Strostkovy
Titanium
- Joined
- Oct 29, 2017
We've just gotten a used 4kw CO2 laser (made by HK) and have managed to cut 1/8" 5052 aluminum at 150 ipm with a 7.5" lens (can probably get to 165 and still be dross free, and maybe 200 with the 5" lens) but I'm having some trouble with 1/4" aluminum.
Basically it seems like either the focus is too deep and the cut quality suffers, or the focus is high enough that reflections ionize the assist gas above surface and attenuate the beam badly.
I've only spent a half hour or so on this material because our main concern was dross free 1/8" aluminum. Does anyone have an idea of where the focal point should sit within the metal? I'm not sure if I should work with the focus being very low, towards the bottom of the sheet and deal with reduced feeds, or if I should try to avoid the reflection problem by focusing directly at the top of the sheet and avoiding the beam overlap at focus all together. It doesn't help much that I don't have a very good factory condition to start with, and I'm brand new to this particular machine.
The beam is well centered in the nozzle and the focal point is set by the HK rep doing the recommission, but I'm not totally sure exactly where the focus is relative to the various focus settings. They seem to do everything quite a bit different than the Mitsubishis I've worked on in the past (though in many ways that's a good thing). To get a usable part we are crawling along at 30-40 ipm, at 4kw and around 14 bar of nitrogen through a 3mm nozzle. Nozzle gap is around 0.04", though I've varied all of those parameters to some extent.
I'll be back at it tomorrow and can probably figure it out, but any input is appreciated.
Basically it seems like either the focus is too deep and the cut quality suffers, or the focus is high enough that reflections ionize the assist gas above surface and attenuate the beam badly.
I've only spent a half hour or so on this material because our main concern was dross free 1/8" aluminum. Does anyone have an idea of where the focal point should sit within the metal? I'm not sure if I should work with the focus being very low, towards the bottom of the sheet and deal with reduced feeds, or if I should try to avoid the reflection problem by focusing directly at the top of the sheet and avoiding the beam overlap at focus all together. It doesn't help much that I don't have a very good factory condition to start with, and I'm brand new to this particular machine.
The beam is well centered in the nozzle and the focal point is set by the HK rep doing the recommission, but I'm not totally sure exactly where the focus is relative to the various focus settings. They seem to do everything quite a bit different than the Mitsubishis I've worked on in the past (though in many ways that's a good thing). To get a usable part we are crawling along at 30-40 ipm, at 4kw and around 14 bar of nitrogen through a 3mm nozzle. Nozzle gap is around 0.04", though I've varied all of those parameters to some extent.
I'll be back at it tomorrow and can probably figure it out, but any input is appreciated.