Hi! I would like to put a laser on the effector of my kossel

Hi! I would like to put a laser on the effector of my kossel and cut cardboard (the thick one, 3 or 5 pieces of paper in its profile, like the one used in agriculture boxes, around 6 mm thick). Does anyone cut cardboard with a laser? How many watts should it have? Thank you in advanced!

Well ive tried witha 2W blue laser and it burns paper and cardboard really fast. Even acrylic went fine but slow. But beware. With that kind of laser or bigger you need a good eyeprotection. It has to fit the wavelength. Also dont use it on reflective surfaces like aluminium.

Thanks for such a quick and complete answer! How many mm thick is the cardboard you tried? Does it burns the edges of the cut?@VolksTrieb

@Javier_Prieto was like 2mm. Paper is cut instantly and catches fire really quick. Yes you burn the edges. Maybe not under certain gases like argon but never tried. Acrylic works fine because it melts first and maybe boils away

I have an Emblaser 1 kit built unit (Kickstarter success!) that I’ve upgraded to the Emblaser provided 4 watt unit. I can cut 3 mm birch plywood by making 7 passes at 100% power and 4 mm / second travel speed. The optics are critical in cutting lasers, especially diode lasers which have a generally rectangular beam prior to the lenses.

I will second the suggestion to be very careful with your laser and interaction with anyone’s eyes nearby. Purchase a set of laser safety glasses for the frequency of the laser you select and wear them at all times. There can be 30-50 mm of air below a focused laser, which provides plenty of space for reflections from unexpected material. Such reflections will be weaker but powerful enough to destroy parts of your vision.

For performance, higher speed means less burn on the edges, while it will require multiple passes. I’ve cut single layer breakfast product boxes at 100% power and 20 mm / second speed, two passes, to reduce edge burning and ensure full cut-through.

Anything with a slight wave or contour will change the focus of the beam, reducing the power available to cut. I’ve since constructed a low profile vacuum table for the emblaser, a mere 18-20 mm high which works great for the thin wavy material.

I have not yet attempted to cut corrugated cardboard, but expect to have to use six to eight passes at 100% power and 20 mm / second or slower as the corrugations become, in effect, a variable thickness/variable focus consideration.

Cooling of the diode laser is important too. My first 4w module failed from my lack of awareness of the cooling fan. As it slowed over time, the laser heated and eventually became fatally hot. The current laser with a higher power fan is running nearly 100 deg F. Heat transfer grease between the module and the heat sink is a requirement, as well as having a tight mechanical connection between the two.

Good luck. Burning things can be as much fun as melting them.

Thank you all! I may look for another solution… I dont want to be aware everytime that cardboard get on fire