Service Home Side Mount Tool Changer (SMTC) - Carousel and Pocket - Troubleshooting Guide - TG0127

Side Mount Tool Changer (SMTC) - Carousel and Pocket - Troubleshooting Guide - TG0127

9.3 Side Mount Tool Changer - Carousel and Pocket - Troubleshooting Guide

Last updated: 10/15/2025

Side Mount Tool Changer (SMTC) - Carousel and Pocket - Troubleshooting Guide

TG0127

Revision A - 08/2025

Introduction

EXPLODED VIEW:

  1. FBHCS 1/4-20 X 1/2
  2. CAROUSEL COVER
  3. BEARING LOCKNUT
  4. JAM NUT 5/8-18
  5. CAROUSEL
  6. CAM FOLLOWER
  7. BEARING
  8. POCKET ASSEMBLY
  9. CAROUSEL WASHER
  10. TOOL CHANGER FRAME
  11. CAROUSEL SHAFT
  12. SPACER
  13. CAM BOX
  14. SHCS 1/2-13 X 2
  15. CAROUSEL CAM ASSEMBLY
  16. POCKET STOP
  17. SHCS 1/2-13 X 5
  18. CAROUSEL MOTOR
  19. POCKET TIPPER ASSEMBLY
  20. DOUBLE ARM

Carousel

  1. Tool In Position Proximity Sensor: It lets the control know that the tool pocket is in position.
  2. Carousel Cam: A DC or Servo Motor turns this Cam that rotates the tool carousel.
  3. Tool One Proximity Sensor: It lets the control know that the tool pocket is tool one position.

Pocket

  1. Cam Follower: Keeps the pocket in the up position as the carousel rotates. The cam follower follows a groove on the carousel housing.
  2. Shaft: The axle upon which the pocket pivots up and down.
  3. Spring: Puts tension on the four plungers inside the tool pocket.
  4. Tool Pocket: Holds the tool.
  5. Plungers: The four plungers grip the tool pull stud. They are lubricated with grease.

Symptom Table

Symptom Possible Cause Corrective Action
Alarm 622 TOOL CHANGER ARM FAULT  100 PKT SMTC Carousel stopping in between pockets unable to recover. Drive sprocket moved out of the motor shaft due to failed bushing causing the idle sprocket to fail.  Replace the idle sprocket and bushing, see 100 PKT SMTC sprocket replacement section.
Alarm 625 CAROUSEL POSITIONING ERROR 100 PKT SMTC Carousel stopping in between pockets unable to recover. Drive sprocket moved out of the motor shaft due to failed bushing causing the idle sprocket to fail.  Replace the idle sprocket and bushing, see 100 PKT SMTC sprocket replacement section.
The carousel tool in position, tool one in position, pocket up or down proximity sensor is damaged or contaminated. Rotate the carousel in recovery mode and test the sensors and cabling.
No power to the carousel motor or the carousel motor is damaged. Check that the carousel can be rotated in the manual recovery mode.

VMC, HMC - Side-Mount Tool Changer - Manual Recovery
Tool change was interrupted before completion. Do a Tool Change Recovery.

VMC, HMC - Side-Mount Tool Changer - Manual Recovery
A tool change was attempted before adequate air pressure was present.
A tool change was attempted with the pocket already down.
Carousel rotation was prevented by an obstruction. Clear the carousel path.
Alarm 626 TOOL-POCKET SLIDE ERROR A tool change was attempted with the pocket already down. Do a Tool Change Recovery.

VMC, HMC - Side-Mount Tool Changer - Manual Recovery
The incoming air flow or pressure is incorrect. Correct the incoming air supply.
There is contamination in the slide guides. Clean and lubricate the slide guides.
The air cylinder for the tool pocket does not move freely. Check the air cylinder for the tool pocket.
The pocket up or pocket down proximity sensors are contaminated, damaged or have loose connections. Clean and inspect the proximity sensors.
There is a problem with the pocket up/down system. Troubleshoot the check valve, air cylinder, and solenoid.
Movement is blocked by debris. Clear debris.
The tool pocket, air cylinder, pocket slide, or slide follower is loose or damaged. Diagnose and correct.
Alarm 2066 TOOL CHANGER HOME POSITION FAULT
 The pocket up and down proximity switches are in the incorrect state. Clean and inspect the proximity sensors.
The tool pocket is noisy. There is a problem with the tool-pocket stop shock-absorber. Check the tool-pocket stop shock-absorber.
The tool pocket, air cylinder, pocket slide, or slide follower is loose or damaged. Diagnose and correct.
The tool falls from the tool pocket. The toolholders or pull studs are incorrect. Check for correct tool specifications.
The spring or the plungers are worn. Check the spring and the plungers for wear.
The tool pocket moves up and down too fast for heavy tools. Install the Pocket Slow Down Service Kit (P/N 93-0254).
The tool pocket is broken. Carousel rotation was prevented by an obstruction. Clear the carousel path.
The pocket up or pocket down proximity sensors are contaminated, damaged or have loose connections. Clean and inspect the proximity sensors.
The tool pocket, air cylinder, pocket slide, or slide follower is loose or damaged. Diagnose and correct.
The carousel makes unusual noises during operation. The cam followers on the carousel need grease. Check and grease the cam followers.
The cam followers on the carousel are worn.
The tool pocket slider set screw is incorrectly adjusted. Make sure the tool pocket slider set screw is correctly adjusted. See VMC - Side-Mount Tool Changer - Pocket Slider Set Screw Adjustment procedure.
The carousel cam bearhug nuts are loose. A loose cam bearhug nut will cause rotational backlash on the carousel assembly, noise and carousel position alarms. Tighten the carousel cam bearhug nuts with a spanner wrench.
The SMTC Arm Motion Speed Is Too Fast. The tool is not flagged as heavy (H) in the tool pocket table. Tools flagged as heavy [1] in the tool pocket table, will cause the SMTC arm to rotate at 25% the speed (VFSS only).
EC/VC tool change cycle is very slow Parameter 223 Tool Changer Air Door Delay Change has a value, this should only have a value if a pnuematic door is present

Update configuration files to the latest, Parameter 223 will be set to zero. This configuration files have been backdated so that all machines will receive this updated value. 

NOTE: Remember to take a back up before loading the latest configuration files.
HSG-N 02-14-2023

100 Pocket SMTC Sprocket Replacement

Corrective Action:

To replace the idler Sprockets [1] and the bushing [2], you must first wrap a chain or strap around the carousel and frame, this is to eliminate the carousel from freely spinning. 

WARNING: If the carousel is not tied it can cause serious injury. 

Incoming Air Flow or Pressure

Corrective Action:

  • Make sure that the air hose to the machine is the correct diameter.
  • Make sure that the air compressor supplies the correct air pressure and air flow.
  • Command a tool change on the machine. When the machine has the correct air pressure and flow, the needle on the air pressure gauge should not drop more than 10 PSI (0.70 bar) during a tool change. This test confirms that the air pressure and air flow into the machine is correct.

Refer to the "Compressed Air" requirements for your machine on New Machine Pre-Installation.

Pocket Slide Guides

Corrective Action:

  1. Visually examine the slide guides [1] for the tool pocket. Remove all contamination.
  2. Lubricate the surfaces with red grease.
  3. Go into tool changer manual recovery VMC, HMC - Side-Mount Tool Changer - Manual Recovery.
  4. Press up or down arrow to move the tool pocket. Make sure the pocked moves smoothy into and out of the tool change position.

Pocket Air Cylinder

Corrective Action:

  1. Power off the machine and disconnect the air supply.
  2. Find the tool pocket cylinder.
  3. If equipped, remove the pilot-operated check valve [1] and the hose to the bottom of the cylinder. For machines that do not have a pilot-operated check valve, disconnect the top and bottom hoses on the air cylinder.
  4. Move the cylinder [2] up and down.
  5. Make sure that the piston moves freely. Spray a small quantity of silicon lubricant into the cylinder to lubricate the piston seal.
  6. If the piston does not move freely, the tool pocket air cylinder is damaged.
  7. Make sure the air supply to the machine is clean and dry.

Pocket Up / Down Proximity Sensors

Corrective Action:

Make sure the pocket up and pocket down proximity sensors [1] are clean. Contamination on the switches may cause the carousel to rotate and break a pocket before it is in the fully up position.

The DIAGNOSTICS page shows the state of the sensors. If the POCKET DOWN or POCKET UP (CHC), or the SMTC_TOOL_POCKET_UP or SMTC_TOOL_POCKET_DOWN (NGC), bits do not change state, the sensors may have chips or contamination on them.

Make sure that the tool pocket is up. Press [PARAMETER/DIAGNOSTIC] and go to the I/O tab.

Touch the end of the proximity sensor with a screwdriver [1]. This test can cause Alarm 626. Ignore the alarm. The proximity sensor operates correctly if the Pocket Down (CHC), SMTC_Pocket_Down (NGC), value changes from a 1 to a 0. Continue troubleshooting if the diagnostic value does not change.

To troubleshoot the pocket up sensor, make sure that the tool pocket is down. Touch the end of the proximity sensor with a screwdriver and monitor Pocket Up (CHC), SMTC_Pocket_Up (NGC). The value must change from a 1 to a 0.

Do these steps on CHC machines only: Find where the 820 cable connects to the I/O PCB at P3. Use an electrical jumper (P/N 33-8521) at P3 [1]. If the Pocket Down value changes from a 1 to a 0, the I/O PCB operates correctly. Replace the SMTC cable assembly. Refer to Proximity Sensor How it Works and Troubleshooting - Video. Use the Proximity Sensor - Troubleshooting Guide to troubleshoot the proximity sensors.

To troubleshoot the pocket up sensor, reconfigure the jumper at P3 as shown [2]. Monitor the Pocket Up value. If the value changes from a 1 to a 0, the I/O PCB operates correctly. Replace the SMTC cable assembly.

If the Pocket Down or Pocket Up value does not change to a 0 when tested, refer to:

 

Pocket Solenoid

Corrective Action:

Be sure to troubleshoot the solenoid correctly. Refer to Solenoid - Troubleshooting Guide to troubleshoot the system. Refer to "4 Port Solenoid Applications."

Tool Contamination

Corrective Action:

Make sure the tool is not contaminated by debris. Look for and remove any "nests" of chips in the mechanism.

Refer to TOTD Episode 33 - Stringy Chips Wrapped Around Your Tools? Chip Clear Solution to troubleshoot the system.

Pocket Shock Absorber

Symptom: The tool pocket is noisy.

Possible Cause: There is a problem with the tool-pocket stop shock-absorber.

Corrective Action:

  1. Make sure that the tool pocket is in the up position [1].
  2. Push the shock-absorber in with your thumb [3].
  3. Release the shock-absorber [2].

For CALM machines, replace the shock-absorber with the correct orifice (P/N: 58-0093) [4] between the solenoid and the muffler if:

  • There is no resistance when you push the shock-absorber.
  • The shock-absorber does not extend after you push it.

 Note: For all other machines, replace the shock-absorber with a new shock-absorber.

Tool Holders and Pull Studs

Symptom: The tool falls from the tool pocket. The tool cannot be removed from the pocket.

Possible Cause: The toolholder or pull studs are incorrect.

Corrective Action:

If the tool cannot be removed, remove the garter spring [3]. Wiggle the tool to loosen the plungers [1]. Be careful not to lose any plungers. Remove the tool. Replace spring.

Refer to the Toolholder and Pull Stud Information document for the correct toolholder and pull stud [2] information.

Pocket Spring and Plungers

Corrective Action:

        BT/CT pocket

  1. Make sure that the (4) plungers [1] are intact in each of the pockets.
  2. Inspect the plungers for wear. Replace them if they are worn.
  3. Make sure that the hook on the spring is not on top of any of the plungers.
  4. Clean all of the debris from the tool pockets and lubricate the plungers [1] with grease. Apply grease to the tool pull stud.

Refer to Replace a Tool Pocket on Your Haas Side Mount Tool Changer (SMTC) - Video for more information on how to remove the pocket.

Some pockets use leaf springs. Look for broken leaf springs. They are stacked (2) per corner. Replace any broken leaf springs.

        HSK pocket

  1. Make sure that the collet assembly is intact in each of the pockets.
  2. Inspect the (3) plungers and center cap in the collet assembly for wear. Replace them if they are worn. 
  3. Inspect the rest of pocket for any damage. Replace if it is needed.
  4. Clean all of the debris from pocket and lubricate the collet assembly with grease to ensure smooth operation.

Refer to HSK Pocket and Plunger - Replacement  for more information on replacing the HSK pocket.

 

Pocket Slow Down Kit

Corrective Action:

Install the Pocket Slow Down Service Kit (P/N 93-0254). This kit restricts the air escaping from the pocket up/down cylinder to slow down the pocket.

Refer to the Toolholder and Pull Stud Information document.