1440

Check Home Switch Status

Press CURRENT COMMANDS, then INPUT, navigate to page showing home switch inputs. Manually rotate A-axis and observe HOME A switch status change.

The switch should activate within the last few degrees of rotation before the mechanical stop

Inspect Switch Mounting

Verify home switch cam or dog is properly secured to rotary table and aligned with proximity switch. Check for loose mounting bolts or damaged cam.

Lock out power and follow LOTO procedures before manual inspection

Test Switch Continuity

With power off, disconnect home switch connector and test continuity across switch terminals while manually actuating the switch mechanism.

Proximity switches should show resistance change, mechanical switches should show open/closed continuity

Check Drive Status LEDs

Observe A-axis drive status LEDs on the drive module. Red fault LED indicates drive fault condition that must be cleared before homing can complete.

Do not reset drives while axis is in motion

Verify Motor Encoder Feedback

Access CURRENT COMMANDS > POSITION and observe A-axis encoder counts change smoothly when manually rotating the table (power off, brakes released).

Erratic or missing encoder counts indicate encoder or cable problems

Check Motor Brake Operation

With power on, verify motor brake releases during homing attempt. Listen for brake release click and confirm axis can move freely when commanded.

Stuck brakes will cause immediate drive fault and prevent homing completion

Verify Homing Direction

Check Parameter 552 (A-axis home direction). Should be 0 for negative direction or 1 for positive direction based on machine configuration.

Direction should move axis toward home switch, not away from it

Check Home Search Distance

Verify Parameter 553 (A-axis home search distance) allows sufficient travel to reach home switch from any position within axis limits.

Setting too small may prevent finding home switch, too large may cause crash

Validate Home Speeds

Check Parameters 554 (fast home speed) and 555 (slow home speed) are appropriate for rotary table inertia and not exceeding axis capabilities.

Start with conservative speeds: 50-100 degrees/min fast, 10-25 degrees/min slow

Manual Rotation Test

With power off and brakes released, manually rotate A-axis through full range checking for binding, excessive friction, or mechanical interference.

Ensure all cutting tools and workholding are clear before manual rotation

Check Lubrication

Verify rotary table gear box oil level and condition. Add or change oil per manufacturer specifications if low or contaminated.

Cold thick oil can cause binding during initial homing after long shutdown periods

Inspect Drive Components

Check coupling between servo motor and rotary table for damage, looseness, or misalignment that could cause binding or slippage.

Look for metal shavings or wear debris indicating mechanical wear or damage