Programmable Pressure Adjustment Valve Troubleshooting Guide

Introduction

The Programmable Pressure Adjustment Valve option allows you to control the gripping force of the hydraulic chuck on new Haas ST and DS Series lathes via the part program, or directly from the Haas control.

Note: Increasing the pressure will increase the gripping force immediately. Decreasing the pressure will not affect the gripping force if the chuck is already clamped. The chuck must be stopped, unclamped, and then reclamped to achieve the lower gripping force. Main spindle chuck only.

Machine Requirements:

Software Version 100.22.000.1016 or higher

Electrical Safety

DANGER: Working with the electrical services required for CNC machines is extremely hazardous and can result in serious injury or death.

Before connecting line wires to the CNC:

Turn off all power to the machine at the source.
Perform a Lockout-Tagout (LOTO) procedure to ensure the power remains off during service.
Verify that power has been disconnected by using an AC voltage detector on all incoming lines.

If you are uncertain about how to safely disconnect power or perform LOTO procedures:

Do not proceed.
Contact qualified personnel or obtain appropriate assistance before continuing.

Failure to follow these precautions may result in electrical shock, equipment damage, or fatal injury.

Danger: Before beginning any work inside the control cabinet, verify that the High Voltage indicator light on the 320V Power Supply / Vector Drive has been off for a minimum of five (5) minutes. This waiting period ensures that residual voltage has dissipated and reduces the risk of electric shock.

Certain service procedures involve high-risk electrical components and may pose serious injury or fatality hazards. Technicians must not attempt any procedure unless they have a complete understanding of the steps involved and the associated risks.

If there is any uncertainty regarding a procedure, contact your Haas Factory Outlet (HFO) to arrange for a qualified service technician.

Symptom Table

Symptom	Possible Cause	Corrective Action
Alarm 9505 or 9505.001 COMMANDED PRESSURE NOT REACHED	The commanded device pressure was not reached within the specified timeout.	Check electrical connections to the pressure switch or motor or for failed hardware such as the pressure valve, hydraulic motor, or coupler.
	The motor binds when commanded to a pressure.	Float the motor in. See Motor Float section below.
	The motor does not turn.	Navigate to Current Commands > Devices > Mechanisms and down to Main Spindle Chuck Pressure. Command the pressure to 100 Psi and then enter the max chuck pressure based on the chuck and spindle size. At the I/O PCB on P39. While the motor is commanded to run, use a multimeter with needle-tip probes to measure the voltage across pins 1 and 2. The voltage must measure 12 VDC. Do not measure the voltage with the cable disconnected. Measure the voltage at each cable connection in the circuit. See the Electrical Diagram below.

Pressure Table

Sub-spindle chuck	Max PSI	kgf/cm²
ST-10/20 SS (5" chuck)	450	32
ST-30 finihsing SS (6" chuck)	330	23
DS-30Y secondary spindle (8" chuck)	400	28
Tailstock	400	28

Float Motor

1

Remove DC motor by loosinig the coupler screw [1] then the motor bracket bolts [2] and finally the the motor and the bracket together [3]

2

Adjust pressure by rotating the coupler [1] (reference the Pressure Table section above). You may need to adjust locking nut to achieve desired pressure.

Note : Check pressure reading in DIAGNOSTICS > GAUGES.

Important : Set the maximum pressure to 10 psi above the values shown.

3

Losen locknut screw [1] and rotate the locknut [2] clockwise until it stops

4

Rotate the locknut and coupler together until the lockut screw is accessible to tighten.

5

Tighten the locknut then rotate the coupler clockwise until it stops and verify that the pressure is within 10 psi of the desired value

Note : Repeat steps 2 through 5 until the desired maximum pressure is reached

6

Important : The locking nut should be properly set / adjusted before this step.

Make sure to adjust distances between clamping hubs [1] and the polyurethane material [2] in middle. When the hydraulic valve is fully in the open position (Anti-clockwise) adjust the coupler to have a visible gap (0.03125in to 0.0625in) then tighten the coupler screw onto the motor.

Note : This is a precautionary step to avoid collapsing the spider coupler which may cause binding

7

Navigate to Current Commands > Devices > Mechanisms and down to Main Spindle Chuck Pressure. Enter the max chuck pressure based on the chuck and spindle size.

Command max pressure via the control.

Verify that the pressure is accurate within 10 PSI.

Command pressure to 100 PSI via the control

Verify that the pressure is accurate within 10 PSI.

Command max pressure again and tighten the SHCS's while motor is running and verify that the pressure is accurate within 10 PSI.

Electrical Diagram

Programmable Pressure Adjustment Valve Motor [1].

Cable [2] labeled 33-2661 or 33-2662 CBL CHUCK PRESS MTR POWER to the Spindle Head Inputs Bracket at P2 [3].

Cable [4] labeled 33-9267, 33-9268, or 33-1199 SPHD COMBO W/ CHUCK PRES & GB to the I/O PCB at P39 [5].