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Deep Hole Drilling Machine Installation Guide

A deep hole drilling machine weighing 30 tons and spanning 16 meters must maintain spindle-to-guideway parallelism within 0.01 mm over its full travel. This precision is not built into the machine alone — it depends on the foundation it sits on, the way it is leveled, and the care with which it is commissioned.

Deep hole drilling machines are among the largest and most precise production machine tools. A typical BTA drilling machine weighs 15–40 tons, has a bed length of 6–20 meters, and must produce bores with straightness measured in hundredths of a millimeter per meter. The installation process — from foundation design through final acceptance — directly determines whether the machine can achieve this precision.

This article provides a practical guide to installing deep hole drilling machines, covering foundation requirements, leveling procedures, alignment verification, and commissioning.

Foundation Design

Machine Classification by Foundation Need

Deep hole drilling machines typically fall into Group II or III based on their size and rigidity requirements:

GroupMachine TypeTypical WeightFoundation Requirement
ISmall gun drilling machines (< 6 tons)2–6 tonsReinforced production floor
IIMedium BTA/gun drilling machines6–25 tonsSeparate concrete foundation, anchored
IIILarge BTA and deep hole boring machines25–50+ tonsIsolated reinforced concrete block, vibration isolation

Foundation Specifications

ParameterGroup IIGroup III
Concrete gradeC25/30 minimumC30/37 minimum
Foundation thickness400–800 mm800–1,500 mm
ReinforcementSteel mesh, φ12–16 mm at 200 mm centersDouble layer, φ16–20 mm at 150 mm centers
Separation from floorExpansion joint, 20–30 mm filled with elastic materialFull isolation joint
Soil bearing capacity≥ 150 kN/m²≥ 200 kN/m²
Curing time before machine loading14 days minimum28 days minimum
Vibration isolationNot typically requiredInertia block with isolation mounts

Critical rule: The foundation must be isolated from the surrounding floor slab. A saw-cut separation joint filled with elastic compound prevents building vibrations from transmitting to the machine and prevents machine vibrations from disturbing adjacent equipment.

Foundation Design Process

  1. Geotechnical survey — Assess soil bearing capacity and groundwater level
  2. Foundation design by structural engineer — Size and reinforce based on machine weight, dynamic loads, and soil conditions
  3. Excavation and formwork — Excavate to design depth, install forms with anchor bolt templates
  4. Reinforcement and embedment — Place rebar, anchor bolts, conduit for cables and coolant lines
  5. Concrete pour — Continuous pour with vibration to eliminate voids
  6. Curing — Maintain moisture for minimum 14 days (Group II) or 28 days (Group III)
  7. Surface preparation — Grind high spots, apply epoxy grout bedding

Anchor Bolt Installation

Anchor bolts transfer machine loads to the foundation and maintain alignment. Two methods are used:

Method 1 — Cast-in-place bolts:

  • Bolts positioned using a template plate matching the machine foot pattern
  • Template must be rigid enough to hold bolt positions within ±1 mm during concrete pour
  • Bolts extend 50–80 mm above finished foundation surface

Method 2 — Epoxy-anchored bolts (retrofit):

  • Holes drilled into cured concrete
  • Epoxy cartridge injected, bolt inserted
  • Suitable for existing foundations but lower pull-out strength

Anchor bolt torque sequence: When tightening anchor bolts during installation, use a cross-sequence pattern and achieve final torque in three increments (30% → 60% → 100% of final torque).

Machine Placement and Leveling

Preparation

Before the machine arrives:

  1. Verify foundation dimensions and anchor bolt positions against the machine base drawing
  2. Clean foundation surface — no oil, dust, or loose material
  3. Place leveling wedges or leveling screws at each mounting point
  4. Check that all anchor bolts are clean and threads are undamaged

Leveling Methods

MethodPrecisionBest ForRe-Levelable?
Steel shims±0.05 mmSmall machines, temporaryNo
Leveling screws±0.02 mmMedium machinesYes
Two-piece leveling wedges±0.01 mmMedium to large machinesYes
Three-piece leveling wedges±0.005 mmLarge, high-precision machinesYes
Hydraulic leveling mounts±0.01 mmMachines requiring frequent re-levelingYes

Recommended wedges for deep hole drilling machines: Two-piece or three-piece leveling wedges placed at each machine foot. Wedges provide rigid support and allow re-leveling as the foundation settles over time.

Leveling Procedure

Step 1 — Rough leveling:

  1. Lower the machine onto the leveling wedges using a crane or hydraulic jacks
  2. Align the machine to the anchor bolts
  3. Tighten anchor bolts to 30% of final torque
  4. Rough-level using a precision spirit level (0.02 mm/m) on the machine bed
  5. Adjust wedges at each foot to bring the bed to within 0.05 mm/m of level

Step 2 — Precision leveling:

  1. Place the precision level at each critical location along the bed:
    • At each guideway section
    • At the spindle mounting area
    • At the tailstock area
  2. Record readings at each position
  3. Adjust wedges incrementally to achieve:
    • Longitudinal level: ≤ 0.02 mm/m over full bed length
    • Lateral level: ≤ 0.02 mm/m across bed width
    • Twist (difference between left and right guideways): ≤ 0.02 mm/m

Step 3 — Tighten and recheck:

  1. Tighten anchor bolts to 60% torque in cross-sequence
  2. Recheck bed level — adjust wedges if tightened bolts changed alignment
  3. Tighten to 100% torque
  4. Final level check — record all readings for baseline documentation

Important: Leveling wedges should be adjusted only when the machine is supported at the correct height. Never force wedges beyond their adjustment range. If a wedge bottoms out, replace it with a thicker wedge before continuing.

Grouting

After leveling is complete and verified, the machine must be grouted to the foundation:

ParameterSpecification
Gap height between foundation and machine base20–40 mm
Grout typeNon-shrink cementitious or epoxy grout
Compressive strength (28 day)≥ 60 MPa
FlowabilitySelf-leveling, capable of filling all voids
Application methodPour from one side, allow gravity to push air out

Grouting procedure:

  1. Build a dam around the foundation perimeter using foam or wood forms
  2. Seal all gaps to prevent grout leakage
  3. Wet the foundation surface (for cementitious grout)
  4. Mix grout per manufacturer specifications
  5. Pour continuously from one side of the machine
  6. Use a thin rod to work grout into all voids under the base
  7. Allow to cure per manufacturer specification (typically 24–72 hours before full loading)

Alignment Verification

After grout has cured and anchor bolts have been retorqued, perform alignment verification.

Spindle-to-Guideway Parallelism

CheckMethodTolerance
Spindle axis horizontal parallel to guidewayTest bar in spindle, dial indicator on carriage0.01 mm over 300 mm
Spindle axis vertical parallel to guidewayTest bar in spindle, dial indicator on carriage (vertical plane)0.01 mm over 300 mm
Spindle center height relative to guidewayMeasure spindle center to guideway reference±0.02 mm

Guideway Straightness

Machine Bed LengthStraightness ToleranceMethod
≤ 3 m0.01 mmPrecision level or laser interferometer
3–6 m0.02 mm over full lengthLaser interferometer
6–10 m0.03 mm over full lengthLaser interferometer
10–16 m0.05 mm over full lengthLaser interferometer

Tailstock Alignment

CheckToleranceMethod
Tailstock center to spindle center (horizontal)0.02 mmTest bar between centers, dial indicator
Tailstock center to spindle center (vertical)0.02 mmTest bar between centers, dial indicator
Tailstock guideway parallelism to spindle axis0.02 mm over full travelDial indicator on tailstock saddle

Coolant System Alignment

The coolant induction system must be aligned to the spindle axis:

ComponentAlignment CheckTolerance
Coolant induction tubeConcentric to spindle axis0.05 mm
Chip evacuation tubeConcentric to bore axis0.10 mm
Coolant return line sealsLeak-free at maximum pressureVisual + pressure hold

Coolant System Commissioning

The coolant system is the most critical subsystem for deep hole drilling and requires dedicated commissioning steps:

Coolant System Checklist

CheckProcedureAcceptance
Pump pressure calibrationRun pump, verify pressure at machine entry pointMeets machine specification
Flow rate verificationMeasure flow at maximum pressureMeets minimum flow for largest bore diameter
Filtration systemLoad filter media, verify differential pressure< 0.5 bar across clean filter
Coolant tank levelFill to operating levelWithin sight glass range
Temperature controlRun system for 1 hour, monitor temperature rise< 5°C rise above ambient
Leak testPressurize entire system to maximum working pressureZero leaks at all connections
Chip evacuation testRun coolant through BTA drill head, verify chip suctionChips pulled cleanly through evacuation tube

Coolant Preparation

  1. Fill system with clean water and circulate to flush debris from piping
  2. Drain and refill with coolant mixture
  3. For oil-based systems: fill with specified oil grade, circulate for 30 minutes, check filter elements
  4. For emulsion systems: mix to specified concentration, verify with refractometer
  5. Add biocides if required for long-term emulsion stability

Electrical and Control Commissioning

SystemCheckMethod
Main power supplyVoltage, phase sequence, frequencyMultimeter, phase rotation meter
CNC controlPower up, boot sequence, no error messagesVisual, control diagnostics
Servo drivesAxis jog in both directions, speed consistencyJog test at multiple feed rates
Spindle driveVariable speed operation across full rangeRun spindle at low/medium/high RPM
Coolant pump motorRotation direction, current drawClamp meter, verify rotation
Chip conveyorForward and reverse operationVisual
Safety systemsEmergency stops, light curtains, interlocksTest each device individually

Axis Calibration

AxisCalibration RequiredTolerance
Spindle axis (Z)Linear scale calibration, backlash compensation0.005 mm over full travel
Boring bar axis (W, if equipped)Position accuracy0.01 mm
Tool positioning axisRepeatability0.005 mm

Test Drilling and Acceptance

Dry Run

Before cutting metal, run the machine through a complete dry cycle:

  1. Jog all axes through full travel — smooth, no binding
  2. Cycle spindle through speed range — no unusual noise or vibration
  3. Cycle coolant system — pressure stable, no leaks
  4. Run chip conveyor — smooth operation

Test Part Drilling

Drill a test part to verify machine capability:

ParameterTest Part Specification
MaterialSame as production (or representative)
Bore diameterMid-range of machine capability
Bore depthFull machine length or representative
Coolant pressureStandard operating pressure
Speed and feedManufacturer recommended parameters

Test part acceptance criteria:

TestToleranceMethod
Bore diameterH8 or betterAir gauge
Straightness0.05 mm/mLaser alignment
Surface finishRa ≤ 1.6 μmProfilometer
Roundness0.02 mmRoundness tester
Concentricity0.05 mm from both endsDial indicator

Acceptance Documentation

Complete the following documentation for the machine record:

  • Foundation drawing and as-built verification
  • Leveling report (all positions before and after grouting)
  • Alignment verification (spindle-to-guideway, tailstock, guideway straightness)
  • Coolant system test results (pressure, flow, filtration)
  • Electrical and control system verification
  • Test part inspection report
  • Machine serial number and installation date
  • Warranty registration

Periodic Re-Leveling

Deep hole drilling machines require periodic re-leveling because foundations settle, particularly in the first year:

Time Since InstallationRe-Leveling FrequencyReason
First 3 monthsMonthlyInitial foundation settlement
3–12 monthsQuarterlyGradual settlement stabilization
After 1 yearAnnuallyNormal maintenance
After any foundation disturbanceImmediatelyNearby excavation, heavy construction

Signs that re-leveling is needed: Increasing bore straightness variation, inconsistent surface finish, growing tool wear, or visible coolant leaks at machine joints.

Summary Table

AspectKey Information
Foundation typesGroup I (floor), Group II (separate slab), Group III (isolated inertia block)
Concrete curing14 days minimum (Group II), 28 days (Group III)
Leveling methodTwo-piece or three-piece leveling wedges — preferred over shims
Bed level tolerance≤ 0.02 mm/m longitudinal and lateral
Spindle-to-guideway parallelism0.01 mm over 300 mm
Grout typeNon-shrink cementitious or epoxy; 20–40 mm gap
Critical coolant checkPressure at machine entry, zero leaks at max pressure
Test part acceptanceH8 bore, 0.05 mm/m straightness, Ra ≤ 1.6 μm
Re-leveling frequencyMonthly (first 3 months), quarterly (to 12 months), annually thereafter
Key principleFoundation must be isolated from building floor slab

FAQ

How long does concrete foundation curing take before installing a deep hole drilling machine?

For Group II machines (typical BTA/gun drilling machines up to 25 tons), minimum 14 days of curing before machine placement is standard, with 28 days recommended for full cure before final grouting. For Group III machines (25+ tons), 28 days minimum is required. The concrete must reach at least 70% of its design compressive strength before machine loading. Rushing the curing process risks foundation cracking and alignment loss.

What leveling method is best for deep hole drilling machines?

Two-piece or three-piece leveling wedges are the recommended method for most deep hole drilling machines. They provide rigid support, allow precise adjustment (0.005–0.01 mm), and — unlike shims — can be re-adjusted after grouting. Leveling screws are acceptable for smaller machines but can creep under heavy dynamic loads. Steel shims are not recommended for permanent installation because they cannot be adjusted if the foundation settles.

How often should a deep hole drilling machine be re-leveled?

Monthly for the first three months after installation, quarterly for the remainder of the first year, and annually thereafter. The first year requires more frequent checks because the foundation undergoes initial settlement under the machine's weight. After the first year, annual re-leveling is sufficient for normal operation. Additional re-leveling is needed if there is any nearby excavation, construction, or if bore quality metrics show a declining trend.

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