Appearance
The first part of the day is the most likely time for a scrap part. Cold machine, cold coolant, untested systems — every startup is a process restart. A disciplined startup procedure catches problems before they become scrap. An equally disciplined shutdown procedure prevents problems from developing overnight.
Pre-Startup Inspection
Visual Check
| Item | Check | Action if Issue Found |
|---|---|---|
| Coolant level | Between min and max on sight glass | Top off to operating level |
| Hydraulic oil level | Between min and max | Add correct oil grade |
| Way oil reservoir | Above 50% | Fill with way oil |
| Chip conveyor | No visible obstructions | Clear any jammed chips |
| Coolant return screen | Screen clean, no blockage | Clean screen |
| Machine bed and ways | No chips or debris | Clean before moving axes |
| Guide bushing area | Clean, no chips | Clean with coolant hose |
| Tool holder and drill | Visually intact | Inspect for damage |
Safety Systems Check
| System | Verification | Action if Faulty |
|---|---|---|
| E-stop buttons | Press and release — all clear | Do not operate — call maintenance |
| Door interlocks | Open door, attempt cycle | Do not operate — repair interlock |
| Light curtain | Break beam during setup | Verify machine stops |
| Coolant pressure switch | Check alarm test (if available) | Repair before production |
| Chip conveyor interlock | Verify conveyor stop works | Repair before production |
Warning: A safety system that failed overnight or during the previous shift is the most dangerous startup condition. Test all safety systems before the first cycle of the day, not after. Do not bypass interlocks for startup.
Warm-Up Sequence
Step-by-Step Warm-Up
| Step | Duration | Action | Purpose |
|---|---|---|---|
| 1 | 5–10 min | Start coolant circulation pump | Warm coolant, stabilize temperature |
| 2 | 5 min | Run spindle at 500–1,000 RPM | Gradually warm spindle bearings |
| 3 | 5 min | Increase spindle to 50% of max operating RPM | Step warm-up |
| 4 | 5 min | Increase spindle to 100% of operating RPM | Full spindle warm-up |
| 5 | 5–10 min | Traverse all axes through full range | Warm ball screws and guideways |
| 6 | 2 min | Turn on through-spindle coolant at low pressure | Check coolant flow at drill tip |
| 7 | 5 min | Run a test cycle without cutting | Confirm all systems functional |
Warm-Up Duration by Condition
| Machine Condition | Minimum Warm-Up | Recommended |
|---|---|---|
| Cold start (overnight) | 20 min | 30 min |
| Weekend idle | 25 min | 35 min |
| Extended shutdown (> 1 week) | 35 min | 45 min |
| Warm start (< 2 hours idle) | 5 min | 10 min |
Pre-Cut Verification
Before the First Part
| Check | Method | Acceptance |
|---|---|---|
| Coolant pressure at drill tip | Observe pressure gauge | Within 5% of target |
| Coolant flow at drill tip | Visual — steady stream | Continuous, no sputtering |
| Coolant temperature | Read temperature gauge | Within operating range (15–35°C) |
| Spindle runout (at tip) | Dial indicator | Within specification |
| Feed and speed in program | Compare to setup sheet | Matches job parameters |
| Entry feed override | Set to 30–50% | Correct for first part |
| Tool life counter | Verify not expired | Reset if needed |
| Workpiece loaded correctly | Confirm center height | Centered and secure |
| Guide bushing | Confirm correct size installed | Matches drill diameter |
First Part Inspection
| Check | Tool | Acceptance |
|---|---|---|
| Hole diameter | Bore gauge or plug gauge | Within print tolerance |
| Surface finish | Visual or profilometer | Acceptable for production |
| Chip shape | Visual | C-shape or short spiral |
| Hole position (if applicable) | CMM or gauge | Within position tolerance |
| Drill condition after first part | Visual inspection | No damage, normal wear |
Tip: The first part of the day tells you the condition of the machine. If the first part is good, the machine is ready. If the first part has defects, investigate before continuing — the problem will not fix itself on the second part.
Production Monitoring
In-Process Checks
| Check | Frequency | Method |
|---|---|---|
| Chip shape | Every part | Visual — check for changes from ideal |
| Coolant pressure | Every part | Observe gauge for fluctuation |
| Spindle load | Every part | Note baseline and trend |
| Surface finish (visual) | Every part | Quick visual check |
| Coolant concentration | Start of shift | Refractometer |
| Coolant temperature | Hourly | Read temperature gauge |
| Chip conveyor | Hourly | Check for free chip flow |
Shutdown Procedure
End-of-Shift Shutdown
| Step | Action | Purpose |
|---|---|---|
| 1 | Complete current hole — do not stop mid-hole | Prevents chip jams in bore |
| 2 | Retract drill fully from workpiece | Clear drill from bore |
| 3 | Run coolant for 2–3 minutes after last cut | Flush chips from system |
| 4 | Run spindle at low RPM (500–1,000) for 2 minutes | Cool spindle bearings gradually |
| 5 | Stop spindle | |
| 6 | Stop coolant pump | |
| 7 | Traverse all axes to center position | Balanced position for thermal relaxation |
| 8 | Remove tool from spindle (if recommended) | Relieves holder pressure |
| 9 | Clean machine bed, tool holder, bushing area | Remove chips and coolant |
| 10 | Empty chip bin (if near full) | Prevent overflow overnight |
Extended Shutdown (Weekend or Longer)
| Additional Step | Action | Purpose |
|---|---|---|
| 1 | Clean coolant tank (if scheduled) | Prevent bacterial growth |
| 2 | Apply rust preventive to exposed guideways | Prevent corrosion from coolant residue |
| 3 | Leave coolant tank cover open (if safe) | Allow ventilation |
| 4 | Check coolant concentration — adjust if needed | Prevent separation during idle |
| 5 | Close coolant supply valves | Prevent leaks |
| 6 | Log machine condition in handover | Communicate status |
Warning: Never stop a gun drill mid-hole at the end of a shift. Chips settle in the bore during shutdown, and the drill will jam when restarting. Complete the hole or retract the drill and clear the bore before shutting down.
End-of-Shift Documentation
Operator Handover
| Information | Detail |
|---|---|
| Date and shift | |
| Parts produced (good/scrap) | |
| Tool life remaining | |
| Issues encountered | |
| Coolant pressure trend | |
| Spindle load trend | |
| Maintenance needed | |
| Tooling needed for next shift |
FAQ
How long should I warm up a deep hole drilling machine?
Minimum 20 minutes for overnight shutdown, 30 minutes recommended for precision work. The coolant system must also reach temperature — starting with cold coolant causes thermal drift during the first 30–60 minutes of production. Longer warm-up is needed after weekends or extended shutdowns.
What is the most important startup check?
Coolant flow at the drill tip. Before any cutting, verify that coolant is reaching the cutting edge. A blocked coolant passage causes a chip jam that breaks the drill. This 30-second check prevents the most common cause of tool breakage.
Should I remove the drill from the holder at the end of shift?
For overnight shutdown, leaving the drill in the holder is acceptable. For extended shutdown (weekend or longer), removing the drill is recommended to relieve holder clamping pressure and prevent corrosion at the clamping interface.
Can I leave the coolant pump running overnight?
No — the coolant pump should be turned off during shutdown. Continuous running heats the coolant unnecessarily, wastes energy, and can cause coolant temperature to rise above the bacterial growth threshold if the chiller is also off.
What should I do if I find a problem during startup checks?
Stop and investigate before starting production. If coolant flow is weak, check the filter and coolant passage. If runout is high, clean and reseat the drill. If the safety interlock fails, lock out the machine and call maintenance. A problem found during startup will only cause a scrap part or broken tool if ignored.
A consistent startup and shutdown procedure is the lowest-cost form of machine insurance. Ten minutes of checks at each end of the shift prevents hours of downtime. This article reflects industry practice as of 2026.