1. What is the dimensional accuracy of laser cutting?
Someone asked me if the accuracy of ± 0.05 millimeters really exists. My answer is yes, provided that the tool stacking is correct. Focus on beam mode, rigid mechanical structure, encoder feedback, and stable cutting parameters. In addition, the workbench should be kept clean as chips and slag can cause deformation of the board, thereby affecting accuracy.
On well calibrated machines, the dimensional accuracy of fiber laser cutting is usually ± 0.05 millimeters. For small parts and small batch production, with stable temperature and firm fixtures, an accuracy of ± 0.03 millimeters can be achieved. I track accuracy deviations through daily calibration, preheating cycles, and cutting tests that simulate actual operations.
Dive deeper
When I talk about accuracy, I break it into machine, process, and environment. I also look at how tolerance stacks up across a full sheet. Static numbers mean little if the sheet moves, heats, or bows.
What shapes real accuracy
Machine: Beam quality (M2), linear guides, ball screws or rack-and-pinion, servo tuning, encoder resolution.
Process: Nozzle centering, focus offset, gas pressure, pierce routine, lead-in strategy, kerf compensation1.
Environment: Sheet flatness, workholding, thermal rise, shop temperature, vibration.
Practical tolerance bands by case
2. How accurate is a laser cutting hole?
Holes challenge every machine. The path is short. Heat is high. The kerf can taper. I treat holes with care. I adjust lead-in, micro tabs, and speed to stabilize the roundness and the size.
Hole accuracy in fiber laser cutting is typically ±0.05 mm for holes over 1.5 mm. For small holes near thickness, I use micro-cycles, lower power, and a special lead-in. I often ream critical holes or use a punch-laser combo for the tightest fits.
Dive deeper
Holes bring three problems: out-of-round shape, taper from top to bottom, and heat-affected oversize. I handle these with path planning, parameter control, and design rules.
Key controls for round holes
Lead-in: I set a short tangent lead-in3 outside the final hole. I avoid starting on the hole edge.
Pierce: I use pre-pierce for thick plate, then I cut at steady state.
Speed and power: I lower power and speed for small holes to reduce taper.
Assist gas: I pick nitrogen for stainless and aluminum to avoid oxide; oxygen for mild steel if needed.
Micro-cycles: I add a short dwell or multi-pass for holes near thickness.
Kerf comp: I bias the hole undersize by 0.02–0.05 mm, then test and tune.
Hole size rules I use
I keep a simple loop for validation. I cut a test coupon with a matrix of holes from 1 mm to 10 mm. I measure each with pin gauges. I update the kerf table for each thickness and gas. I lock those into the job card. This turns hole accuracy into a repeatable process, not hope.
For tight fits, I mix processes. I cut the hole 0.1–0.2 mm undersize on the laser. Then I ream or countersink on a drill stand. This still saves time because the laser does all the complex shapes. The ream gives the fit class, like H7, with no burr.
I also watch circularity. I keep the motion loop tight with high encoder resolution. I avoid tiny segments in the CAM4. I use true arcs where I can. Smooth toolpaths give round holes. Choppy toolpaths do not.
3. Why is my laser cutter not accurate?
When the accuracy is low, I check a short list first. The cause is often simple. The fix is often fast. I do not change ten things at once. I test and move step by step.
Most accuracy problems come from focus height, nozzle misalignment, dirty optics, bad sheet support, or thermal drift. I fix these with a focus gauge, a nozzle centering test, clean lenses, flat slats, stable gas, and a warm-up routine. I verify with a 20 mm square and hole test.
Dive deeper
I split accuracy issues into geometry, process, and environment. I map symptoms to likely causes. Then I confirm with a quick cut-and-measure test. This keeps me from guessing and wasting time.
Symptom to cause map
