Side Mount Tool Changer (SMTC) - Double Arm / Cambox

Cambox Inspection Report

Download and fillout the Cambox Inspection Report Checklist below before replacing any parts.

Cambox Inspection Report

Introduction

EXPLODED VIEW:

ARM COVER
BHCS 1/4-20 X 1/2 ZINC PLATED
SHCS 3/8-16 X 3/4 ZINC PLATED
DOUBLE ARM HUB
ARM SLIDE
WASHER 5/16 STEEL
PLUNGER
RETURN SPRING
ADJUSTER ROD
SHCS 1/4-20 X 5/8 ZINC PLATED
FHCS 1/4-20 X 5/8 LOCTITE
ARM KEY
DOUBLE ARM
NUT 1/4-20 HEX BLK
SPRING CAP
DOUBLE ARM CLAMP
SHCS 5/16-18 X 2 1/4

Double arm: Moves tools to the carousel and the spindle.
Slide: Pushes against the tool to hold it in place during double arm movement.
Return spring: Pushes the slide against the tool.
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.
Adjuster rod: Locks the slide in place during a tool change.
Jam nut: This nut tightens against the slide to prevent the adjuster rod from rotating loose.
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.

Symptom Table

Symptom	Possible Cause	Corrective Action
Alarm 11.103 TA-AXIS SERVO ERROR TOO LARGE Alarm 11.108 TA-AXIS SERVO OVERLOAD Alarm 11.994 TA (TC ARM) AMPLIFIER OVERLOAD	The cambox is damaged.	Test the cambox. Refer to Cambox Test section below on this page.
Alarm 103 AXIS SERVO ERROR TOO LARGE	The cambox drive belt is worn or damaged.	Inspect the belt.
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.
Alarm 627 ATC ARM MOTION TIMEOUT	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. Refer to Cambox Test section below on this page.
	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.
	The gap between the tool holder and slide is not within specifications.	Refer to: Side-Mount Tool Changer - Double Arm - Plunger and Adjuster Assembly - Inspection - Mill
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.
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
Replacmenet double arm is not the correct length	The incorrect double arm may have been ordered. Verify the correct part number and supersession has been ordered.	Refer to the Double Arm Replacement Verification Section for futher information on how to verify that the double arm ordered is correct for your machine.
The double arm is the incorrect taper size and type
The double arm key offset is not correct
Vertical Cambox's built June 15 2023 and later Oil is leaking out of the cambox arm shaft. Note: This does not affect DT/DM/UMC-350 camboxes.	There may be a problem with the exhaust check valve assembly.	Starting in June 2023 a check valve is now included with the cambox exhaust assembly. Verfiy that the check vavle is facing the correct way, reference the Cambox Exhaust Check Valve section below. HSG-N 07-12-2023

SMTC Double Arm Replacement Verification

NOTE: The same verification steps will apply to machined [1] and casted [2] double arm replacements.Some machines may still received machined [1] double arm replacements. Use the image below as reference.

Verify the double arm length

Check that the replacement double arm [2] is the correct length, measure from the center to center of the tool holder flange between the original [1] and replacement double arm [2].

NOTE: The same verification steps will apply to machined [1] and casted [2] double arm replacements.Some machines may still received machined [1] double arm replacements.

Verify that the double arm is the correct taper size and type

To differentiate between the BT, CT, and HSK verify that the BT V-flange is as shown in image [1] and the CT V-flange is as shown in image [2], and the HSK V-flange is as shown in image [3].

Verify that the double arm has the correct key slot offset

Now the casted double arm will have the key slot machined in a 0 degree angle position [1] or at a 2.5 degree angled position [2], both double arms will use only a straight key instead of an offset key.

HSG - 7/5/2023

Cambox Exhaust Check Valve

Verify the check valve [1] arrow is facing away from the cambox as shown.

The check valve (PN 58-2754) [1] should be install between the brass fitting (PN 58-1674) [2] and muffler fitting (PN 58-1865) [3].

HSG - 7/12/2023

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:

Toolholder and Pull Stud Information

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

Cambox Lost Motion Test

Go to Tool changer recovery.

Rotate the double arm to clamp/unclamp position.

Push and pull on the arm. Record the movement.
Pull down and push up on the arm. Record the movement.

There should be less than 1/4" (6 mm) of lost motion in the rotation or lift of the arm.

Cambox Internal Mechanical Test

Remove the cambox motor and rotate the pulley or coupling [1] to cycle the cambox through a complete tool changer cycle. Listen for any abnormal internal noise when cycling the cambox. Run cambox forward or backwards looking for any particular section of binding. Check oil level while noting the viscosity and coloration of the oil.

Note: Be sure to rotate the cambox to the complete tool changer cycle as some components are only engaged every other tool changer.

There should not be any binding in the cambox. You should be able to turn the pulley by hand. It will take more effort to turn the pulley when the output shaft is retracting.

Note: On machine with a servo driven cambox it is necessary to re-set the double arm origin position after reinstalling the servo motor. Refer to the SMTC - Double Arm - Grid and Tool Change Offset procedure.

Double Arm Tool and Slide Adjustment

Push down on the plunger [3] and hold it down.

Put a tool holder [2] into the arm. During correct operation, the slide [1] moves in.

Release the plunger [5].

Try to remove the tool holder [4]. During correct operation, the slide does not move in and the tool holder locks in position.

Measure the space between the slide and the tool holder. Use a feeler gauge [6]. The correct space is between 0.014 in (0.36 mm) and 0.020 in (0.51 mm). If the machine is a DM-1 or DT-1, the correct space is between 0.005 in (0.13 mm) and 0.015 in (0.38 mm).

Add or remove 0.01 in (0.25 mm) shim washers, part number 45-0075, until the space is correct.

Once the gap is set reassemble the slider assembly with the spring and washer installed. Apply a layer of Lithium Tacky Grease to the finger, spring and washer.