TROUBLESHOOTING

LET US DO THE PROBLEM-SOLVING FOR YOU
CALL US FOR HELP TROUBLSHOOTING YOUR EXISTING OR IN-PROGRESS MECHANICAL MACHINE.
Call us...  or try doing it yourself by using the checklist below, written and developed by California Mechatronics Center Sr. Mechatronic Engineer, Nick Repanich.

THE PROVEN PROCEDURE

1.  IS EVERYTHING PLUGGED IN AND POWERED ON?

  • Are all power supplies providing voltages within proper tolerances?
  • Are the power supplies rated for the current being drawn, especially inductive loads with inrush current. 

2. DO YOU HAVE COMMUNICATIONS TO ALL THE DEVICES?

3.  START AT MECHANICS, WORK TOWARD ELECTRONICS, THEN PARAMETER SETUP, THEN PROGRAMMING SOFTWARE

  • It's always tempting to start at the other end, however rigorous application of this concept will almost always result in far shorter de-bug sessions.

4.  CHANGE ONLY ONE THING AT A TIME AND CHECK TO SEE THE RESULTS.

COMMON THINGS TO CHECK
WHEN THINGS GO WRONG IN AUTOMATED MACHINES

COMMUNICATIONS

  • ​RS-232
    - Ethernet - right subnet
  • Check comm ports on laptop/controller
  • Check for echo by shorting Tx and Rx wires on device end of cable. Hit spacebar. If cursor moves, you have the right comm port, and are sending and receiving.
  • Null modem - swap receive/transmit on RS232
  • Pinouts
    - 9-pin D-cell 2 Rx, 3 Tx, 5 Gnd
    - 25-pin D-cell 2 Rx, 3 Tx, 7 Gnd
  • Terminal setting
    - baud rate
    - echo - on transmission lines
    -     handshaking - on separate lines
    - parity - stop bit

MOTOR

  • ​Bearings
    - runaway motor can destroy bearings
    - causes roughness from wear
    - axial or radial displacement / bad coupler
  •  Brushes
    - see a slow deterioration in performance
  • Thermal damage
    - insulation melts - smell motor
  • Phase to phase shorts
  • Phase to ground shorts
  • Phase to case shorts
  • Winding resistance not to spec
  • Phase to phase resistance on brushless or different from phase to phase • end to end on steppers, brushed motors
  • Hall effects
    ​- apply power and check w/voltmeter to see if each of the three fluctuates between 0-5v

WIRING

  • ​Whiskers/strays
  • Low voltage near high voltage
  • Insulation damaged
  • Bad connection/hidden
  • Improper stripping
    - too much/copper showing
    - too little/no connection
  • Wrong place
  • Using ferrules gives a better connection, strain relief
  • Neatness

CONTROLLER

  • ​Configured correctly - jumpers
    - communications - address
  • Program/parameters burned into EPROM
  • Tuning
  • Wiring
    - feedback
    - swapping encoder polarity
  • Unknown/CPU crash
  • Software setup
  • Master reset if all else fails
  • Software debug tools if available
  • Check encoder counts/rev
  • Electrical noise

MECHANICS

  • ​Coupler missing, too tight, misaligned, broken, too small causing excessive windup
  • Manual movement to look for
    -Binding -Roughness -Lock-up
  • Visual inspection
  • Belt tension
  • Lack of grease, lubrication
  • Check for correct components
    -Pitch -Wrong pinion -Gear ratio
  • Preloads on bearings, etc.
  • Limit switches in the wrong place

GEARHEADS

  • ​Bearings
  • Poor manufacturing
  • Poor assembly by user
  • Lubrication in vertical applications
  • Use motor shaft seal in vertical applications to prevent lubrication leaking from gearhead into motor; causes extra friction and noise

CABLING

  • ​Hooked up?
  • Right place?
  • Right orientation of connector?
  • Right cable?
  • Fatigue/near/strain relief?
  • Shielding, grounded in right place?
  • Length – getting voltage drop due to long length? 25 ft for 5 Vdc signals
  • Gauge, correct for power level

AMPLIFIER

  • ​Not enabled
  • Damaged
    - burned-up, smell it
    - physical damage (dents, carbon) - shake test (listen)
  • Wrong settings (file for digital/dip or pots for analog) • Current loop gains
  • Current level settings
  • Offsets
  • Polarity
  • Limit switches active • Resolver mis-wired
  • Halls mis-wired 

SOFTWARE | PROGRAMMING

  • ​Flowchart
  • "Comment" code
  • use Print statements to see if program flows to end
  • Remove code line by line
  • Use software debug tools/trace mode
  • Display variables

LET US DO THE PROBLEM-SOLVING FOR YOU