"Should we buy a CNC cutting table?" Every shop that starts out with handheld cutting faces this question eventually. An entry-level gantry plasma table costs as much as several handheld machines put together, so the decision gets postponed again and again. Run the four variables that actually matter — throughput, material yield, grinding and rework, and labour — and the answer is usually much clearer than intuition suggests. This article puts real shop-floor numbers behind the comparison: a throughput table, an investment and payback model, and an honest look at when handheld cutting remains the right answer.
1. Throughput: what one shift actually produces
Take a representative flange-type part: 12 mm Q235 carbon steel, twenty holes plus an outer profile, roughly 6 m of total cut length. Here is an eight-hour shift, side by side:
| Item | Handheld (2 operators) | CNC table (1 operator) |
|---|---|---|
| Cutting speed | 250–400 mm/min (limited by hand stability) | 1 200–1 800 mm/min (process chart limit) |
| Marking and layout | 4–8 min per part | 0 — the program already knows |
| Piercing and arc start | 3–6 s per hole (manual alignment) | 1–2 s per hole (automatic positioning) |
| Effective arc-on time | 35 %–50 % | 75 %–88 % |
| Cycle time per part | 22–30 min | 5–7 min |
| Parts per shift | 16–22 | 65–90 |
| Labour | 2 people | 1 person, who can also stage material |
The CNC line delivers roughly four times the shift output with half the labour — about eight times the output per person. Crucially, that gap is driven less by raw cutting speed than by effective arc-on time. In manual work, marking out, flipping plate, re-positioning and waiting for parts to cool consume more than half the shift.
2. Consistency: the cost you cannot see
| Quality metric | Handheld | CNC |
|---|---|---|
| Dimensional tolerance | ±1.5–3.0 mm, operator-dependent | ±0.5–1.0 mm, repeatable |
| Bevel angle | 3°–8°, varies with hand shake | 1°–3°, held by THC |
| Dross | Frequent, from uneven travel | Uniform and controlled; often weld-ready |
| Material yield | 55 %–70 % (manual nesting) | 80 %–92 % (auto-nesting and common-line cutting) |
| Rework rate | 5 %–12 % | Below 2 % |
The dimensional tolerance and bevel figures above are graded formally in ISO 9013 for thermal cut surface quality — worth citing as the acceptance basis between buyer and supplier. Weld-preparation requirements are documented by the American Welding Society at www.aws.org.
Material yield is the line item most shops underestimate. On 500 t of plate a year at ¥4 500/t, moving yield from 65 % to 85 % saves roughly ¥580 000 annually — on its own, often enough to pay for the machine within two or three years. Auto-nesting and common-line cutting are handled by StarCAM nesting software, which together with the MNC CNC controller outputs cutting programs complete with lead-ins and kerf compensation.
3. Investment breakdown and payback
Typical configuration: 3 m × 6 m table, 200 A plasma source. All figures in CNY and indicative only — actual pricing depends on the final specification.
| Item | Cost (¥) | Notes |
|---|---|---|
| Gantry cutting table (rails, servos, downdraft bed) | 180 000 – 280 000 | Driven by table size and accuracy class |
| High-precision plasma power source | 60 000 – 120 000 | 200 A class, e.g. Max-200HPR |
| CNC controller + nesting software | 25 000 – 45 000 | Includes THC arc-voltage module |
| Fume extraction, installation and commissioning | 30 000 – 60 000 | Required for environmental compliance |
| Total investment | 295 000 – 505 000 | Midpoint ≈ ¥400 000 |
| Annual benefit | Saving (¥/yr) | Basis |
|---|---|---|
| Labour | 120 000 – 180 000 | 1 to 1.5 fewer operators |
| Material yield | 200 000 – 580 000 | 300–500 t/yr, +15 %–20 % yield |
| Grinding and rework | 40 000 – 90 000 | 60 %–80 % less grinding time |
| Extra capacity for new orders | Order-dependent | Usually the largest single benefit |
| Total, excluding new orders | 360 000 – 850 000 | — |
Payback typically lands between 8 and 18 months. With a stable order book, plate mostly in the 6–30 mm band and annual consumption above 200 t, expect payback inside twelve months.
4. When handheld is still the right answer
CNC is not a universal answer. Keep the torches in these situations:
- Under 50 t of plate per year — the machine sits idle and fixed cost never amortises.
- Repair, breakdown and site work — the workpiece does not move, so a table is irrelevant.
- Rough cutting above 60 mm — tolerance is irrelevant; flame or manual cutting is cheaper.
- One-off oversized fabrications — anything beyond the table still needs a human.
- Extremely fragmented order structure — programming and setup time can eat the throughput gain.
The pragmatic answer is a mixed fleet: let the table handle batch blanking and keep two or three handheld units for maintenance, site work and odd shapes. For handheld duty we recommend the LGK-100IGBT or LGK-200IGBT; where no compressed air is available on site, a built-in compressor model such as the Max-200AH is the better fit.
5. A three-stage path from handheld to CNC
Stage 1 — standardise the process (1–2 months)
Build a cut chart for every thickness you regularly run: current, gas pressure, speed, standoff. Produce reference edge coupons. Do this even if you never buy a table — it alone cuts manual rework rates.
Stage 2 — semi-automation (¥30 000–80 000)
Fit a tractor or boom travel carriage and THC arc-voltage height control to your existing handheld machine. Travel consistency immediately approaches CNC level and bevel falls inside 3°. This is the highest return-per-yuan step available.
Stage 3 — the CNC table (¥300 000–500 000)
Add the gantry table, a high-precision plasma source and StarCAM nesting software to digitise nesting, programming and cutting end to end. Budget for fume extraction and operator training in the same step — both are mandatory, neither is optional.
6. Frequently asked questions
How do I size the table?
Take your most common plate size (1.5 m × 6 m or 2 m × 6 m) and add 200–300 mm. If you mostly cut fixed-length stock, size to plate length + 300 mm. Oversizing inflates both capital cost and extraction load; undersizing forces constant plate repositioning.
Can I reuse my existing handheld plasma unit on the table?
Often yes, but confirm three things: external arc-start and remote current control (a CNC interface), a 100 % duty cycle rating, and support for the THC arc-voltage signal. Older low-frequency machines usually fail on all three and need replacing with an IGBT inverter plasma power source.
What level of fume extraction is needed?
Plasma fume carries fine metal-oxide particulates. Use zoned downdraft with a cartridge filter, sized at roughly 1 200 m³ per hour per square metre of table area, and verify against your local emission standard. Occupational exposure limits for metal fume in workshop air are published by the US Occupational Safety and Health Administration at www.osha.gov. Skipping this creates both a workplace health problem and a compliance problem.
How long does operator training take?
An experienced handheld operator usually needs three to five days to become productive on the nesting software and the machine, and two to four weeks before they can independently optimise parameters and diagnose edge defects. Insist on on-site training and a delivered cut chart from your supplier.
What is most often overestimated in a payback calculation?
The material yield gain. Actual improvement depends on part geometry and batch size — regular rectangles gain little, complex profiles gain a lot. Run a real nesting trial on your existing orders before committing to a number, rather than trusting a theoretical figure.
7. Where to start
Whether a CNC table makes sense is not really an equipment question; it is an arithmetic problem about your order book. Annual tonnage, thickness mix, part complexity and labour cost are four numbers that essentially determine the payback period. Standardise the process first, automate second. Get that order wrong and no amount of capital equipment will deliver the throughput you were promised.
If you want the calculation done for your own shop, contact the Icyrobot technical team with your annual tonnage, thickness distribution and a few typical part drawings, and we will return an assessment covering throughput, material yield and payback. Further reading: our plasma cut quality troubleshooting manual and guide to sizing an air plasma cutter by thickness. Related equipment: the MNC CNC controller series and StarCAM nesting software.
