Plan fabrication schedules with clear cycle time estimates. Track every motion, reduce delays, and export results for teams and records across sites.
| Operation | Cut distance (mm) | Feed (mm/min) | Rapid distance (mm) | Rapid (mm/min) | Passes | Dwell (s) | Tool change (s) |
|---|---|---|---|---|---|---|---|
| Plate contour milling | 3200 | 900 | 800 | 6500 | 1 | 0 | 10 |
| Hole drilling pattern | 450 | 300 | 1200 | 6500 | 1 | 2 | 12 |
| Edge chamfer pass | 2100 | 700 | 500 | 6500 | 2 | 0 | 0 |
Cycle time planning helps fabrication shops align CNC capacity with steel erection sequences and delivery windows.
Accurate estimates come from measured feeds, verified rapids, and consistent fixturing practices. Validate one part, then update inputs for better forecasts across production runs and changing material batches.
Reliable cycle estimates keep crews productive and schedules intact.
In construction fabrication, CNC throughput can decide the week’s look-ahead plan. A late bracket package can ripple into fit-up, inspection, and field welding. Separating cutting, rapids, dwells, tool changes, setup, and handling lets you forecast machine hours per delivery lot. Even small savings per part scale quickly across batches. Use the estimate to quote lead times with confidence.
Use CAM summaries for total cut distance, rapid distance, and commanded feeds and rapids. Verify against shop limits because controllers may cap rapids. Record average tool-change time (often 6–20 seconds) and note dwells used for peck drilling, probing, or coolant pauses.
The main term is Tcut = (CutDistance ÷ FeedRate) × Passes. Example: 3200 mm at 900 mm/min equals 3.56 minutes per pass. If you step down twice, Passes becomes 2 and cutting doubles, even if everything else stays constant.
Rapid time follows Trapid = (RapidDistance ÷ RapidRate) × Passes. One reposition may be under a second, but high-mix programs can include hundreds. Reasonable retract heights and safer linking moves can reduce rapid distance while maintaining clearance.
Dwells add fixed seconds that do not scale with feed. Tool changes are predictable but vary with carousel position. Four tools with 12-second changes add nearly a minute per part. The calculator totals these items per operation so they are easy to audit.
Setup typically happens once per lot, while load/unload scales with quantity. Add overhead for inspection, chip clearing, deburr, and short stops. Many shops start with 5–15% and refine it from run logs to match real production conditions.
Convert totals to machine-hours and compare against available shifts. If a batch needs 6.5 hours and the cell has 5 productive hours today, split the lot or prioritize critical parts. CSV and PDF outputs support production meetings and documentation.
Run one representative part and compare actual cycle time to the estimate. If actual is higher, adjust overhead or handling and tool-change inputs. If cutting differs, confirm feeds, acceleration limits, and material conditions. Two or three updates usually sharpen forecasts.
1) What distances should I enter for cut and rapid?
Use CAM reports for total toolpath distance. If unavailable, estimate from feature lengths and patterns, then refine after a test run. Distances should match your selected unit family.
2) How do I handle drilling cycles with pecking?
Add drilling travel as cut distance, then include dwell seconds for each peck pause if programmed. If peck timing is unknown, measure one hole cycle and scale by hole count.
3) Does the calculator include spindle ramp or acceleration?
Not directly. Those effects usually appear as extra time and can be captured with the overhead percent. For high-speed, short-stroke toolpaths, consider increasing overhead slightly.
4) What overhead percent should I start with?
For stable production, 5–10% is common. For prototype or high-mix work, 10–20% may be more realistic. Calibrate using actual run times and keep updating monthly.
5) How do passes relate to depth of cut?
Passes represent repeated toolpath execution, such as step-downs, step-overs, or pattern loops. If you cut the same contour three times at different depths, set passes to three.
6) Can I estimate multi-part fixtures in one cycle?
Yes. Treat the fixture as one “part” and set batch quantity to the number of fixture cycles. If there is per-piece handling inside the fixture, add that to load/unload.
7) Why is my rapid time surprisingly high?
Large safe heights, long retracts, and conservative clearances increase rapid distance. Reduce unnecessary Z lifts, optimize linking moves, and confirm the controller’s real rapid limit is used.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.