Laser Cutter Notes
Bright-VikBot or a good name.
Laser Light Sources
~45 sealed CO2 laser ...
1 watt pigtail diode laser with optical head (focus ~50 microns):
- comercial 'naked' diodelaser with [email protected] and 0.1mm atached glass fibre: ~230 Euros (in quantities above 5 pcs).
- turnkey-system with [email protected], a visible red pilot-laser and jack for the glass fibre: ~1000 Euros (in quantities above 5 pcs).
- CO2-lasertube ... sealed (RF) or 'naked' glass-tube
- diode-laser ... best with atached glass fibre (=pigtailed)
2. beam-feeding optics:
- CO2: - mirrors
- diode-lasers: - glass fibre and/or lenses and mirrors
3. focussing optics:
- CO2: - Germanium- or ZnSe-lens for CO2-laser ... concave mirror is possible too
- diode-lasers: - 'normal' optical lenses
3.1. Embedding a Pilotlaser as guide or beam-indicator:
- CO2: - mostly monolithic PS, good when below 40 Volts for RF-CO2-lasers, 'naked' and DIY-CO2-tubes need above 1000 Volts
- diode-lasers: - constant-current-driver (e.g. more LM317 in parallel)
5. output-power controller:
- CO2: - embedded in RF-CO2-lasers - mostly TTL-input capable of switching the laser output with some ten kHz
- diode-lasers: - current-modulation and/or PWM-switching for diode-lasers until some kHz
- diode-lasers: - AOM (AcoustoOpticalModulator) switching until some hundred kHz
6. controlling the output-power:
- generating geometrically defined pulses from the XY-clocks of the CNC-controller:
- calculating the needed power relative to moving speed of the laser focus
- brazing / hard soldering:
- similar to an inkjet-printer, where many nozzles ar aligned in an array to print many dot-lines synchrone, you can align multiple diode-lasers in an array to process parallel lines simultanuous.
With falling prices of laserdiodes it should be possible to build a head with 8 hating/burning spots in a line with a distance of 5mm (diameter of typical small collimaton-lenses) between them (or less, when arranging in a zigzag-array) in a DIY-range below 1000 Euros.
With a software separating the processing data for the single lasers you can speedup the time per sheet along with the count of lasers ...
- Nitrogen tank or clean dry compressed air.
Health and Safety
Laser-goggles are essential when working with lasers!
This laser-goggles have blocking ranges of 700-1100nm (for diode-lasers and NdYAG) and 10600nm (for CO2-lasers)
Fumes and vapours are extremely toxic and carcinogenic!
You can absorb the toxic vapours by exhausting the fuming area through a charcoalabsorber - e.g. the disc-shaped filters often used in deep fat fryers, or filtering units for soldering ...
When using inert (and other) gases in an enclosed room you have to test for leakage or monitor the oxygen-concentration in the room.