La secuencia de cinco pasos de la programación CNC y los principales escollos a tener en cuenta
09 oct, 2018
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Ya sea que & #039;re haciendo la programación manual o el uso de CAM (la lógica se ejecuta en paralelo), CNC parte preparación del programa sigue una secuencia de cinco pasos. A continuación, cada paso se presenta junto con los errores comunes que vale la pena ver.
Los cinco pasos
Paso 1: Análisis de dibujo y planificación de procesos
Antes de tocar cualquier código, resuelva estas cosas primero:
Leer el dibujo: dimension chains, tolerances (±0.05? ±0.01?), geometric tolerances, surface roughness, material (aluminum / steel / stainless / titanium — cutting parameters differ a lot).
Define the process route: roughing first, then finishing; face before hole; primary features before secondary. Avoid repeated setups.
Decide workholding: vise / clamp / dedicated fixture / 4th-axis rotary table. Consider rigidity, tool clearance, and anti-deformation.
Set machining sequence: which face first, which face carries the datum forward.
📌Si este paso se equivoca, todo lo que sube es una reelaboración.
Step 2: Numerical Calculation (Math Processing)
Calculate all tool center point coordinates (X/Y/Z), especially non-integer dimensions, arc tangent points, chamfers, ball-nose cutter contact points.
For complex surfaces CAM handles it, but manual programming still needs: base points, nodes, arc centers, intersections.
Factor in cutter radius compensation direction (G41/G42) and length compensation number.
⚠️ Common pitfalls: drawing is metric but the machine is set to imperial; missing decimal point (on some controls G01 X50vs X50.behave differently); arc I/J/K direction reversed.
Content layers:
Program header: coordinate system, absolute/incremental, cancel compensations, tool change, spindle start.
Machining body: roughing → semi-finish → finish, leave allowance per pass.
Program tail: retract, return to zero or tool-change position, coolant off, M30.
Step 4: Program Verification (Simulation / Dry Run)
Do three things before running on the real part:
Software simulation: VERICUT / Mastercam backplot / machine's built-in graphics — check collisions, overtravel, table crash.
Dry run + single block: Machine Lock mode, watch coordinate movement.
First Article Trial Cut: run one piece in aluminum / modeling board / free-cutting stock, measure, then switch to real material.
⚠️ Skip this step = gambling. One spindle crash costs more than ten reports.
Step 5: Trial Correction and Archiving
Full First Article Inspection (FAI), adjust compensation / feed / speed against the drawing.
Finalizar el programa con Comentarios, número de versión, lista de herramientas y boceto de fijación Archivados juntos.
If tooling or material changes during production, update the program synchronously — don't let "program unchanged, tool swapped" cause a defect.
Key Pitfalls by Stage (Summary Table)
Stage | Where It Usually Goes Wrong |
|---|---|
Process Planning | Insufficient clearance in workholding, poor rigidity causing chatter, cumulative error from bad sequence |
Numerical Calculation | Metric/imperial mix-up, IJK direction, decimal places, compensation direction |
Programming | G-code dialect differences (Fanuc / Mitsubishi / Siemens — same code, different meaning), Z safety height too low |
Verification | Simulation only, no dry run; dry run only, no first article; first article not fully measured |
Archiving | No version, no comments — can't even read your own program six months later |
One point worth repeating: About 70% of CNC programming effort sits in Step 1 (process)and Step 2 (math). The code itself is the easiest part. A lot of people spend time debugging G-code syntax, but the real accidents almost always trace back to "process not thought through + first article not verified.
