Cutting Metal

[Nick Marchesani]

What is the easiest metal to cut?

I have a 30w fiber laser.

[Dave Sheldrake]

with a 30watt Fibre?
None of them, while 30 watts can cut very thin metal, the finish and general quality will be very poor (not to mention slow as molasses on a winter day)

Start thinking 500 watts base line, typically most industrial cutters are 2kw+ with many in the 6kw+ range still being considered basic.
cheers
Dave

[Nick Marchesani]

I want to make something from .5mm sheet metal. I've seen many videos of people cutting different types of sheet metal. All had nice clean cuts.

What I am asking is what type of metal is the easiest to cut?

[Dave Sheldrake]

define "easiest"

The one that will give the best quality or the one that will cut quickly etc?

[Nick Marchesani]

define "easiest"

The one that will give the best quality or the one that will cut quickly etc?

Since you put it that way which will cut quicker and which will give the best quality.
thanks!

[Rob Damon]

https://www.youtube.com/watch?v=g9xgMF_y6Nk

Although a 20/30/50 can cut metal, it takes a lot of passes and a lot of time at full power.

Here's one with a 100w fiber cutting metal (midway through video.)

https://www.youtube.com/watch?v=hs6W3AwJyN8

Another:

https://www.youtube.com/watch?v=s02G3C2UFJQ

[Dave Sheldrake]

Surprisingly many grades of stainless cut very well and give a good edge finish (not so much on a galvo but on a flatbed where you can have gas shielding) 316 (S32) is great, takes a bit of power but quality when you get it right is amazing.
As a rule even the metals that respond well to fibre cutting on a flatbed don't do so well on a galvo as although they may use the same wavelength they are very different animals.

Quality wise, with power being a given, I'd say stainless steel sheet and aluminium both give great results, (Al being one of the worst metals to cut for power requirements though)

Avoid copper, nimonics, stellites, high carbon steels (EN16, 24, (T) etc), bronze is an absolute belter to try and get right (so probably don't go there) Brass....varies a lot

The problem is, power and density.. galvo systems typically have some funky beam modes due to the very long focal lengths (and mirror irregularities) anything under 300 watts is simply the wrong tool to be using to cut metal. On budget I'd probably use my plasma system, about the same cost as a Galvo and 1000x faster.

hope that helps a bit

Rob above posted a couple of great videos that demonstrate the failings of Galvo's

[Nick Marchesani]

Surprisingly many grades of stainless cut very well and give a good edge finish (not so much on a galvo but on a flatbed where you can have gas shielding) 316 (S32) is great, takes a bit of power but quality when you get it right is amazing.
As a rule even the metals that respond well to fibre cutting on a flatbed don't do so well on a galvo as although they may use the same wavelength they are very different animals.

Quality wise, with power being a given, I'd say stainless steel sheet and aluminium both give great results, (Al being one of the worst metals to cut for power requirements though)

Avoid copper, nimonics, stellites, high carbon steels (EN16, 24, (T) etc), bronze is an absolute belter to try and get right (so probably don't go there) Brass....varies a lot

The problem is, power and density.. galvo systems typically have some funky beam modes due to the very long focal lengths (and mirror irregularities) anything under 300 watts is simply the wrong tool to be using to cut metal. On budget I'd probably use my plasma system, about the same cost as a Galvo and 1000x faster.

hope that helps a bit

Rob above posted a couple of great videos that demonstrate the failings of Galvo's

Ok great thanks

How about colored acrylics? Will a fiber cut or just engrave or change colors or something else.

[Bill George]

You have the machine, try it yourself? Lots faster than posting a question and waiting for an answer.

[Dave Sheldrake]

Ok great thanks

How about colored acrylics? Will a fiber cut or just engrave or change colors or something else.

Fibre is the wrong machine for acrylics, some plastics can be leeched with a fibre (think of keyboard keys) but in general fibre for cutting plastics is a no go.

when I get a bit of spare time (my current day job is a bit crazy at the moment) I'll post up the reasons behind it all (the differences between photothermal and photochemical effects and band gap energies) it won't help much but it will go some way to explaining why wavelength and pulse rates (on a pulsed laser) make such huge differences.

best wishes
Dave