Reasons for poor laser cutting
Some reasons your laser cutter might be cutting poorly, from most probable to least probable:
- Dirty lens. Clean with care, never touch the lens with your fingers.
- Dirty mirrors. The #3 and #2 mirrors get dirty - the #1 mirror almost never does.
- Scratches or other flaws on mirrors and lens. Probably due to mishandling, excessive cleaning or insufficient cleaning.
- Poor focus. For acrylic, focus onto the top surface of the material, for other materials, focus halfway through the material. Warped material or a poorly leveled bed can also cause this.
- Bad alignment resulting in the beam clipping the edge of the nozzle tip. This causes the nozzle to get insanely hot - which is a good clue that it's happening. Running with bad alignment can trash your lens within minutes - so don't do that!
- Poor smoke removal. Smoke in the path of the laser attenuates it. A puff of smoke should leave your machine within a couple of seconds. Your smoke extraction system should pull the smoke AWAY from the path of the laser, not towards it.
- Mis-adjusted laser power supply delivering too little beam current. You can measure this with an ammeter - but be VERY careful - the laser power supply produces enough voltage to kill you...even when it's unplugged...and it can generate 3" long sparks!
- Inadequate air-assist. Lack of good air-assist airflow reduces the depth of cut - and it also allows smoke to get onto the underside of the lens.
- Ineffective water chilling resulting in the tube overheating. Did you clean out the air filters on your water chiller recently?
- Water condensation on the lens - possibly due to air-assist issues.
- Aging laser tube. Expect your tube to last for 3,000 to 5,000 hours of operation and to gradually degrade in power over that time.