50W CO2 Laser Machine Unboxing, Review, Modifications & More

[gavztheouch]

Mike all laser cutters will cut with a draft angle on the edge and not 90 degrees to the surface. this is down to the focus lens. The lens takes the 1mm wide co2 laser beam and concentates the beam down to a focused ~0.1mm dot. There is only a narrow range in which the beam is in focus, so with your 6mm sheet fir example maybe only 1mm is in focus then the beam starts the spread apart. Its this spreading of the beam that causes the non straight cuts. Hope that made sense?

[Lee Roberts]

Mike all laser cutters will cut with a draft angle on the edge and not 90 degrees to the surface. this is down to the focus lens. The lens takes the 1mm wide co2 laser beam and concentates the beam down to a focused ~0.1mm dot. There is only a narrow range in which the beam is in focus, so with your 6mm sheet fir example maybe only 1mm is in focus then the beam starts the spread apart. Its this spreading of the beam that causes the non straight cuts. Hope that made sense?

So, when setting the machine up, are we trying to find the “sweet spot” for the distance the laser is away from the material that it cuts with minimal draft angle but isn’t too close that the power needed to cut burns? the material, or is there more to it?

.Me

[Want2build1]

So, when setting the machine up, are we trying to find the “sweet spot” for the distance the laser is away from the material that it cuts with minimal draft angle but isn’t too close that the power needed to cut burns? the material, or is there more to it?

.Me

haha ! MUCH more to it than that !
I'm just learning, but it depends a lot on the material being cut, then the thickness, and the focal length of the lens.

I'l post more as I learn, but for thin material a short focal length give a narrow 'pin point' for the 'z' if you like.
For thick material, you want a long focal length which gives a narrower 'pin point over a longer 'z'

Think of the beam as a triangle from the lens to the cut. then follow the lines through to make a cross (X) .
A short focus gives a stubby triangle (eg. 90deg V bit in CNC)
a long focus gives a tall pointy triangle. (eg. 60deg V bit in CNC)


Must get on with work now !!!