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A structured machine trial tells you more than any specification sheet. A poorly planned demo is worse than no demo — it gives false confidence. Test your hardest part, at your production parameters, with your operator present.
Test Part Selection
Choose the Right Test Part
| Selection Criterion | Why It Matters |
|---|---|
| Most difficult hole in your production | Reveals machine limitations |
| Typical production material | Tests real-world chip formation |
| Tolerance-sensitive feature | Validates machine accuracy |
| High-volume part | Demonstrates cycle time and repeatability |
Warning: Never let the manufacturer select the test part. They will choose the easiest part they can run, which tells you nothing about your production capability.
Test Part Requirements
- Provide your own material (same grade, heat treat, and size as production)
- Supply the part print with tolerance callouts
- Specify the required surface finish
- Identify critical features that matter for your application
Preparation Checklist
Before the Demo
- [ ] Send test part drawing and material at least 2 weeks in advance
- [ ] Confirm the manufacturer has the correct tooling (or agree who supplies it)
- [ ] Agree on test parameters: speeds, feeds, peck cycle, coolant pressure
- [ ] Agree on acceptance criteria: diameter tolerance, straightness, surface finish, cycle time
- [ ] Ask what measurements will be taken and with what instruments
- [ ] Confirm the machine is fully commissioned and not a showroom special
- [ ] Bring your own measurement tools as backup
- [ ] Bring your operator or lead technician
What to Bring
| Item | Purpose |
|---|---|
| Your part print with tolerances | Reference for measurements |
| Calibrated measurement tools | Independent verification |
| Camera or phone with timestamp | Document results |
| Notebook and pen | Record observations |
| Stopwatch | Independent cycle time measurement |
| Chip collection bag | Save chips for analysis later |
During the Demo: What to Observe
Setup Phase
- How long does it take to change tooling and set up the workpiece?
- Is the bushing alignment straightforward?
- Does the operator reference setup sheets or rely on memory?
- How is the workpiece indicated and verified?
Cutting Phase
| Observation Point | What to Look For |
|---|---|
| Drill entry | Smooth entry, no chatter or skidding |
| Coolant pressure gauge | Stable pressure within 5% of setpoint |
| Chip formation | Short, broken chips in consistent colour |
| Spindle load meter | Stable load, no sudden spikes |
| Cutting sounds | Consistent tonal quality, no squealing or fluctuation |
| Coolant return | Clear return, no chip blockages |
Measurement Phase
- Be present when the part is measured
- Verify critical dimensions with your own instruments
- Measure at multiple depths, not just the entry and exit
- Check surface finish at the bore entry, mid-point, and exit
- Document all measurements with photos
Evaluation Scorecard
| Criterion | Weight | Scoring (1–5) | Notes |
|---|---|---|---|
| Cycle time meets target | 20% | ||
| Diameter tolerance IT8 or better | 20% | ||
| Surface finish within spec | 15% | ||
| Hole straightness within spec | 15% | ||
| Setup time acceptable | 10% | ||
| Coolant system stable | 10% | ||
| Operator skill and support quality | 10% |
Score: _____ / 100
Post-Demo Actions
- Take chips and test parts with you — they are evidence and can be analysed later
- Request the CNC program used during the demo
- Request the coolant pressure and flow data if the machine logged it
- Follow up within 48 hours with any additional questions while details are fresh
- Compare results across multiple manufacturers using the same scorecard
FAQ
How many test holes should I run during a demo?
Minimum three holes at conservative parameters and three at production parameters. For repeatability assessment, run a continuous batch of ten holes.
Should I bring my own tooling to the demo?
If you have specific tooling preferences, yes. Otherwise, let the manufacturer use their recommended tooling — this tests their application engineering capability.
What if the machine fails the test cut?
Document the failure, discuss root cause with the manufacturer's engineers, and decide whether to retry with different parameters or consider this a disqualification.
Can I run a demo remotely via video?
Remote demos are acceptable for initial screening but should not replace an in-person trial for final selection. Subtle issues like chip formation sounds and coolant pressure fluctuations are hard to evaluate remotely.
How long after the demo should I expect the quotation?
A professional manufacturer will provide a formal quotation within one week of the demo, incorporating the test results and any parameter adjustments made during the trial.
Trial procedures vary by machine type and part complexity. Adapt this framework to your specific requirements and quality standards. This article reflects industry practice as of 2026.