking Motor Home Position Distance (61Ii) - Horizon Fitness APC-61 Manual

1-7 Checking Motor Home Position Distance
Explanation of "Home Positioning"
1. At first, the backgauge moves backward and
B21 home position sensor (Fig.2) detects the
sensor plate and turns on.
2. When B21 turns on, the servo motor M20
rotates in the reverse direction and moves the
backgauge forward, and B21 turns off.
3. The motor stops at the position where Z-phase
from the encoder is detected for the first time
in one rotation of M20. This position is the
home position.
- The encoder is housed in M20.
Explanation of "Motor Home Position
Distance"
- The motor home position distance is the
distance between the position which the B21
home position sensor turns off from on and
the position where the Z-phase from the
encoder is detected for the first time in one
rotation of M20. (steps 2 and 3 above).
- One rotation of M20 servo motor is set to 250
in APC-61II. The position of the home posi-
tion sensor B21 is set so that Z-phase will be
detected at the middle of the motor rotation.
Therefore, the motor home position distance
should be around 125. (Fig.1)
Checking the Motor Home Position
Distance
- The Z-phase cannot be detected correctly
around the area that the B21 home position
sensor turned off from on, and the boundary
line of the first and second rotation of M20.
If the Z-phase appears at these areas, the
encoder may misread it, and detects the Z-
phase which appears next. This will set the
home position to the wrong position.
Therefore, checking the home position dis-
tance is necessary to make sure the encoder
reads Z-phase correctly in the stable area.
1-11
Fig.1 "Service" Screen
Sensor Plate
Home Position Sensor
M20
Servo Motor
Fig.2 Home Position Sensor B21
504007
1_7_1A
B21
404007
1_7_1B