Service Home Side Mount Tool Changer (SMTC) - Double Arm - Troubleshooting Guide
Last updated: 03/22/2022

Side Mount Tool Changer (SMTC) - Double Arm - Troubleshooting Guide

Introduction

EXPLODED VIEW:

  1. ARM COVER
  2. BHCS 1/4-20 X 1/2 ZINC PLATED
  3. SHCS 3/8-16 X 3/4 ZINC PLATED
  4. DOUBLE ARM HUB
  5. ARM SLIDE
  6. WASHER 5/16 STEEL
  7. PLUNGER
  8. RETURN SPRING
  9. ADJUSTER ROD
  10. SHCS 1/4-20 X 5/8 ZINC PLATED
  11. FHCS 1/4-20 X 5/8 LOCTITE
  12. ARM KEY
  13. DOUBLE ARM
  14. NUT 1/4-20 HEX BLK
  15. SPRING CAP
  16. DOUBLE ARM CLAMP
  17. SHCS 5/16-18 X 2 1/4
  1. Double arm: Moves tools to the carousel and the spindle.
  2. Slide: Pushes against the tool to hold it in place during double arm movement.
  3. Return spring: Pushes the slide against the tool.
  4. Shim washers: Shims adjust the slide for proper clearance. If the slide is adjusted too tightly against the tool, it may not lock during rotation. If adjusted too loosely, tools will rock or fall out during rotation.
  5. Adjuster rod: Locks the slide in place during a tool change.
  6. Jam nut: This nut tightens against the slide to prevent the adjuster rod from rotating loose.
  7. Plunger: Locks the adjuster rod during arm motion. The adjuster rod and slide cannot release the tool when the plunger is in the extended position.

Service Troubleshooting Videos

Symptom Table

Symptom Possible Cause Corrective Action

Alarm 622 TOOL CHANGER ARM FAULT

Alarm 2066 TOOL CHANGER HOME POSITION FAULT

 The tool changer arm is not at the origin position when the machine is powered on, or it was not recovered correctly.

Do a tool change recovery.

Video - Tool Changer Recovery - Side Mount Tool Changer (SMTC)

VMC, HMC - Side-Mount Tool Changer - Manual Recovery
One or more of the proximity sensors or cables on the cambox have a bad connection or is damaged. Rotate the arm in recovery mode and test the sensors.
Pressing [Power-Up/Restart] after updating software generates a 2066 alarm Do an Option 5 Clean Install
Alarm 627 ATC ARM MOTION TIMEOUT One or more of the proximity sensors or cables on the cambox have a bad connection or is damaged. Rotate the arm in recovery mode and test the sensors.
The cambox drive belt is worn or damaged. Inspect the belt.

Alarm 628/673 ATC/TA ARM POSITIONING ERROR

Alarm 855 ATC ARM DRIVE-TRAIN FAILURE

 The double arm's travel was obstructed.

Check the double arm alignment.

Move the obstructions or set a safe tool change position.
The spindle orientation is incorrect. Find the cause of the spindle orientation error.
The cambox is damaged. Test the cambox.
The values of Parameters 481 or 487 are incorrect in a machine with a servo-driven side-mount tool changer. Set the correct values for the Parameters 481 and 487 .Parameter 481 is TT Grid Offset. Parameter 487 is TT Tool Change Offset. Set these parameters correctly. Refer to VMC - Servo-Driven Side-Mount Tool Changer - Grid Offset and Tool Changer Offset.
The TRP quick exhaust is not functioning properly If the quick exhaust is not working properly it may cause the tool to drop slightly or be miss positioned during the tool change. Inspect and replace the quick exhaust if needed.
Tools fall out of the spindle side during a tool change. The toolholders or pull studs are incorrect. Check for correct tool specifications.
The tool is too heavy. Check for correct tool weight specifications. Flag large or heavy tools.
The arm or plunger is worn. The double arm cannot correctly engage with the tool. Replace the worn parts in the double arm.
The spindle orientation is incorrect. Find the cause of the spindle orientation error.
The double arm is bent or damaged. Find the cause of the double arm bending. Straighten and smooth the double arm or replace it.
Tools fall out of the arm during rotation. The arm and plunger are worn. The double arm cannot correctly engage with the tool. Replace the worn parts in the double arm.
Tools fall out of carousel tool pockets. The pocket spring or plungers are worn or damaged. Refer to : Side Mount (SMTC) - VF/VM/UMC/EC - Carousel and Pocket - Troubleshooting Guide
The cambox on a DT/DM is unable to rotate by hand  The cambox will not be able to rotate by hand because it will eventually contact the rocker arm and try to unclamp the spindle. DO NOT replace the cambox because you are unable to rotate by hand contact your local Haas Factory Outlet for further assistance. 

Cambox Proximity Sensors

Corrective Action:

Remove the carousel number plate to get access to the sensors [1]. Go into the manual tool recovery and push ATC FWD to move the arm through a complete cycle. Make sure the LED on the sensor and the diagnostic bit state change at the correct stage of the tool change cycle. See the chart below.

If the sensors fail to change state, refer to the Proximity Sensor - Troubleshooting Guide.

SENSOR Origin Rotation Tool Pick - Up Down / Rotation 180 / Up Tool Exchange Arm Backup (Reverse) Origin
Clamp/unclamp On / 0 On / 0 Off / 1 On /0 Off / 1 On / 0 On / 0
Origin Off / 1 On / 0 On / 0 On / 0 On / 0 On / 0 Off / 1
Motor stop Off / 1 On / 0 Off / 1 Red / 0 On / 1 On / 0 Off / 1

Spindle Orientation

Corrective Action:

Find the cause of the spindle orientation error.

Make sure spindle drive and encoder belts have the correct tension. Make sure the spindle motor pulley [1] and encoder pulley [2] are not worn.

Refer to VMC - Side-Mount Tool Changer - Spindle Orientation Offset - Parameter 257.

Double Arm Alignment

Corrective Action:

Use a straightedge to find out if the arm is bent. If the arm is bent, these are some of the possible causes:

 

1: The tool release piston (TRP) sensor(s) are not adjusted correctly.

If the TRP sensors are not adjusted correctly, a tool can get stuck in the spindle taper, or the drawbar might not release a tool. Damage to the double arm can occur. Adjust the tool release piston switches correctly. Refer to VMC - 20/30/40-Taper- TRP - Proximity Sensor - Adjustment.

2: The arm crashed into a rotary or a fixture during a tool change.

Refer to your operator's manual to set the tool change offset, or alias an M06 command, to move the spindle to a safe height. Move the obstacle on the table to a safe distance away before the tool change. If you install a rotary or trunnion unit, mount it as far to the right as your setup will allow. This gives you more room for safe tool changes.

Go to Episode 21 - How to Command a Safe Tool Change Position to Avoid Fixtures and Rotaries for more information.

3: A failed cambox position cable or sensor may cause the machine to think the arm is at the home position. The Z Axis comes down and bends the arm. Refer to Cambox Proximity Sensors section in this document.

Minor burrs or gouges on the double arm can visually be removed with a small file without needing replacement.

Go to parts.haascnc.com to find the correct double arm for your machine. Follow the replacement instructions that ship with the assembly.

If the double arm is not bent check the double arm alingment. Refer to Side Mount (SMTC) - VMC - Double Arm - Alignment for instructions on how to check the alignment.

Cambox Drive Belt

Corrective Action:

Inspect the belt for damage and replace it if necessary. Refer to VMC - Side-Mount Tool Changer (SMTC) - Carousel Motor - Replacement for how to replace the cambox belt.

Toolholder and Pull Studs

Corrective Action:

Refer to this document for the correct pull stud and tool weight specifications:

If you have a very heavy tool, install the Pocket slow down Service Kit (P/N 93-0254). This kit restricts the air exiting the pocket up/down cylinder to slow down the pocket.

Double Arm Plungers

Corrective Action:

Inspect the plunger and adjuster assembly. Refer to Side-Mount Tool Changer - Double Arm - Plunger and Adjuster Assembly - Inspection

Refer to Video - Side Mount Tool Changer (SMTC) Double Arm Maintenance for more information on how to maintain the double arm.

Cambox Test

Corrective Action:

Remove the motor and cycle the cambox by hand. 45 revolutions of the input shaft will move the cambox thru (1) tool changer. Be sure to rotate thru (2) complete tool changer as some components are only engaged every other tool changer. There should not be any binding in the arm. You should be able to turn the pulley by hand. It will take more effort to turn the pulley when the output shaft is in motion. There should be less than 1/4" (6 mm) of lost motion in the rotation or lift of the arm.

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